| /* |
| * |
| * Copyright 2015, 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/ext/client_config/subchannel_call_holder.h" |
| |
| #include <grpc/support/alloc.h> |
| |
| #include "src/core/lib/profiling/timers.h" |
| |
| #define GET_CALL(holder) \ |
| ((grpc_subchannel_call *)(gpr_atm_acq_load(&(holder)->subchannel_call))) |
| |
| #define CANCELLED_CALL ((grpc_subchannel_call *)1) |
| |
| static void subchannel_ready(grpc_exec_ctx *exec_ctx, void *holder, |
| grpc_error *error); |
| static void retry_ops(grpc_exec_ctx *exec_ctx, void *retry_ops_args, |
| grpc_error *error); |
| |
| static void add_waiting_locked(grpc_subchannel_call_holder *holder, |
| grpc_transport_stream_op *op); |
| static void fail_locked(grpc_exec_ctx *exec_ctx, |
| grpc_subchannel_call_holder *holder, grpc_error *error); |
| static void retry_waiting_locked(grpc_exec_ctx *exec_ctx, |
| grpc_subchannel_call_holder *holder); |
| |
| void grpc_subchannel_call_holder_init( |
| grpc_subchannel_call_holder *holder, |
| grpc_subchannel_call_holder_pick_subchannel pick_subchannel, |
| void *pick_subchannel_arg, grpc_call_stack *owning_call) { |
| gpr_atm_rel_store(&holder->subchannel_call, 0); |
| holder->pick_subchannel = pick_subchannel; |
| holder->pick_subchannel_arg = pick_subchannel_arg; |
| gpr_mu_init(&holder->mu); |
| holder->connected_subchannel = NULL; |
| holder->waiting_ops = NULL; |
| holder->waiting_ops_count = 0; |
| holder->waiting_ops_capacity = 0; |
| holder->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING; |
| holder->owning_call = owning_call; |
| holder->pollent = NULL; |
| } |
| |
| void grpc_subchannel_call_holder_destroy(grpc_exec_ctx *exec_ctx, |
| grpc_subchannel_call_holder *holder) { |
| grpc_subchannel_call *call = GET_CALL(holder); |
| if (call != NULL && call != CANCELLED_CALL) { |
| GRPC_SUBCHANNEL_CALL_UNREF(exec_ctx, call, "holder"); |
| } |
| GPR_ASSERT(holder->creation_phase == |
| GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING); |
| gpr_mu_destroy(&holder->mu); |
| GPR_ASSERT(holder->waiting_ops_count == 0); |
| gpr_free(holder->waiting_ops); |
| } |
| |
| // The logic here is fairly complicated, due to (a) the fact that we |
| // need to handle the case where we receive the send op before the |
| // initial metadata op, and (b) the need for efficiency, especially in |
| // the streaming case. |
| // TODO(ctiller): Explain this more thoroughly. |
| void grpc_subchannel_call_holder_perform_op(grpc_exec_ctx *exec_ctx, |
| grpc_subchannel_call_holder *holder, |
| grpc_transport_stream_op *op) { |
| /* try to (atomically) get the call */ |
| grpc_subchannel_call *call = GET_CALL(holder); |
| GPR_TIMER_BEGIN("grpc_subchannel_call_holder_perform_op", 0); |
| if (call == CANCELLED_CALL) { |
| grpc_transport_stream_op_finish_with_failure(exec_ctx, op, |
| GRPC_ERROR_CANCELLED); |
| GPR_TIMER_END("grpc_subchannel_call_holder_perform_op", 0); |
| return; |
| } |
| if (call != NULL) { |
| grpc_subchannel_call_process_op(exec_ctx, call, op); |
| GPR_TIMER_END("grpc_subchannel_call_holder_perform_op", 0); |
| return; |
| } |
| /* we failed; lock and figure out what to do */ |
| gpr_mu_lock(&holder->mu); |
| retry: |
| /* need to recheck that another thread hasn't set the call */ |
| call = GET_CALL(holder); |
| if (call == CANCELLED_CALL) { |
| gpr_mu_unlock(&holder->mu); |
| grpc_transport_stream_op_finish_with_failure(exec_ctx, op, |
