aboutsummaryrefslogtreecommitdiffhomepage
path: root/src/core/lib/client_config
diff options
context:
space:
mode:
Diffstat (limited to 'src/core/lib/client_config')
-rw-r--r--src/core/lib/client_config/README.md66
-rw-r--r--src/core/lib/client_config/client_config.c74
-rw-r--r--src/core/lib/client_config/client_config.h53
-rw-r--r--src/core/lib/client_config/connector.c55
-rw-r--r--src/core/lib/client_config/connector.h92
-rw-r--r--src/core/lib/client_config/default_initial_connect_string.c39
-rw-r--r--src/core/lib/client_config/initial_connect_string.c53
-rw-r--r--src/core/lib/client_config/initial_connect_string.h50
-rw-r--r--src/core/lib/client_config/lb_policies/load_balancer_api.c163
-rw-r--r--src/core/lib/client_config/lb_policies/load_balancer_api.h85
-rw-r--r--src/core/lib/client_config/lb_policies/pick_first.c444
-rw-r--r--src/core/lib/client_config/lb_policies/pick_first.h43
-rw-r--r--src/core/lib/client_config/lb_policies/round_robin.c563
-rw-r--r--src/core/lib/client_config/lb_policies/round_robin.h46
-rw-r--r--src/core/lib/client_config/lb_policy.c134
-rw-r--r--src/core/lib/client_config/lb_policy.h144
-rw-r--r--src/core/lib/client_config/lb_policy_factory.c49
-rw-r--r--src/core/lib/client_config/lb_policy_factory.h78
-rw-r--r--src/core/lib/client_config/lb_policy_registry.c88
-rw-r--r--src/core/lib/client_config/lb_policy_registry.h55
-rw-r--r--src/core/lib/client_config/resolver.c82
-rw-r--r--src/core/lib/client_config/resolver.h94
-rw-r--r--src/core/lib/client_config/resolver_factory.c55
-rw-r--r--src/core/lib/client_config/resolver_factory.h82
-rw-r--r--src/core/lib/client_config/resolver_registry.c137
-rw-r--r--src/core/lib/client_config/resolver_registry.h65
-rw-r--r--src/core/lib/client_config/resolvers/dns_resolver.c294
-rw-r--r--src/core/lib/client_config/resolvers/dns_resolver.h42
-rw-r--r--src/core/lib/client_config/resolvers/sockaddr_resolver.c354
-rw-r--r--src/core/lib/client_config/resolvers/sockaddr_resolver.h50
-rw-r--r--src/core/lib/client_config/resolvers/zookeeper_resolver.c514
-rw-r--r--src/core/lib/client_config/resolvers/zookeeper_resolver.h42
-rw-r--r--src/core/lib/client_config/subchannel.c678
-rw-r--r--src/core/lib/client_config/subchannel.h174
-rw-r--r--src/core/lib/client_config/subchannel_factory.c49
-rw-r--r--src/core/lib/client_config/subchannel_factory.h66
-rw-r--r--src/core/lib/client_config/subchannel_index.c262
-rw-r--r--src/core/lib/client_config/subchannel_index.h77
-rw-r--r--src/core/lib/client_config/uri_parser.c242
-rw-r--r--src/core/lib/client_config/uri_parser.h51
40 files changed, 5784 insertions, 0 deletions
diff --git a/src/core/lib/client_config/README.md b/src/core/lib/client_config/README.md
new file mode 100644
index 0000000000..fff7a5af5b
--- /dev/null
+++ b/src/core/lib/client_config/README.md
@@ -0,0 +1,66 @@
+Client Configuration Support for GRPC
+=====================================
+
+This library provides high level configuration machinery to construct client
+channels and load balance between them.
+
+Each grpc_channel is created with a grpc_resolver. It is the resolver's duty
+to resolve a name into configuration data for the channel. Such configuration
+data might include:
+
+- a list of (ip, port) addresses to connect to
+- a load balancing policy to decide which server to send a request to
+- a set of filters to mutate outgoing requests (say, by adding metadata)
+
+The resolver provides this data as a stream of grpc_client_config objects to
+the channel. We represent configuration as a stream so that it can be changed
+by the resolver during execution, by reacting to external events (such as a
+new configuration file being pushed to some store).
+
+
+Load Balancing
+--------------
+
+Load balancing configuration is provided by a grpc_lb_policy object, stored as
+part of grpc_client_config.
+
+The primary job of the load balancing policies is to pick a target server given only the
+initial metadata for a request. It does this by providing a grpc_subchannel
+object to the owning channel.
+
+
+Sub-Channels
+------------
+
+A sub-channel provides a connection to a server for a client channel. It has a
+connectivity state like a regular channel, and so can be connected or
+disconnected. This connectivity state can be used to inform load balancing
+decisions (for example, by avoiding disconnected backends).
+
+Configured sub-channels are fully setup to participate in the grpc data plane.
+Their behavior is specified by a set of grpc channel filters defined at their
+construction. To customize this behavior, resolvers build
+grpc_subchannel_factory objects, which use the decorator pattern to customize
+construction arguments for concrete grpc_subchannel instances.
+
+
+Naming for GRPC
+===============
+
+Names in GRPC are represented by a URI (as defined in
+[RFC 3986](https://tools.ietf.org/html/rfc3986)).
+
+The following schemes are currently supported:
+
+dns:///host:port - dns schemes are currently supported so long as authority is
+ empty (authority based dns resolution is expected in a future
+ release)
+
+unix:path - the unix scheme is used to create and connect to unix domain
+ sockets - the authority must be empty, and the path
+ represents the absolute or relative path to the desired
+ socket
+
+ipv4:host:port - a pre-resolved ipv4 dotted decimal address/port combination
+
+ipv6:[host]:port - a pre-resolved ipv6 address/port combination
diff --git a/src/core/lib/client_config/client_config.c b/src/core/lib/client_config/client_config.c
new file mode 100644
index 0000000000..82c8d68099
--- /dev/null
+++ b/src/core/lib/client_config/client_config.c
@@ -0,0 +1,74 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/client_config/client_config.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+
+struct grpc_client_config {
+ gpr_refcount refs;
+ grpc_lb_policy *lb_policy;
+};
+
+grpc_client_config *grpc_client_config_create() {
+ grpc_client_config *c = gpr_malloc(sizeof(*c));
+ memset(c, 0, sizeof(*c));
+ gpr_ref_init(&c->refs, 1);
+ return c;
+}
+
+void grpc_client_config_ref(grpc_client_config *c) { gpr_ref(&c->refs); }
+
+void grpc_client_config_unref(grpc_exec_ctx *exec_ctx, grpc_client_config *c) {
+ if (gpr_unref(&c->refs)) {
+ if (c->lb_policy != NULL) {
+ GRPC_LB_POLICY_UNREF(exec_ctx, c->lb_policy, "client_config");
+ }
+ gpr_free(c);
+ }
+}
+
+void grpc_client_config_set_lb_policy(grpc_client_config *c,
+ grpc_lb_policy *lb_policy) {
+ GPR_ASSERT(c->lb_policy == NULL);
+ if (lb_policy) {
+ GRPC_LB_POLICY_REF(lb_policy, "client_config");
+ }
+ c->lb_policy = lb_policy;
+}
+
+grpc_lb_policy *grpc_client_config_get_lb_policy(grpc_client_config *c) {
+ return c->lb_policy;
+}
diff --git a/src/core/lib/client_config/client_config.h b/src/core/lib/client_config/client_config.h
new file mode 100644
index 0000000000..404ec0d3a5
--- /dev/null
+++ b/src/core/lib/client_config/client_config.h
@@ -0,0 +1,53 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_CLIENT_CONFIG_H
+#define GRPC_CORE_LIB_CLIENT_CONFIG_CLIENT_CONFIG_H
+
+#include "src/core/lib/client_config/lb_policy.h"
+
+/** Total configuration for a client. Provided, and updated, by
+ grpc_resolver */
+typedef struct grpc_client_config grpc_client_config;
+
+grpc_client_config *grpc_client_config_create();
+void grpc_client_config_ref(grpc_client_config *client_config);
+void grpc_client_config_unref(grpc_exec_ctx *exec_ctx,
+ grpc_client_config *client_config);
+
+void grpc_client_config_set_lb_policy(grpc_client_config *client_config,
+ grpc_lb_policy *lb_policy);
+grpc_lb_policy *grpc_client_config_get_lb_policy(
+ grpc_client_config *client_config);
+
+#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_CLIENT_CONFIG_H */
diff --git a/src/core/lib/client_config/connector.c b/src/core/lib/client_config/connector.c
new file mode 100644
index 0000000000..f51d862c6d
--- /dev/null
+++ b/src/core/lib/client_config/connector.c
@@ -0,0 +1,55 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/client_config/connector.h"
+
+grpc_connector* grpc_connector_ref(grpc_connector* connector) {
+ connector->vtable->ref(connector);
+ return connector;
+}
+
+void grpc_connector_unref(grpc_exec_ctx* exec_ctx, grpc_connector* connector) {
+ connector->vtable->unref(exec_ctx, connector);
+}
+
+void grpc_connector_connect(grpc_exec_ctx* exec_ctx, grpc_connector* connector,
+ const grpc_connect_in_args* in_args,
+ grpc_connect_out_args* out_args,
+ grpc_closure* notify) {
+ connector->vtable->connect(exec_ctx, connector, in_args, out_args, notify);
+}
+
+void grpc_connector_shutdown(grpc_exec_ctx* exec_ctx,
+ grpc_connector* connector) {
+ connector->vtable->shutdown(exec_ctx, connector);
+}
diff --git a/src/core/lib/client_config/connector.h b/src/core/lib/client_config/connector.h
new file mode 100644
index 0000000000..21b925aade
--- /dev/null
+++ b/src/core/lib/client_config/connector.h
@@ -0,0 +1,92 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_CONNECTOR_H
+#define GRPC_CORE_LIB_CLIENT_CONFIG_CONNECTOR_H
+
+#include "src/core/lib/channel/channel_stack.h"
+#include "src/core/lib/iomgr/sockaddr.h"
+#include "src/core/lib/transport/transport.h"
+
+typedef struct grpc_connector grpc_connector;
+typedef struct grpc_connector_vtable grpc_connector_vtable;
+
+struct grpc_connector {
+ const grpc_connector_vtable *vtable;
+};
+
+typedef struct {
+ /** set of pollsets interested in this connection */
+ grpc_pollset_set *interested_parties;
+ /** address to connect to */
+ const struct sockaddr *addr;
+ size_t addr_len;
+ /** initial connect string to send */
+ gpr_slice initial_connect_string;
+ /** deadline for connection */
+ gpr_timespec deadline;
+ /** channel arguments (to be passed to transport) */
+ const grpc_channel_args *channel_args;
+} grpc_connect_in_args;
+
+typedef struct {
+ /** the connected transport */
+ grpc_transport *transport;
+
+ /** channel arguments (to be passed to the filters) */
+ const grpc_channel_args *channel_args;
+} grpc_connect_out_args;
+
+struct grpc_connector_vtable {
+ void (*ref)(grpc_connector *connector);
+ void (*unref)(grpc_exec_ctx *exec_ctx, grpc_connector *connector);
+ /** Implementation of grpc_connector_shutdown */
+ void (*shutdown)(grpc_exec_ctx *exec_ctx, grpc_connector *connector);
+ /** Implementation of grpc_connector_connect */
+ void (*connect)(grpc_exec_ctx *exec_ctx, grpc_connector *connector,
+ const grpc_connect_in_args *in_args,
+ grpc_connect_out_args *out_args, grpc_closure *notify);
+};
+
+grpc_connector *grpc_connector_ref(grpc_connector *connector);
+void grpc_connector_unref(grpc_exec_ctx *exec_ctx, grpc_connector *connector);
+/** Connect using the connector: max one outstanding call at a time */
+void grpc_connector_connect(grpc_exec_ctx *exec_ctx, grpc_connector *connector,
+ const grpc_connect_in_args *in_args,
+ grpc_connect_out_args *out_args,
+ grpc_closure *notify);
+/** Cancel any pending connection */
+void grpc_connector_shutdown(grpc_exec_ctx *exec_ctx,
+ grpc_connector *connector);
+
+#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_CONNECTOR_H */
diff --git a/src/core/lib/client_config/default_initial_connect_string.c b/src/core/lib/client_config/default_initial_connect_string.c
new file mode 100644
index 0000000000..86eb37de77
--- /dev/null
+++ b/src/core/lib/client_config/default_initial_connect_string.c
@@ -0,0 +1,39 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/support/slice.h>
+#include "src/core/lib/iomgr/sockaddr.h"
+
+void grpc_set_default_initial_connect_string(struct sockaddr **addr,
+ size_t *addr_len,
+ gpr_slice *initial_str) {}
diff --git a/src/core/lib/client_config/initial_connect_string.c b/src/core/lib/client_config/initial_connect_string.c
new file mode 100644
index 0000000000..95ae728316
--- /dev/null
+++ b/src/core/lib/client_config/initial_connect_string.c
@@ -0,0 +1,53 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/client_config/initial_connect_string.h"
+
+#include <stddef.h>
+
+extern void grpc_set_default_initial_connect_string(struct sockaddr **addr,
+ size_t *addr_len,
+ gpr_slice *initial_str);
+
+static grpc_set_initial_connect_string_func g_set_initial_connect_string_func =
+ grpc_set_default_initial_connect_string;
+
+void grpc_test_set_initial_connect_string_function(
+ grpc_set_initial_connect_string_func func) {
+ g_set_initial_connect_string_func = func;
+}
+
+void grpc_set_initial_connect_string(struct sockaddr **addr, size_t *addr_len,
+ gpr_slice *initial_str) {
+ g_set_initial_connect_string_func(addr, addr_len, initial_str);
+}
diff --git a/src/core/lib/client_config/initial_connect_string.h b/src/core/lib/client_config/initial_connect_string.h
new file mode 100644
index 0000000000..eec42fa240
--- /dev/null
+++ b/src/core/lib/client_config/initial_connect_string.h
@@ -0,0 +1,50 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_INITIAL_CONNECT_STRING_H
+#define GRPC_CORE_LIB_CLIENT_CONFIG_INITIAL_CONNECT_STRING_H
+
+#include <grpc/support/slice.h>
+#include "src/core/lib/iomgr/sockaddr.h"
+
+typedef void (*grpc_set_initial_connect_string_func)(struct sockaddr **addr,
+ size_t *addr_len,
+ gpr_slice *initial_str);
+void grpc_test_set_initial_connect_string_function(
+ grpc_set_initial_connect_string_func func);
+
+/** Set a string to be sent once connected. Optionally reset addr. */
+void grpc_set_initial_connect_string(struct sockaddr **addr, size_t *addr_len,
+ gpr_slice *connect_string);
+
+#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_INITIAL_CONNECT_STRING_H */
diff --git a/src/core/lib/client_config/lb_policies/load_balancer_api.c b/src/core/lib/client_config/lb_policies/load_balancer_api.c
new file mode 100644
index 0000000000..4cbed200df
--- /dev/null
+++ b/src/core/lib/client_config/lb_policies/load_balancer_api.c
@@ -0,0 +1,163 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/client_config/lb_policies/load_balancer_api.h"
+#include "third_party/nanopb/pb_decode.h"
+#include "third_party/nanopb/pb_encode.h"
+
+#include <grpc/support/alloc.h>
+
+typedef struct decode_serverlist_arg {
+ int first_pass;
+ int i;
+ size_t num_servers;
+ grpc_grpclb_server **servers;
+} decode_serverlist_arg;
+
+/* invoked once for every Server in ServerList */
+static bool decode_serverlist(pb_istream_t *stream, const pb_field_t *field,
+ void **arg) {
+ decode_serverlist_arg *dec_arg = *arg;
+ if (dec_arg->first_pass != 0) { /* first pass */
+ grpc_grpclb_server server;
+ if (!pb_decode(stream, grpc_lb_v0_Server_fields, &server)) {
+ return false;
+ }
+ dec_arg->num_servers++;
+ } else { /* second pass */
+ grpc_grpclb_server *server = gpr_malloc(sizeof(grpc_grpclb_server));
+ GPR_ASSERT(dec_arg->num_servers > 0);
+ if (dec_arg->i == 0) { /* first iteration of second pass */
+ dec_arg->servers =
+ gpr_malloc(sizeof(grpc_grpclb_server *) * dec_arg->num_servers);
+ }
+ if (!pb_decode(stream, grpc_lb_v0_Server_fields, server)) {
+ return false;
+ }
+ dec_arg->servers[dec_arg->i++] = server;
+ }
+
+ return true;
+}
+
+grpc_grpclb_request *grpc_grpclb_request_create(const char *lb_service_name) {
+ grpc_grpclb_request *req = gpr_malloc(sizeof(grpc_grpclb_request));
+
+ req->has_client_stats = 0; /* TODO(dgq): add support for stats once defined */
+ req->has_initial_request = 1;
+ req->initial_request.has_name = 1;
+ strncpy(req->initial_request.name, lb_service_name,
+ GRPC_GRPCLB_SERVICE_NAME_MAX_LENGTH);
+ return req;
+}
+
+gpr_slice grpc_grpclb_request_encode(const grpc_grpclb_request *request) {
+ size_t encoded_length;
+ pb_ostream_t sizestream;
+ pb_ostream_t outputstream;
+ gpr_slice slice;
+ memset(&sizestream, 0, sizeof(pb_ostream_t));
+ pb_encode(&sizestream, grpc_lb_v0_LoadBalanceRequest_fields, request);
+ encoded_length = sizestream.bytes_written;
+
+ slice = gpr_slice_malloc(encoded_length);
+ outputstream =
+ pb_ostream_from_buffer(GPR_SLICE_START_PTR(slice), encoded_length);
+ GPR_ASSERT(pb_encode(&outputstream, grpc_lb_v0_LoadBalanceRequest_fields,
+ request) != 0);
+ return slice;
+}
+
+void grpc_grpclb_request_destroy(grpc_grpclb_request *request) {
+ gpr_free(request);
+}
+
+grpc_grpclb_response *grpc_grpclb_response_parse(gpr_slice encoded_response) {
+ bool status;
+ pb_istream_t stream =
+ pb_istream_from_buffer(GPR_SLICE_START_PTR(encoded_response),
+ GPR_SLICE_LENGTH(encoded_response));
+ grpc_grpclb_response *res = gpr_malloc(sizeof(grpc_grpclb_response));
+ memset(res, 0, sizeof(*res));
+ status = pb_decode(&stream, grpc_lb_v0_LoadBalanceResponse_fields, res);
+ GPR_ASSERT(status == true);
+ return res;
+}
+
+grpc_grpclb_serverlist *grpc_grpclb_response_parse_serverlist(
+ gpr_slice encoded_response) {
+ grpc_grpclb_serverlist *sl = gpr_malloc(sizeof(grpc_grpclb_serverlist));
+ bool status;
+ decode_serverlist_arg arg;
+ pb_istream_t stream =
+ pb_istream_from_buffer(GPR_SLICE_START_PTR(encoded_response),
+ GPR_SLICE_LENGTH(encoded_response));
+ pb_istream_t stream_at_start = stream;
+ grpc_grpclb_response *res = gpr_malloc(sizeof(grpc_grpclb_response));
+ memset(res, 0, sizeof(*res));
+ memset(&arg, 0, sizeof(decode_serverlist_arg));
+
+ res->server_list.servers.funcs.decode = decode_serverlist;
+ res->server_list.servers.arg = &arg;
+ arg.first_pass = 1;
+ status = pb_decode(&stream, grpc_lb_v0_LoadBalanceResponse_fields, res);
+ GPR_ASSERT(status == true);
+ GPR_ASSERT(arg.num_servers > 0);
+
+ arg.first_pass = 0;
+ status =
+ pb_decode(&stream_at_start, grpc_lb_v0_LoadBalanceResponse_fields, res);
+ GPR_ASSERT(status == true);
+ GPR_ASSERT(arg.servers != NULL);
+
+ sl->num_servers = arg.num_servers;
+ sl->servers = arg.servers;
+ if (res->server_list.has_expiration_interval) {
+ sl->expiration_interval = res->server_list.expiration_interval;
+ }
+ grpc_grpclb_response_destroy(res);
+ return sl;
+}
+
+void grpc_grpclb_destroy_serverlist(grpc_grpclb_serverlist *serverlist) {
+ size_t i;
+ for (i = 0; i < serverlist->num_servers; i++) {
+ gpr_free(serverlist->servers[i]);
+ }
+ gpr_free(serverlist->servers);
+ gpr_free(serverlist);
+}
+
+void grpc_grpclb_response_destroy(grpc_grpclb_response *response) {
+ gpr_free(response);
+}
diff --git a/src/core/lib/client_config/lb_policies/load_balancer_api.h b/src/core/lib/client_config/lb_policies/load_balancer_api.h
new file mode 100644
index 0000000000..83299adfa9
--- /dev/null
+++ b/src/core/lib/client_config/lb_policies/load_balancer_api.h
@@ -0,0 +1,85 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICIES_LOAD_BALANCER_API_H
+#define GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICIES_LOAD_BALANCER_API_H
+
+#include <grpc/support/slice_buffer.h>
+
+#include "src/core/lib/client_config/lb_policy_factory.h"
+#include "src/core/lib/proto/grpc/lb/v0/load_balancer.pb.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define GRPC_GRPCLB_SERVICE_NAME_MAX_LENGTH 128
+
+typedef grpc_lb_v0_LoadBalanceRequest grpc_grpclb_request;
+typedef grpc_lb_v0_LoadBalanceResponse grpc_grpclb_response;
+typedef grpc_lb_v0_Server grpc_grpclb_server;
+typedef grpc_lb_v0_Duration grpc_grpclb_duration;
+typedef struct grpc_grpclb_serverlist {
+ grpc_grpclb_server **servers;
+ size_t num_servers;
+ grpc_grpclb_duration expiration_interval;
+} grpc_grpclb_serverlist;
+
+/** Create a request for a gRPC LB service under \a lb_service_name */
+grpc_grpclb_request *grpc_grpclb_request_create(const char *lb_service_name);
+
+/** Protocol Buffers v3-encode \a request */
+gpr_slice grpc_grpclb_request_encode(const grpc_grpclb_request *request);
+
+/** Destroy \a request */
+void grpc_grpclb_request_destroy(grpc_grpclb_request *request);
+
+/** Parse (ie, decode) the bytes in \a encoded_response as a \a
+ * grpc_grpclb_response */
+grpc_grpclb_response *grpc_grpclb_response_parse(gpr_slice encoded_response);
+
+/** Destroy \a serverlist */
+void grpc_grpclb_destroy_serverlist(grpc_grpclb_serverlist *serverlist);
+
+/** Parse the list of servers from an encoded \a grpc_grpclb_response */
+grpc_grpclb_serverlist *grpc_grpclb_response_parse_serverlist(
+ gpr_slice encoded_response);
+
+/** Destroy \a response */
+void grpc_grpclb_response_destroy(grpc_grpclb_response *response);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICIES_LOAD_BALANCER_API_H */
diff --git a/src/core/lib/client_config/lb_policies/pick_first.c b/src/core/lib/client_config/lb_policies/pick_first.c
new file mode 100644
index 0000000000..9ac550d9e7
--- /dev/null
+++ b/src/core/lib/client_config/lb_policies/pick_first.c
@@ -0,0 +1,444 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/client_config/lb_policies/pick_first.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include "src/core/lib/client_config/lb_policy_factory.h"
+#include "src/core/lib/transport/connectivity_state.h"
+
+typedef struct pending_pick {
+ struct pending_pick *next;
+ grpc_pollset *pollset;
+ grpc_connected_subchannel **target;
+ grpc_closure *on_complete;
+} pending_pick;
+
+typedef struct {
+ /** base policy: must be first */
+ grpc_lb_policy base;
+ /** all our subchannels */
+ grpc_subchannel **subchannels;
+ size_t num_subchannels;
+
+ grpc_closure connectivity_changed;
+
+ /** the selected channel (a grpc_connected_subchannel) */
+ gpr_atm selected;
+
+ /** mutex protecting remaining members */
+ gpr_mu mu;
+ /** have we started picking? */
+ int started_picking;
+ /** are we shut down? */
+ int shutdown;
+ /** which subchannel are we watching? */
+ size_t checking_subchannel;
+ /** what is the connectivity of that channel? */
+ grpc_connectivity_state checking_connectivity;
+ /** list of picks that are waiting on connectivity */
+ pending_pick *pending_picks;
+
+ /** our connectivity state tracker */
+ grpc_connectivity_state_tracker state_tracker;
+} pick_first_lb_policy;
+
+#define GET_SELECTED(p) \
+ ((grpc_connected_subchannel *)gpr_atm_acq_load(&(p)->selected))
+
+void pf_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
+ pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+ grpc_connected_subchannel *selected = GET_SELECTED(p);
+ size_t i;
+ GPR_ASSERT(p->pending_picks == NULL);
+ for (i = 0; i < p->num_subchannels; i++) {
+ GRPC_SUBCHANNEL_UNREF(exec_ctx, p->subchannels[i], "pick_first");
