starboard/shared/pthread/condition_variable_wait_timed.cc

// Copyright 2015 The Cobalt Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "starboard/common/condition_variable.h"

#include <errno.h>
#include <pthread.h>
#include <time.h>

#include "starboard/common/time.h"
#include "starboard/shared/pthread/is_success.h"
#include "starboard/shared/pthread/types_internal.h"
#include "starboard/shared/starboard/lazy_initialization_internal.h"

using starboard::shared::starboard::EnsureInitialized;

SbConditionVariableResult SbConditionVariableWaitTimed(
    SbConditionVariable* condition,
    SbMutex* mutex,
    int64_t timeout) {
  if (!condition || !mutex) {
    return kSbConditionVariableFailed;
  }

  if (timeout < 0) {
    timeout = 0;
  }

#if !SB_HAS_QUIRK(NO_CONDATTR_SETCLOCK_SUPPORT)
  int64_t timeout_time_usec = starboard::CurrentMonotonicTime() + timeout;
#else   // !SB_HAS_QUIRK(NO_CONDATTR_SETCLOCK_SUPPORT)
  int64_t timeout_time_usec = starboard::CurrentPosixTime() + timeout;
#endif  // !SB_HAS_QUIRK(NO_CONDATTR_SETCLOCK_SUPPORT)

  // Detect overflow if timeout is near kSbInt64Max. Since timeout can't be
  // negative at this point, if it goes negative after adding now, we know we've
  // gone over. Especially posix now, which has a 400 year advantage over
  // Chromium (Windows) now.
  if (timeout_time_usec < 0) {
    timeout_time_usec = kSbInt64Max;
  }

  struct timespec timeout_ts;
  timeout_ts.tv_sec = timeout_time_usec / 1'000'000;
  timeout_ts.tv_nsec = (timeout_time_usec % 1'000'000) * 1000;

  if (!EnsureInitialized(
          &(SB_PTHREAD_INTERNAL_CONDITION(condition)->initialized_state))) {
    // The condition variable is set to SB_CONDITION_VARIABLE_INITIALIZER and
    // is uninitialized, so call SbConditionVariableCreate() to initialize the
    // condition variable. SbConditionVariableCreate() is responsible for
    // marking the variable as initialized.
    SbConditionVariableCreate(condition, mutex);
  }

  int result = pthread_cond_timedwait(
      &(SB_PTHREAD_INTERNAL_CONDITION(condition)->condition),
      SB_PTHREAD_INTERNAL_MUTEX(mutex), &timeout_ts);
  if (IsSuccess(result)) {
    return kSbConditionVariableSignaled;
  }

  if (result == ETIMEDOUT) {
    return kSbConditionVariableTimedOut;
  }

  return kSbConditionVariableFailed;
}