Reland "EDK: Move //mojo/edk/system/waitable_event* to edk/util."

mojo/edk/system/waitable_event.cc

Index: mojo/edk/system/waitable_event.cc
diff --git a/mojo/edk/system/waitable_event.cc b/mojo/edk/system/waitable_event.cc
deleted file mode 100644
index c05d038e0e45e49d1980da91a41fabf17388a614..0000000000000000000000000000000000000000
--- a/mojo/edk/system/waitable_event.cc
+++ /dev/null
@@ -1,168 +0,0 @@
-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "mojo/edk/system/waitable_event.h"
-
-#include "base/logging.h"
-#include "base/time/time.h"
-
-using mojo::util::CondVar;
-using mojo::util::Mutex;
-using mojo::util::MutexLocker;
-
-namespace mojo {
-namespace system {
-
-namespace {
-
-// Waits with a timeout on |condition()|. Returns true on timeout, or false if
-// |condition()| ever returns true. |condition()| should have no side effects
-// (and will always be called with |*mutex| held).
-template <typename ConditionFn>
-bool WaitWithTimeoutImpl(Mutex* mutex,
-                         CondVar* cv,
-                         ConditionFn condition,
-                         uint64_t timeout_microseconds)
-    MOJO_EXCLUSIVE_LOCKS_REQUIRED(mutex) {
-  mutex->AssertHeld();
-
-  if (condition())
-    return false;
-
-  // We may get spurious wakeups.
-  uint64_t wait_remaining = timeout_microseconds;
-  auto start = base::TimeTicks::Now();
-  while (true) {
-    if (cv->WaitWithTimeout(mutex, wait_remaining))
-      return true;  // Definitely timed out.
-
-    // We may have been awoken.
-    if (condition())
-      return false;
-
-    // Or the wakeup may have been spurious.
-    auto now = base::TimeTicks::Now();
-    DCHECK_GE(now, start);
-    uint64_t elapsed = static_cast<uint64_t>((now - start).InMicroseconds());
-    // It's possible that we may have timed out anyway.
-    if (elapsed >= timeout_microseconds)
-      return true;
-
-    // Otherwise, recalculate the amount that we have left to wait.
-    wait_remaining = timeout_microseconds - elapsed;
-  }
-}
-
-}  // namespace
-
-// AutoResetWaitableEvent ------------------------------------------------------
-
-void AutoResetWaitableEvent::Signal() {
-  MutexLocker locker(&mutex_);
-  signaled_ = true;
-  cv_.Signal();
-}
-
-void AutoResetWaitableEvent::Reset() {
-  MutexLocker locker(&mutex_);
-  signaled_ = false;
-}
-
-void AutoResetWaitableEvent::Wait() {
-  MutexLocker locker(&mutex_);
-  while (!signaled_)
-    cv_.Wait(&mutex_);
-  signaled_ = false;
-}
-
-bool AutoResetWaitableEvent::WaitWithTimeout(uint64_t timeout_microseconds) {
-  MutexLocker locker(&mutex_);
-
-  if (signaled_) {
-    signaled_ = false;
-    return false;
-  }
-
-  // We may get spurious wakeups.
-  uint64_t wait_remaining = timeout_microseconds;
-  auto start = base::TimeTicks::Now();
-  while (true) {
-    if (cv_.WaitWithTimeout(&mutex_, wait_remaining))
-      return true;  // Definitely timed out.
-
-    // We may have been awoken.
-    if (signaled_)
-      break;
-
-    // Or the wakeup may have been spurious.
-    auto now = base::TimeTicks::Now();
-    DCHECK_GE(now, start);
-    uint64_t elapsed = static_cast<uint64_t>((now - start).InMicroseconds());
-    // It's possible that we may have timed out anyway.
-    if (elapsed >= timeout_microseconds)
-      return true;
-
-    // Otherwise, recalculate the amount that we have left to wait.
-    wait_remaining = timeout_microseconds - elapsed;
-  }
-
-  signaled_ = false;
-  return false;
-}
-
-bool AutoResetWaitableEvent::IsSignaledForTest() {
-  MutexLocker locker(&mutex_);
-  return signaled_;
-}
-
-// ManualResetWaitableEvent ----------------------------------------------------
-
-void ManualResetWaitableEvent::Signal() {
-  MutexLocker locker(&mutex_);
-  signaled_ = true;
-  signal_id_++;
-  cv_.SignalAll();
-}
-
-void ManualResetWaitableEvent::Reset() {
-  MutexLocker locker(&mutex_);
-  signaled_ = false;
-}
-
-void ManualResetWaitableEvent::Wait() {
-  MutexLocker locker(&mutex_);
-
-  if (signaled_)
-    return;
-
-  auto last_signal_id = signal_id_;
-  do {
-    cv_.Wait(&mutex_);
-  } while (signal_id_ == last_signal_id);
-}
-
-bool ManualResetWaitableEvent::WaitWithTimeout(uint64_t timeout_microseconds) {
-  MutexLocker locker(&mutex_);
-
-  auto last_signal_id = signal_id_;
-  // Disable thread-safety analysis for the lambda: We could annotate it with
-  // |MOJO_EXCLUSIVE_LOCKS_REQUIRED(mutex_)|, but then the analyzer currently
-  // isn't able to figure out that |WaitWithTimeoutImpl()| calls it while
-  // holding |mutex_|.
-  bool rv = WaitWithTimeoutImpl(
-      &mutex_, &cv_, [this, last_signal_id]() MOJO_NO_THREAD_SAFETY_ANALYSIS {
-        // Also check |signaled_| in case we're already signaled.
-        return signaled_ || signal_id_ != last_signal_id;
-      }, timeout_microseconds);
-  DCHECK(rv || signaled_ || signal_id_ != last_signal_id);
-  return rv;
-}
-
-bool ManualResetWaitableEvent::IsSignaledForTest() {
-  MutexLocker locker(&mutex_);
-  return signaled_;
-}
-
-}  // namespace system
-}  // namespace mojo