Merge pull request #10427 from ctiller/c++lame

Convert Lame Client Channel code to C++

6 files changed, 276 insertions, 26 deletions

diff --git a/src/core/lib/iomgr/socket_mutator.h b/src/core/lib/iomgr/socket_mutator.h
index 2f5b6c248e..28b1710ec4 100644
--- a/src/core/lib/iomgr/socket_mutator.h
+++ b/src/core/lib/iomgr/socket_mutator.h
@@ -37,6 +37,8 @@
 #include <grpc/impl/codegen/grpc_types.h>
 #include <grpc/support/sync.h>
 
+#include <stdbool.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/src/core/lib/support/atomic.h b/src/core/lib/support/atomic.h
new file mode 100644
index 0000000000..2226189b68
--- /dev/null
+++ b/src/core/lib/support/atomic.h
@@ -0,0 +1,45 @@
+/*
+ *
+ * Copyright 2017, 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_SUPPORT_ATOMIC_H
+#define GRPC_CORE_LIB_SUPPORT_ATOMIC_H
+
+#include <grpc/support/port_platform.h>
+
+#ifdef GPR_HAS_CXX11_ATOMIC
+#include "src/core/lib/support/atomic_with_std.h"
+#else
+#include "src/core/lib/support/atomic_with_atm.h"
+#endif
+
+#endif /* GRPC_CORE_LIB_SUPPORT_ATOMIC_H */
diff --git a/src/core/lib/support/atomic_with_atm.h b/src/core/lib/support/atomic_with_atm.h
new file mode 100644
index 0000000000..55727f1dee
--- /dev/null
+++ b/src/core/lib/support/atomic_with_atm.h
@@ -0,0 +1,70 @@
+/*
+ *
+ * Copyright 2017, 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_SUPPORT_ATOMIC_WITH_ATM_H
+#define GRPC_CORE_LIB_SUPPORT_ATOMIC_WITH_ATM_H
+
+#include <grpc/support/atm.h>
+
+namespace grpc_core {
+
+enum MemoryOrderRelaxed { memory_order_relaxed };
+
+template <class T>
+class atomic;
+
+template <>
+class atomic<bool> {
+ public:
+  atomic() { gpr_atm_no_barrier_store(&x_, static_cast<gpr_atm>(false)); }
+  explicit atomic(bool x) {
+    gpr_atm_no_barrier_store(&x_, static_cast<gpr_atm>(x));
+  }
+
+  bool compare_exchange_strong(bool& expected, bool update, MemoryOrderRelaxed,
+                               MemoryOrderRelaxed) {
+    if (!gpr_atm_no_barrier_cas(&x_, static_cast<gpr_atm>(expected),
+                                static_cast<gpr_atm>(update))) {
+      expected = gpr_atm_no_barrier_load(&x_) != 0;
+      return false;
+    }
+    return true;
+  }
+
+ private:
+  gpr_atm x_;
+};
+
+}  // namespace grpc_core
+
+#endif /* GRPC_CORE_LIB_SUPPORT_ATOMIC_WITH_ATM_H */
diff --git a/src/core/lib/support/atomic_with_std.h b/src/core/lib/support/atomic_with_std.h
new file mode 100644
index 0000000000..7e9c19efe8
--- /dev/null
+++ b/src/core/lib/support/atomic_with_std.h
@@ -0,0 +1,48 @@
+/*
+ *
+ * Copyright 2017, 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_SUPPORT_ATOMIC_WITH_STD_H
+#define GRPC_CORE_LIB_SUPPORT_ATOMIC_WITH_STD_H
+
+#include <atomic>
+
+namespace grpc_core {
+
+template <class T>
+using atomic = std::atomic<T>;
+
+typedef std::memory_order memory_order;
+
+}  // namespace grpc_core
+
+#endif /* GRPC_CORE_LIB_SUPPORT_ATOMIC_WITH_STD_H */
diff --git a/src/core/lib/support/memory.h b/src/core/lib/support/memory.h
new file mode 100644
index 0000000000..6eff94eff7
--- /dev/null
+++ b/src/core/lib/support/memory.h
@@ -0,0 +1,74 @@
+/*
+ *
+ * Copyright 2017, 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_SUPPORT_MEMORY_H
+#define GRPC_CORE_LIB_SUPPORT_MEMORY_H
+
+#include <grpc/support/alloc.h>
+
+#include <memory>
+#include <utility>
+
+namespace grpc_core {
+
+// Alternative to new, since we cannot use it (for fear of libstdc++)
+template <typename T, typename... Args>
+inline T* New(Args&&... args) {
+  void* p = gpr_malloc(sizeof(T));
+  return new (p) T(std::forward<Args>(args)...);
+}
+
+// Alternative to delete, since we cannot use it (for fear of libstdc++)
+template <typename T>
+inline void Delete(T* p) {
+  p->~T();
+  gpr_free(p);
+}
+
+template <typename T>
+class DefaultDelete {
+ public:
+  void operator()(T* p) { Delete(p); }
+};
+
+template <typename T, typename Deleter = DefaultDelete<T>>
+using UniquePtr = std::unique_ptr<T, Deleter>;
+
+template <typename T, typename... Args>
+inline UniquePtr<T> MakeUnique(Args&&... args) {
+  return UniquePtr<T>(New<T>(std::forward<Args>(args)...));
+}
+
+}  // namespace grpc_core
+
+#endif /* GRPC_CORE_LIB_SUPPORT_MEMORY_H */
diff --git a/src/core/lib/surface/lame_client.c b/src/core/lib/surface/lame_client.cc
index 82428c42c0..88f4eaac08 100644
--- a/src/core/lib/surface/lame_client.c
+++ b/src/core/lib/surface/lame_client.cc
@@ -31,39 +31,50 @@
  *
  */
 