+ }
+ if (selected != NULL) {
+ GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, selected, "picked_first");
+ }
+ grpc_connectivity_state_destroy(exec_ctx, &p->state_tracker);
+ gpr_free(p->subchannels);
+ gpr_mu_destroy(&p->mu);
+ gpr_free(p);
+}
+
+void pf_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
+ pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+ pending_pick *pp;
+ grpc_connected_subchannel *selected;
+ gpr_mu_lock(&p->mu);
+ selected = GET_SELECTED(p);
+ p->shutdown = 1;
+ pp = p->pending_picks;
+ p->pending_picks = NULL;
+ grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
+ GRPC_CHANNEL_FATAL_FAILURE, "shutdown");
+ /* cancel subscription */
+ if (selected != NULL) {
+ grpc_connected_subchannel_notify_on_state_change(
+ exec_ctx, selected, NULL, NULL, &p->connectivity_changed);
+ } else {
+ grpc_subchannel_notify_on_state_change(
+ exec_ctx, p->subchannels[p->checking_subchannel], NULL, NULL,
+ &p->connectivity_changed);
+ }
+ gpr_mu_unlock(&p->mu);
+ while (pp != NULL) {
+ pending_pick *next = pp->next;
+ *pp->target = NULL;
+ grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
+ pp->pollset);
+ grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, true, NULL);
+ gpr_free(pp);
+ pp = next;
+ }
+}
+
+static void pf_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+ grpc_connected_subchannel **target) {
+ pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+ pending_pick *pp;
+ gpr_mu_lock(&p->mu);
+ pp = p->pending_picks;
+ p->pending_picks = NULL;
+ while (pp != NULL) {
+ pending_pick *next = pp->next;
+ if (pp->target == target) {
+ grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
+ pp->pollset);
+ *target = NULL;
+ grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, false, NULL);
+ gpr_free(pp);
+ } else {
+ pp->next = p->pending_picks;
+ p->pending_picks = pp;
+ }
+ pp = next;
+ }
+ gpr_mu_unlock(&p->mu);
+}
+
+static void start_picking(grpc_exec_ctx *exec_ctx, pick_first_lb_policy *p) {
+ p->started_picking = 1;
+ p->checking_subchannel = 0;
+ p->checking_connectivity = GRPC_CHANNEL_IDLE;
+ GRPC_LB_POLICY_WEAK_REF(&p->base, "pick_first_connectivity");
+ grpc_subchannel_notify_on_state_change(
+ exec_ctx, p->subchannels[p->checking_subchannel],
+ p->base.interested_parties, &p->checking_connectivity,
+ &p->connectivity_changed);
+}
+
+void pf_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
+ pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+ gpr_mu_lock(&p->mu);
+ if (!p->started_picking) {
+ start_picking(exec_ctx, p);
+ }
+ gpr_mu_unlock(&p->mu);
+}
+
+int pf_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_pollset *pollset,
+ grpc_metadata_batch *initial_metadata,
+ grpc_connected_subchannel **target, grpc_closure *on_complete) {
+ pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+ pending_pick *pp;
+
+ /* Check atomically for a selected channel */
+ grpc_connected_subchannel *selected = GET_SELECTED(p);
+ if (selected != NULL) {
+ *target = selected;
+ return 1;
+ }
+
+ /* No subchannel selected yet, so acquire lock and then attempt again */
+ gpr_mu_lock(&p->mu);
+ selected = GET_SELECTED(p);
+ if (selected) {
+ gpr_mu_unlock(&p->mu);
+ *target = selected;
+ return 1;
+ } else {
+ if (!p->started_picking) {
+ start_picking(exec_ctx, p);
+ }
+ grpc_pollset_set_add_pollset(exec_ctx, p->base.interested_parties, pollset);
+ pp = gpr_malloc(sizeof(*pp));
+ pp->next = p->pending_picks;
+ pp->pollset = pollset;
+ pp->target = target;
+ pp->on_complete = on_complete;
+ p->pending_picks = pp;
+ gpr_mu_unlock(&p->mu);
+ return 0;
+ }
+}
+
+static void destroy_subchannels(grpc_exec_ctx *exec_ctx, void *arg,
+ bool iomgr_success) {
+ pick_first_lb_policy *p = arg;
+ size_t i;
+ size_t num_subchannels = p->num_subchannels;
+ grpc_subchannel **subchannels;
+
+ gpr_mu_lock(&p->mu);
+ subchannels = p->subchannels;
+ p->num_subchannels = 0;
+ p->subchannels = NULL;
+ gpr_mu_unlock(&p->mu);
+ GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "destroy_subchannels");
+
+ for (i = 0; i < num_subchannels; i++) {
+ GRPC_SUBCHANNEL_UNREF(exec_ctx, subchannels[i], "pick_first");
+ }
+
+ gpr_free(subchannels);
+}
+
+static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
+ bool iomgr_success) {
+ pick_first_lb_policy *p = arg;
+ grpc_subchannel *selected_subchannel;
+ pending_pick *pp;
+ grpc_connected_subchannel *selected;
+
+ gpr_mu_lock(&p->mu);
+
+ selected = GET_SELECTED(p);
+
+ if (p->shutdown) {
+ gpr_mu_unlock(&p->mu);
+ GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "pick_first_connectivity");
+ return;
+ } else if (selected != NULL) {
+ if (p->checking_connectivity == GRPC_CHANNEL_TRANSIENT_FAILURE) {
+ /* if the selected channel goes bad, we're done */
+ p->checking_connectivity = GRPC_CHANNEL_FATAL_FAILURE;
+ }
+ grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
+ p->checking_connectivity, "selected_changed");
+ if (p->checking_connectivity != GRPC_CHANNEL_FATAL_FAILURE) {
+ grpc_connected_subchannel_notify_on_state_change(
+ exec_ctx, selected, p->base.interested_parties,
+ &p->checking_connectivity, &p->connectivity_changed);
+ } else {
+ GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "pick_first_connectivity");
+ }
+ } else {
+ loop:
+ switch (p->checking_connectivity) {
+ case GRPC_CHANNEL_READY:
+ grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
+ GRPC_CHANNEL_READY, "connecting_ready");
+ selected_subchannel = p->subchannels[p->checking_subchannel];
+ selected =
+ grpc_subchannel_get_connected_subchannel(selected_subchannel);
+ GPR_ASSERT(selected != NULL);
+ GRPC_CONNECTED_SUBCHANNEL_REF(selected, "picked_first");
+ /* drop the pick list: we are connected now */
+ GRPC_LB_POLICY_WEAK_REF(&p->base, "destroy_subchannels");
+ gpr_atm_rel_store(&p->selected, (gpr_atm)selected);
+ grpc_exec_ctx_enqueue(
+ exec_ctx, grpc_closure_create(destroy_subchannels, p), true, NULL);
+ /* update any calls that were waiting for a pick */
+ while ((pp = p->pending_picks)) {
+ p->pending_picks = pp->next;
+ *pp->target = selected;
+ grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
+ pp->pollset);
+ grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, true, NULL);
+ gpr_free(pp);
+ }
+ grpc_connected_subchannel_notify_on_state_change(
+ exec_ctx, selected, p->base.interested_parties,
+ &p->checking_connectivity, &p->connectivity_changed);
+ break;
+ case GRPC_CHANNEL_TRANSIENT_FAILURE:
+ grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
+ GRPC_CHANNEL_TRANSIENT_FAILURE,
+ "connecting_transient_failure");
+ p->checking_subchannel =
+ (p->checking_subchannel + 1) % p->num_subchannels;
+ p->checking_connectivity = grpc_subchannel_check_connectivity(
+ p->subchannels[p->checking_subchannel]);
+ if (p->checking_connectivity == GRPC_CHANNEL_TRANSIENT_FAILURE) {
+ grpc_subchannel_notify_on_state_change(
+ exec_ctx, p->subchannels[p->checking_subchannel],
+ p->base.interested_parties, &p->checking_connectivity,
+ &p->connectivity_changed);
+ } else {
+ goto loop;
+ }
+ break;
+ case GRPC_CHANNEL_CONNECTING:
+ case GRPC_CHANNEL_IDLE:
+ grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
+ GRPC_CHANNEL_CONNECTING,
+ "connecting_changed");
+ grpc_subchannel_notify_on_state_change(
+ exec_ctx, p->subchannels[p->checking_subchannel],
+ p->base.interested_parties, &p->checking_connectivity,
+ &p->connectivity_changed);
+ break;
+ case GRPC_CHANNEL_FATAL_FAILURE:
+ p->num_subchannels--;
+ GPR_SWAP(grpc_subchannel *, p->subchannels[p->checking_subchannel],
+ p->subchannels[p->num_subchannels]);
+ GRPC_SUBCHANNEL_UNREF(exec_ctx, p->subchannels[p->num_subchannels],
+ "pick_first");
+ if (p->num_subchannels == 0) {
+ grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
+ GRPC_CHANNEL_FATAL_FAILURE,
+ "no_more_channels");
+ while ((pp = p->pending_picks)) {
+ p->pending_picks = pp->next;
+ *pp->target = NULL;
+ grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, true, NULL);
+ gpr_free(pp);
+ }
+ GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base,
+ "pick_first_connectivity");
+ } else {
+ grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
+ GRPC_CHANNEL_TRANSIENT_FAILURE,
+ "subchannel_failed");
+ p->checking_subchannel %= p->num_subchannels;
+ p->checking_connectivity = grpc_subchannel_check_connectivity(
+ p->subchannels[p->checking_subchannel]);
+ goto loop;
+ }
+ }
+ }
+
+ gpr_mu_unlock(&p->mu);
+}
+
+static grpc_connectivity_state pf_check_connectivity(grpc_exec_ctx *exec_ctx,
+ grpc_lb_policy *pol) {
+ pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+ grpc_connectivity_state st;
+ gpr_mu_lock(&p->mu);
+ st = grpc_connectivity_state_check(&p->state_tracker);
+ gpr_mu_unlock(&p->mu);
+ return st;
+}
+
+void pf_notify_on_state_change(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+ grpc_connectivity_state *current,
+ grpc_closure *notify) {
+ pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+ gpr_mu_lock(&p->mu);
+ grpc_connectivity_state_notify_on_state_change(exec_ctx, &p->state_tracker,
+ current, notify);
+ gpr_mu_unlock(&p->mu);
+}
+
+void pf_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+ grpc_closure *closure) {
+ pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+ grpc_connected_subchannel *selected = GET_SELECTED(p);
+ if (selected) {
+ grpc_connected_subchannel_ping(exec_ctx, selected, closure);
+ } else {
+ grpc_exec_ctx_enqueue(exec_ctx, closure, false, NULL);
+ }
+}
+
+static const grpc_lb_policy_vtable pick_first_lb_policy_vtable = {
+ pf_destroy,
+ pf_shutdown,
+ pf_pick,
+ pf_cancel_pick,
+ pf_ping_one,
+ pf_exit_idle,
+ pf_check_connectivity,
+ pf_notify_on_state_change};
+
+static void pick_first_factory_ref(grpc_lb_policy_factory *factory) {}
+
+static void pick_first_factory_unref(grpc_lb_policy_factory *factory) {}
+
+static grpc_lb_policy *create_pick_first(grpc_exec_ctx *exec_ctx,
+ grpc_lb_policy_factory *factory,
+ grpc_lb_policy_args *args) {
+ GPR_ASSERT(args->addresses != NULL);
+ GPR_ASSERT(args->subchannel_factory != NULL);
+
+ if (args->addresses->naddrs == 0) return NULL;
+
+ pick_first_lb_policy *p = gpr_malloc(sizeof(*p));
+ memset(p, 0, sizeof(*p));
+
+ p->subchannels =
+ gpr_malloc(sizeof(grpc_subchannel *) * args->addresses->naddrs);
+ memset(p->subchannels, 0, sizeof(*p->subchannels) * args->addresses->naddrs);
+ grpc_subchannel_args sc_args;
+ size_t subchannel_idx = 0;
+ for (size_t i = 0; i < args->addresses->naddrs; i++) {
+ memset(&sc_args, 0, sizeof(grpc_subchannel_args));
+ sc_args.addr = (struct sockaddr *)(args->addresses->addrs[i].addr);
+ sc_args.addr_len = (size_t)args->addresses->addrs[i].len;
+
+ grpc_subchannel *subchannel = grpc_subchannel_factory_create_subchannel(
+ exec_ctx, args->subchannel_factory, &sc_args);
+
+ if (subchannel != NULL) {
+ p->subchannels[subchannel_idx++] = subchannel;
+ }
+ }
+ if (subchannel_idx == 0) {
+ gpr_free(p->subchannels);
+ gpr_free(p);
+ return NULL;
+ }
+ p->num_subchannels = subchannel_idx;
+
+ grpc_lb_policy_init(&p->base, &pick_first_lb_policy_vtable);
+ grpc_closure_init(&p->connectivity_changed, pf_connectivity_changed, p);
+ gpr_mu_init(&p->mu);
+ return &p->base;
+}
+
+static const grpc_lb_policy_factory_vtable pick_first_factory_vtable = {
+ pick_first_factory_ref, pick_first_factory_unref, create_pick_first,
+ "pick_first"};
+
+static grpc_lb_policy_factory pick_first_lb_policy_factory = {
+ &pick_first_factory_vtable};
+
+grpc_lb_policy_factory *grpc_pick_first_lb_factory_create() {
+ return &pick_first_lb_policy_factory;
+}
diff --git a/src/core/lib/client_config/lb_policies/pick_first.h b/src/core/lib/client_config/lb_policies/pick_first.h
new file mode 100644
index 0000000000..dba86ea7ad
--- /dev/null
+++ b/src/core/lib/client_config/lb_policies/pick_first.h
@@ -0,0 +1,43 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICIES_PICK_FIRST_H
+#define GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICIES_PICK_FIRST_H
+
+#include "src/core/lib/client_config/lb_policy_factory.h"
+
+/** Returns a load balancing factory for the pick first policy, which picks up
+ * the first subchannel from \a subchannels to succesfully connect */
+grpc_lb_policy_factory *grpc_pick_first_lb_factory_create();
+
+#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICIES_PICK_FIRST_H */
diff --git a/src/core/lib/client_config/lb_policies/round_robin.c b/src/core/lib/client_config/lb_policies/round_robin.c
new file mode 100644
index 0000000000..a4bc2c4786
--- /dev/null
+++ b/src/core/lib/client_config/lb_policies/round_robin.c
@@ -0,0 +1,563 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/client_config/lb_policies/round_robin.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include "src/core/lib/transport/connectivity_state.h"
+
+typedef struct round_robin_lb_policy round_robin_lb_policy;
+
+int grpc_lb_round_robin_trace = 0;
+
+/** List of entities waiting for a pick.
+ *
+ * Once a pick is available, \a target is updated and \a on_complete called. */
+typedef struct pending_pick {
+ struct pending_pick *next;
+ grpc_pollset *pollset;
+ grpc_connected_subchannel **target;
+ grpc_closure *on_complete;
+} pending_pick;
+
+/** List of subchannels in a connectivity READY state */
+typedef struct ready_list {
+ grpc_subchannel *subchannel;
+ struct ready_list *next;
+ struct ready_list *prev;
+} ready_list;
+
+typedef struct {
+ /** index within policy->subchannels */
+ size_t index;
+ /** backpointer to owning policy */
+ round_robin_lb_policy *policy;
+ /** subchannel itself */
+ grpc_subchannel *subchannel;
+ /** notification that connectivity has changed on subchannel */
+ grpc_closure connectivity_changed_closure;
+ /** this subchannels current position in subchannel->ready_list */
+ ready_list *ready_list_node;
+ /** last observed connectivity */
+ grpc_connectivity_state connectivity_state;
+} subchannel_data;
+
+struct round_robin_lb_policy {
+ /** base policy: must be first */
+ grpc_lb_policy base;
+
+ /** all our subchannels */
+ size_t num_subchannels;
+ subchannel_data **subchannels;
+
+ /** mutex protecting remaining members */
+ gpr_mu mu;
+ /** have we started picking? */
+ int started_picking;
+ /** are we shutting down? */
+ int shutdown;
+ /** List of picks that are waiting on connectivity */
+ pending_pick *pending_picks;
+
+ /** our connectivity state tracker */
+ grpc_connectivity_state_tracker state_tracker;
+
+ /** (Dummy) root of the doubly linked list containing READY subchannels */
+ ready_list ready_list;
+ /** Last pick from the ready list. */
+ ready_list *ready_list_last_pick;
+};
+
+/** Returns the next subchannel from the connected list or NULL if the list is
+ * empty.
+ *
+ * Note that this function does *not* advance p->ready_list_last_pick. Use \a
+ * advance_last_picked_locked() for that. */
+static ready_list *peek_next_connected_locked(const round_robin_lb_policy *p) {
+ ready_list *selected;
+ selected = p->ready_list_last_pick->next;
+
+ while (selected != NULL) {
+ if (selected == &p->ready_list) {
+ GPR_ASSERT(selected->subchannel == NULL);
+ /* skip dummy root */
+ selected = selected->next;
+ } else {
+ GPR_ASSERT(selected->subchannel != NULL);
+ return selected;
+ }
+ }
+ return NULL;
+}
+
+/** Advance the \a ready_list picking head. */
+static void advance_last_picked_locked(round_robin_lb_policy *p) {
+ if (p->ready_list_last_pick->next != NULL) { /* non-empty list */
+ p->ready_list_last_pick = p->ready_list_last_pick->next;
+ if (p->ready_list_last_pick == &p->ready_list) {
+ /* skip dummy root */
+ p->ready_list_last_pick = p->ready_list_last_pick->next;
+ }
+ } else { /* should be an empty list */
+ GPR_ASSERT(p->ready_list_last_pick == &p->ready_list);
+ }
+
+ if (grpc_lb_round_robin_trace) {
+ gpr_log(GPR_DEBUG, "[READYLIST] ADVANCED LAST PICK. NOW AT NODE %p (SC %p)",
+ p->ready_list_last_pick, p->ready_list_last_pick->subchannel);
+ }
+}
+
+/** Prepends (relative to the root at p->ready_list) the connected subchannel \a
+ * csc to the list of ready subchannels. */
+static ready_list *add_connected_sc_locked(round_robin_lb_policy *p,
+ grpc_subchannel *sc) {
+ ready_list *new_elem = gpr_malloc(sizeof(ready_list));
+ new_elem->subchannel = sc;
+ if (p->ready_list.prev == NULL) {
+ /* first element */
+ new_elem->next = &p->ready_list;
+ new_elem->prev = &p->ready_list;
+ p->ready_list.next = new_elem;
+ p->ready_list.prev = new_elem;
+ } else {
+ new_elem->next = &p->ready_list;
+ new_elem->prev = p->ready_list.prev;
+ p->ready_list.prev->next = new_elem;
+ p->ready_list.prev = new_elem;
+ }
+ if (grpc_lb_round_robin_trace) {
+ gpr_log(GPR_DEBUG, "[READYLIST] ADDING NODE %p (SC %p)", new_elem, sc);
+ }
+ return new_elem;
+}
+
+/** Removes \a node from the list of connected subchannels */
+static void remove_disconnected_sc_locked(round_robin_lb_policy *p,
+ ready_list *node) {
+ if (node == NULL) {
+ return;
+ }
+ if (node == p->ready_list_last_pick) {
+ /* If removing the lastly picked node, reset the last pick pointer to the
+ * dummy root of the list */
+ p->ready_list_last_pick = &p->ready_list;
+ }
+
+ /* removing last item */
+ if (node->next == &p->ready_list && node->prev == &p->ready_list) {
+ GPR_ASSERT(p->ready_list.next == node);
+ GPR_ASSERT(p->ready_list.prev == node);
+ p->ready_list.next = NULL;
+ p->ready_list.prev = NULL;
+ } else {
+ node->prev->next = node->next;
+ node->next->prev = node->prev;
+ }
+
+ if (grpc_lb_round_robin_trace) {
+ gpr_log(GPR_DEBUG, "[READYLIST] REMOVED NODE %p (SC %p)", node,
+ node->subchannel);
+ }
+
+ node->next = NULL;
+ node->prev = NULL;
+ node->subchannel = NULL;
+
+ gpr_free(node);
+}
+
+void rr_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
+ round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
+ size_t i;
+ ready_list *elem;
+ for (i = 0; i < p->num_subchannels; i++) {
+ subchannel_data *sd = p->subchannels[i];
+ GRPC_SUBCHANNEL_UNREF(exec_ctx, sd->subchannel, "round_robin");
+ gpr_free(sd);
+ }
+
+ grpc_connectivity_state_destroy(exec_ctx, &p->state_tracker);
+ gpr_free(p->subchannels);
+ gpr_mu_destroy(&p->mu);
+
+ elem = p->ready_list.next;
+ while (elem != NULL && elem != &p->ready_list) {
+ ready_list *tmp;
+ tmp = elem->next;
+ elem->next = NULL;
+ elem->prev = NULL;
+ elem->subchannel = NULL;
+ gpr_free(elem);
+ elem = tmp;
+ }
+ gpr_free(p);
+}
+
+void rr_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
+ round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
+ pending_pick *pp;
+ size_t i;
+
+ gpr_mu_lock(&p->mu);
+
+ p->shutdown = 1;
+ while ((pp = p->pending_picks)) {
+ p->pending_picks = pp->next;
+ *pp->target = NULL;
+ grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, false, NULL);
+ gpr_free(pp);
+ }
+ grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
+ GRPC_CHANNEL_FATAL_FAILURE, "shutdown");
+ for (i = 0; i < p->num_subchannels; i++) {
+ subchannel_data *sd = p->subchannels[i];
+ grpc_subchannel_notify_on_state_change(exec_ctx, sd->subchannel, NULL, NULL,
+ &sd->connectivity_changed_closure);
+ }
+ gpr_mu_unlock(&p->mu);
+}
+
+static void rr_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+ grpc_connected_subchannel **target) {
+ round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
+ pending_pick *pp;
+ gpr_mu_lock(&p->mu);
+ pp = p->pending_picks;
+ p->pending_picks = NULL;
+ while (pp != NULL) {
+ pending_pick *next = pp->next;
+ if (pp->target == target) {
+ grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
+ pp->pollset);
+ *target = NULL;
+ grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, false, NULL);
+ gpr_free(pp);
+ } else {
+ pp->next = p->pending_picks;
+ p->pending_picks = pp;
+ }
+ pp = next;
+ }
+ gpr_mu_unlock(&p->mu);
+}
+
+static void start_picking(grpc_exec_ctx *exec_ctx, round_robin_lb_policy *p) {
+ size_t i;
+ p->started_picking = 1;
+
+ gpr_log(GPR_DEBUG, "LB_POLICY: p=%p num_subchannels=%d", p,
+ p->num_subchannels);
+
+ for (i = 0; i < p->num_subchannels; i++) {
+ subchannel_data *sd = p->subchannels[i];
+ sd->connectivity_state = GRPC_CHANNEL_IDLE;
+ grpc_subchannel_notify_on_state_change(
+ exec_ctx, sd->subchannel, p->base.interested_parties,
+ &sd->connectivity_state, &sd->connectivity_changed_closure);
+ GRPC_LB_POLICY_WEAK_REF(&p->base, "round_robin_connectivity");
+ }
+}
+
+void rr_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
+ round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
+ gpr_mu_lock(&p->mu);
+ if (!p->started_picking) {
+ start_picking(exec_ctx, p);
+ }
+ gpr_mu_unlock(&p->mu);
+}
+
+int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_pollset *pollset,
+ grpc_metadata_batch *initial_metadata,
+ grpc_connected_subchannel **target, grpc_closure *on_complete) {
+ round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
+ pending_pick *pp;
+ ready_list *selected;
+ gpr_mu_lock(&p->mu);
+ if ((selected = peek_next_connected_locked(p))) {
+ gpr_mu_unlock(&p->mu);
+ *target = grpc_subchannel_get_connected_subchannel(selected->subchannel);
+ if (grpc_lb_round_robin_trace) {
+ gpr_log(GPR_DEBUG,
+ "[RR PICK] TARGET <-- CONNECTED SUBCHANNEL %p (NODE %p)",
+ selected->subchannel, selected);
+ }
+ /* only advance the last picked pointer if the selection was used */
+ advance_last_picked_locked(p);
+ return 1;
+ } else {
+ if (!p->started_picking) {
+ start_picking(exec_ctx, p);
+ }
+ grpc_pollset_set_add_pollset(exec_ctx, p->base.interested_parties, pollset);
+ pp = gpr_malloc(sizeof(*pp));
+ pp->next = p->pending_picks;
+ pp->pollset = pollset;
+ pp->target = target;
+ pp->on_complete = on_complete;
+ p->pending_picks = pp;
+ gpr_mu_unlock(&p->mu);
+ return 0;
+ }
+}
+
+static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
+ bool iomgr_success) {
+ subchannel_data *sd = arg;
+ round_robin_lb_policy *p = sd->policy;
+ pending_pick *pp;
+ ready_list *selected;
+
+ int unref = 0;
+
+ gpr_mu_lock(&p->mu);
+
+ if (p->shutdown) {
+ unref = 1;
+ } else {
+ switch (sd->connectivity_state) {
+ case GRPC_CHANNEL_READY:
+ grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
+ GRPC_CHANNEL_READY, "connecting_ready");
+ /* add the newly connected subchannel to the list of connected ones.
