| /* |
| * |
| * 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/surface/completion_queue.h" |
| |
| #include <stdio.h> |
| #include <string.h> |
| |
| #include "src/core/iomgr/pollset.h" |
| #include "src/core/support/string.h" |
| #include "src/core/surface/call.h" |
| #include "src/core/surface/event_string.h" |
| #include "src/core/surface/surface_trace.h" |
| #include <grpc/support/alloc.h> |
| #include <grpc/support/atm.h> |
| #include <grpc/support/log.h> |
| |
| typedef struct { |
| grpc_pollset_worker *worker; |
| void *tag; |
| } plucker; |
| |
| /* Completion queue structure */ |
| struct grpc_completion_queue { |
| /** completed events */ |
| grpc_cq_completion completed_head; |
| grpc_cq_completion *completed_tail; |
| /** Number of pending events (+1 if we're not shutdown) */ |
| gpr_refcount pending_events; |
| /** Once owning_refs drops to zero, we will destroy the cq */ |
| gpr_refcount owning_refs; |
| /** the set of low level i/o things that concern this cq */ |
| grpc_pollset pollset; |
| /** 0 initially, 1 once we've begun shutting down */ |
| int shutdown; |
| int shutdown_called; |
| int is_server_cq; |
| int num_pluckers; |
| plucker pluckers[GRPC_MAX_COMPLETION_QUEUE_PLUCKERS]; |
| }; |
| |
| grpc_completion_queue *grpc_completion_queue_create(void) { |
| grpc_completion_queue *cc = gpr_malloc(sizeof(grpc_completion_queue)); |
| memset(cc, 0, sizeof(*cc)); |
| /* Initial ref is dropped by grpc_completion_queue_shutdown */ |
| gpr_ref_init(&cc->pending_events, 1); |
| /* One for destroy(), one for pollset_shutdown */ |
| gpr_ref_init(&cc->owning_refs, 2); |
| grpc_pollset_init(&cc->pollset); |
| cc->completed_tail = &cc->completed_head; |
| cc->completed_head.next = (gpr_uintptr)cc->completed_tail; |
| return cc; |
| } |
| |
| #ifdef GRPC_CQ_REF_COUNT_DEBUG |
| void grpc_cq_internal_ref(grpc_completion_queue *cc, const char *reason, |
| const char *file, int line) { |
| gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "CQ:%p ref %d -> %d %s", cc, |
| (int)cc->owning_refs.count, (int)cc->owning_refs.count + 1, reason); |
| #else |
| void grpc_cq_internal_ref(grpc_completion_queue *cc) { |
| #endif |
| gpr_ref(&cc->owning_refs); |
| } |
| |
| static void on_pollset_destroy_done(void *arg) { |
| grpc_completion_queue *cc = arg; |
| GRPC_CQ_INTERNAL_UNREF(cc, "pollset_destroy"); |
| } |
| |
| #ifdef GRPC_CQ_REF_COUNT_DEBUG |
| void grpc_cq_internal_unref(grpc_completion_queue *cc, const char *reason, |
| const char *file, int line) { |
| gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "CQ:%p unref %d -> %d %s", cc, |
| (int)cc->owning_refs.count, (int)cc->owning_refs.count - 1, reason); |
| #else |
| void grpc_cq_internal_unref(grpc_completion_queue *cc) { |
| #endif |
| if (gpr_unref(&cc->owning_refs)) { |
| GPR_ASSERT(cc->completed_head.next == (gpr_uintptr)&cc->completed_head); |
| grpc_pollset_destroy(&cc->pollset); |
| gpr_free(cc); |
| } |
| } |
| |
| void grpc_cq_begin_op(grpc_completion_queue *cc) { |
| gpr_ref(&cc->pending_events); |
| } |
| |
| /* Signal the end of an operation - if this is the last waiting-to-be-queued |
| event, then enter shutdown mode */ |
| /* Queue a GRPC_OP_COMPLETED operation */ |
| void grpc_cq_end_op(grpc_completion_queue *cc, void *tag, int success, |
