gecko-dev/xpcom/threads/nsThreadSyncDispatch.h
Xidorn Quan f90e2e16b2 Bug 1237909 part 2 - Do not return value from task for sync dispatch. r=froydnj
--HG--
extra : source : 5ed6de4d870f5eecc24ffba3f752ad43d57cd514
2016-01-25 14:52:34 +11:00

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1.5 KiB
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/* -*- 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/. */
#ifndef nsThreadSyncDispatch_h_
#define nsThreadSyncDispatch_h_
#include "nsThreadUtils.h"
#include "LeakRefPtr.h"
#include "mozilla/DebugOnly.h"
class nsThreadSyncDispatch : public nsRunnable
{
public:
nsThreadSyncDispatch(nsIThread* aOrigin, already_AddRefed<nsIRunnable>&& aTask)
: mOrigin(aOrigin)
, mSyncTask(mozilla::Move(aTask))
{
}
bool IsPending()
{
return !!mSyncTask;
}
private:
NS_IMETHOD Run() override
{
if (nsIRunnable* task = mSyncTask.get()) {
mozilla::DebugOnly<nsresult> result = task->Run();
MOZ_ASSERT(NS_SUCCEEDED(result),
"task in sync dispatch should not fail");
// We must release the task here to ensure that when the original
// thread is unblocked, this task has been released.
mSyncTask.release();
// unblock the origin thread
mOrigin->Dispatch(this, NS_DISPATCH_NORMAL);
}
return NS_OK;
}
nsCOMPtr<nsIThread> mOrigin;
// The task is leaked by default when Run() is not called, because
// otherwise we may release it in an incorrect thread.
mozilla::LeakRefPtr<nsIRunnable> mSyncTask;
};
#endif // nsThreadSyncDispatch_h_