+ * Note that it goes to the "end of the line". */
+ sd->ready_list_node = add_connected_sc_locked(p, sd->subchannel);
+ /* at this point we know there's at least one suitable subchannel. Go
+ * ahead and pick one and notify the pending suitors in
+ * p->pending_picks. This preemtively replicates rr_pick()'s actions. */
+ selected = peek_next_connected_locked(p);
+ if (p->pending_picks != NULL) {
+ /* if the selected subchannel is going to be used for the pending
+ * picks, update the last picked pointer */
+ advance_last_picked_locked(p);
+ }
+ while ((pp = p->pending_picks)) {
+ p->pending_picks = pp->next;
+ *pp->target =
+ grpc_subchannel_get_connected_subchannel(selected->subchannel);
+ if (grpc_lb_round_robin_trace) {
+ gpr_log(GPR_DEBUG,
+ "[RR CONN CHANGED] TARGET <-- SUBCHANNEL %p (NODE %p)",
+ selected->subchannel, selected);
+ }
+ grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
+ pp->pollset);
+ grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, true, NULL);
+ gpr_free(pp);
+ }
+ grpc_subchannel_notify_on_state_change(
+ exec_ctx, sd->subchannel, p->base.interested_parties,
+ &sd->connectivity_state, &sd->connectivity_changed_closure);
+ break;
+ case GRPC_CHANNEL_CONNECTING:
+ case GRPC_CHANNEL_IDLE:
+ grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
+ sd->connectivity_state,
+ "connecting_changed");
+ grpc_subchannel_notify_on_state_change(
+ exec_ctx, sd->subchannel, p->base.interested_parties,
+ &sd->connectivity_state, &sd->connectivity_changed_closure);
+ break;
+ case GRPC_CHANNEL_TRANSIENT_FAILURE:
+ /* renew state notification */
+ grpc_subchannel_notify_on_state_change(
+ exec_ctx, sd->subchannel, p->base.interested_parties,
+ &sd->connectivity_state, &sd->connectivity_changed_closure);
+
+ /* remove from ready list if still present */
+ if (sd->ready_list_node != NULL) {
+ remove_disconnected_sc_locked(p, sd->ready_list_node);
+ sd->ready_list_node = NULL;
+ }
+ grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
+ GRPC_CHANNEL_TRANSIENT_FAILURE,
+ "connecting_transient_failure");
+ break;
+ case GRPC_CHANNEL_FATAL_FAILURE:
+ if (sd->ready_list_node != NULL) {
+ remove_disconnected_sc_locked(p, sd->ready_list_node);
+ sd->ready_list_node = NULL;
+ }
+
+ p->num_subchannels--;
+ GPR_SWAP(subchannel_data *, p->subchannels[sd->index],
+ p->subchannels[p->num_subchannels]);
+ GRPC_SUBCHANNEL_UNREF(exec_ctx, sd->subchannel, "round_robin");
+ p->subchannels[sd->index]->index = sd->index;
+ gpr_free(sd);
+
+ unref = 1;
+ if (p->num_subchannels == 0) {
+ grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
+ GRPC_CHANNEL_FATAL_FAILURE,
+ "no_more_channels");
+ while ((pp = p->pending_picks)) {
+ p->pending_picks = pp->next;
+ *pp->target = NULL;
+ grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, true, NULL);
+ gpr_free(pp);
+ }
+ } else {
+ grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
+ GRPC_CHANNEL_TRANSIENT_FAILURE,
+ "subchannel_failed");
+ }
+ } /* switch */
+ } /* !unref */
+
+ gpr_mu_unlock(&p->mu);
+
+ if (unref) {
+ GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "round_robin_connectivity");
+ }
+}
+
+static grpc_connectivity_state rr_check_connectivity(grpc_exec_ctx *exec_ctx,
+ grpc_lb_policy *pol) {
+ round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
+ grpc_connectivity_state st;
+ gpr_mu_lock(&p->mu);
+ st = grpc_connectivity_state_check(&p->state_tracker);
+ gpr_mu_unlock(&p->mu);
+ return st;
+}
+
+static void rr_notify_on_state_change(grpc_exec_ctx *exec_ctx,
+ grpc_lb_policy *pol,
+ grpc_connectivity_state *current,
+ grpc_closure *notify) {
+ round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
+ gpr_mu_lock(&p->mu);
+ grpc_connectivity_state_notify_on_state_change(exec_ctx, &p->state_tracker,
+ current, notify);
+ gpr_mu_unlock(&p->mu);
+}
+
+static void rr_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+ grpc_closure *closure) {
+ round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
+ ready_list *selected;
+ grpc_connected_subchannel *target;
+ gpr_mu_lock(&p->mu);
+ if ((selected = peek_next_connected_locked(p))) {
+ gpr_mu_unlock(&p->mu);
+ target = grpc_subchannel_get_connected_subchannel(selected->subchannel);
+ grpc_connected_subchannel_ping(exec_ctx, target, closure);
+ } else {
+ gpr_mu_unlock(&p->mu);
+ grpc_exec_ctx_enqueue(exec_ctx, closure, false, NULL);
+ }
+}
+
+static const grpc_lb_policy_vtable round_robin_lb_policy_vtable = {
+ rr_destroy,
+ rr_shutdown,
+ rr_pick,
+ rr_cancel_pick,
+ rr_ping_one,
+ rr_exit_idle,
+ rr_check_connectivity,
+ rr_notify_on_state_change};
+
+static void round_robin_factory_ref(grpc_lb_policy_factory *factory) {}
+
+static void round_robin_factory_unref(grpc_lb_policy_factory *factory) {}
+
+static grpc_lb_policy *create_round_robin(grpc_exec_ctx *exec_ctx,
+ grpc_lb_policy_factory *factory,
+ grpc_lb_policy_args *args) {
+ GPR_ASSERT(args->addresses != NULL);
+ GPR_ASSERT(args->subchannel_factory != NULL);
+
+ round_robin_lb_policy *p = gpr_malloc(sizeof(*p));
+ memset(p, 0, sizeof(*p));
+
+ p->subchannels =
+ gpr_malloc(sizeof(*p->subchannels) * args->addresses->naddrs);
+ memset(p->subchannels, 0, sizeof(*p->subchannels) * args->addresses->naddrs);
+
+ grpc_subchannel_args sc_args;
+ size_t subchannel_idx = 0;
+ for (size_t i = 0; i < args->addresses->naddrs; i++) {
+ memset(&sc_args, 0, sizeof(grpc_subchannel_args));
+ sc_args.addr = (struct sockaddr *)(args->addresses->addrs[i].addr);
+ sc_args.addr_len = (size_t)args->addresses->addrs[i].len;
+
+ grpc_subchannel *subchannel = grpc_subchannel_factory_create_subchannel(
+ exec_ctx, args->subchannel_factory, &sc_args);
+
+ if (subchannel != NULL) {
+ subchannel_data *sd = gpr_malloc(sizeof(*sd));
+ memset(sd, 0, sizeof(*sd));
+ p->subchannels[subchannel_idx] = sd;
+ sd->policy = p;
+ sd->index = subchannel_idx;
+ sd->subchannel = subchannel;
+ ++subchannel_idx;
+ grpc_closure_init(&sd->connectivity_changed_closure,
+ rr_connectivity_changed, sd);
+ }
+ }
+ if (subchannel_idx == 0) {
+ gpr_free(p->subchannels);
+ gpr_free(p);
+ return NULL;
+ }
+ p->num_subchannels = subchannel_idx;
+
+ /* The (dummy node) root of the ready list */
+ p->ready_list.subchannel = NULL;
+ p->ready_list.prev = NULL;
+ p->ready_list.next = NULL;
+ p->ready_list_last_pick = &p->ready_list;
+
+ grpc_lb_policy_init(&p->base, &round_robin_lb_policy_vtable);
+ grpc_connectivity_state_init(&p->state_tracker, GRPC_CHANNEL_IDLE,
+ "round_robin");
+ gpr_mu_init(&p->mu);
+ return &p->base;
+}
+
+static const grpc_lb_policy_factory_vtable round_robin_factory_vtable = {
+ round_robin_factory_ref, round_robin_factory_unref, create_round_robin,
+ "round_robin"};
+
+static grpc_lb_policy_factory round_robin_lb_policy_factory = {
+ &round_robin_factory_vtable};
+
+grpc_lb_policy_factory *grpc_round_robin_lb_factory_create() {
+ return &round_robin_lb_policy_factory;
+}
diff --git a/src/core/lib/client_config/lb_policies/round_robin.h b/src/core/lib/client_config/lb_policies/round_robin.h
new file mode 100644
index 0000000000..52db1caa0c
--- /dev/null
+++ b/src/core/lib/client_config/lb_policies/round_robin.h
@@ -0,0 +1,46 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICIES_ROUND_ROBIN_H
+#define GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICIES_ROUND_ROBIN_H
+
+#include "src/core/lib/client_config/lb_policy.h"
+
+extern int grpc_lb_round_robin_trace;
+
+#include "src/core/lib/client_config/lb_policy_factory.h"
+
+/** Returns a load balancing factory for the round robin policy */
+grpc_lb_policy_factory *grpc_round_robin_lb_factory_create();
+
+#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICIES_ROUND_ROBIN_H */
diff --git a/src/core/lib/client_config/lb_policy.c b/src/core/lib/client_config/lb_policy.c
new file mode 100644
index 0000000000..ee20ccd76a
--- /dev/null
+++ b/src/core/lib/client_config/lb_policy.c
@@ -0,0 +1,134 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/client_config/lb_policy.h"
+
+#define WEAK_REF_BITS 16
+
+void grpc_lb_policy_init(grpc_lb_policy *policy,
+ const grpc_lb_policy_vtable *vtable) {
+ policy->vtable = vtable;
+ gpr_atm_no_barrier_store(&policy->ref_pair, 1 << WEAK_REF_BITS);
+ policy->interested_parties = grpc_pollset_set_create();
+}
+
+#ifdef GRPC_LB_POLICY_REFCOUNT_DEBUG
+#define REF_FUNC_EXTRA_ARGS , const char *file, int line, const char *reason
+#define REF_MUTATE_EXTRA_ARGS REF_FUNC_EXTRA_ARGS, const char *purpose
+#define REF_FUNC_PASS_ARGS(new_reason) , file, line, new_reason
+#define REF_MUTATE_PASS_ARGS(purpose) , file, line, reason, purpose
+#else
+#define REF_FUNC_EXTRA_ARGS
+#define REF_MUTATE_EXTRA_ARGS
+#define REF_FUNC_PASS_ARGS(new_reason)
+#define REF_MUTATE_PASS_ARGS(x)
+#endif
+
+static gpr_atm ref_mutate(grpc_lb_policy *c, gpr_atm delta,
+ int barrier REF_MUTATE_EXTRA_ARGS) {
+ gpr_atm old_val = barrier ? gpr_atm_full_fetch_add(&c->ref_pair, delta)
+ : gpr_atm_no_barrier_fetch_add(&c->ref_pair, delta);
+#ifdef GRPC_LB_POLICY_REFCOUNT_DEBUG
+ gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG,
+ "LB_POLICY: %p % 12s 0x%08x -> 0x%08x [%s]", c, purpose, old_val,
+ old_val + delta, reason);
+#endif
+ return old_val;
+}
+
+void grpc_lb_policy_ref(grpc_lb_policy *policy REF_FUNC_EXTRA_ARGS) {
+ ref_mutate(policy, 1 << WEAK_REF_BITS, 0 REF_MUTATE_PASS_ARGS("STRONG_REF"));
+}
+
+void grpc_lb_policy_unref(grpc_exec_ctx *exec_ctx,
+ grpc_lb_policy *policy REF_FUNC_EXTRA_ARGS) {
+ gpr_atm old_val =
+ ref_mutate(policy, (gpr_atm)1 - (gpr_atm)(1 << WEAK_REF_BITS),
+ 1 REF_MUTATE_PASS_ARGS("STRONG_UNREF"));
+ gpr_atm mask = ~(gpr_atm)((1 << WEAK_REF_BITS) - 1);
+ gpr_atm check = 1 << WEAK_REF_BITS;
+ if ((old_val & mask) == check) {
+ policy->vtable->shutdown(exec_ctx, policy);
+ }
+ grpc_lb_policy_weak_unref(exec_ctx,
+ policy REF_FUNC_PASS_ARGS("strong-unref"));
+}
+
+void grpc_lb_policy_weak_ref(grpc_lb_policy *policy REF_FUNC_EXTRA_ARGS) {
+ ref_mutate(policy, 1, 0 REF_MUTATE_PASS_ARGS("WEAK_REF"));
+}
+
+void grpc_lb_policy_weak_unref(grpc_exec_ctx *exec_ctx,
+ grpc_lb_policy *policy REF_FUNC_EXTRA_ARGS) {
+ gpr_atm old_val =
+ ref_mutate(policy, -(gpr_atm)1, 1 REF_MUTATE_PASS_ARGS("WEAK_UNREF"));
+ if (old_val == 1) {
+ grpc_pollset_set_destroy(policy->interested_parties);
+ policy->vtable->destroy(exec_ctx, policy);
+ }
+}
+
+int grpc_lb_policy_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+ grpc_pollset *pollset,
+ grpc_metadata_batch *initial_metadata,
+ grpc_connected_subchannel **target,
+ grpc_closure *on_complete) {
+ return policy->vtable->pick(exec_ctx, policy, pollset, initial_metadata,
+ target, on_complete);
+}
+
+void grpc_lb_policy_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+ grpc_connected_subchannel **target) {
+ policy->vtable->cancel_pick(exec_ctx, policy, target);
+}
+
+void grpc_lb_policy_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy) {
+ policy->vtable->exit_idle(exec_ctx, policy);
+}
+
+void grpc_lb_policy_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+ grpc_closure *closure) {
+ policy->vtable->ping_one(exec_ctx, policy, closure);
+}
+
+void grpc_lb_policy_notify_on_state_change(grpc_exec_ctx *exec_ctx,
+ grpc_lb_policy *policy,
+ grpc_connectivity_state *state,
+ grpc_closure *closure) {
+ policy->vtable->notify_on_state_change(exec_ctx, policy, state, closure);
+}
+
+grpc_connectivity_state grpc_lb_policy_check_connectivity(
+ grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy) {
+ return policy->vtable->check_connectivity(exec_ctx, policy);
+}
diff --git a/src/core/lib/client_config/lb_policy.h b/src/core/lib/client_config/lb_policy.h
new file mode 100644
index 0000000000..58a0a04d85
--- /dev/null
+++ b/src/core/lib/client_config/lb_policy.h
@@ -0,0 +1,144 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_H
+#define GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_H
+
+#include "src/core/lib/client_config/subchannel.h"
+#include "src/core/lib/transport/connectivity_state.h"
+
+/** A load balancing policy: specified by a vtable and a struct (which
+ is expected to be extended to contain some parameters) */
+typedef struct grpc_lb_policy grpc_lb_policy;
+typedef struct grpc_lb_policy_vtable grpc_lb_policy_vtable;
+
+typedef void (*grpc_lb_completion)(void *cb_arg, grpc_subchannel *subchannel,
+ grpc_status_code status, const char *errmsg);
+
+struct grpc_lb_policy {
+ const grpc_lb_policy_vtable *vtable;
+ gpr_atm ref_pair;
+ /* owned pointer to interested parties in load balancing decisions */
+ grpc_pollset_set *interested_parties;
+};
+
+struct grpc_lb_policy_vtable {
+ void (*destroy)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
+
+ void (*shutdown)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
+
+ /** implement grpc_lb_policy_pick */
+ int (*pick)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+ grpc_pollset *pollset, grpc_metadata_batch *initial_metadata,
+ grpc_connected_subchannel **target, grpc_closure *on_complete);
+ void (*cancel_pick)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+ grpc_connected_subchannel **target);
+
+ void (*ping_one)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+ grpc_closure *closure);
+
+ /** try to enter a READY connectivity state */
+ void (*exit_idle)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
+
+ /** check the current connectivity of the lb_policy */
+ grpc_connectivity_state (*check_connectivity)(grpc_exec_ctx *exec_ctx,
+ grpc_lb_policy *policy);
+
+ /** call notify when the connectivity state of a channel changes from *state.
+ Updates *state with the new state of the policy */
+ void (*notify_on_state_change)(grpc_exec_ctx *exec_ctx,
+ grpc_lb_policy *policy,
+ grpc_connectivity_state *state,
+ grpc_closure *closure);
+};
+
+/*#define GRPC_LB_POLICY_REFCOUNT_DEBUG*/
+#ifdef GRPC_LB_POLICY_REFCOUNT_DEBUG
+#define GRPC_LB_POLICY_REF(p, r) \
+ grpc_lb_policy_ref((p), __FILE__, __LINE__, (r))
+#define GRPC_LB_POLICY_UNREF(exec_ctx, p, r) \
+ grpc_lb_policy_unref((exec_ctx), (p), __FILE__, __LINE__, (r))
+#define GRPC_LB_POLICY_WEAK_REF(p, r) \
+ grpc_lb_policy_weak_ref((p), __FILE__, __LINE__, (r))
+#define GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, p, r) \
+ grpc_lb_policy_weak_unref((exec_ctx), (p), __FILE__, __LINE__, (r))
+void grpc_lb_policy_ref(grpc_lb_policy *policy, const char *file, int line,
+ const char *reason);
+void grpc_lb_policy_unref(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+ const char *file, int line, const char *reason);
+void grpc_lb_policy_weak_ref(grpc_lb_policy *policy, const char *file, int line,
+ const char *reason);
+void grpc_lb_policy_weak_unref(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+ const char *file, int line, const char *reason);
+#else
+#define GRPC_LB_POLICY_REF(p, r) grpc_lb_policy_ref((p))
+#define GRPC_LB_POLICY_UNREF(cl, p, r) grpc_lb_policy_unref((cl), (p))
+#define GRPC_LB_POLICY_WEAK_REF(p, r) grpc_lb_policy_weak_ref((p))
+#define GRPC_LB_POLICY_WEAK_UNREF(cl, p, r) grpc_lb_policy_weak_unref((cl), (p))
+void grpc_lb_policy_ref(grpc_lb_policy *policy);
+void grpc_lb_policy_unref(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
+void grpc_lb_policy_weak_ref(grpc_lb_policy *policy);
+void grpc_lb_policy_weak_unref(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
+#endif
+
+/** called by concrete implementations to initialize the base struct */
+void grpc_lb_policy_init(grpc_lb_policy *policy,
+ const grpc_lb_policy_vtable *vtable);
+
+/** Given initial metadata in \a initial_metadata, find an appropriate
+ target for this rpc, and 'return' it by calling \a on_complete after setting
+ \a target.