| void (*done)(void *done_arg, grpc_cq_completion *storage), |
| void *done_arg, grpc_cq_completion *storage) { |
| int shutdown; |
| int i; |
| grpc_pollset_worker *pluck_worker; |
| |
| storage->tag = tag; |
| storage->done = done; |
| storage->done_arg = done_arg; |
| storage->next = |
| ((gpr_uintptr)&cc->completed_head) | ((gpr_uintptr)(success != 0)); |
| |
| gpr_mu_lock(GRPC_POLLSET_MU(&cc->pollset)); |
| shutdown = gpr_unref(&cc->pending_events); |
| if (!shutdown) { |
| cc->completed_tail->next = |
| ((gpr_uintptr)storage) | (1u & (gpr_uintptr)cc->completed_tail->next); |
| cc->completed_tail = storage; |
| pluck_worker = NULL; |
| for (i = 0; i < cc->num_pluckers; i++) { |
| if (cc->pluckers[i].tag == tag) { |
| pluck_worker = cc->pluckers[i].worker; |
| break; |
| } |
| } |
| grpc_pollset_kick(&cc->pollset, pluck_worker); |
| gpr_mu_unlock(GRPC_POLLSET_MU(&cc->pollset)); |
| } else { |
| cc->completed_tail->next = |
| ((gpr_uintptr)storage) | (1u & (gpr_uintptr)cc->completed_tail->next); |
| cc->completed_tail = storage; |
| GPR_ASSERT(!cc->shutdown); |
| GPR_ASSERT(cc->shutdown_called); |
| cc->shutdown = 1; |
| gpr_mu_unlock(GRPC_POLLSET_MU(&cc->pollset)); |
| grpc_pollset_shutdown(&cc->pollset, on_pollset_destroy_done, cc); |
| } |
| } |
| |
| grpc_event grpc_completion_queue_next(grpc_completion_queue *cc, |
| gpr_timespec deadline) { |
| grpc_event ret; |
| grpc_pollset_worker worker; |
| int first_loop = 1; |
| gpr_timespec now; |
| |
| deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC); |
| |
| GRPC_CQ_INTERNAL_REF(cc, "next"); |
| gpr_mu_lock(GRPC_POLLSET_MU(&cc->pollset)); |
| for (;;) { |
| if (cc->completed_tail != &cc->completed_head) { |
| grpc_cq_completion *c = (grpc_cq_completion *)cc->completed_head.next; |
| cc->completed_head.next = c->next & ~(gpr_uintptr)1; |
| if (c == cc->completed_tail) { |
| cc->completed_tail = &cc->completed_head; |
| } |
| gpr_mu_unlock(GRPC_POLLSET_MU(&cc->pollset)); |
| ret.type = GRPC_OP_COMPLETE; |
| ret.success = c->next & 1u; |
| ret.tag = c->tag; |
| c->done(c->done_arg, c); |
| break; |
| } |
| if (cc->shutdown) { |
| gpr_mu_unlock(GRPC_POLLSET_MU(&cc->pollset)); |
| memset(&ret, 0, sizeof(ret)); |
| ret.type = GRPC_QUEUE_SHUTDOWN; |
| break; |
| } |
| now = gpr_now(GPR_CLOCK_MONOTONIC); |
| if (!first_loop && gpr_time_cmp(now, deadline) >= 0) { |
| gpr_mu_unlock(GRPC_POLLSET_MU(&cc->pollset)); |
| memset(&ret, 0, sizeof(ret)); |
| ret.type = GRPC_QUEUE_TIMEOUT; |
| break; |
| } |
| first_loop = 0; |
| grpc_pollset_work(&cc->pollset, &worker, now, deadline); |
| } |
| GRPC_SURFACE_TRACE_RETURNED_EVENT(cc, &ret); |
| GRPC_CQ_INTERNAL_UNREF(cc, "next"); |
| return ret; |
| } |
| |
| static int add_plucker(grpc_completion_queue *cc, void *tag, |
| grpc_pollset_worker *worker) { |
| if (cc->num_pluckers == GRPC_MAX_COMPLETION_QUEUE_PLUCKERS) { |
| return 0; |
| } |
| cc->pluckers[cc->num_pluckers].tag = tag; |
| cc->pluckers[cc->num_pluckers].worker = worker; |
| cc->num_pluckers++; |
| return 1; |
| } |
| |
| static void del_plucker(grpc_completion_queue *cc, void *tag, |
| grpc_pollset_worker *worker) { |
| int i; |
| for (i = 0; i < cc->num_pluckers; i++) { |
| if (cc->pluckers[i].tag == tag && cc->pluckers[i].worker == worker) { |
| cc->num_pluckers--; |