| GRPC_ERROR_CANCELLED); |
| GPR_TIMER_END("grpc_subchannel_call_holder_perform_op", 0); |
| return; |
| } |
| if (call != NULL) { |
| gpr_mu_unlock(&holder->mu); |
| grpc_subchannel_call_process_op(exec_ctx, call, op); |
| GPR_TIMER_END("grpc_subchannel_call_holder_perform_op", 0); |
| return; |
| } |
| /* if this is a cancellation, then we can raise our cancelled flag */ |
| if (op->cancel_error != GRPC_ERROR_NONE) { |
| if (!gpr_atm_rel_cas(&holder->subchannel_call, 0, |
| (gpr_atm)(uintptr_t)CANCELLED_CALL)) { |
| goto retry; |
| } else { |
| switch (holder->creation_phase) { |
| case GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING: |
| fail_locked(exec_ctx, holder, GRPC_ERROR_REF(op->cancel_error)); |
| break; |
| case GRPC_SUBCHANNEL_CALL_HOLDER_PICKING_SUBCHANNEL: |
| holder->pick_subchannel(exec_ctx, holder->pick_subchannel_arg, NULL, |
| 0, &holder->connected_subchannel, NULL); |
| break; |
| } |
| gpr_mu_unlock(&holder->mu); |
| grpc_transport_stream_op_finish_with_failure(exec_ctx, op, |
| GRPC_ERROR_CANCELLED); |
| GPR_TIMER_END("grpc_subchannel_call_holder_perform_op", 0); |
| return; |
| } |
| } |
| /* if we don't have a subchannel, try to get one */ |
| if (holder->creation_phase == GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING && |
| holder->connected_subchannel == NULL && |
| op->send_initial_metadata != NULL) { |
| holder->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_PICKING_SUBCHANNEL; |
| grpc_closure_init(&holder->next_step, subchannel_ready, holder); |
| GRPC_CALL_STACK_REF(holder->owning_call, "pick_subchannel"); |
| if (holder->pick_subchannel( |
| exec_ctx, holder->pick_subchannel_arg, op->send_initial_metadata, |
| op->send_initial_metadata_flags, &holder->connected_subchannel, |
| &holder->next_step)) { |
| holder->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING; |
| GRPC_CALL_STACK_UNREF(exec_ctx, holder->owning_call, "pick_subchannel"); |
| } |
| } |
| /* if we've got a subchannel, then let's ask it to create a call */ |
| if (holder->creation_phase == GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING && |
| holder->connected_subchannel != NULL) { |
| grpc_subchannel_call *subchannel_call = NULL; |
| grpc_error *error = grpc_connected_subchannel_create_call( |
| exec_ctx, holder->connected_subchannel, holder->pollent, |
| &subchannel_call); |
| if (error != GRPC_ERROR_NONE) { |
| subchannel_call = CANCELLED_CALL; |
| fail_locked(exec_ctx, holder, GRPC_ERROR_REF(error)); |
| grpc_transport_stream_op_finish_with_failure(exec_ctx, op, error); |
| } |
| gpr_atm_rel_store(&holder->subchannel_call, |
| (gpr_atm)(uintptr_t)subchannel_call); |
| retry_waiting_locked(exec_ctx, holder); |
| goto retry; |
| } |
| /* nothing to be done but wait */ |
| add_waiting_locked(holder, op); |
| gpr_mu_unlock(&holder->mu); |
| GPR_TIMER_END("grpc_subchannel_call_holder_perform_op", 0); |
| } |
| |
| static void subchannel_ready(grpc_exec_ctx *exec_ctx, void *arg, |
| grpc_error *error) { |
| grpc_subchannel_call_holder *holder = arg; |
| gpr_mu_lock(&holder->mu); |
| GPR_ASSERT(holder->creation_phase == |
| GRPC_SUBCHANNEL_CALL_HOLDER_PICKING_SUBCHANNEL); |
| holder->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING; |
| if (holder->connected_subchannel == NULL) { |
| gpr_atm_no_barrier_store(&holder->subchannel_call, 1); |
| fail_locked(exec_ctx, holder, |