+ Picking can be asynchronous. Any IO should be done under \a pollset. */
+int grpc_lb_policy_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+ grpc_pollset *pollset,
+ grpc_metadata_batch *initial_metadata,
+ grpc_connected_subchannel **target,
+ grpc_closure *on_complete);
+
+void grpc_lb_policy_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+ grpc_closure *closure);
+
+void grpc_lb_policy_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+ grpc_connected_subchannel **target);
+
+void grpc_lb_policy_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
+
+void grpc_lb_policy_notify_on_state_change(grpc_exec_ctx *exec_ctx,
+ grpc_lb_policy *policy,
+ grpc_connectivity_state *state,
+ grpc_closure *closure);
+
+grpc_connectivity_state grpc_lb_policy_check_connectivity(
+ grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
+
+#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_H */
diff --git a/src/core/lib/client_config/lb_policy_factory.c b/src/core/lib/client_config/lb_policy_factory.c
new file mode 100644
index 0000000000..ede1d624af
--- /dev/null
+++ b/src/core/lib/client_config/lb_policy_factory.c
@@ -0,0 +1,49 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/client_config/lb_policy_factory.h"
+
+void grpc_lb_policy_factory_ref(grpc_lb_policy_factory* factory) {
+ factory->vtable->ref(factory);
+}
+
+void grpc_lb_policy_factory_unref(grpc_lb_policy_factory* factory) {
+ factory->vtable->unref(factory);
+}
+
+grpc_lb_policy* grpc_lb_policy_factory_create_lb_policy(
+ grpc_exec_ctx* exec_ctx, grpc_lb_policy_factory* factory,
+ grpc_lb_policy_args* args) {
+ if (factory == NULL) return NULL;
+ return factory->vtable->create_lb_policy(exec_ctx, factory, args);
+}
diff --git a/src/core/lib/client_config/lb_policy_factory.h b/src/core/lib/client_config/lb_policy_factory.h
new file mode 100644
index 0000000000..9a93a8ca3f
--- /dev/null
+++ b/src/core/lib/client_config/lb_policy_factory.h
@@ -0,0 +1,78 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_FACTORY_H
+#define GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_FACTORY_H
+
+#include "src/core/lib/client_config/lb_policy.h"
+#include "src/core/lib/client_config/subchannel_factory.h"
+#include "src/core/lib/iomgr/resolve_address.h"
+
+#include "src/core/lib/iomgr/exec_ctx.h"
+
+typedef struct grpc_lb_policy_factory grpc_lb_policy_factory;
+typedef struct grpc_lb_policy_factory_vtable grpc_lb_policy_factory_vtable;
+
+/** grpc_lb_policy provides grpc_client_config objects to grpc_channel
+ objects */
+struct grpc_lb_policy_factory {
+ const grpc_lb_policy_factory_vtable *vtable;
+};
+
+typedef struct grpc_lb_policy_args {
+ grpc_resolved_addresses *addresses;
+ grpc_subchannel_factory *subchannel_factory;
+} grpc_lb_policy_args;
+
+struct grpc_lb_policy_factory_vtable {
+ void (*ref)(grpc_lb_policy_factory *factory);
+ void (*unref)(grpc_lb_policy_factory *factory);
+
+ /** Implementation of grpc_lb_policy_factory_create_lb_policy */
+ grpc_lb_policy *(*create_lb_policy)(grpc_exec_ctx *exec_ctx,
+ grpc_lb_policy_factory *factory,
+ grpc_lb_policy_args *args);
+
+ /** Name for the LB policy this factory implements */
+ const char *name;
+};
+
+void grpc_lb_policy_factory_ref(grpc_lb_policy_factory *factory);
+void grpc_lb_policy_factory_unref(grpc_lb_policy_factory *factory);
+
+/** Create a lb_policy instance. */
+grpc_lb_policy *grpc_lb_policy_factory_create_lb_policy(
+ grpc_exec_ctx *exec_ctx, grpc_lb_policy_factory *factory,
+ grpc_lb_policy_args *args);
+
+#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_FACTORY_H */
diff --git a/src/core/lib/client_config/lb_policy_registry.c b/src/core/lib/client_config/lb_policy_registry.c
new file mode 100644
index 0000000000..f703e630a0
--- /dev/null
+++ b/src/core/lib/client_config/lb_policy_registry.c
@@ -0,0 +1,88 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/client_config/lb_policy_registry.h"
+
+#include <string.h>
+
+#define MAX_POLICIES 10
+
+static grpc_lb_policy_factory *g_all_of_the_lb_policies[MAX_POLICIES];
+static int g_number_of_lb_policies = 0;
+
+static grpc_lb_policy_factory *g_default_lb_policy_factory;
+
+void grpc_lb_policy_registry_init(grpc_lb_policy_factory *default_factory) {
+ g_number_of_lb_policies = 0;
+ g_default_lb_policy_factory = default_factory;
+}
+
+void grpc_lb_policy_registry_shutdown(void) {
+ int i;
+ for (i = 0; i < g_number_of_lb_policies; i++) {
+ grpc_lb_policy_factory_unref(g_all_of_the_lb_policies[i]);
+ }
+}
+
+void grpc_register_lb_policy(grpc_lb_policy_factory *factory) {
+ int i;
+ for (i = 0; i < g_number_of_lb_policies; i++) {
+ GPR_ASSERT(0 != strcmp(factory->vtable->name,
+ g_all_of_the_lb_policies[i]->vtable->name));
+ }
+ GPR_ASSERT(g_number_of_lb_policies != MAX_POLICIES);
+ grpc_lb_policy_factory_ref(factory);
+ g_all_of_the_lb_policies[g_number_of_lb_policies++] = factory;
+}
+
+static grpc_lb_policy_factory *lookup_factory(const char *name) {
+ int i;
+
+ if (name == NULL) return NULL;
+
+ for (i = 0; i < g_number_of_lb_policies; i++) {
+ if (0 == strcmp(name, g_all_of_the_lb_policies[i]->vtable->name)) {
+ return g_all_of_the_lb_policies[i];
+ }
+ }
+
+ return NULL;
+}
+
+grpc_lb_policy *grpc_lb_policy_create(grpc_exec_ctx *exec_ctx, const char *name,
+ grpc_lb_policy_args *args) {
+ grpc_lb_policy_factory *factory = lookup_factory(name);
+ grpc_lb_policy *lb_policy =
+ grpc_lb_policy_factory_create_lb_policy(exec_ctx, factory, args);
+ return lb_policy;
+}
diff --git a/src/core/lib/client_config/lb_policy_registry.h b/src/core/lib/client_config/lb_policy_registry.h
new file mode 100644
index 0000000000..789854bd20
--- /dev/null
+++ b/src/core/lib/client_config/lb_policy_registry.h
@@ -0,0 +1,55 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_REGISTRY_H
+#define GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_REGISTRY_H
+
+#include "src/core/lib/client_config/lb_policy_factory.h"
+#include "src/core/lib/iomgr/exec_ctx.h"
+
+/** Initialize the registry and set \a default_factory as the factory to be
+ * returned when no name is provided in a lookup */
+void grpc_lb_policy_registry_init(grpc_lb_policy_factory *default_factory);
+void grpc_lb_policy_registry_shutdown(void);
+
+/** Register a LB policy factory. */
+void grpc_register_lb_policy(grpc_lb_policy_factory *factory);
+
+/** Create a \a grpc_lb_policy instance.
+ *
+ * If \a name is NULL, the default factory from \a grpc_lb_policy_registry_init
+ * will be returned. */
+grpc_lb_policy *grpc_lb_policy_create(grpc_exec_ctx *exec_ctx, const char *name,
+ grpc_lb_policy_args *args);
+
+#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_REGISTRY_H */
diff --git a/src/core/lib/client_config/resolver.c b/src/core/lib/client_config/resolver.c
new file mode 100644
index 0000000000..32f0643adb
--- /dev/null
+++ b/src/core/lib/client_config/resolver.c
@@ -0,0 +1,82 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/client_config/resolver.h"
+
+void grpc_resolver_init(grpc_resolver *resolver,
+ const grpc_resolver_vtable *vtable) {
+ resolver->vtable = vtable;
+ gpr_ref_init(&resolver->refs, 1);
+}
+
+#ifdef GRPC_RESOLVER_REFCOUNT_DEBUG
+void grpc_resolver_ref(grpc_resolver *resolver, grpc_closure_list *closure_list,
+ const char *file, int line, const char *reason) {
+ gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "RESOLVER:%p ref %d -> %d %s",
+ resolver, (int)resolver->refs.count, (int)resolver->refs.count + 1,
+ reason);
+#else
+void grpc_resolver_ref(grpc_resolver *resolver) {
+#endif
+ gpr_ref(&resolver->refs);
+}
+
+#ifdef GRPC_RESOLVER_REFCOUNT_DEBUG
+void grpc_resolver_unref(grpc_resolver *resolver,
+ grpc_closure_list *closure_list, const char *file,
+ int line, const char *reason) {
+ gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "RESOLVER:%p unref %d -> %d %s",
+ resolver, (int)resolver->refs.count, (int)resolver->refs.count - 1,
+ reason);
+#else
+void grpc_resolver_unref(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver) {
+#endif
+ if (gpr_unref(&resolver->refs)) {
+ resolver->vtable->destroy(exec_ctx, resolver);
+ }
+}
+
+void grpc_resolver_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver) {
+ resolver->vtable->shutdown(exec_ctx, resolver);
+}
+
+void grpc_resolver_channel_saw_error(grpc_exec_ctx *exec_ctx,
+ grpc_resolver *resolver) {
+ resolver->vtable->channel_saw_error(exec_ctx, resolver);
+}
+
+void grpc_resolver_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
+ grpc_client_config **target_config,
+ grpc_closure *on_complete) {
+ resolver->vtable->next(exec_ctx, resolver, target_config, on_complete);
+}
diff --git a/src/core/lib/client_config/resolver.h b/src/core/lib/client_config/resolver.h
new file mode 100644
index 0000000000..1ee879293a
--- /dev/null
+++ b/src/core/lib/client_config/resolver.h
@@ -0,0 +1,94 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVER_H
+#define GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVER_H
+
+#include "src/core/lib/client_config/client_config.h"
+#include "src/core/lib/client_config/subchannel.h"
+#include "src/core/lib/iomgr/iomgr.h"
+
+typedef struct grpc_resolver grpc_resolver;
+typedef struct grpc_resolver_vtable grpc_resolver_vtable;
+
+/** grpc_resolver provides grpc_client_config objects to grpc_channel
+ objects */
+struct grpc_resolver {
+ const grpc_resolver_vtable *vtable;
+ gpr_refcount refs;
+};
+
+struct grpc_resolver_vtable {
+ void (*destroy)(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver);
+ void (*shutdown)(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver);
+ void (*channel_saw_error)(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver);
+ void (*next)(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
+ grpc_client_config **target_config, grpc_closure *on_complete);
+};
+
+#ifdef GRPC_RESOLVER_REFCOUNT_DEBUG
+#define GRPC_RESOLVER_REF(p, r) grpc_resolver_ref((p), __FILE__, __LINE__, (r))
+#define GRPC_RESOLVER_UNREF(cl, p, r) \
+ grpc_resolver_unref((cl), (p), __FILE__, __LINE__, (r))
+void grpc_resolver_ref(grpc_resolver *policy, const char *file, int line,
+ const char *reason);
+void grpc_resolver_unref(grpc_resolver *policy, grpc_closure_list *closure_list,
+ const char *file, int line, const char *reason);
+#else
+#define GRPC_RESOLVER_REF(p, r) grpc_resolver_ref((p))
+#define GRPC_RESOLVER_UNREF(cl, p, r) grpc_resolver_unref((cl), (p))
+void grpc_resolver_ref(grpc_resolver *policy);
+void grpc_resolver_unref(grpc_exec_ctx *exec_ctx, grpc_resolver *policy);
+#endif
+
+void grpc_resolver_init(grpc_resolver *resolver,
+ const grpc_resolver_vtable *vtable);
+
+void grpc_resolver_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver);
+
+/** Notification that the channel has seen an error on some address.
+ Can be used as a hint that re-resolution is desirable soon. */
+void grpc_resolver_channel_saw_error(grpc_exec_ctx *exec_ctx,
+ grpc_resolver *resolver);
+
+/** Get the next client config. Called by the channel to fetch a new
+ configuration. Expected to set *target_config with a new configuration,
+ and then schedule on_complete for execution.
+
+ If resolution is fatally broken, set *target_config to NULL and
+ schedule on_complete. */
+void grpc_resolver_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
+ grpc_client_config **target_config,
+ grpc_closure *on_complete);
+
+#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVER_H */
diff --git a/src/core/lib/client_config/resolver_factory.c b/src/core/lib/client_config/resolver_factory.c
new file mode 100644
index 0000000000..0f76c664fa
--- /dev/null
+++ b/src/core/lib/client_config/resolver_factory.c
@@ -0,0 +1,55 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/client_config/resolver_factory.h"
+
+void grpc_resolver_factory_ref(grpc_resolver_factory* factory) {
+ factory->vtable->ref(factory);
+}
+
+void grpc_resolver_factory_unref(grpc_resolver_factory* factory) {
+ factory->vtable->unref(factory);
+}
+
+/** Create a resolver instance for a name */
+grpc_resolver* grpc_resolver_factory_create_resolver(
+ grpc_resolver_factory* factory, grpc_resolver_args* args) {
+ if (factory == NULL) return NULL;
+ return factory->vtable->create_resolver(factory, args);
+}
+
+char* grpc_resolver_factory_get_default_authority(
+ grpc_resolver_factory* factory, grpc_uri* uri) {
+ if (factory == NULL) return NULL;
+ return factory->vtable->get_default_authority(factory, uri);
+}
diff --git a/src/core/lib/client_config/resolver_factory.h b/src/core/lib/client_config/resolver_factory.h
new file mode 100644
index 0000000000..7765c3c844
--- /dev/null
+++ b/src/core/lib/client_config/resolver_factory.h
@@ -0,0 +1,82 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVER_FACTORY_H
+#define GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVER_FACTORY_H
+
+#include "src/core/lib/client_config/resolver.h"
+#include "src/core/lib/client_config/subchannel_factory.h"
+#include "src/core/lib/client_config/uri_parser.h"
+
+typedef struct grpc_resolver_factory grpc_resolver_factory;
+typedef struct grpc_resolver_factory_vtable grpc_resolver_factory_vtable;
+
+/** grpc_resolver provides grpc_client_config objects to grpc_channel
+ objects */
+struct grpc_resolver_factory {
+ const grpc_resolver_factory_vtable *vtable;
+};
+
+typedef struct grpc_resolver_args {
+ grpc_uri *uri;
+ grpc_subchannel_factory *subchannel_factory;
+} grpc_resolver_args;
+
+struct grpc_resolver_factory_vtable {
+ void (*ref)(grpc_resolver_factory *factory);
+ void (*unref)(grpc_resolver_factory *factory);
+
+ /** Implementation of grpc_resolver_factory_create_resolver */
+ grpc_resolver *(*create_resolver)(grpc_resolver_factory *factory,
+ grpc_resolver_args *args);
+
+ /** Implementation of grpc_resolver_factory_get_default_authority */
+ char *(*get_default_authority)(grpc_resolver_factory *factory, grpc_uri *uri);
+
+ /** URI scheme that this factory implements */
+ const char *scheme;
+};
+
+void grpc_resolver_factory_ref(grpc_resolver_factory *resolver);
+void grpc_resolver_factory_unref(grpc_resolver_factory *resolver);
+
+/** Create a resolver instance for a name */
+grpc_resolver *grpc_resolver_factory_create_resolver(
+ grpc_resolver_factory *factory, grpc_resolver_args *args);
+
+/** Return a (freshly allocated with gpr_malloc) string representing
+ the default authority to use for this scheme. */
+char *grpc_resolver_factory_get_default_authority(
+ grpc_resolver_factory *factory, grpc_uri *uri);
+
+#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVER_FACTORY_H */
diff --git a/src/core/lib/client_config/resolver_registry.c b/src/core/lib/client_config/resolver_registry.c
new file mode 100644
index 0000000000..29bd00c284
--- /dev/null
+++ b/src/core/lib/client_config/resolver_registry.c
@@ -0,0 +1,137 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/client_config/resolver_registry.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+
+#define MAX_RESOLVERS 10
+
+static grpc_resolver_factory *g_all_of_the_resolvers[MAX_RESOLVERS];
+static int g_number_of_resolvers = 0;
+
+static char *g_default_resolver_prefix;
+
+void grpc_resolver_registry_init(const char *default_resolver_prefix) {
+ g_number_of_resolvers = 0;
+ g_default_resolver_prefix = gpr_strdup(default_resolver_prefix);
+}
+
+void grpc_resolver_registry_shutdown(void) {
+ int i;
+ for (i = 0; i < g_number_of_resolvers; i++) {
+ grpc_resolver_factory_unref(g_all_of_the_resolvers[i]);
+ }
+ gpr_free(g_default_resolver_prefix);
+}
+
+void grpc_register_resolver_type(grpc_resolver_factory *factory) {
+ int i;
+ for (i = 0; i < g_number_of_resolvers; i++) {
+ GPR_ASSERT(0 != strcmp(factory->vtable->scheme,
+ g_all_of_the_resolvers[i]->vtable->scheme));
+ }
+ GPR_ASSERT(g_number_of_resolvers != MAX_RESOLVERS);
+ grpc_resolver_factory_ref(factory);
+ g_all_of_the_resolvers[g_number_of_resolvers++] = factory;
+}
+
+static grpc_resolver_factory *lookup_factory(grpc_uri *uri) {
+ int i;
+
+ /* handling NULL uri's here simplifies grpc_resolver_create */
+ if (!uri) return NULL;
+
+ for (i = 0; i < g_number_of_resolvers; i++) {
+ if (0 == strcmp(uri->scheme, g_all_of_the_resolvers[i]->vtable->scheme)) {
+ return g_all_of_the_resolvers[i];
+ }
+ }
+
+ return NULL;
+}
+
+static grpc_resolver_factory *resolve_factory(const char *target,
+ grpc_uri **uri) {
+ char *tmp;
+ grpc_resolver_factory *factory = NULL;
+
+ GPR_ASSERT(uri != NULL);
+ *uri = grpc_uri_parse(target, 1);
+ factory = lookup_factory(*uri);
+ if (factory == NULL) {
+ if (g_default_resolver_prefix != NULL) {
+ grpc_uri_destroy(*uri);
+ gpr_asprintf(&tmp, "%s%s", g_default_resolver_prefix, target);
+ *uri = grpc_uri_parse(tmp, 1);
+ factory = lookup_factory(*uri);
+ if (factory == NULL) {
+ grpc_uri_destroy(grpc_uri_parse(target, 0));
+ grpc_uri_destroy(grpc_uri_parse(tmp, 0));
+ gpr_log(GPR_ERROR, "don't know how to resolve '%s' or '%s'", target,
+ tmp);
+ }
+ gpr_free(tmp);
+ } else {
+ grpc_uri_destroy(grpc_uri_parse(target, 0));
+ gpr_log(GPR_ERROR, "don't know how to resolve '%s'", target);
+ }
+ }
+ return factory;
+}
+
+grpc_resolver *grpc_resolver_create(
+ const char *target, grpc_subchannel_factory *subchannel_factory) {
+ grpc_uri *uri = NULL;
+ grpc_resolver_factory *factory = resolve_factory(target, &uri);
+ grpc_resolver *resolver;
+ grpc_resolver_args args;
+ memset(&args, 0, sizeof(args));
+ args.uri = uri;
+ args.subchannel_factory = subchannel_factory;
+ resolver = grpc_resolver_factory_create_resolver(factory, &args);
+ grpc_uri_destroy(uri);
+ return resolver;
+}
+
+char *grpc_get_default_authority(const char *target) {
+ grpc_uri *uri = NULL;
+ grpc_resolver_factory *factory = resolve_factory(target, &uri);
+ char *authority = grpc_resolver_factory_get_default_authority(factory, uri);
+ grpc_uri_destroy(uri);
+ return authority;
+}
diff --git a/src/core/lib/client_config/resolver_registry.h b/src/core/lib/client_config/resolver_registry.h
new file mode 100644
index 0000000000..22289ca6bd
--- /dev/null
+++ b/src/core/lib/client_config/resolver_registry.h
@@ -0,0 +1,65 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVER_REGISTRY_H
+#define GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVER_REGISTRY_H
+
+#include "src/core/lib/client_config/resolver_factory.h"
+
+void grpc_resolver_registry_init(const char *default_prefix);
+void grpc_resolver_registry_shutdown(void);
+
+/** Register a resolver type.
+ URI's of \a scheme will be resolved with the given resolver.
+ If \a priority is greater than zero, then the resolver will be eligible
+ to resolve names that are passed in with no scheme. Higher priority
+ resolvers will be tried before lower priority schemes. */
+void grpc_register_resolver_type(grpc_resolver_factory *factory);
+
+/** Create a resolver given \a target.
+ First tries to parse \a target as a URI. If this succeeds, tries
+ to locate a registered resolver factory based on the URI scheme.
+ If parsing or location fails, prefixes default_prefix from
+ grpc_resolver_registry_init to target, and tries again (if default_prefix
+ was not NULL).
+ If a resolver factory was found, use it to instantiate a resolver and
+ return it.