| GPR_SWAP(plucker, cc->pluckers[i], cc->pluckers[cc->num_pluckers]); |
| return; |
| } |
| } |
| gpr_log(GPR_ERROR, "should never reach here"); |
| abort(); |
| } |
| |
| grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag, |
| gpr_timespec deadline) { |
| grpc_event ret; |
| grpc_cq_completion *c; |
| grpc_cq_completion *prev; |
| grpc_pollset_worker worker; |
| int first_loop = 1; |
| |
| deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC); |
| |
| GRPC_CQ_INTERNAL_REF(cc, "pluck"); |
| gpr_mu_lock(GRPC_POLLSET_MU(&cc->pollset)); |
| for (;;) { |
| prev = &cc->completed_head; |
| while ((c = (grpc_cq_completion *)(prev->next & ~(gpr_uintptr)1)) != |
| &cc->completed_head) { |
| if (c->tag == tag) { |
| prev->next = |
| (prev->next & (gpr_uintptr)1) | (c->next & ~(gpr_uintptr)1); |
| if (c == cc->completed_tail) { |
| cc->completed_tail = prev; |
| } |
| gpr_mu_unlock(GRPC_POLLSET_MU(&cc->pollset)); |
| ret.type = GRPC_OP_COMPLETE; |
| ret.success = c->next & 1u; |
| ret.tag = c->tag; |
| c->done(c->done_arg, c); |
| goto done; |
| } |
| prev = c; |
| } |
| if (cc->shutdown) { |
| gpr_mu_unlock(GRPC_POLLSET_MU(&cc->pollset)); |
| memset(&ret, 0, sizeof(ret)); |
| ret.type = GRPC_QUEUE_SHUTDOWN; |
| break; |
| } |
| if (!add_plucker(cc, tag, &worker)) { |
| gpr_log(GPR_DEBUG, |
| "Too many outstanding grpc_completion_queue_pluck calls: maximum is %d", |
| GRPC_MAX_COMPLETION_QUEUE_PLUCKERS); |
| gpr_mu_unlock(GRPC_POLLSET_MU(&cc->pollset)); |
| memset(&ret, 0, sizeof(ret)); |
| /* TODO(ctiller): should we use a different result here */ |
| ret.type = GRPC_QUEUE_TIMEOUT; |
| break; |
| } |
| now = gpr_now(GPR_CLOCK_MONOTONIC); |
| if (!first_loop && gpr_time_cmp(now, deadline) >= 0) { |
| del_plucker(cc, tag, &worker); |
| gpr_mu_unlock(GRPC_POLLSET_MU(&cc->pollset)); |
| memset(&ret, 0, sizeof(ret)); |
| ret.type = GRPC_QUEUE_TIMEOUT; |
| break; |
| } |
| first_loop = 0; |
| grpc_pollset_work(&cc->pollset, &worker, now, deadline); |
| } |
| done: |
| GRPC_SURFACE_TRACE_RETURNED_EVENT(cc, &ret); |
| GRPC_CQ_INTERNAL_UNREF(cc, "pluck"); |
| return ret; |
| } |
| |
| /* Shutdown simply drops a ref that we reserved at creation time; if we drop |
| to zero here, then enter shutdown mode and wake up any waiters */ |
| void grpc_completion_queue_shutdown(grpc_completion_queue *cc) { |
| gpr_mu_lock(GRPC_POLLSET_MU(&cc->pollset)); |
| if (cc->shutdown_called) { |
| gpr_mu_unlock(GRPC_POLLSET_MU(&cc->pollset)); |
| return; |
| } |
| cc->shutdown_called = 1; |
| gpr_mu_unlock(GRPC_POLLSET_MU(&cc->pollset)); |
| |
| if (gpr_unref(&cc->pending_events)) { |
| gpr_mu_lock(GRPC_POLLSET_MU(&cc->pollset)); |
| GPR_ASSERT(!cc->shutdown); |
| cc->shutdown = 1; |
| gpr_mu_unlock(GRPC_POLLSET_MU(&cc->pollset)); |
| grpc_pollset_shutdown(&cc->pollset, on_pollset_destroy_done, cc); |
| } |
| } |
| |
| void grpc_completion_queue_destroy(grpc_completion_queue *cc) { |
| grpc_completion_queue_shutdown(cc); |
| GRPC_CQ_INTERNAL_UNREF(cc, "destroy"); |
| } |
| |
| grpc_pollset *grpc_cq_pollset(grpc_completion_queue *cc) { |
| return &cc->pollset; |
| } |
| |
| void grpc_cq_mark_server_cq(grpc_completion_queue *cc) { cc->is_server_cq = 1; } |
| |
| int grpc_cq_is_server_cq(grpc_completion_queue *cc) { return cc->is_server_cq; } |