| GRPC_ERROR_CREATE_REFERENCING("Failed to create subchannel", |
| &error, 1)); |
| } else if (1 == gpr_atm_acq_load(&holder->subchannel_call)) { |
| /* already cancelled before subchannel became ready */ |
| fail_locked(exec_ctx, holder, |
| GRPC_ERROR_CREATE_REFERENCING( |
| "Cancelled before creating subchannel", &error, 1)); |
| } else { |
| grpc_subchannel_call *subchannel_call = NULL; |
| grpc_error *new_error = grpc_connected_subchannel_create_call( |
| exec_ctx, holder->connected_subchannel, holder->pollent, |
| &subchannel_call); |
| if (new_error != GRPC_ERROR_NONE) { |
| new_error = grpc_error_add_child(new_error, error); |
| subchannel_call = CANCELLED_CALL; |
| fail_locked(exec_ctx, holder, new_error); |
| } |
| gpr_atm_rel_store(&holder->subchannel_call, |
| (gpr_atm)(uintptr_t)subchannel_call); |
| retry_waiting_locked(exec_ctx, holder); |
| } |
| gpr_mu_unlock(&holder->mu); |
| GRPC_CALL_STACK_UNREF(exec_ctx, holder->owning_call, "pick_subchannel"); |
| } |
| |
| typedef struct { |
| grpc_transport_stream_op *ops; |
| size_t nops; |
| grpc_subchannel_call *call; |
| } retry_ops_args; |
| |
| static void retry_waiting_locked(grpc_exec_ctx *exec_ctx, |
| grpc_subchannel_call_holder *holder) { |
| retry_ops_args *a = gpr_malloc(sizeof(*a)); |
| a->ops = holder->waiting_ops; |
| a->nops = holder->waiting_ops_count; |
| a->call = GET_CALL(holder); |
| if (a->call == CANCELLED_CALL) { |
| gpr_free(a); |
| fail_locked(exec_ctx, holder, GRPC_ERROR_CANCELLED); |
| return; |
| } |
| holder->waiting_ops = NULL; |
| holder->waiting_ops_count = 0; |
| holder->waiting_ops_capacity = 0; |
| GRPC_SUBCHANNEL_CALL_REF(a->call, "retry_ops"); |
| grpc_exec_ctx_sched(exec_ctx, grpc_closure_create(retry_ops, a), |
| GRPC_ERROR_NONE, NULL); |
| } |
| |
| static void retry_ops(grpc_exec_ctx *exec_ctx, void *args, grpc_error *error) { |
| retry_ops_args *a = args; |
| size_t i; |
| for (i = 0; i < a->nops; i++) { |
| grpc_subchannel_call_process_op(exec_ctx, a->call, &a->ops[i]); |
| } |
| GRPC_SUBCHANNEL_CALL_UNREF(exec_ctx, a->call, "retry_ops"); |
| gpr_free(a->ops); |
| gpr_free(a); |
| } |
| |
| static void add_waiting_locked(grpc_subchannel_call_holder *holder, |
| grpc_transport_stream_op *op) { |
| GPR_TIMER_BEGIN("add_waiting_locked", 0); |
| if (holder->waiting_ops_count == holder->waiting_ops_capacity) { |
| holder->waiting_ops_capacity = GPR_MAX(3, 2 * holder->waiting_ops_capacity); |
| holder->waiting_ops = |
| gpr_realloc(holder->waiting_ops, holder->waiting_ops_capacity * |
| sizeof(*holder->waiting_ops)); |
| } |
| holder->waiting_ops[holder->waiting_ops_count++] = *op; |
| GPR_TIMER_END("add_waiting_locked", 0); |
| } |
| |
| static void fail_locked(grpc_exec_ctx *exec_ctx, |
| grpc_subchannel_call_holder *holder, |
| grpc_error *error) { |
| size_t i; |
| for (i = 0; i < holder->waiting_ops_count; i++) { |
| grpc_transport_stream_op_finish_with_failure( |
| exec_ctx, &holder->waiting_ops[i], GRPC_ERROR_REF(error)); |
| } |
| holder->waiting_ops_count = 0; |
| GRPC_ERROR_UNREF(error); |
| } |
| |
| char *grpc_subchannel_call_holder_get_peer( |
| grpc_exec_ctx *exec_ctx, grpc_subchannel_call_holder *holder) { |
| grpc_subchannel_call *subchannel_call = GET_CALL(holder); |
| |
| if (subchannel_call == NULL || subchannel_call == CANCELLED_CALL) { |
| return NULL; |
| } else { |
| return grpc_subchannel_call_get_peer(exec_ctx, subchannel_call); |
| } |
| } |