+ If a resolver factory was not found, return NULL. */
+grpc_resolver *grpc_resolver_create(
+ const char *target, grpc_subchannel_factory *subchannel_factory);
+
+/** Given a target, return a (freshly allocated with gpr_malloc) string
+ representing the default authority to pass from a client. */
+char *grpc_get_default_authority(const char *target);
+
+#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVER_REGISTRY_H */
diff --git a/src/core/lib/client_config/resolvers/dns_resolver.c b/src/core/lib/client_config/resolvers/dns_resolver.c
new file mode 100644
index 0000000000..62bccdd045
--- /dev/null
+++ b/src/core/lib/client_config/resolvers/dns_resolver.c
@@ -0,0 +1,294 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/client_config/resolvers/dns_resolver.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/host_port.h>
+#include <grpc/support/string_util.h>
+
+#include "src/core/lib/client_config/lb_policy_registry.h"
+#include "src/core/lib/iomgr/resolve_address.h"
+#include "src/core/lib/iomgr/timer.h"
+#include "src/core/lib/support/backoff.h"
+#include "src/core/lib/support/string.h"
+
+#define BACKOFF_MULTIPLIER 1.6
+#define BACKOFF_JITTER 0.2
+#define BACKOFF_MIN_SECONDS 1
+#define BACKOFF_MAX_SECONDS 120
+
+typedef struct {
+ /** base class: must be first */
+ grpc_resolver base;
+ /** refcount */
+ gpr_refcount refs;
+ /** name to resolve */
+ char *name;
+ /** default port to use */
+ char *default_port;
+ /** subchannel factory */
+ grpc_subchannel_factory *subchannel_factory;
+ /** load balancing policy name */
+ char *lb_policy_name;
+
+ /** mutex guarding the rest of the state */
+ gpr_mu mu;
+ /** are we currently resolving? */
+ int resolving;
+ /** which version of resolved_config have we published? */
+ int published_version;
+ /** which version of resolved_config is current? */
+ int resolved_version;
+ /** pending next completion, or NULL */
+ grpc_closure *next_completion;
+ /** target config address for next completion */
+ grpc_client_config **target_config;
+ /** current (fully resolved) config */
+ grpc_client_config *resolved_config;
+ /** retry timer */
+ bool have_retry_timer;
+ grpc_timer retry_timer;
+ /** retry backoff state */
+ gpr_backoff backoff_state;
+} dns_resolver;
+
+static void dns_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
+
+static void dns_start_resolving_locked(dns_resolver *r);
+static void dns_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
+ dns_resolver *r);
+
+static void dns_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
+static void dns_channel_saw_error(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
+static void dns_next(grpc_exec_ctx *exec_ctx, grpc_resolver *r,
+ grpc_client_config **target_config,
+ grpc_closure *on_complete);
+
+static const grpc_resolver_vtable dns_resolver_vtable = {
+ dns_destroy, dns_shutdown, dns_channel_saw_error, dns_next};
+
+static void dns_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver) {
+ dns_resolver *r = (dns_resolver *)resolver;
+ gpr_mu_lock(&r->mu);
+ if (r->have_retry_timer) {
+ grpc_timer_cancel(exec_ctx, &r->retry_timer);
+ }
+ if (r->next_completion != NULL) {
+ *r->target_config = NULL;
+ grpc_exec_ctx_enqueue(exec_ctx, r->next_completion, true, NULL);
+ r->next_completion = NULL;
+ }
+ gpr_mu_unlock(&r->mu);
+}
+
+static void dns_channel_saw_error(grpc_exec_ctx *exec_ctx,
+ grpc_resolver *resolver) {
+ dns_resolver *r = (dns_resolver *)resolver;
+ gpr_mu_lock(&r->mu);
+ if (!r->resolving) {
+ gpr_backoff_reset(&r->backoff_state);
+ dns_start_resolving_locked(r);
+ }
+ gpr_mu_unlock(&r->mu);
+}
+
+static void dns_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
+ grpc_client_config **target_config,
+ grpc_closure *on_complete) {
+ dns_resolver *r = (dns_resolver *)resolver;
+ gpr_mu_lock(&r->mu);
+ GPR_ASSERT(!r->next_completion);
+ r->next_completion = on_complete;
+ r->target_config = target_config;
+ if (r->resolved_version == 0 && !r->resolving) {
+ gpr_backoff_reset(&r->backoff_state);
+ dns_start_resolving_locked(r);
+ } else {
+ dns_maybe_finish_next_locked(exec_ctx, r);
+ }
+ gpr_mu_unlock(&r->mu);
+}
+
+static void dns_on_retry_timer(grpc_exec_ctx *exec_ctx, void *arg,
+ bool success) {
+ dns_resolver *r = arg;
+
+ gpr_mu_lock(&r->mu);
+ r->have_retry_timer = false;
+ if (success) {
+ if (!r->resolving) {
+ dns_start_resolving_locked(r);
+ }
+ }
+ gpr_mu_unlock(&r->mu);
+
+ GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "retry-timer");
+}
+
+static void dns_on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
+ grpc_resolved_addresses *addresses) {
+ dns_resolver *r = arg;
+ grpc_client_config *config = NULL;
+ grpc_lb_policy *lb_policy;
+ gpr_mu_lock(&r->mu);
+ GPR_ASSERT(r->resolving);
+ r->resolving = 0;
+ if (addresses != NULL) {
+ grpc_lb_policy_args lb_policy_args;
+ config = grpc_client_config_create();
+ memset(&lb_policy_args, 0, sizeof(lb_policy_args));
+ lb_policy_args.addresses = addresses;
+ lb_policy_args.subchannel_factory = r->subchannel_factory;
+ lb_policy =
+ grpc_lb_policy_create(exec_ctx, r->lb_policy_name, &lb_policy_args);
+ if (lb_policy != NULL) {
+ grpc_client_config_set_lb_policy(config, lb_policy);
+ GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "construction");
+ }
+ grpc_resolved_addresses_destroy(addresses);
+ } else {
+ gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
+ gpr_timespec next_try = gpr_backoff_step(&r->backoff_state, now);
+ gpr_timespec timeout = gpr_time_sub(next_try, now);
+ gpr_log(GPR_DEBUG, "dns resolution failed: retrying in %d.%09d seconds",
+ timeout.tv_sec, timeout.tv_nsec);
+ GPR_ASSERT(!r->have_retry_timer);
+ r->have_retry_timer = true;
+ GRPC_RESOLVER_REF(&r->base, "retry-timer");
+ grpc_timer_init(exec_ctx, &r->retry_timer, next_try, dns_on_retry_timer, r,
+ now);
+ }
+ if (r->resolved_config) {
+ grpc_client_config_unref(exec_ctx, r->resolved_config);
+ }
+ r->resolved_config = config;
+ r->resolved_version++;
+ dns_maybe_finish_next_locked(exec_ctx, r);
+ gpr_mu_unlock(&r->mu);
+
+ GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "dns-resolving");
+}
+
+static void dns_start_resolving_locked(dns_resolver *r) {
+ GRPC_RESOLVER_REF(&r->base, "dns-resolving");
+ GPR_ASSERT(!r->resolving);
+ r->resolving = 1;
+ grpc_resolve_address(r->name, r->default_port, dns_on_resolved, r);
+}
+
+static void dns_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
+ dns_resolver *r) {
+ if (r->next_completion != NULL &&
+ r->resolved_version != r->published_version) {
+ *r->target_config = r->resolved_config;
+ if (r->resolved_config) {
+ grpc_client_config_ref(r->resolved_config);
+ }
+ grpc_exec_ctx_enqueue(exec_ctx, r->next_completion, true, NULL);
+ r->next_completion = NULL;
+ r->published_version = r->resolved_version;
+ }
+}
+
+static void dns_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *gr) {
+ dns_resolver *r = (dns_resolver *)gr;
+ gpr_mu_destroy(&r->mu);
+ if (r->resolved_config) {
+ grpc_client_config_unref(exec_ctx, r->resolved_config);
+ }
+ grpc_subchannel_factory_unref(exec_ctx, r->subchannel_factory);
+ gpr_free(r->name);
+ gpr_free(r->default_port);
+ gpr_free(r->lb_policy_name);
+ gpr_free(r);
+}
+
+static grpc_resolver *dns_create(grpc_resolver_args *args,
+ const char *default_port,
+ const char *lb_policy_name) {
+ dns_resolver *r;
+ const char *path = args->uri->path;
+
+ if (0 != strcmp(args->uri->authority, "")) {
+ gpr_log(GPR_ERROR, "authority based dns uri's not supported");
+ return NULL;
+ }
+
+ if (path[0] == '/') ++path;
+
+ r = gpr_malloc(sizeof(dns_resolver));
+ memset(r, 0, sizeof(*r));
+ gpr_ref_init(&r->refs, 1);
+ gpr_mu_init(&r->mu);
+ grpc_resolver_init(&r->base, &dns_resolver_vtable);
+ r->name = gpr_strdup(path);
+ r->default_port = gpr_strdup(default_port);
+ r->subchannel_factory = args->subchannel_factory;
+ gpr_backoff_init(&r->backoff_state, BACKOFF_MULTIPLIER, BACKOFF_JITTER,
+ BACKOFF_MIN_SECONDS * 1000, BACKOFF_MAX_SECONDS * 1000);
+ grpc_subchannel_factory_ref(r->subchannel_factory);
+ r->lb_policy_name = gpr_strdup(lb_policy_name);
+ return &r->base;
+}
+
+/*
+ * FACTORY
+ */
+
+static void dns_factory_ref(grpc_resolver_factory *factory) {}
+
+static void dns_factory_unref(grpc_resolver_factory *factory) {}
+
+static grpc_resolver *dns_factory_create_resolver(
+ grpc_resolver_factory *factory, grpc_resolver_args *args) {
+ return dns_create(args, "https", "pick_first");
+}
+
+char *dns_factory_get_default_host_name(grpc_resolver_factory *factory,
+ grpc_uri *uri) {
+ const char *path = uri->path;
+ if (path[0] == '/') ++path;
+ return gpr_strdup(path);
+}
+
+static const grpc_resolver_factory_vtable dns_factory_vtable = {
+ dns_factory_ref, dns_factory_unref, dns_factory_create_resolver,
+ dns_factory_get_default_host_name, "dns"};
+static grpc_resolver_factory dns_resolver_factory = {&dns_factory_vtable};
+
+grpc_resolver_factory *grpc_dns_resolver_factory_create() {
+ return &dns_resolver_factory;
+}
diff --git a/src/core/lib/client_config/resolvers/dns_resolver.h b/src/core/lib/client_config/resolvers/dns_resolver.h
new file mode 100644
index 0000000000..eb46e41c77
--- /dev/null
+++ b/src/core/lib/client_config/resolvers/dns_resolver.h
@@ -0,0 +1,42 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVERS_DNS_RESOLVER_H
+#define GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVERS_DNS_RESOLVER_H
+
+#include "src/core/lib/client_config/resolver_factory.h"
+
+/** Create a dns resolver factory */
+grpc_resolver_factory *grpc_dns_resolver_factory_create(void);
+
+#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVERS_DNS_RESOLVER_H */
diff --git a/src/core/lib/client_config/resolvers/sockaddr_resolver.c b/src/core/lib/client_config/resolvers/sockaddr_resolver.c
new file mode 100644
index 0000000000..c787bd57d6
--- /dev/null
+++ b/src/core/lib/client_config/resolvers/sockaddr_resolver.c
@@ -0,0 +1,354 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/lib/client_config/resolvers/sockaddr_resolver.h"
+
+#include <stdio.h>
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/host_port.h>
+#include <grpc/support/string_util.h>
+
+#include "src/core/lib/client_config/lb_policy_registry.h"
+#include "src/core/lib/iomgr/resolve_address.h"
+#include "src/core/lib/iomgr/unix_sockets_posix.h"
+#include "src/core/lib/support/string.h"
+
+typedef struct {
+ /** base class: must be first */
+ grpc_resolver base;
+ /** refcount */
+ gpr_refcount refs;
+ /** subchannel factory */
+ grpc_subchannel_factory *subchannel_factory;
+ /** load balancing policy name */
+ char *lb_policy_name;
+
+ /** the addresses that we've 'resolved' */
+ grpc_resolved_addresses *addresses;
+
+ /** mutex guarding the rest of the state */
+ gpr_mu mu;
+ /** have we published? */
+ int published;
+ /** pending next completion, or NULL */
+ grpc_closure *next_completion;
+ /** target config address for next completion */
+ grpc_client_config **target_config;
+} sockaddr_resolver;
+
+static void sockaddr_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
+
+static void sockaddr_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
+ sockaddr_resolver *r);
+
+static void sockaddr_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
+static void sockaddr_channel_saw_error(grpc_exec_ctx *exec_ctx,
+ grpc_resolver *r);
+static void sockaddr_next(grpc_exec_ctx *exec_ctx, grpc_resolver *r,
+ grpc_client_config **target_config,
+ grpc_closure *on_complete);
+
+static const grpc_resolver_vtable sockaddr_resolver_vtable = {
+ sockaddr_destroy, sockaddr_shutdown, sockaddr_channel_saw_error,
+ sockaddr_next};
+
+static void sockaddr_shutdown(grpc_exec_ctx *exec_ctx,
+ grpc_resolver *resolver) {
+ sockaddr_resolver *r = (sockaddr_resolver *)resolver;
+ gpr_mu_lock(&r->mu);
+ if (r->next_completion != NULL) {
+ *r->target_config = NULL;
+ grpc_exec_ctx_enqueue(exec_ctx, r->next_completion, true, NULL);
+ r->next_completion = NULL;
+ }
+ gpr_mu_unlock(&r->mu);
+}
+
+static void sockaddr_channel_saw_error(grpc_exec_ctx *exec_ctx,
+ grpc_resolver *resolver) {
+ sockaddr_resolver *r = (sockaddr_resolver *)resolver;
+ gpr_mu_lock(&r->mu);
+ r->published = 0;
+ sockaddr_maybe_finish_next_locked(exec_ctx, r);
+ gpr_mu_unlock(&r->mu);
+}
+
+static void sockaddr_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
+ grpc_client_config **target_config,
+ grpc_closure *on_complete) {
+ sockaddr_resolver *r = (sockaddr_resolver *)resolver;
+ gpr_mu_lock(&r->mu);
+ GPR_ASSERT(!r->next_completion);
+ r->next_completion = on_complete;
+ r->target_config = target_config;
+ sockaddr_maybe_finish_next_locked(exec_ctx, r);
+ gpr_mu_unlock(&r->mu);
+}
+
+static void sockaddr_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
+ sockaddr_resolver *r) {
+ if (r->next_completion != NULL && !r->published) {
+ grpc_client_config *cfg = grpc_client_config_create();
+ grpc_lb_policy_args lb_policy_args;
+ memset(&lb_policy_args, 0, sizeof(lb_policy_args));
+ lb_policy_args.addresses = r->addresses;
+ lb_policy_args.subchannel_factory = r->subchannel_factory;
+ grpc_lb_policy *lb_policy =
+ grpc_lb_policy_create(exec_ctx, r->lb_policy_name, &lb_policy_args);
+ grpc_client_config_set_lb_policy(cfg, lb_policy);
+ GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "sockaddr");
+ r->published = 1;
+ *r->target_config = cfg;
+ grpc_exec_ctx_enqueue(exec_ctx, r->next_completion, true, NULL);
+ r->next_completion = NULL;
+ }
+}
+
+static void sockaddr_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *gr) {
+ sockaddr_resolver *r = (sockaddr_resolver *)gr;
+ gpr_mu_destroy(&r->mu);
+ grpc_subchannel_factory_unref(exec_ctx, r->subchannel_factory);
+ grpc_resolved_addresses_destroy(r->addresses);
+ gpr_free(r->lb_policy_name);
+ gpr_free(r);
+}
+
+static char *ip_get_default_authority(grpc_uri *uri) {
+ const char *path = uri->path;
+ if (path[0] == '/') ++path;
+ return gpr_strdup(path);
+}
+
+static char *ipv4_get_default_authority(grpc_resolver_factory *factory,
+ grpc_uri *uri) {
+ return ip_get_default_authority(uri);
+}
+
+static char *ipv6_get_default_authority(grpc_resolver_factory *factory,
+ grpc_uri *uri) {
+ return ip_get_default_authority(uri);
+}
+
+static int parse_ipv4(grpc_uri *uri, struct sockaddr_storage *addr,
+ size_t *len) {
+ const char *host_port = uri->path;
+ char *host;
+ char *port;
+ int port_num;
+ int result = 0;
+ struct sockaddr_in *in = (struct sockaddr_in *)addr;
+
+ if (*host_port == '/') ++host_port;
+ if (!gpr_split_host_port(host_port, &host, &port)) {
+ return 0;
+ }
+
+ memset(in, 0, sizeof(*in));
+ *len = sizeof(*in);
+ in->sin_family = AF_INET;
+ if (inet_pton(AF_INET, host, &in->sin_addr) == 0) {
+ gpr_log(GPR_ERROR, "invalid ipv4 address: '%s'", host);
+ goto done;
+ }
+
+ if (port != NULL) {
+ if (sscanf(port, "%d", &port_num) != 1 || port_num < 0 ||
+ port_num > 65535) {
+ gpr_log(GPR_ERROR, "invalid ipv4 port: '%s'", port);
+ goto done;
+ }
+ in->sin_port = htons((uint16_t)port_num);
+ } else {
+ gpr_log(GPR_ERROR, "no port given for ipv4 scheme");
+ goto done;
+ }
+
+ result = 1;
+done:
+ gpr_free(host);
+ gpr_free(port);
+ return result;
+}
+
+static int parse_ipv6(grpc_uri *uri, struct sockaddr_storage *addr,
+ size_t *len) {
+ const char *host_port = uri->path;
+ char *host;
+ char *port;
+ int port_num;
+ int result = 0;
+ struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)addr;
+
+ if (*host_port == '/') ++host_port;
+ if (!gpr_split_host_port(host_port, &host, &port)) {
+ return 0;
+ }
+
+ memset(in6, 0, sizeof(*in6));
+ *len = sizeof(*in6);
+ in6->sin6_family = AF_INET6;
+ if (inet_pton(AF_INET6, host, &in6->sin6_addr) == 0) {
+ gpr_log(GPR_ERROR, "invalid ipv6 address: '%s'", host);
+ goto done;
+ }
+
+ if (port != NULL) {
+ if (sscanf(port, "%d", &port_num) != 1 || port_num < 0 ||
+ port_num > 65535) {
+ gpr_log(GPR_ERROR, "invalid ipv6 port: '%s'", port);
+ goto done;
+ }
+ in6->sin6_port = htons((uint16_t)port_num);
+ } else {
+ gpr_log(GPR_ERROR, "no port given for ipv6 scheme");
+ goto done;
+ }
+
+ result = 1;
+done:
+ gpr_free(host);
+ gpr_free(port);
+ return result;
+}
+
+static void do_nothing(void *ignored) {}
+
+static grpc_resolver *sockaddr_create(
+ grpc_resolver_args *args, const char *default_lb_policy_name,
+ int parse(grpc_uri *uri, struct sockaddr_storage *dst, size_t *len)) {
+ int errors_found = 0; /* GPR_FALSE */
+ sockaddr_resolver *r;
+ gpr_slice path_slice;
+ gpr_slice_buffer path_parts;
+
+ if (0 != strcmp(args->uri->authority, "")) {
+ gpr_log(GPR_ERROR, "authority based uri's not supported by the %s scheme",
+ args->uri->scheme);
+ return NULL;
+ }
+
+ r = gpr_malloc(sizeof(sockaddr_resolver));
+ memset(r, 0, sizeof(*r));
+
+ r->lb_policy_name = NULL;
+ if (0 != strcmp(args->uri->query, "")) {
+ gpr_slice query_slice;
+ gpr_slice_buffer query_parts;
+
+ query_slice =
+ gpr_slice_new(args->uri->query, strlen(args->uri->query), do_nothing);
+ gpr_slice_buffer_init(&query_parts);
+ gpr_slice_split(query_slice, "=", &query_parts);
+ GPR_ASSERT(query_parts.count == 2);
+ if (0 == gpr_slice_str_cmp(query_parts.slices[0], "lb_policy")) {
+ r->lb_policy_name = gpr_dump_slice(query_parts.slices[1], GPR_DUMP_ASCII);
+ }
+ gpr_slice_buffer_destroy(&query_parts);
+ gpr_slice_unref(query_slice);
+ }
+ if (r->lb_policy_name == NULL) {
+ r->lb_policy_name = gpr_strdup(default_lb_policy_name);
+ }
+
+ path_slice =
+ gpr_slice_new(args->uri->path, strlen(args->uri->path), do_nothing);
+ gpr_slice_buffer_init(&path_parts);
+
+ gpr_slice_split(path_slice, ",", &path_parts);
+ r->addresses = gpr_malloc(sizeof(grpc_resolved_addresses));
+ r->addresses->naddrs = path_parts.count;
+ r->addresses->addrs =
+ gpr_malloc(sizeof(grpc_resolved_address) * r->addresses->naddrs);
+
+ for (size_t i = 0; i < r->addresses->naddrs; i++) {
+ grpc_uri ith_uri = *args->uri;
+ char *part_str = gpr_dump_slice(path_parts.slices[i], GPR_DUMP_ASCII);
+ ith_uri.path = part_str;
+ if (!parse(&ith_uri,
+ (struct sockaddr_storage *)(&r->addresses->addrs[i].addr),
+ &r->addresses->addrs[i].len)) {
+ errors_found = 1; /* GPR_TRUE */
+ }
+ gpr_free(part_str);
+ if (errors_found) break;
+ }
+
+ gpr_slice_buffer_destroy(&path_parts);
+ gpr_slice_unref(path_slice);
+ if (errors_found) {
+ gpr_free(r->lb_policy_name);
+ grpc_resolved_addresses_destroy(r->addresses);
+ gpr_free(r);
+ return NULL;
+ }
+
+ gpr_ref_init(&r->refs, 1);
+ gpr_mu_init(&r->mu);
+ grpc_resolver_init(&r->base, &sockaddr_resolver_vtable);
+ r->subchannel_factory = args->subchannel_factory;
+ grpc_subchannel_factory_ref(r->subchannel_factory);
+
+ return &r->base;
+}
+
+/*
+ * FACTORY
+ */
+
+static void sockaddr_factory_ref(grpc_resolver_factory *factory) {}
+
+static void sockaddr_factory_unref(grpc_resolver_factory *factory) {}
+
+#define DECL_FACTORY(name, prefix) \
+ static grpc_resolver *name##_factory_create_resolver( \
+ grpc_resolver_factory *factory, grpc_resolver_args *args) { \
+ return sockaddr_create(args, "pick_first", prefix##parse_##name); \
+ } \
+ static const grpc_resolver_factory_vtable name##_factory_vtable = { \
+ sockaddr_factory_ref, sockaddr_factory_unref, \
+ name##_factory_create_resolver, prefix##name##_get_default_authority, \
+ #name}; \
+ static grpc_resolver_factory name##_resolver_factory = { \
+ &name##_factory_vtable}; \
+ grpc_resolver_factory *grpc_##name##_resolver_factory_create() { \
+ return &name##_resolver_factory; \
+ }
+
+#ifdef GPR_HAVE_UNIX_SOCKET
+DECL_FACTORY(unix, grpc_)
+#endif
+DECL_FACTORY(ipv4, ) DECL_FACTORY(ipv6, )
diff --git a/src/core/lib/client_config/resolvers/sockaddr_resolver.h b/src/core/lib/client_config/resolvers/sockaddr_resolver.h
new file mode 100644
index 0000000000..45c55bd160
--- /dev/null
+++ b/src/core/lib/client_config/resolvers/sockaddr_resolver.h
@@ -0,0 +1,50 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVERS_SOCKADDR_RESOLVER_H
+#define GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVERS_SOCKADDR_RESOLVER_H
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/lib/client_config/resolver_factory.h"
+
+grpc_resolver_factory *grpc_ipv4_resolver_factory_create(void);
+
+grpc_resolver_factory *grpc_ipv6_resolver_factory_create(void);
+
+#ifdef GPR_POSIX_SOCKET
+/** Create a unix resolver factory */
+grpc_resolver_factory *grpc_unix_resolver_factory_create(void);
+#endif
+
+#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVERS_SOCKADDR_RESOLVER_H */
diff --git a/src/core/lib/client_config/resolvers/zookeeper_resolver.c b/src/core/lib/client_config/resolvers/zookeeper_resolver.c
new file mode 100644
index 0000000000..404dfcd423
--- /dev/null
+++ b/src/core/lib/client_config/resolvers/zookeeper_resolver.c
@@ -0,0 +1,514 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/client_config/resolvers/zookeeper_resolver.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/string_util.h>
+
