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Diffstat (limited to 'src/core/lib/client_config/lb_policy.h')
| -rw-r--r-- | src/core/lib/client_config/lb_policy.h | 144 |
1 files changed, 144 insertions, 0 deletions
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 */ |