-#include "src/core/lib/surface/lame_client.h"
-
 #include <grpc/grpc.h>
 
 #include <string.h>
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
+
+#include "src/core/lib/support/atomic.h"
+
+extern "C" {
 #include "src/core/lib/channel/channel_stack.h"
 #include "src/core/lib/support/string.h"
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/surface/call.h"
 #include "src/core/lib/surface/channel.h"
+#include "src/core/lib/surface/lame_client.h"
 #include "src/core/lib/transport/static_metadata.h"
+}
 
-typedef struct {
+namespace grpc_core {
+
+namespace {
+
+struct CallData {
   grpc_linked_mdelem status;
   grpc_linked_mdelem details;
-  gpr_atm filled_metadata;
-} call_data;
+  grpc_core::atomic<bool> filled_metadata;
+};
 
-typedef struct {
+struct ChannelData {
   grpc_status_code error_code;
   const char *error_message;
-} channel_data;
+};
 
 static void fill_metadata(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
                           grpc_metadata_batch *mdb) {
-  call_data *calld = elem->call_data;
-  if (!gpr_atm_no_barrier_cas(&calld->filled_metadata, 0, 1)) {
+  CallData *calld = static_cast<CallData *>(elem->call_data);
+  bool expected = false;
+  if (!calld->filled_metadata.compare_exchange_strong(
+          expected, true, grpc_core::memory_order_relaxed,
+          grpc_core::memory_order_relaxed)) {
     return;
   }
-  channel_data *chand = elem->channel_data;
+  ChannelData *chand = static_cast<ChannelData *>(elem->channel_data);
   char tmp[GPR_LTOA_MIN_BUFSIZE];
   gpr_ltoa(chand->error_code, tmp);
   calld->status.md = grpc_mdelem_from_slices(
@@ -83,7 +94,6 @@ static void fill_metadata(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
 static void lame_start_transport_stream_op_batch(
     grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
     grpc_transport_stream_op_batch *op) {
-  GRPC_CALL_LOG_OP(GPR_INFO, elem, op);
   if (op->recv_initial_metadata) {
     fill_metadata(exec_ctx, elem,
                   op->payload->recv_initial_metadata.recv_initial_metadata);
@@ -127,8 +137,6 @@ static void lame_start_transport_op(grpc_exec_ctx *exec_ctx,
 static grpc_error *init_call_elem(grpc_exec_ctx *exec_ctx,
                                   grpc_call_element *elem,
                                   const grpc_call_element_args *args) {
-  call_data *calld = elem->call_data;
-  gpr_atm_no_barrier_store(&calld->filled_metadata, 0);
   return GRPC_ERROR_NONE;
 }
 
@@ -149,18 +157,22 @@ static grpc_error *init_channel_elem(grpc_exec_ctx *exec_ctx,
 static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
                                  grpc_channel_element *elem) {}
 
-const grpc_channel_filter grpc_lame_filter = {
-    lame_start_transport_stream_op_batch,
-    lame_start_transport_op,
-    sizeof(call_data),
-    init_call_elem,
+}  // namespace
+
+}  // namespace grpc_core
+
+extern "C" const grpc_channel_filter grpc_lame_filter = {
+    grpc_core::lame_start_transport_stream_op_batch,
+    grpc_core::lame_start_transport_op,
+    sizeof(grpc_core::CallData),
+    grpc_core::init_call_elem,
     grpc_call_stack_ignore_set_pollset_or_pollset_set,
-    destroy_call_elem,
-    sizeof(channel_data),
-    init_channel_elem,
-    destroy_channel_elem,
-    lame_get_peer,
-    lame_get_channel_info,
+    grpc_core::destroy_call_elem,
+    sizeof(grpc_core::ChannelData),
+    grpc_core::init_channel_elem,
+    grpc_core::destroy_channel_elem,
+    grpc_core::lame_get_peer,
+    grpc_core::lame_get_channel_info,
     "lame-client",
 };
 
@@ -171,7 +183,6 @@ grpc_channel *grpc_lame_client_channel_create(const char *target,
                                               const char *error_message) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_channel_element *elem;
-  channel_data *chand;
   grpc_channel *channel = grpc_channel_create(&exec_ctx, target, NULL,
                                               GRPC_CLIENT_LAME_CHANNEL, NULL);
   elem = grpc_channel_stack_element(grpc_channel_get_channel_stack(channel), 0);
@@ -180,7 +191,7 @@ grpc_channel *grpc_lame_client_channel_create(const char *target,
       "error_message=%s)",
       3, (target, (int)error_code, error_message));
   GPR_ASSERT(elem->filter == &grpc_lame_filter);
-  chand = (channel_data *)elem->channel_data;
+  auto chand = static_cast<grpc_core::ChannelData *>(elem->channel_data);
   chand->error_code = error_code;
   chand->error_message = error_message;
   grpc_exec_ctx_finish(&exec_ctx);