+#include <grpc/grpc_zookeeper.h>
+#include <zookeeper/zookeeper.h>
+
+#include "src/core/lib/client_config/lb_policy_registry.h"
+#include "src/core/lib/client_config/resolver_registry.h"
+#include "src/core/lib/iomgr/resolve_address.h"
+#include "src/core/lib/json/json.h"
+#include "src/core/lib/support/string.h"
+#include "src/core/lib/surface/api_trace.h"
+
+/** Zookeeper session expiration time in milliseconds */
+#define GRPC_ZOOKEEPER_SESSION_TIMEOUT 15000
+
+typedef struct {
+ /** base class: must be first */
+ grpc_resolver base;
+ /** refcount */
+ gpr_refcount refs;
+ /** name to resolve */
+ char *name;
+ /** subchannel factory */
+ grpc_subchannel_factory *subchannel_factory;
+ /** load balancing policy name */
+ char *lb_policy_name;
+
+ /** mutex guarding the rest of the state */
+ gpr_mu mu;
+ /** are we currently resolving? */
+ int resolving;
+ /** which version of resolved_config have we published? */
+ int published_version;
+ /** which version of resolved_config is current? */
+ int resolved_version;
+ /** pending next completion, or NULL */
+ grpc_closure *next_completion;
+ /** target config address for next completion */
+ grpc_client_config **target_config;
+ /** current (fully resolved) config */
+ grpc_client_config *resolved_config;
+
+ /** zookeeper handle */
+ zhandle_t *zookeeper_handle;
+ /** zookeeper resolved addresses */
+ grpc_resolved_addresses *resolved_addrs;
+ /** total number of addresses to be resolved */
+ int resolved_total;
+ /** number of addresses resolved */
+ int resolved_num;
+} zookeeper_resolver;
+
+static void zookeeper_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
+
+static void zookeeper_start_resolving_locked(zookeeper_resolver *r);
+static void zookeeper_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
+ zookeeper_resolver *r);
+
+static void zookeeper_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
+static void zookeeper_channel_saw_error(grpc_exec_ctx *exec_ctx,
+ grpc_resolver *r);
+static void zookeeper_next(grpc_exec_ctx *exec_ctx, grpc_resolver *r,
+ grpc_client_config **target_config,
+ grpc_closure *on_complete);
+
+static const grpc_resolver_vtable zookeeper_resolver_vtable = {
+ zookeeper_destroy, zookeeper_shutdown, zookeeper_channel_saw_error,
+ zookeeper_next};
+
+static void zookeeper_shutdown(grpc_exec_ctx *exec_ctx,
+ grpc_resolver *resolver) {
+ zookeeper_resolver *r = (zookeeper_resolver *)resolver;
+ grpc_closure *call = NULL;
+ gpr_mu_lock(&r->mu);
+ if (r->next_completion != NULL) {
+ *r->target_config = NULL;
+ call = r->next_completion;
+ r->next_completion = NULL;
+ }
+ zookeeper_close(r->zookeeper_handle);
+ gpr_mu_unlock(&r->mu);
+ if (call != NULL) {
+ call->cb(exec_ctx, call->cb_arg, 1);
+ }
+}
+
+static void zookeeper_channel_saw_error(grpc_exec_ctx *exec_ctx,
+ grpc_resolver *resolver) {
+ zookeeper_resolver *r = (zookeeper_resolver *)resolver;
+ gpr_mu_lock(&r->mu);
+ if (r->resolving == 0) {
+ zookeeper_start_resolving_locked(r);
+ }
+ gpr_mu_unlock(&r->mu);
+}
+
+static void zookeeper_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
+ grpc_client_config **target_config,
+ grpc_closure *on_complete) {
+ zookeeper_resolver *r = (zookeeper_resolver *)resolver;
+ gpr_mu_lock(&r->mu);
+ GPR_ASSERT(r->next_completion == NULL);
+ r->next_completion = on_complete;
+ r->target_config = target_config;
+ if (r->resolved_version == 0 && r->resolving == 0) {
+ zookeeper_start_resolving_locked(r);
+ } else {
+ zookeeper_maybe_finish_next_locked(exec_ctx, r);
+ }
+ gpr_mu_unlock(&r->mu);
+}
+
+/** Zookeeper global watcher for connection management
+ TODO: better connection management besides logs */
+static void zookeeper_global_watcher(zhandle_t *zookeeper_handle, int type,
+ int state, const char *path,
+ void *watcher_ctx) {
+ if (type == ZOO_SESSION_EVENT) {
+ if (state == ZOO_EXPIRED_SESSION_STATE) {
+ gpr_log(GPR_ERROR, "Zookeeper session expired");
+ } else if (state == ZOO_AUTH_FAILED_STATE) {
+ gpr_log(GPR_ERROR, "Zookeeper authentication failed");
+ }
+ }
+}
+
+/** Zookeeper watcher triggered by changes to watched nodes
+ Once triggered, it tries to resolve again to get updated addresses */
+static void zookeeper_watcher(zhandle_t *zookeeper_handle, int type, int state,
+ const char *path, void *watcher_ctx) {
+ if (watcher_ctx != NULL) {
+ zookeeper_resolver *r = (zookeeper_resolver *)watcher_ctx;
+ if (state == ZOO_CONNECTED_STATE) {
+ gpr_mu_lock(&r->mu);
+ if (r->resolving == 0) {
+ zookeeper_start_resolving_locked(r);
+ }
+ gpr_mu_unlock(&r->mu);
+ }
+ }
+}
+
+/** Callback function after getting all resolved addresses
+ Creates a subchannel for each address */
+static void zookeeper_on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
+ grpc_resolved_addresses *addresses) {
+ zookeeper_resolver *r = arg;
+ grpc_client_config *config = NULL;
+ grpc_lb_policy *lb_policy;
+
+ if (addresses != NULL) {
+ grpc_lb_policy_args lb_policy_args;
+ config = grpc_client_config_create();
+
+ lb_policy_args.addresses = addresses;
+ lb_policy_args.subchannel_factory = r->subchannel_factory;
+ lb_policy =
+ grpc_lb_policy_create(exec_ctx, r->lb_policy_name, &lb_policy_args);
+
+ if (lb_policy != NULL) {
+ grpc_client_config_set_lb_policy(config, lb_policy);
+ GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "construction");
+ }
+ grpc_resolved_addresses_destroy(addresses);
+ }
+ gpr_mu_lock(&r->mu);
+ GPR_ASSERT(r->resolving == 1);
+ r->resolving = 0;
+ if (r->resolved_config != NULL) {
+ grpc_client_config_unref(exec_ctx, r->resolved_config);
+ }
+ r->resolved_config = config;
+ r->resolved_version++;
+ zookeeper_maybe_finish_next_locked(exec_ctx, r);
+ gpr_mu_unlock(&r->mu);
+
+ GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "zookeeper-resolving");
+}
+
+/** Callback function for each DNS resolved address */
+static void zookeeper_dns_resolved(grpc_exec_ctx *exec_ctx, void *arg,
+ grpc_resolved_addresses *addresses) {
+ size_t i;
+ zookeeper_resolver *r = arg;
+ int resolve_done = 0;
+
+ gpr_mu_lock(&r->mu);
+ r->resolved_num++;
+ r->resolved_addrs->addrs =
+ gpr_realloc(r->resolved_addrs->addrs,
+ sizeof(grpc_resolved_address) *
+ (r->resolved_addrs->naddrs + addresses->naddrs));
+ for (i = 0; i < addresses->naddrs; i++) {
+ memcpy(r->resolved_addrs->addrs[i + r->resolved_addrs->naddrs].addr,
+ addresses->addrs[i].addr, addresses->addrs[i].len);
+ r->resolved_addrs->addrs[i + r->resolved_addrs->naddrs].len =
+ addresses->addrs[i].len;
+ }
+
+ r->resolved_addrs->naddrs += addresses->naddrs;
+ grpc_resolved_addresses_destroy(addresses);
+
+ /** Wait for all addresses to be resolved */
+ resolve_done = (r->resolved_num == r->resolved_total);
+ gpr_mu_unlock(&r->mu);
+ if (resolve_done) {
+ zookeeper_on_resolved(exec_ctx, r, r->resolved_addrs);
+ }
+}
+
+/** Parses JSON format address of a zookeeper node */
+static char *zookeeper_parse_address(const char *value, size_t value_len) {
+ grpc_json *json;
+ grpc_json *cur;
+ const char *host;
+ const char *port;
+ char *buffer;
+ char *address = NULL;
+
+ buffer = gpr_malloc(value_len);
+ memcpy(buffer, value, value_len);
+ json = grpc_json_parse_string_with_len(buffer, value_len);
+ if (json != NULL) {
+ host = NULL;
+ port = NULL;
+ for (cur = json->child; cur != NULL; cur = cur->next) {
+ if (!strcmp(cur->key, "host")) {
+ host = cur->value;
+ if (port != NULL) {
+ break;
+ }
+ } else if (!strcmp(cur->key, "port")) {
+ port = cur->value;
+ if (host != NULL) {
+ break;
+ }
+ }
+ }
+ if (host != NULL && port != NULL) {
+ gpr_asprintf(&address, "%s:%s", host, port);
+ }
+ grpc_json_destroy(json);
+ }
+ gpr_free(buffer);
+
+ return address;
+}
+
+static void zookeeper_get_children_node_completion(int rc, const char *value,
+ int value_len,
+ const struct Stat *stat,
+ const void *arg) {
+ char *address = NULL;
+ zookeeper_resolver *r = (zookeeper_resolver *)arg;
+ int resolve_done = 0;
+ grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+
+ if (rc != 0) {
+ gpr_log(GPR_ERROR, "Error in getting a child node of %s", r->name);
+ grpc_exec_ctx_finish(&exec_ctx);
+ return;
+ }
+
+ address = zookeeper_parse_address(value, (size_t)value_len);
+ if (address != NULL) {
+ /** Further resolves address by DNS */
+ grpc_resolve_address(address, NULL, zookeeper_dns_resolved, r);
+ gpr_free(address);
+ } else {
+ gpr_log(GPR_ERROR, "Error in resolving a child node of %s", r->name);
+ gpr_mu_lock(&r->mu);
+ r->resolved_total--;
+ resolve_done = (r->resolved_num == r->resolved_total);
+ gpr_mu_unlock(&r->mu);
+ if (resolve_done) {
+ zookeeper_on_resolved(&exec_ctx, r, r->resolved_addrs);
+ }
+ }
+
+ grpc_exec_ctx_finish(&exec_ctx);
+}
+
+static void zookeeper_get_children_completion(
+ int rc, const struct String_vector *children, const void *arg) {
+ char *path;
+ int status;
+ int i;
+ zookeeper_resolver *r = (zookeeper_resolver *)arg;
+
+ if (rc != 0) {
+ gpr_log(GPR_ERROR, "Error in getting zookeeper children of %s", r->name);
+ return;
+ }
+
+ if (children->count == 0) {
+ gpr_log(GPR_ERROR, "Error in resolving zookeeper address %s", r->name);
+ return;
+ }
+
+ r->resolved_addrs = gpr_malloc(sizeof(grpc_resolved_addresses));
+ r->resolved_addrs->addrs = NULL;
+ r->resolved_addrs->naddrs = 0;
+ r->resolved_total = children->count;
+
+ /** TODO: Replace expensive heap allocation with stack
+ if we can get maximum length of zookeeper path */
+ for (i = 0; i < children->count; i++) {
+ gpr_asprintf(&path, "%s/%s", r->name, children->data[i]);
+ status = zoo_awget(r->zookeeper_handle, path, zookeeper_watcher, r,
+ zookeeper_get_children_node_completion, r);
+ gpr_free(path);
+ if (status != 0) {
+ gpr_log(GPR_ERROR, "Error in getting zookeeper node %s", path);
+ }
+ }
+}
+
+static void zookeeper_get_node_completion(int rc, const char *value,
+ int value_len,
+ const struct Stat *stat,
+ const void *arg) {
+ int status;
+ char *address = NULL;
+ zookeeper_resolver *r = (zookeeper_resolver *)arg;
+ r->resolved_addrs = NULL;
+ r->resolved_total = 0;
+ r->resolved_num = 0;
+
+ if (rc != 0) {
+ gpr_log(GPR_ERROR, "Error in getting zookeeper node %s", r->name);
+ return;
+ }
+
+ /** If zookeeper node of path r->name does not have address
+ (i.e. service node), get its children */
+ address = zookeeper_parse_address(value, (size_t)value_len);
+ if (address != NULL) {
+ r->resolved_addrs = gpr_malloc(sizeof(grpc_resolved_addresses));
+ r->resolved_addrs->addrs = NULL;
+ r->resolved_addrs->naddrs = 0;
+ r->resolved_total = 1;
+ /** Further resolves address by DNS */
+ grpc_resolve_address(address, NULL, zookeeper_dns_resolved, r);
+ gpr_free(address);
+ return;
+ }
+
+ status = zoo_awget_children(r->zookeeper_handle, r->name, zookeeper_watcher,
+ r, zookeeper_get_children_completion, r);
+ if (status != 0) {
+ gpr_log(GPR_ERROR, "Error in getting zookeeper children of %s", r->name);
+ }
+}
+
+static void zookeeper_resolve_address(zookeeper_resolver *r) {
+ int status;
+ status = zoo_awget(r->zookeeper_handle, r->name, zookeeper_watcher, r,
+ zookeeper_get_node_completion, r);
+ if (status != 0) {
+ gpr_log(GPR_ERROR, "Error in getting zookeeper node %s", r->name);
+ }
+}
+
+static void zookeeper_start_resolving_locked(zookeeper_resolver *r) {
+ GRPC_RESOLVER_REF(&r->base, "zookeeper-resolving");
+ GPR_ASSERT(r->resolving == 0);
+ r->resolving = 1;
+ zookeeper_resolve_address(r);
+}
+
+static void zookeeper_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
+ zookeeper_resolver *r) {
+ if (r->next_completion != NULL &&
+ r->resolved_version != r->published_version) {
+ *r->target_config = r->resolved_config;
+ if (r->resolved_config != NULL) {
+ grpc_client_config_ref(r->resolved_config);
+ }
+ grpc_exec_ctx_enqueue(exec_ctx, r->next_completion, true, NULL);
+ r->next_completion = NULL;
+ r->published_version = r->resolved_version;
+ }
+}
+
+static void zookeeper_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *gr) {
+ zookeeper_resolver *r = (zookeeper_resolver *)gr;
+ gpr_mu_destroy(&r->mu);
+ if (r->resolved_config != NULL) {
+ grpc_client_config_unref(exec_ctx, r->resolved_config);
+ }
+ grpc_subchannel_factory_unref(exec_ctx, r->subchannel_factory);
+ gpr_free(r->name);
+ gpr_free(r->lb_policy_name);
+ gpr_free(r);
+}
+
+static grpc_resolver *zookeeper_create(grpc_resolver_args *args,
+ const char *lb_policy_name) {
+ zookeeper_resolver *r;
+ size_t length;
+ char *path = args->uri->path;
+
+ if (0 == strcmp(args->uri->authority, "")) {
+ gpr_log(GPR_ERROR, "No authority specified in zookeeper uri");
+ return NULL;
+ }
+
+ /** Removes the trailing slash if exists */
+ length = strlen(path);
+ if (length > 1 && path[length - 1] == '/') {
+ path[length - 1] = 0;
+ }
+
+ r = gpr_malloc(sizeof(zookeeper_resolver));
+ memset(r, 0, sizeof(*r));
+ gpr_ref_init(&r->refs, 1);
+ gpr_mu_init(&r->mu);
+ grpc_resolver_init(&r->base, &zookeeper_resolver_vtable);
+ r->name = gpr_strdup(path);
+
+ r->subchannel_factory = args->subchannel_factory;
+ grpc_subchannel_factory_ref(r->subchannel_factory);
+
+ r->lb_policy_name = gpr_strdup(lb_policy_name);
+
+ /** Initializes zookeeper client */
+ zoo_set_debug_level(ZOO_LOG_LEVEL_WARN);
+ r->zookeeper_handle =
+ zookeeper_init(args->uri->authority, zookeeper_global_watcher,
+ GRPC_ZOOKEEPER_SESSION_TIMEOUT, 0, 0, 0);
+ if (r->zookeeper_handle == NULL) {
+ gpr_log(GPR_ERROR, "Unable to connect to zookeeper server");
+ return NULL;
+ }
+
+ return &r->base;
+}
+
+static void zookeeper_plugin_init() {
+ grpc_register_resolver_type(grpc_zookeeper_resolver_factory_create());
+}
+
+void grpc_zookeeper_register() {
+ GRPC_API_TRACE("grpc_zookeeper_register(void)", 0, ());
+ grpc_register_plugin(zookeeper_plugin_init, NULL);
+}
+
+/*
+ * FACTORY
+ */
+
+static void zookeeper_factory_ref(grpc_resolver_factory *factory) {}
+
+static void zookeeper_factory_unref(grpc_resolver_factory *factory) {}
+
+static char *zookeeper_factory_get_default_hostname(
+ grpc_resolver_factory *factory, grpc_uri *uri) {
+ return NULL;
+}
+
+static grpc_resolver *zookeeper_factory_create_resolver(
+ grpc_resolver_factory *factory, grpc_resolver_args *args) {
+ return zookeeper_create(args, "pick_first");
+}
+
+static const grpc_resolver_factory_vtable zookeeper_factory_vtable = {
+ zookeeper_factory_ref, zookeeper_factory_unref,
+ zookeeper_factory_create_resolver, zookeeper_factory_get_default_hostname,
+ "zookeeper"};
+
+static grpc_resolver_factory zookeeper_resolver_factory = {
+ &zookeeper_factory_vtable};
+
+grpc_resolver_factory *grpc_zookeeper_resolver_factory_create() {
+ return &zookeeper_resolver_factory;
+}
diff --git a/src/core/lib/client_config/resolvers/zookeeper_resolver.h b/src/core/lib/client_config/resolvers/zookeeper_resolver.h
new file mode 100644
index 0000000000..7ee7604360
--- /dev/null
+++ b/src/core/lib/client_config/resolvers/zookeeper_resolver.h
@@ -0,0 +1,42 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVERS_ZOOKEEPER_RESOLVER_H
+#define GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVERS_ZOOKEEPER_RESOLVER_H
+
+#include "src/core/lib/client_config/resolver_factory.h"
+
+/** Create a zookeeper resolver factory */
+grpc_resolver_factory *grpc_zookeeper_resolver_factory_create(void);
+
+#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVERS_ZOOKEEPER_RESOLVER_H */
diff --git a/src/core/lib/client_config/subchannel.c b/src/core/lib/client_config/subchannel.c
new file mode 100644
index 0000000000..41242f0dd7
--- /dev/null
+++ b/src/core/lib/client_config/subchannel.c
@@ -0,0 +1,678 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/client_config/subchannel.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/avl.h>
+
+#include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/channel/client_channel.h"
+#include "src/core/lib/channel/connected_channel.h"
+#include "src/core/lib/client_config/initial_connect_string.h"
+#include "src/core/lib/client_config/subchannel_index.h"
+#include "src/core/lib/iomgr/timer.h"
+#include "src/core/lib/profiling/timers.h"
+#include "src/core/lib/support/backoff.h"
+#include "src/core/lib/surface/channel.h"
+#include "src/core/lib/surface/channel_init.h"
+#include "src/core/lib/transport/connectivity_state.h"
+
+#define INTERNAL_REF_BITS 16
+#define STRONG_REF_MASK (~(gpr_atm)((1 << INTERNAL_REF_BITS) - 1))
+
+#define GRPC_SUBCHANNEL_MIN_CONNECT_TIMEOUT_SECONDS 20
+#define GRPC_SUBCHANNEL_INITIAL_CONNECT_BACKOFF_SECONDS 1
+#define GRPC_SUBCHANNEL_RECONNECT_BACKOFF_MULTIPLIER 1.6
+#define GRPC_SUBCHANNEL_RECONNECT_MAX_BACKOFF_SECONDS 120
+#define GRPC_SUBCHANNEL_RECONNECT_JITTER 0.2
+
+#define GET_CONNECTED_SUBCHANNEL(subchannel, barrier) \
+ ((grpc_connected_subchannel *)(gpr_atm_##barrier##_load( \
+ &(subchannel)->connected_subchannel)))
+
+typedef struct {
+ grpc_closure closure;
+ grpc_subchannel *subchannel;
+ grpc_connectivity_state connectivity_state;
+} state_watcher;
+
+typedef struct external_state_watcher {
+ grpc_subchannel *subchannel;
+ grpc_pollset_set *pollset_set;
+ grpc_closure *notify;
+ grpc_closure closure;
+ struct external_state_watcher *next;
+ struct external_state_watcher *prev;
+} external_state_watcher;
+
+struct grpc_subchannel {
+ grpc_connector *connector;
+
+ /** refcount
+ - lower INTERNAL_REF_BITS bits are for internal references:
+ these do not keep the subchannel open.
+ - upper remaining bits are for public references: these do
+ keep the subchannel open */
+ gpr_atm ref_pair;
+
+ /** non-transport related channel filters */
+ const grpc_channel_filter **filters;
+ size_t num_filters;
+ /** channel arguments */
+ grpc_channel_args *args;
+ /** address to connect to */
+ struct sockaddr *addr;
+ size_t addr_len;
+
+ grpc_subchannel_key *key;
+
+ /** initial string to send to peer */
+ gpr_slice initial_connect_string;
+
+ /** set during connection */
+ grpc_connect_out_args connecting_result;
+
+ /** callback for connection finishing */
+ grpc_closure connected;
+
+ /** pollset_set tracking who's interested in a connection
+ being setup */
+ grpc_pollset_set *pollset_set;
+
+ /** active connection, or null; of type grpc_connected_subchannel */
+ gpr_atm connected_subchannel;
+
+ /** mutex protecting remaining elements */
+ gpr_mu mu;
+
+ /** have we seen a disconnection? */
+ int disconnected;
+ /** are we connecting */
+ int connecting;
+ /** connectivity state tracking */
+ grpc_connectivity_state_tracker state_tracker;
+
+ external_state_watcher root_external_state_watcher;
+
+ /** next connect attempt time */
+ gpr_timespec next_attempt;
+ /** backoff state */
+ gpr_backoff backoff_state;
+ /** do we have an active alarm? */
+ int have_alarm;
+ /** our alarm */
+ grpc_timer alarm;
+ /** current random value */
+ uint32_t random;
+};
+
+struct grpc_subchannel_call {
+ grpc_connected_subchannel *connection;
+};
+
+#define SUBCHANNEL_CALL_TO_CALL_STACK(call) ((grpc_call_stack *)((call) + 1))
+#define CHANNEL_STACK_FROM_CONNECTION(con) ((grpc_channel_stack *)(con))
+#define CALLSTACK_TO_SUBCHANNEL_CALL(callstack) \
+ (((grpc_subchannel_call *)(callstack)) - 1)
+
+static void subchannel_connected(grpc_exec_ctx *exec_ctx, void *subchannel,
+ bool iomgr_success);
+
+#ifdef GRPC_STREAM_REFCOUNT_DEBUG
+#define REF_REASON reason
+#define REF_LOG(name, p) \
+ gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "%s: %p ref %d -> %d %s", \
+ (name), (p), (p)->refs.count, (p)->refs.count + 1, reason)
+#define UNREF_LOG(name, p) \
+ gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "%s: %p unref %d -> %d %s", \
+ (name), (p), (p)->refs.count, (p)->refs.count - 1, reason)
+#define REF_MUTATE_EXTRA_ARGS \
+ GRPC_SUBCHANNEL_REF_EXTRA_ARGS, const char *purpose
+#define REF_MUTATE_PURPOSE(x) , file, line, reason, x
+#else
+#define REF_REASON ""
+#define REF_LOG(name, p) \
+ do { \
+ } while (0)
+#define UNREF_LOG(name, p) \
+ do { \
+ } while (0)
+#define REF_MUTATE_EXTRA_ARGS
+#define REF_MUTATE_PURPOSE(x)
+#endif
+
+/*
+ * connection implementation
+ */
+
+static void connection_destroy(grpc_exec_ctx *exec_ctx, void *arg,
+ bool success) {
+ grpc_connected_subchannel *c = arg;
+ grpc_channel_stack_destroy(exec_ctx, CHANNEL_STACK_FROM_CONNECTION(c));
+ gpr_free(c);
+}
+
+void grpc_connected_subchannel_ref(
+ grpc_connected_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+ GRPC_CHANNEL_STACK_REF(CHANNEL_STACK_FROM_CONNECTION(c), REF_REASON);
+}
+
+void grpc_connected_subchannel_unref(grpc_exec_ctx *exec_ctx,
+ grpc_connected_subchannel *c
+ GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+ GRPC_CHANNEL_STACK_UNREF(exec_ctx, CHANNEL_STACK_FROM_CONNECTION(c),
+ REF_REASON);
+}
+
+/*
+ * grpc_subchannel implementation
+ */
+
+static void subchannel_destroy(grpc_exec_ctx *exec_ctx, void *arg,
+ bool success) {
+ grpc_subchannel *c = arg;
+ gpr_free((void *)c->filters);
+ grpc_channel_args_destroy(c->args);
+ gpr_free(c->addr);
+ gpr_slice_unref(c->initial_connect_string);
