1 files changed, 113 insertions, 0 deletions
diff --git a/xpcom/threads/DelayedRunnable.cpp b/xpcom/threads/DelayedRunnable.cpp
new file mode 100644
index 0000000000..a9231442a7
--- /dev/null
+++ b/xpcom/threads/DelayedRunnable.cpp
@@ -0,0 +1,113 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "DelayedRunnable.h"
+
+#include "mozilla/ProfilerRunnable.h"
+
+namespace mozilla {
+
+DelayedRunnable::DelayedRunnable(already_AddRefed<nsISerialEventTarget> aTarget,
+                                 already_AddRefed<nsIRunnable> aRunnable,
+                                 uint32_t aDelay)
+    : mozilla::Runnable("DelayedRunnable"),
+      mTarget(aTarget),
+      mDelayedFrom(TimeStamp::NowLoRes()),
+      mDelay(aDelay),
+      mWrappedRunnable(aRunnable) {}
+
+nsresult DelayedRunnable::Init() {
+  MutexAutoLock lock(mMutex);
+  if (!mWrappedRunnable) {
+    MOZ_ASSERT_UNREACHABLE();
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  nsresult rv = mTarget->RegisterShutdownTask(this);
+  if (NS_FAILED(rv)) {
+    MOZ_DIAGNOSTIC_ASSERT(
+        rv == NS_ERROR_UNEXPECTED,
+        "DelayedRunnable target must support RegisterShutdownTask");
+    NS_WARNING("DelayedRunnable init after target is shutdown");
+    return rv;
+  }
+
+  rv = NS_NewTimerWithCallback(getter_AddRefs(mTimer), this, mDelay,
+                               nsITimer::TYPE_ONE_SHOT, mTarget);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    mTarget->UnregisterShutdownTask(this);
+  }
+  return rv;
+}
+
+NS_IMETHODIMP DelayedRunnable::Run() {
+  MOZ_ASSERT(mTarget->IsOnCurrentThread());
+
+  nsCOMPtr<nsIRunnable> runnable;
+  {
+    MutexAutoLock lock(mMutex);
+    MOZ_ASSERT(mTimer, "Init() must have been called");
+
+    // Already ran?
+    if (!mWrappedRunnable) {
+      return NS_OK;
+    }
+
+    // Are we too early?
+    if ((mozilla::TimeStamp::NowLoRes() - mDelayedFrom).ToMilliseconds() <
+        mDelay) {
+      return NS_OK;  // Let the nsITimer run us.
+    }
+
+    mTimer->Cancel();
+    mTarget->UnregisterShutdownTask(this);
+    runnable = mWrappedRunnable.forget();
+  }
+
+  AUTO_PROFILE_FOLLOWING_RUNNABLE(runnable);
+  return runnable->Run();
+}
+
+NS_IMETHODIMP DelayedRunnable::Notify(nsITimer* aTimer) {
+  MOZ_ASSERT(mTarget->IsOnCurrentThread());
+
+  nsCOMPtr<nsIRunnable> runnable;
+  {
+    MutexAutoLock lock(mMutex);
+    MOZ_ASSERT(mTimer, "Init() must have been called");
+
+    // We may have already run due to races
+    if (!mWrappedRunnable) {
+      return NS_OK;
+    }
+
+    mTarget->UnregisterShutdownTask(this);
+    runnable = mWrappedRunnable.forget();
+  }
+
+  AUTO_PROFILE_FOLLOWING_RUNNABLE(runnable);
+  return runnable->Run();
+}
+
+void DelayedRunnable::TargetShutdown() {
+  MOZ_ASSERT(mTarget->IsOnCurrentThread());
+
+  // Called at shutdown
+  MutexAutoLock lock(mMutex);
+  if (!mWrappedRunnable) {
+    return;
+  }
+  mWrappedRunnable = nullptr;
+
+  if (mTimer) {
+    mTimer->Cancel();
+  }
+}
+
+NS_IMPL_ISUPPORTS_INHERITED(DelayedRunnable, Runnable, nsITimerCallback,
+                            nsITargetShutdownTask)
+
+}  // namespace mozilla