| /* |
| * |
| * 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/lib/iomgr/executor.h" |
| |
| #include <string.h> |
| |
| #include <grpc/support/alloc.h> |
| #include <grpc/support/log.h> |
| #include <grpc/support/sync.h> |
| #include <grpc/support/thd.h> |
| #include "src/core/lib/iomgr/exec_ctx.h" |
| |
| typedef struct grpc_executor_data { |
| int busy; /**< is the thread currently running? */ |
| int shutting_down; /**< has \a grpc_shutdown() been invoked? */ |
| int pending_join; /**< has the thread finished but not been joined? */ |
| grpc_closure_list closures; /**< collection of pending work */ |
| gpr_thd_id tid; /**< thread id of the thread, only valid if \a busy or \a |
| pending_join are true */ |
| gpr_thd_options options; |
| gpr_mu mu; |
| } grpc_executor; |
| |
| static grpc_executor g_executor; |
| |
| void grpc_executor_init() { |
| memset(&g_executor, 0, sizeof(grpc_executor)); |
| gpr_mu_init(&g_executor.mu); |
| g_executor.options = gpr_thd_options_default(); |
| gpr_thd_options_set_joinable(&g_executor.options); |
| } |
| |
| /* thread body */ |
| static void closure_exec_thread_func(void *ignored) { |
| grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT; |
| while (1) { |
| gpr_mu_lock(&g_executor.mu); |
| if (g_executor.shutting_down != 0) { |
| gpr_mu_unlock(&g_executor.mu); |
| break; |
| } |
| if (grpc_closure_list_empty(g_executor.closures)) { |
| /* no more work, time to die */ |
| GPR_ASSERT(g_executor.busy == 1); |
| g_executor.busy = 0; |
| gpr_mu_unlock(&g_executor.mu); |
| break; |
| } else { |
| grpc_exec_ctx_enqueue_list(&exec_ctx, &g_executor.closures, NULL); |
| } |
| gpr_mu_unlock(&g_executor.mu); |
| grpc_exec_ctx_flush(&exec_ctx); |
| } |
| grpc_exec_ctx_finish(&exec_ctx); |
| } |
| |
| /* Spawn the thread if new work has arrived a no thread is up */ |
| static void maybe_spawn_locked() { |
| if (grpc_closure_list_empty(g_executor.closures) == 1) { |
| return; |
| } |
| if (g_executor.shutting_down == 1) { |
| return; |
| } |
| |
| if (g_executor.busy != 0) { |
| /* Thread still working. New work will be picked up by already running |
| * thread. Not spawning anything. */ |
| return; |
| } else if (g_executor.pending_join != 0) { |
| /* Pickup the remains of the previous incarnations of the thread. */ |
| gpr_thd_join(g_executor.tid); |
| g_executor.pending_join = 0; |
| } |
| |
| /* All previous instances of the thread should have been joined at this point. |
| * Spawn time! */ |
| g_executor.busy = 1; |
| gpr_thd_new(&g_executor.tid, closure_exec_thread_func, NULL, |
| &g_executor.options); |
| g_executor.pending_join = 1; |
| } |
| |
| void grpc_executor_push(grpc_closure *closure, grpc_error *error) { |
| gpr_mu_lock(&g_executor.mu); |
| if (g_executor.shutting_down == 0) { |
| grpc_closure_list_append(&g_executor.closures, closure, error); |
| maybe_spawn_locked(); |
| } |
| gpr_mu_unlock(&g_executor.mu); |
| } |
| |
| void grpc_executor_shutdown() { |
| int pending_join; |
| grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT; |
| |
| gpr_mu_lock(&g_executor.mu); |
| pending_join = g_executor.pending_join; |
| g_executor.shutting_down = 1; |
| gpr_mu_unlock(&g_executor.mu); |
| /* we can release the lock at this point despite the access to the closure |
| * list below because we aren't accepting new work */ |
| |
| /* Execute pending callbacks, some may be performing cleanups */ |
| grpc_exec_ctx_enqueue_list(&exec_ctx, &g_executor.closures, NULL); |
| grpc_exec_ctx_finish(&exec_ctx); |
| GPR_ASSERT(grpc_closure_list_empty(g_executor.closures)); |
| if (pending_join) { |
| gpr_thd_join(g_executor.tid); |
| } |
| gpr_mu_destroy(&g_executor.mu); |
| } |