+ grpc_connectivity_state_destroy(exec_ctx, &c->state_tracker);
+ grpc_connector_unref(exec_ctx, c->connector);
+ grpc_pollset_set_destroy(c->pollset_set);
+ grpc_subchannel_key_destroy(exec_ctx, c->key);
+ gpr_free(c);
+}
+
+static gpr_atm ref_mutate(grpc_subchannel *c, gpr_atm delta,
+ int barrier REF_MUTATE_EXTRA_ARGS) {
+ gpr_atm old_val = barrier ? gpr_atm_full_fetch_add(&c->ref_pair, delta)
+ : gpr_atm_no_barrier_fetch_add(&c->ref_pair, delta);
+#ifdef GRPC_STREAM_REFCOUNT_DEBUG
+ gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG,
+ "SUBCHANNEL: %p % 12s 0x%08x -> 0x%08x [%s]", c, purpose, old_val,
+ old_val + delta, reason);
+#endif
+ return old_val;
+}
+
+grpc_subchannel *grpc_subchannel_ref(
+ grpc_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+ gpr_atm old_refs;
+ old_refs = ref_mutate(c, (1 << INTERNAL_REF_BITS),
+ 0 REF_MUTATE_PURPOSE("STRONG_REF"));
+ GPR_ASSERT((old_refs & STRONG_REF_MASK) != 0);
+ return c;
+}
+
+grpc_subchannel *grpc_subchannel_weak_ref(
+ grpc_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+ gpr_atm old_refs;
+ old_refs = ref_mutate(c, 1, 0 REF_MUTATE_PURPOSE("WEAK_REF"));
+ GPR_ASSERT(old_refs != 0);
+ return c;
+}
+
+grpc_subchannel *grpc_subchannel_ref_from_weak_ref(
+ grpc_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+ if (!c) return NULL;
+ for (;;) {
+ gpr_atm old_refs = gpr_atm_acq_load(&c->ref_pair);
+ if (old_refs >= (1 << INTERNAL_REF_BITS)) {
+ gpr_atm new_refs = old_refs + (1 << INTERNAL_REF_BITS);
+ if (gpr_atm_rel_cas(&c->ref_pair, old_refs, new_refs)) {
+ return c;
+ }
+ } else {
+ return NULL;
+ }
+ }
+}
+
+static void disconnect(grpc_exec_ctx *exec_ctx, grpc_subchannel *c) {
+ grpc_connected_subchannel *con;
+ grpc_subchannel_index_unregister(exec_ctx, c->key, c);
+ gpr_mu_lock(&c->mu);
+ GPR_ASSERT(!c->disconnected);
+ c->disconnected = 1;
+ grpc_connector_shutdown(exec_ctx, c->connector);
+ con = GET_CONNECTED_SUBCHANNEL(c, no_barrier);
+ if (con != NULL) {
+ GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, con, "connection");
+ gpr_atm_no_barrier_store(&c->connected_subchannel, 0xdeadbeef);
+ }
+ gpr_mu_unlock(&c->mu);
+}
+
+void grpc_subchannel_unref(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+ gpr_atm old_refs;
+ old_refs = ref_mutate(c, (gpr_atm)1 - (gpr_atm)(1 << INTERNAL_REF_BITS),
+ 1 REF_MUTATE_PURPOSE("STRONG_UNREF"));
+ if ((old_refs & STRONG_REF_MASK) == (1 << INTERNAL_REF_BITS)) {
+ disconnect(exec_ctx, c);
+ }
+ GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, c, "strong-unref");
+}
+
+void grpc_subchannel_weak_unref(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel *c
+ GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+ gpr_atm old_refs;
+ old_refs = ref_mutate(c, -(gpr_atm)1, 1 REF_MUTATE_PURPOSE("WEAK_UNREF"));
+ if (old_refs == 1) {
+ grpc_exec_ctx_enqueue(exec_ctx, grpc_closure_create(subchannel_destroy, c),
+ true, NULL);
+ }
+}
+
+static uint32_t random_seed() {
+ return (uint32_t)(gpr_time_to_millis(gpr_now(GPR_CLOCK_MONOTONIC)));
+}
+
+grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
+ grpc_connector *connector,
+ grpc_subchannel_args *args) {
+ grpc_subchannel_key *key = grpc_subchannel_key_create(connector, args);
+ grpc_subchannel *c = grpc_subchannel_index_find(exec_ctx, key);
+ if (c) {
+ grpc_subchannel_key_destroy(exec_ctx, key);
+ return c;
+ }
+
+ c = gpr_malloc(sizeof(*c));
+ memset(c, 0, sizeof(*c));
+ c->key = key;
+ gpr_atm_no_barrier_store(&c->ref_pair, 1 << INTERNAL_REF_BITS);
+ c->connector = connector;
+ grpc_connector_ref(c->connector);
+ c->num_filters = args->filter_count;
+ if (c->num_filters > 0) {
+ c->filters = gpr_malloc(sizeof(grpc_channel_filter *) * c->num_filters);
+ memcpy((void *)c->filters, args->filters,
+ sizeof(grpc_channel_filter *) * c->num_filters);
+ } else {
+ c->filters = NULL;
+ }
+ c->addr = gpr_malloc(args->addr_len);
+ memcpy(c->addr, args->addr, args->addr_len);
+ c->pollset_set = grpc_pollset_set_create();
+ c->addr_len = args->addr_len;
+ grpc_set_initial_connect_string(&c->addr, &c->addr_len,
+ &c->initial_connect_string);
+ c->args = grpc_channel_args_copy(args->args);
+ c->random = random_seed();
+ c->root_external_state_watcher.next = c->root_external_state_watcher.prev =
+ &c->root_external_state_watcher;
+ grpc_closure_init(&c->connected, subchannel_connected, c);
+ grpc_connectivity_state_init(&c->state_tracker, GRPC_CHANNEL_IDLE,
+ "subchannel");
+ gpr_backoff_init(&c->backoff_state,
+ GRPC_SUBCHANNEL_RECONNECT_BACKOFF_MULTIPLIER,
+ GRPC_SUBCHANNEL_RECONNECT_JITTER,
+ GRPC_SUBCHANNEL_INITIAL_CONNECT_BACKOFF_SECONDS * 1000,
+ GRPC_SUBCHANNEL_RECONNECT_MAX_BACKOFF_SECONDS * 1000);
+ if (c->args) {
+ for (size_t i = 0; i < c->args->num_args; i++) {
+ if (0 == strcmp(c->args->args[i].key,
+ "grpc.testing.fixed_reconnect_backoff")) {
+ GPR_ASSERT(c->args->args[i].type == GRPC_ARG_INTEGER);
+ gpr_backoff_init(&c->backoff_state, 1.0, 0.0,
+ c->args->args[i].value.integer,
+ c->args->args[i].value.integer);
+ }
+ }
+ }
+ gpr_mu_init(&c->mu);
+
+ return grpc_subchannel_index_register(exec_ctx, key, c);
+}
+
+static void continue_connect(grpc_exec_ctx *exec_ctx, grpc_subchannel *c) {
+ grpc_connect_in_args args;
+
+ args.interested_parties = c->pollset_set;
+ args.addr = c->addr;
+ args.addr_len = c->addr_len;
+ args.deadline = c->next_attempt;
+ args.channel_args = c->args;
+ args.initial_connect_string = c->initial_connect_string;
+
+ grpc_connectivity_state_set(exec_ctx, &c->state_tracker,
+ GRPC_CHANNEL_CONNECTING, "state_change");
+ grpc_connector_connect(exec_ctx, c->connector, &args, &c->connecting_result,
+ &c->connected);
+}
+
+static void start_connect(grpc_exec_ctx *exec_ctx, grpc_subchannel *c) {
+ c->next_attempt =
+ gpr_backoff_begin(&c->backoff_state, gpr_now(GPR_CLOCK_MONOTONIC));
+ continue_connect(exec_ctx, c);
+}
+
+grpc_connectivity_state grpc_subchannel_check_connectivity(grpc_subchannel *c) {
+ grpc_connectivity_state state;
+ gpr_mu_lock(&c->mu);
+ state = grpc_connectivity_state_check(&c->state_tracker);
+ gpr_mu_unlock(&c->mu);
+ return state;
+}
+
+static void on_external_state_watcher_done(grpc_exec_ctx *exec_ctx, void *arg,
+ bool success) {
+ external_state_watcher *w = arg;
+ grpc_closure *follow_up = w->notify;
+ if (w->pollset_set != NULL) {
+ grpc_pollset_set_del_pollset_set(exec_ctx, w->subchannel->pollset_set,
+ w->pollset_set);
+ }
+ gpr_mu_lock(&w->subchannel->mu);
+ w->next->prev = w->prev;
+ w->prev->next = w->next;
+ gpr_mu_unlock(&w->subchannel->mu);
+ GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, w->subchannel, "external_state_watcher");
+ gpr_free(w);
+ follow_up->cb(exec_ctx, follow_up->cb_arg, success);
+}
+
+void grpc_subchannel_notify_on_state_change(
+ grpc_exec_ctx *exec_ctx, grpc_subchannel *c,
+ grpc_pollset_set *interested_parties, grpc_connectivity_state *state,
+ grpc_closure *notify) {
+ external_state_watcher *w;
+
+ if (state == NULL) {
+ gpr_mu_lock(&c->mu);
+ for (w = c->root_external_state_watcher.next;
+ w != &c->root_external_state_watcher; w = w->next) {
+ if (w->notify == notify) {
+ grpc_connectivity_state_notify_on_state_change(
+ exec_ctx, &c->state_tracker, NULL, &w->closure);
+ }
+ }
+ gpr_mu_unlock(&c->mu);
+ } else {
+ w = gpr_malloc(sizeof(*w));
+ w->subchannel = c;
+ w->pollset_set = interested_parties;
+ w->notify = notify;
+ grpc_closure_init(&w->closure, on_external_state_watcher_done, w);
+ if (interested_parties != NULL) {
+ grpc_pollset_set_add_pollset_set(exec_ctx, c->pollset_set,
+ interested_parties);
+ }
+ GRPC_SUBCHANNEL_WEAK_REF(c, "external_state_watcher");
+ gpr_mu_lock(&c->mu);
+ w->next = &c->root_external_state_watcher;
+ w->prev = w->next->prev;
+ w->next->prev = w->prev->next = w;
+ if (grpc_connectivity_state_notify_on_state_change(
+ exec_ctx, &c->state_tracker, state, &w->closure)) {
+ c->connecting = 1;
+ /* released by connection */
+ GRPC_SUBCHANNEL_WEAK_REF(c, "connecting");
+ start_connect(exec_ctx, c);
+ }
+ gpr_mu_unlock(&c->mu);
+ }
+}
+
+void grpc_connected_subchannel_process_transport_op(
+ grpc_exec_ctx *exec_ctx, grpc_connected_subchannel *con,
+ grpc_transport_op *op) {
+ grpc_channel_stack *channel_stack = CHANNEL_STACK_FROM_CONNECTION(con);
+ grpc_channel_element *top_elem = grpc_channel_stack_element(channel_stack, 0);
+ top_elem->filter->start_transport_op(exec_ctx, top_elem, op);
+}
+
+static void subchannel_on_child_state_changed(grpc_exec_ctx *exec_ctx, void *p,
+ bool iomgr_success) {
+ state_watcher *sw = p;
+ grpc_subchannel *c = sw->subchannel;
+ gpr_mu *mu = &c->mu;
+
+ gpr_mu_lock(mu);
+
+ /* if we failed just leave this closure */
+ if (iomgr_success) {
+ if (sw->connectivity_state == GRPC_CHANNEL_TRANSIENT_FAILURE) {
+ /* any errors on a subchannel ==> we're done, create a new one */
+ sw->connectivity_state = GRPC_CHANNEL_FATAL_FAILURE;
+ }
+ grpc_connectivity_state_set(exec_ctx, &c->state_tracker,
+ sw->connectivity_state, "reflect_child");
+ if (sw->connectivity_state != GRPC_CHANNEL_FATAL_FAILURE) {
+ grpc_connected_subchannel_notify_on_state_change(
+ exec_ctx, GET_CONNECTED_SUBCHANNEL(c, no_barrier), NULL,
+ &sw->connectivity_state, &sw->closure);
+ GRPC_SUBCHANNEL_WEAK_REF(c, "state_watcher");
+ sw = NULL;
+ }
+ }
+
+ gpr_mu_unlock(mu);
+ GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, c, "state_watcher");
+ gpr_free(sw);
+}
+
+static void connected_subchannel_state_op(grpc_exec_ctx *exec_ctx,
+ grpc_connected_subchannel *con,
+ grpc_pollset_set *interested_parties,
+ grpc_connectivity_state *state,
+ grpc_closure *closure) {
+ grpc_transport_op op;
+ grpc_channel_element *elem;
+ memset(&op, 0, sizeof(op));
+ op.connectivity_state = state;
+ op.on_connectivity_state_change = closure;
+ op.bind_pollset_set = interested_parties;
+ elem = grpc_channel_stack_element(CHANNEL_STACK_FROM_CONNECTION(con), 0);
+ elem->filter->start_transport_op(exec_ctx, elem, &op);
+}
+
+void grpc_connected_subchannel_notify_on_state_change(
+ grpc_exec_ctx *exec_ctx, grpc_connected_subchannel *con,
+ grpc_pollset_set *interested_parties, grpc_connectivity_state *state,
+ grpc_closure *closure) {
+ connected_subchannel_state_op(exec_ctx, con, interested_parties, state,
+ closure);
+}
+
+void grpc_connected_subchannel_ping(grpc_exec_ctx *exec_ctx,
+ grpc_connected_subchannel *con,
+ grpc_closure *closure) {
+ grpc_transport_op op;
+ grpc_channel_element *elem;
+ memset(&op, 0, sizeof(op));
+ op.send_ping = closure;
+ elem = grpc_channel_stack_element(CHANNEL_STACK_FROM_CONNECTION(con), 0);
+ elem->filter->start_transport_op(exec_ctx, elem, &op);
+}
+
+static void publish_transport_locked(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel *c) {
+ grpc_connected_subchannel *con;
+ grpc_channel_stack *stk;
+ state_watcher *sw_subchannel;
+
+ /* construct channel stack */
+ con = grpc_channel_init_create_stack(
+ exec_ctx, GRPC_CLIENT_SUBCHANNEL, 0, c->connecting_result.channel_args, 1,
+ connection_destroy, NULL, c->connecting_result.transport);
+ stk = CHANNEL_STACK_FROM_CONNECTION(con);
+ memset(&c->connecting_result, 0, sizeof(c->connecting_result));
+
+ /* initialize state watcher */
+ sw_subchannel = gpr_malloc(sizeof(*sw_subchannel));
+ sw_subchannel->subchannel = c;
+ sw_subchannel->connectivity_state = GRPC_CHANNEL_READY;
+ grpc_closure_init(&sw_subchannel->closure, subchannel_on_child_state_changed,
+ sw_subchannel);
+
+ if (c->disconnected) {
+ gpr_free(sw_subchannel);
+ grpc_channel_stack_destroy(exec_ctx, stk);
+ gpr_free(con);
+ GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, c, "connecting");
+ return;
+ }
+
+ /* publish */
+ /* TODO(ctiller): this full barrier seems to clear up a TSAN failure.
+ I'd have expected the rel_cas below to be enough, but
+ seemingly it's not.
+ Re-evaluate if we really need this. */
+ gpr_atm_full_barrier();
+ GPR_ASSERT(gpr_atm_rel_cas(&c->connected_subchannel, 0, (gpr_atm)con));
+ c->connecting = 0;
+
+ /* setup subchannel watching connected subchannel for changes; subchannel ref
+ for connecting is donated
+ to the state watcher */
+ GRPC_SUBCHANNEL_WEAK_REF(c, "state_watcher");
+ GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, c, "connecting");
+ grpc_connected_subchannel_notify_on_state_change(
+ exec_ctx, con, c->pollset_set, &sw_subchannel->connectivity_state,
+ &sw_subchannel->closure);
+
+ /* signal completion */
+ grpc_connectivity_state_set(exec_ctx, &c->state_tracker, GRPC_CHANNEL_READY,
+ "connected");
+}
+
+static void on_alarm(grpc_exec_ctx *exec_ctx, void *arg, bool iomgr_success) {
+ grpc_subchannel *c = arg;
+ gpr_mu_lock(&c->mu);
+ c->have_alarm = 0;
+ if (c->disconnected) {
+ iomgr_success = 0;
+ }
+ if (iomgr_success) {
+ c->next_attempt =
+ gpr_backoff_step(&c->backoff_state, gpr_now(GPR_CLOCK_MONOTONIC));
+ continue_connect(exec_ctx, c);
+ gpr_mu_unlock(&c->mu);
+ } else {
+ gpr_mu_unlock(&c->mu);
+ GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, c, "connecting");
+ }
+}
+
+static void subchannel_connected(grpc_exec_ctx *exec_ctx, void *arg,
+ bool iomgr_success) {
+ grpc_subchannel *c = arg;
+
+ GRPC_SUBCHANNEL_WEAK_REF(c, "connected");
+ gpr_mu_lock(&c->mu);
+ if (c->connecting_result.transport != NULL) {
+ publish_transport_locked(exec_ctx, c);
+ } else if (c->disconnected) {
+ GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, c, "connecting");
+ } else {
+ gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
+ GPR_ASSERT(!c->have_alarm);
+ c->have_alarm = 1;
+ grpc_connectivity_state_set(exec_ctx, &c->state_tracker,
+ GRPC_CHANNEL_TRANSIENT_FAILURE,
+ "connect_failed");
+ grpc_timer_init(exec_ctx, &c->alarm, c->next_attempt, on_alarm, c, now);
+ }
+ gpr_mu_unlock(&c->mu);
+ GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, c, "connecting");
+}
+
+/*
+ * grpc_subchannel_call implementation
+ */
+
+static void subchannel_call_destroy(grpc_exec_ctx *exec_ctx, void *call,
+ bool success) {
+ grpc_subchannel_call *c = call;
+ GPR_TIMER_BEGIN("grpc_subchannel_call_unref.destroy", 0);
+ grpc_call_stack_destroy(exec_ctx, SUBCHANNEL_CALL_TO_CALL_STACK(c));
+ GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, c->connection, "subchannel_call");
+ gpr_free(c);
+ GPR_TIMER_END("grpc_subchannel_call_unref.destroy", 0);
+}
+
+void grpc_subchannel_call_ref(
+ grpc_subchannel_call *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+ GRPC_CALL_STACK_REF(SUBCHANNEL_CALL_TO_CALL_STACK(c), REF_REASON);
+}
+
+void grpc_subchannel_call_unref(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel_call *c
+ GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+ GRPC_CALL_STACK_UNREF(exec_ctx, SUBCHANNEL_CALL_TO_CALL_STACK(c), REF_REASON);
+}
+
+char *grpc_subchannel_call_get_peer(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel_call *call) {
+ grpc_call_stack *call_stack = SUBCHANNEL_CALL_TO_CALL_STACK(call);
+ grpc_call_element *top_elem = grpc_call_stack_element(call_stack, 0);
+ return top_elem->filter->get_peer(exec_ctx, top_elem);
+}
+
+void grpc_subchannel_call_process_op(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel_call *call,
+ grpc_transport_stream_op *op) {
+ grpc_call_stack *call_stack = SUBCHANNEL_CALL_TO_CALL_STACK(call);
+ grpc_call_element *top_elem = grpc_call_stack_element(call_stack, 0);
+ top_elem->filter->start_transport_stream_op(exec_ctx, top_elem, op);
+}
+
+grpc_connected_subchannel *grpc_subchannel_get_connected_subchannel(
+ grpc_subchannel *c) {
+ return GET_CONNECTED_SUBCHANNEL(c, acq);
+}
+
+grpc_subchannel_call *grpc_connected_subchannel_create_call(
+ grpc_exec_ctx *exec_ctx, grpc_connected_subchannel *con,
+ grpc_pollset *pollset) {
+ grpc_channel_stack *chanstk = CHANNEL_STACK_FROM_CONNECTION(con);
+ grpc_subchannel_call *call =
+ gpr_malloc(sizeof(grpc_subchannel_call) + chanstk->call_stack_size);
+ grpc_call_stack *callstk = SUBCHANNEL_CALL_TO_CALL_STACK(call);
+ call->connection = con;
+ GRPC_CONNECTED_SUBCHANNEL_REF(con, "subchannel_call");
+ grpc_call_stack_init(exec_ctx, chanstk, 1, subchannel_call_destroy, call,
+ NULL, NULL, callstk);
+ grpc_call_stack_set_pollset(exec_ctx, callstk, pollset);
+ return call;
+}
+
+grpc_call_stack *grpc_subchannel_call_get_call_stack(
+ grpc_subchannel_call *subchannel_call) {
+ return SUBCHANNEL_CALL_TO_CALL_STACK(subchannel_call);
+}
diff --git a/src/core/lib/client_config/subchannel.h b/src/core/lib/client_config/subchannel.h
new file mode 100644
index 0000000000..b4f545be52
--- /dev/null
+++ b/src/core/lib/client_config/subchannel.h
@@ -0,0 +1,174 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_SUBCHANNEL_H
+#define GRPC_CORE_LIB_CLIENT_CONFIG_SUBCHANNEL_H
+
+#include "src/core/lib/channel/channel_stack.h"
+#include "src/core/lib/client_config/connector.h"
+#include "src/core/lib/transport/connectivity_state.h"
+
+/** A (sub-)channel that knows how to connect to exactly one target
+ address. Provides a target for load balancing. */
+typedef struct grpc_subchannel grpc_subchannel;
+typedef struct grpc_connected_subchannel grpc_connected_subchannel;
+typedef struct grpc_subchannel_call grpc_subchannel_call;
+typedef struct grpc_subchannel_args grpc_subchannel_args;
+
+#ifdef GRPC_STREAM_REFCOUNT_DEBUG
+#define GRPC_SUBCHANNEL_REF(p, r) \
+ grpc_subchannel_ref((p), __FILE__, __LINE__, (r))
+#define GRPC_SUBCHANNEL_REF_FROM_WEAK_REF(p, r) \
+ grpc_subchannel_ref_from_weak_ref((p), __FILE__, __LINE__, (r))
+#define GRPC_SUBCHANNEL_UNREF(cl, p, r) \
+ grpc_subchannel_unref((cl), (p), __FILE__, __LINE__, (r))
+#define GRPC_SUBCHANNEL_WEAK_REF(p, r) \
+ grpc_subchannel_weak_ref((p), __FILE__, __LINE__, (r))
+#define GRPC_SUBCHANNEL_WEAK_UNREF(cl, p, r) \
+ grpc_subchannel_weak_unref((cl), (p), __FILE__, __LINE__, (r))
+#define GRPC_CONNECTED_SUBCHANNEL_REF(p, r) \
+ grpc_connected_subchannel_ref((p), __FILE__, __LINE__, (r))
+#define GRPC_CONNECTED_SUBCHANNEL_UNREF(cl, p, r) \
+ grpc_connected_subchannel_unref((cl), (p), __FILE__, __LINE__, (r))
+#define GRPC_SUBCHANNEL_CALL_REF(p, r) \
+ grpc_subchannel_call_ref((p), __FILE__, __LINE__, (r))
+#define GRPC_SUBCHANNEL_CALL_UNREF(cl, p, r) \
+ grpc_subchannel_call_unref((cl), (p), __FILE__, __LINE__, (r))
+#define GRPC_SUBCHANNEL_REF_EXTRA_ARGS \
+ , const char *file, int line, const char *reason
+#else
+#define GRPC_SUBCHANNEL_REF(p, r) grpc_subchannel_ref((p))
+#define GRPC_SUBCHANNEL_REF_FROM_WEAK_REF(p, r) \
+ grpc_subchannel_ref_from_weak_ref((p))
+#define GRPC_SUBCHANNEL_UNREF(cl, p, r) grpc_subchannel_unref((cl), (p))
+#define GRPC_SUBCHANNEL_WEAK_REF(p, r) grpc_subchannel_weak_ref((p))
+#define GRPC_SUBCHANNEL_WEAK_UNREF(cl, p, r) \
+ grpc_subchannel_weak_unref((cl), (p))
+#define GRPC_CONNECTED_SUBCHANNEL_REF(p, r) grpc_connected_subchannel_ref((p))
+#define GRPC_CONNECTED_SUBCHANNEL_UNREF(cl, p, r) \
+ grpc_connected_subchannel_unref((cl), (p))
+#define GRPC_SUBCHANNEL_CALL_REF(p, r) grpc_subchannel_call_ref((p))
+#define GRPC_SUBCHANNEL_CALL_UNREF(cl, p, r) \
+ grpc_subchannel_call_unref((cl), (p))
+#define GRPC_SUBCHANNEL_REF_EXTRA_ARGS
+#endif
+
+grpc_subchannel *grpc_subchannel_ref(
+ grpc_subchannel *channel GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+grpc_subchannel *grpc_subchannel_ref_from_weak_ref(
+ grpc_subchannel *channel GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+void grpc_subchannel_unref(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel *channel
+ GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+grpc_subchannel *grpc_subchannel_weak_ref(
+ grpc_subchannel *channel GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+void grpc_subchannel_weak_unref(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel *channel
+ GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+void grpc_connected_subchannel_ref(
+ grpc_connected_subchannel *channel GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+void grpc_connected_subchannel_unref(grpc_exec_ctx *exec_ctx,
+ grpc_connected_subchannel *channel
+ GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+void grpc_subchannel_call_ref(
+ grpc_subchannel_call *call GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+void grpc_subchannel_call_unref(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel_call *call
+ GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+
+/** construct a subchannel call */
+grpc_subchannel_call *grpc_connected_subchannel_create_call(
+ grpc_exec_ctx *exec_ctx, grpc_connected_subchannel *connected_subchannel,
+ grpc_pollset *pollset);
+
+/** process a transport level op */
+void grpc_connected_subchannel_process_transport_op(
+ grpc_exec_ctx *exec_ctx, grpc_connected_subchannel *subchannel,
+ grpc_transport_op *op);
+
+/** poll the current connectivity state of a channel */
+grpc_connectivity_state grpc_subchannel_check_connectivity(
+ grpc_subchannel *channel);
+
+/** call notify when the connectivity state of a channel changes from *state.
