diff options
Diffstat (limited to 'src/core/lib')
| -rw-r--r-- | src/core/lib/iomgr/timer_generic.c | 9 | ||||
| -rw-r--r-- | src/core/lib/support/spinlock.h | 50 |
2 files changed, 54 insertions, 5 deletions
diff --git a/src/core/lib/iomgr/timer_generic.c b/src/core/lib/iomgr/timer_generic.c index 6d638bcbaa..09ff2d0c3c 100644 --- a/src/core/lib/iomgr/timer_generic.c +++ b/src/core/lib/iomgr/timer_generic.c @@ -42,6 +42,7 @@ #include <grpc/support/useful.h> #include "src/core/lib/iomgr/time_averaged_stats.h" #include "src/core/lib/iomgr/timer_heap.h" +#include "src/core/lib/support/spinlock.h" #define INVALID_HEAP_INDEX 0xffffffffu @@ -69,7 +70,7 @@ typedef struct { /* Protects g_shard_queue */ static gpr_mu g_mu; /* Allow only one run_some_expired_timers at once */ -static gpr_mu g_checker_mu; +static gpr_spinlock g_checker_mu = GPR_SPINLOCK_INITIALIZER; static gpr_clock_type g_clock_type; static shard_type g_shards[NUM_SHARDS]; /* Protected by g_mu */ @@ -90,7 +91,6 @@ void grpc_timer_list_init(gpr_timespec now) { g_initialized = true; gpr_mu_init(&g_mu); - gpr_mu_init(&g_checker_mu); g_clock_type = now.clock_type; for (i = 0; i < NUM_SHARDS; i++) { @@ -117,7 +117,6 @@ void grpc_timer_list_shutdown(grpc_exec_ctx *exec_ctx) { grpc_timer_heap_destroy(&shard->heap); } gpr_mu_destroy(&g_mu); - gpr_mu_destroy(&g_checker_mu); g_initialized = false; } @@ -324,7 +323,7 @@ static int run_some_expired_timers(grpc_exec_ctx *exec_ctx, gpr_timespec now, /* TODO(ctiller): verify that there are any timers (atomically) here */ - if (gpr_mu_trylock(&g_checker_mu)) { + if (gpr_spinlock_trylock(&g_checker_mu)) { gpr_mu_lock(&g_mu); while (gpr_time_cmp(g_shard_queue[0]->min_deadline, now) < 0) { @@ -350,7 +349,7 @@ static int run_some_expired_timers(grpc_exec_ctx *exec_ctx, gpr_timespec now, } gpr_mu_unlock(&g_mu); - gpr_mu_unlock(&g_checker_mu); + gpr_spinlock_unlock(&g_checker_mu); } else if (next != NULL) { /* TODO(ctiller): this forces calling code to do an short poll, and then retry the timer check (because this time through the timer list was diff --git a/src/core/lib/support/spinlock.h b/src/core/lib/support/spinlock.h new file mode 100644 index 0000000000..aeb5622726 --- /dev/null +++ b/src/core/lib/support/spinlock.h @@ -0,0 +1,50 @@ +/* + * + * 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. + * + */ + +#ifndef GRPC_CORE_LIB_SUPPORT_SPINLOCK_H +#define GRPC_CORE_LIB_SUPPORT_SPINLOCK_H + +#include <grpc/support/atm.h> + +/* Simple spinlock. No backoff strategy, gpr_spinlock_lock is almost always + a concurrency code smell. */ +typedef struct { gpr_atm atm; } gpr_spinlock; + +#define GPR_SPINLOCK_INITIALIZER ((gpr_spinlock){0}) +#define gpr_spinlock_trylock(lock) (gpr_atm_acq_cas(&(lock)->atm, 0, 1)) +#define gpr_spinlock_unlock(lock) (gpr_atm_rel_store(&(lock)->atm, 0)) +#define gpr_spinlock_lock(lock) \ + do { \ + } while (!gpr_spinlock_trylock((lock))) + +#endif // GRPC_CORE_LIB_SUPPORT_SPINLOCK_H |