+ Updates *state with the new state of the channel */
+void grpc_subchannel_notify_on_state_change(
+ grpc_exec_ctx *exec_ctx, grpc_subchannel *channel,
+ grpc_pollset_set *interested_parties, grpc_connectivity_state *state,
+ grpc_closure *notify);
+void grpc_connected_subchannel_notify_on_state_change(
+ grpc_exec_ctx *exec_ctx, grpc_connected_subchannel *channel,
+ grpc_pollset_set *interested_parties, grpc_connectivity_state *state,
+ grpc_closure *notify);
+void grpc_connected_subchannel_ping(grpc_exec_ctx *exec_ctx,
+ grpc_connected_subchannel *channel,
+ grpc_closure *notify);
+
+/** retrieve the grpc_connected_subchannel - or NULL if called before
+ the subchannel becomes connected */
+grpc_connected_subchannel *grpc_subchannel_get_connected_subchannel(
+ grpc_subchannel *subchannel);
+
+/** continue processing a transport op */
+void grpc_subchannel_call_process_op(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel_call *subchannel_call,
+ grpc_transport_stream_op *op);
+
+/** continue querying for peer */
+char *grpc_subchannel_call_get_peer(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel_call *subchannel_call);
+
+grpc_call_stack *grpc_subchannel_call_get_call_stack(
+ grpc_subchannel_call *subchannel_call);
+
+struct grpc_subchannel_args {
+ /* When updating this struct, also update subchannel_index.c */
+
+ /** Channel filters for this channel - wrapped factories will likely
+ want to mutate this */
+ const grpc_channel_filter **filters;
+ /** The number of filters in the above array */
+ size_t filter_count;
+ /** Channel arguments to be supplied to the newly created channel */
+ const grpc_channel_args *args;
+ /** Address to connect to */
+ struct sockaddr *addr;
+ size_t addr_len;
+};
+
+/** create a subchannel given a connector */
+grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
+ grpc_connector *connector,
+ grpc_subchannel_args *args);
+
+#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_SUBCHANNEL_H */
diff --git a/src/core/lib/client_config/subchannel_factory.c b/src/core/lib/client_config/subchannel_factory.c
new file mode 100644
index 0000000000..727a48a6c8
--- /dev/null
+++ b/src/core/lib/client_config/subchannel_factory.c
@@ -0,0 +1,49 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/client_config/subchannel_factory.h"
+
+void grpc_subchannel_factory_ref(grpc_subchannel_factory* factory) {
+ factory->vtable->ref(factory);
+}
+
+void grpc_subchannel_factory_unref(grpc_exec_ctx* exec_ctx,
+ grpc_subchannel_factory* factory) {
+ factory->vtable->unref(exec_ctx, factory);
+}
+
+grpc_subchannel* grpc_subchannel_factory_create_subchannel(
+ grpc_exec_ctx* exec_ctx, grpc_subchannel_factory* factory,
+ grpc_subchannel_args* args) {
+ return factory->vtable->create_subchannel(exec_ctx, factory, args);
+}
diff --git a/src/core/lib/client_config/subchannel_factory.h b/src/core/lib/client_config/subchannel_factory.h
new file mode 100644
index 0000000000..3ba2f860fe
--- /dev/null
+++ b/src/core/lib/client_config/subchannel_factory.h
@@ -0,0 +1,66 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_SUBCHANNEL_FACTORY_H
+#define GRPC_CORE_LIB_CLIENT_CONFIG_SUBCHANNEL_FACTORY_H
+
+#include "src/core/lib/channel/channel_stack.h"
+#include "src/core/lib/client_config/subchannel.h"
+
+typedef struct grpc_subchannel_factory grpc_subchannel_factory;
+typedef struct grpc_subchannel_factory_vtable grpc_subchannel_factory_vtable;
+
+/** Constructor for new configured channels.
+ Creating decorators around this type is encouraged to adapt behavior. */
+struct grpc_subchannel_factory {
+ const grpc_subchannel_factory_vtable *vtable;
+};
+
+struct grpc_subchannel_factory_vtable {
+ void (*ref)(grpc_subchannel_factory *factory);
+ void (*unref)(grpc_exec_ctx *exec_ctx, grpc_subchannel_factory *factory);
+ grpc_subchannel *(*create_subchannel)(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel_factory *factory,
+ grpc_subchannel_args *args);
+};
+
+void grpc_subchannel_factory_ref(grpc_subchannel_factory *factory);
+void grpc_subchannel_factory_unref(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel_factory *factory);
+
+/** Create a new grpc_subchannel */
+grpc_subchannel *grpc_subchannel_factory_create_subchannel(
+ grpc_exec_ctx *exec_ctx, grpc_subchannel_factory *factory,
+ grpc_subchannel_args *args);
+
+#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_SUBCHANNEL_FACTORY_H */
diff --git a/src/core/lib/client_config/subchannel_index.c b/src/core/lib/client_config/subchannel_index.c
new file mode 100644
index 0000000000..2c545002a2
--- /dev/null
+++ b/src/core/lib/client_config/subchannel_index.c
@@ -0,0 +1,262 @@
+//
+//
+// Copyright 2016, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+//
+
+#include "src/core/lib/client_config/subchannel_index.h"
+
+#include <stdbool.h>
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/avl.h>
+#include <grpc/support/tls.h>
+
+#include "src/core/lib/channel/channel_args.h"
+
+// a map of subchannel_key --> subchannel, used for detecting connections
+// to the same destination in order to share them
+static gpr_avl g_subchannel_index;
+
+static gpr_mu g_mu;
+
+struct grpc_subchannel_key {
+ grpc_connector *connector;
+ grpc_subchannel_args args;
+};
+
+GPR_TLS_DECL(subchannel_index_exec_ctx);
+
+static void enter_ctx(grpc_exec_ctx *exec_ctx) {
+ GPR_ASSERT(gpr_tls_get(&subchannel_index_exec_ctx) == 0);
+ gpr_tls_set(&subchannel_index_exec_ctx, (intptr_t)exec_ctx);
+}
+
+static void leave_ctx(grpc_exec_ctx *exec_ctx) {
+ GPR_ASSERT(gpr_tls_get(&subchannel_index_exec_ctx) == (intptr_t)exec_ctx);
+ gpr_tls_set(&subchannel_index_exec_ctx, 0);
+}
+
+static grpc_exec_ctx *current_ctx() {
+ grpc_exec_ctx *c = (grpc_exec_ctx *)gpr_tls_get(&subchannel_index_exec_ctx);
+ GPR_ASSERT(c != NULL);
+ return c;
+}
+
+static grpc_subchannel_key *create_key(
+ grpc_connector *connector, grpc_subchannel_args *args,
+ grpc_channel_args *(*copy_channel_args)(const grpc_channel_args *args)) {
+ grpc_subchannel_key *k = gpr_malloc(sizeof(*k));
+ k->connector = grpc_connector_ref(connector);
+ k->args.filter_count = args->filter_count;
+ k->args.filters = gpr_malloc(sizeof(*k->args.filters) * k->args.filter_count);
+ memcpy((grpc_channel_filter *)k->args.filters, args->filters,
+ sizeof(*k->args.filters) * k->args.filter_count);
+ k->args.addr_len = args->addr_len;
+ k->args.addr = gpr_malloc(args->addr_len);
+ memcpy(k->args.addr, args->addr, k->args.addr_len);
+ k->args.args = copy_channel_args(args->args);
+ return k;
+}
+
+grpc_subchannel_key *grpc_subchannel_key_create(grpc_connector *connector,
+ grpc_subchannel_args *args) {
+ return create_key(connector, args, grpc_channel_args_normalize);
+}
+
+static grpc_subchannel_key *subchannel_key_copy(grpc_subchannel_key *k) {
+ return create_key(k->connector, &k->args, grpc_channel_args_copy);
+}
+
+static int subchannel_key_compare(grpc_subchannel_key *a,
+ grpc_subchannel_key *b) {
+ int c = GPR_ICMP(a->connector, b->connector);
+ if (c != 0) return c;
+ c = GPR_ICMP(a->args.addr_len, b->args.addr_len);
+ if (c != 0) return c;
+ c = GPR_ICMP(a->args.filter_count, b->args.filter_count);
+ if (c != 0) return c;
+ c = memcmp(a->args.addr, b->args.addr, a->args.addr_len);
+ if (c != 0) return c;
+ c = memcmp(a->args.filters, b->args.filters,
+ a->args.filter_count * sizeof(*a->args.filters));
+ if (c != 0) return c;
+ return grpc_channel_args_compare(a->args.args, b->args.args);
+}
+
+void grpc_subchannel_key_destroy(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel_key *k) {
+ grpc_connector_unref(exec_ctx, k->connector);
+ gpr_free(k->args.addr);
+ gpr_free((grpc_channel_args *)k->args.filters);
+ grpc_channel_args_destroy((grpc_channel_args *)k->args.args);
+ gpr_free(k);
+}
+
+static void sck_avl_destroy(void *p) {
+ grpc_subchannel_key_destroy(current_ctx(), p);
+}
+
+static void *sck_avl_copy(void *p) { return subchannel_key_copy(p); }
+
+static long sck_avl_compare(void *a, void *b) {
+ return subchannel_key_compare(a, b);
+}
+
+static void scv_avl_destroy(void *p) {
+ GRPC_SUBCHANNEL_WEAK_UNREF(current_ctx(), p, "subchannel_index");
+}
+
+static void *scv_avl_copy(void *p) {
+ GRPC_SUBCHANNEL_WEAK_REF(p, "subchannel_index");
+ return p;
+}
+
+static const gpr_avl_vtable subchannel_avl_vtable = {
+ .destroy_key = sck_avl_destroy,
+ .copy_key = sck_avl_copy,
+ .compare_keys = sck_avl_compare,
+ .destroy_value = scv_avl_destroy,
+ .copy_value = scv_avl_copy};
+
+void grpc_subchannel_index_init(void) {
+ g_subchannel_index = gpr_avl_create(&subchannel_avl_vtable);
+ gpr_mu_init(&g_mu);
+ gpr_tls_init(&subchannel_index_exec_ctx);
+}
+
+void grpc_subchannel_index_shutdown(void) {
+ gpr_mu_destroy(&g_mu);
+ gpr_avl_unref(g_subchannel_index);
+ gpr_tls_destroy(&subchannel_index_exec_ctx);
+}
+
+grpc_subchannel *grpc_subchannel_index_find(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel_key *key) {
+ enter_ctx(exec_ctx);
+
+ // Lock, and take a reference to the subchannel index.
+ // We don't need to do the search under a lock as avl's are immutable.
+ gpr_mu_lock(&g_mu);
+ gpr_avl index = gpr_avl_ref(g_subchannel_index);
+ gpr_mu_unlock(&g_mu);
+
+ grpc_subchannel *c =
+ GRPC_SUBCHANNEL_REF_FROM_WEAK_REF(gpr_avl_get(index, key), "index_find");
+ gpr_avl_unref(index);
+
+ leave_ctx(exec_ctx);
+ return c;
+}
+
+grpc_subchannel *grpc_subchannel_index_register(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel_key *key,
+ grpc_subchannel *constructed) {
+ enter_ctx(exec_ctx);
+
+ grpc_subchannel *c = NULL;
+
+ while (c == NULL) {
+ // Compare and swap loop:
+ // - take a reference to the current index
+ gpr_mu_lock(&g_mu);
+ gpr_avl index = gpr_avl_ref(g_subchannel_index);
+ gpr_mu_unlock(&g_mu);
+
+ // - Check to see if a subchannel already exists
+ c = gpr_avl_get(index, key);
+ if (c != NULL) {
+ // yes -> we're done
+ GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, constructed, "index_register");
+ } else {
+ // no -> update the avl and compare/swap
+ gpr_avl updated =
+ gpr_avl_add(gpr_avl_ref(index), subchannel_key_copy(key),
+ GRPC_SUBCHANNEL_WEAK_REF(constructed, "index_register"));
+
+ // it may happen (but it's expected to be unlikely)
+ // that some other thread has changed the index:
+ // compare/swap here to check that, and retry as necessary
+ gpr_mu_lock(&g_mu);
+ if (index.root == g_subchannel_index.root) {
+ GPR_SWAP(gpr_avl, updated, g_subchannel_index);
+ c = constructed;
+ }
+ gpr_mu_unlock(&g_mu);
+
+ gpr_avl_unref(updated);
+ }
+ gpr_avl_unref(index);
+ }
+
+ leave_ctx(exec_ctx);
+
+ return c;
+}
+
+void grpc_subchannel_index_unregister(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel_key *key,
+ grpc_subchannel *constructed) {
+ enter_ctx(exec_ctx);
+
+ bool done = false;
+ while (!done) {
+ // Compare and swap loop:
+ // - take a reference to the current index
+ gpr_mu_lock(&g_mu);
+ gpr_avl index = gpr_avl_ref(g_subchannel_index);
+ gpr_mu_unlock(&g_mu);
+
+ // Check to see if this key still refers to the previously
+ // registered subchannel
+ grpc_subchannel *c = gpr_avl_get(index, key);
+ if (c != constructed) {
+ gpr_avl_unref(index);
+ break;
+ }
+
+ // compare and swap the update (some other thread may have
+ // mutated the index behind us)
+ gpr_avl updated = gpr_avl_remove(gpr_avl_ref(index), key);
+
+ gpr_mu_lock(&g_mu);
+ if (index.root == g_subchannel_index.root) {
+ GPR_SWAP(gpr_avl, updated, g_subchannel_index);
+ done = true;
+ }
+ gpr_mu_unlock(&g_mu);
+
+ gpr_avl_unref(updated);
+ gpr_avl_unref(index);
+ }
+
+ leave_ctx(exec_ctx);
+}
diff --git a/src/core/lib/client_config/subchannel_index.h b/src/core/lib/client_config/subchannel_index.h
new file mode 100644
index 0000000000..bc5f03beb4
--- /dev/null
+++ b/src/core/lib/client_config/subchannel_index.h
@@ -0,0 +1,77 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_SUBCHANNEL_INDEX_H
+#define GRPC_CORE_LIB_CLIENT_CONFIG_SUBCHANNEL_INDEX_H
+
+#include "src/core/lib/client_config/connector.h"
+#include "src/core/lib/client_config/subchannel.h"
+
+/** \file Provides an index of active subchannels so that they can be
+ shared amongst channels */
+
+typedef struct grpc_subchannel_key grpc_subchannel_key;
+
+/** Create a key that can be used to uniquely identify a subchannel */
+grpc_subchannel_key *grpc_subchannel_key_create(grpc_connector *con,
+ grpc_subchannel_args *args);
+
+/** Destroy a subchannel key */
+void grpc_subchannel_key_destroy(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel_key *key);
+
+/** Given a subchannel key, find the subchannel registered for it.
+ Returns NULL if no such channel exists.
+ Thread-safe. */
+grpc_subchannel *grpc_subchannel_index_find(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel_key *key);
+
+/** Register a subchannel against a key.
+ Takes ownership of \a constructed.
+ Returns the registered subchannel. This may be different from
+ \a constructed in the case of a registration race. */
+grpc_subchannel *grpc_subchannel_index_register(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel_key *key,
+ grpc_subchannel *constructed);
+
+/** Remove \a constructed as the registered subchannel for \a key. */
+void grpc_subchannel_index_unregister(grpc_exec_ctx *exec_ctx,
+ grpc_subchannel_key *key,
+ grpc_subchannel *constructed);
+
+/** Initialize the subchannel index (global) */
+void grpc_subchannel_index_init(void);
+/** Shutdown the subchannel index (global) */
+void grpc_subchannel_index_shutdown(void);
+
+#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_SUBCHANNEL_INDEX_H */
diff --git a/src/core/lib/client_config/uri_parser.c b/src/core/lib/client_config/uri_parser.c
new file mode 100644
index 0000000000..d3228dec5f
--- /dev/null
+++ b/src/core/lib/client_config/uri_parser.c
@@ -0,0 +1,242 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/client_config/uri_parser.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/port_platform.h>
+#include <grpc/support/string_util.h>
+
+/** a size_t default value... maps to all 1's */
+#define NOT_SET (~(size_t)0)
+
+static grpc_uri *bad_uri(const char *uri_text, size_t pos, const char *section,
+ int suppress_errors) {
+ char *line_prefix;
+ size_t pfx_len;
+
+ if (!suppress_errors) {
+ gpr_asprintf(&line_prefix, "bad uri.%s: '", section);
+ pfx_len = strlen(line_prefix) + pos;
+ gpr_log(GPR_ERROR, "%s%s'", line_prefix, uri_text);
+ gpr_free(line_prefix);
+
+ line_prefix = gpr_malloc(pfx_len + 1);
+ memset(line_prefix, ' ', pfx_len);
+ line_prefix[pfx_len] = 0;
+ gpr_log(GPR_ERROR, "%s^ here", line_prefix);
+ gpr_free(line_prefix);
+ }
+
+ return NULL;
+}
+
+/** Returns a copy of \a src[begin, end) */
+static char *copy_component(const char *src, size_t begin, size_t end) {
+ char *out = gpr_malloc(end - begin + 1);
+ memcpy(out, src + begin, end - begin);
+ out[end - begin] = 0;
+ return out;
+}
+
+/** Returns how many chars to advance if \a uri_text[i] begins a valid \a pchar
+ * production. If \a uri_text[i] introduces an invalid \a pchar (such as percent
+ * sign not followed by two hex digits), NOT_SET is returned. */
+static size_t parse_pchar(const char *uri_text, size_t i) {
+ /* pchar = unreserved / pct-encoded / sub-delims / ":" / "@"
+ * unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"
+ * pct-encoded = "%" HEXDIG HEXDIG
+ * sub-delims = "!" / "$" / "&" / "'" / "(" / ")"
+ / "*" / "+" / "," / ";" / "=" */
+ char c = uri_text[i];
+ if (((c >= 'A') && (c <= 'Z')) || ((c >= 'a') && (c <= 'z')) ||
+ ((c >= '0') && (c <= '9')) ||
+ (c == '-' || c == '.' || c == '_' || c == '~') || /* unreserved */
+ (c == '!' || c == '$' || c == '&' || c == '\'' || c == '$' || c == '&' ||
+ c == '(' || c == ')' || c == '*' || c == '+' || c == ',' || c == ';' ||
+ c == '=') /* sub-delims */) {
+ return 1;
+ }
+ if (c == '%') { /* pct-encoded */
+ size_t j;
+ if (uri_text[i + 1] == 0 || uri_text[i + 2] == 0) {
+ return NOT_SET;
+ }
+ for (j = i + 1; j < 2; j++) {
+ c = uri_text[j];
+ if (!(((c >= '0') && (c <= '9')) || ((c >= 'a') && (c <= 'f')) ||
+ ((c >= 'A') && (c <= 'F')))) {
+ return NOT_SET;
+ }
+ }
+ return 2;
+ }
+ return 0;
+}
+
+/* *( pchar / "?" / "/" ) */
+static int parse_fragment_or_query(const char *uri_text, size_t *i) {
+ char c;
+ while ((c = uri_text[*i]) != 0) {
+ const size_t advance = parse_pchar(uri_text, *i); /* pchar */
+ switch (advance) {
+ case 0: /* uri_text[i] isn't in pchar */
+ /* maybe it's ? or / */
+ if (uri_text[*i] == '?' || uri_text[*i] == '/') {
+ (*i)++;
+ break;
+ } else {
+ return 1;
+ }
+ GPR_UNREACHABLE_CODE(return 0);
+ default:
+ (*i) += advance;
+ break;
+ case NOT_SET: /* uri_text[i] introduces an invalid URI */
+ return 0;
+ }
+ }
+ /* *i is the first uri_text position past the \a query production, maybe \0 */
+ return 1;
+}
+
+grpc_uri *grpc_uri_parse(const char *uri_text, int suppress_errors) {
+ grpc_uri *uri;
+ size_t scheme_begin = 0;
+ size_t scheme_end = NOT_SET;
+ size_t authority_begin = NOT_SET;
+ size_t authority_end = NOT_SET;
+ size_t path_begin = NOT_SET;
+ size_t path_end = NOT_SET;
+ size_t query_begin = NOT_SET;
+ size_t query_end = NOT_SET;
+ size_t fragment_begin = NOT_SET;
+ size_t fragment_end = NOT_SET;
+ size_t i;
+
+ for (i = scheme_begin; uri_text[i] != 0; i++) {
+ if (uri_text[i] == ':') {
+ scheme_end = i;
+ break;
+ }
+ if (uri_text[i] >= 'a' && uri_text[i] <= 'z') continue;
+ if (uri_text[i] >= 'A' && uri_text[i] <= 'Z') continue;
+ if (i != scheme_begin) {
+ if (uri_text[i] >= '0' && uri_text[i] <= '9') continue;
+ if (uri_text[i] == '+') continue;
+ if (uri_text[i] == '-') continue;
+ if (uri_text[i] == '.') continue;
+ }
+ break;
+ }
+ if (scheme_end == NOT_SET) {
+ return bad_uri(uri_text, i, "scheme", suppress_errors);
+ }
+
+ if (uri_text[scheme_end + 1] == '/' && uri_text[scheme_end + 2] == '/') {
+ authority_begin = scheme_end + 3;
+ for (i = authority_begin; uri_text[i] != 0 && authority_end == NOT_SET;
+ i++) {
+ if (uri_text[i] == '/' || uri_text[i] == '?' || uri_text[i] == '#') {
+ authority_end = i;
+ }
+ }
+ if (authority_end == NOT_SET && uri_text[i] == 0) {
+ authority_end = i;
+ }
+ if (authority_end == NOT_SET) {
+ return bad_uri(uri_text, i, "authority", suppress_errors);
+ }
+ /* TODO(ctiller): parse the authority correctly */
+ path_begin = authority_end;
+ } else {
+ path_begin = scheme_end + 1;
+ }
+
+ for (i = path_begin; uri_text[i] != 0; i++) {
+ if (uri_text[i] == '?' || uri_text[i] == '#') {
+ path_end = i;
+ break;
+ }
+ }
+ if (path_end == NOT_SET && uri_text[i] == 0) {
+ path_end = i;
+ }
+ if (path_end == NOT_SET) {
+ return bad_uri(uri_text, i, "path", suppress_errors);
+ }
+
+ if (uri_text[i] == '?') {
+ query_begin = ++i;
+ if (!parse_fragment_or_query(uri_text, &i)) {
+ return bad_uri(uri_text, i, "query", suppress_errors);
+ } else if (uri_text[i] != 0 && uri_text[i] != '#') {
+ /* We must be at the end or at the beginning of a fragment */
+ return bad_uri(uri_text, i, "query", suppress_errors);
+ }
+ query_end = i;
+ }
+ if (uri_text[i] == '#') {
+ fragment_begin = ++i;
+ if (!parse_fragment_or_query(uri_text, &i)) {
+ return bad_uri(uri_text, i - fragment_end, "fragment", suppress_errors);
+ } else if (uri_text[i] != 0) {
+ /* We must be at the end */
+ return bad_uri(uri_text, i, "fragment", suppress_errors);
+ }
+ fragment_end = i;
+ }
+
+ uri = gpr_malloc(sizeof(*uri));
+ memset(uri, 0, sizeof(*uri));
+ uri->scheme = copy_component(uri_text, scheme_begin, scheme_end);
+ uri->authority = copy_component(uri_text, authority_begin, authority_end);
+ uri->path = copy_component(uri_text, path_begin, path_end);
+ uri->query = copy_component(uri_text, query_begin, query_end);
+ uri->fragment = copy_component(uri_text, fragment_begin, fragment_end);
+
+ return uri;
+}
+
+void grpc_uri_destroy(grpc_uri *uri) {
+ if (!uri) return;
+ gpr_free(uri->scheme);
+ gpr_free(uri->authority);
+ gpr_free(uri->path);
+ gpr_free(uri->query);
+ gpr_free(uri->fragment);
+ gpr_free(uri);
+}
diff --git a/src/core/lib/client_config/uri_parser.h b/src/core/lib/client_config/uri_parser.h
new file mode 100644
index 0000000000..d70d451e60
--- /dev/null
+++ b/src/core/lib/client_config/uri_parser.h
@@ -0,0 +1,51 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_URI_PARSER_H
+#define GRPC_CORE_LIB_CLIENT_CONFIG_URI_PARSER_H
+
+typedef struct {
+ char *scheme;
+ char *authority;
+ char *path;
+ char *query;
+ char *fragment;
+} grpc_uri;
+
+/** parse a uri, return NULL on failure */
+grpc_uri *grpc_uri_parse(const char *uri_text, int suppress_errors);
+
+/** destroy a uri */
+void grpc_uri_destroy(grpc_uri *uri);
+
+#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_URI_PARSER_H */