gecko-dev/xpcom/threads/nsThreadPool.h
Karl Tomlinson 4fdafba88d b=928222 remove nsThreadPool per-thread event queues r=bsmedberg
The way idle nsThreadPool threads wait with a timeout doesn't work well with
shutdown from nsThreadManager.

nsThreadPool doesn't need to use nsIThread for its threads.  The nsIThread
interface is not useful for threads running in an nsThreadPool.
The nsIEventTarget on the nsIThreadPool should be used for dispatching events,
not an interface on the individual threads, and the threads don't need an
nsEventQueue because they use the nsEventQueue on the nsThreadPool.

Shutdown of single event threads is easier than running nested event loops for
nsIThreads, avoiding the multilevel nested event loop situations when several
threads finish and are shutdown.  While the ThreadFunc is running, a nested
event loop is still used in Shutdown() in case some consumers might need it
and because that is the documented API.

This also simplifies thread creation, avoiding races that could mean there was
temporarily an extra thread or more.

--HG--
extra : transplant_source : %F7%14%16%12%EF%E9%84%19D%26%3C%FE%1F%EC%FF%A3%BAG%C4%F3
2013-10-24 09:31:15 +13:00

57 lines
1.6 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* 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 nsThreadPool_h__
#define nsThreadPool_h__
#include "nsIThreadPool.h"
#include "nsIThread.h"
#include "nsIRunnable.h"
#include "nsEventQueue.h"
#include "nsCOMArray.h"
#include "nsCOMPtr.h"
#include "nsThreadUtils.h"
#include "mozilla/Attributes.h"
class nsThreadPool MOZ_FINAL : public nsIThreadPool
{
public:
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSIEVENTTARGET
NS_DECL_NSITHREADPOOL
nsThreadPool();
private:
~nsThreadPool();
void ShutdownThread(PRThread *thread);
static void ThreadFunc(void *arg);
void Run();
nsresult PutEvent(nsIRunnable *event);
nsTArray<PRThread*> mThreads;
nsEventQueue mEvents;
uint32_t mThreadLimit;
uint32_t mIdleThreadLimit;
uint32_t mIdleThreadTimeout;
uint32_t mIdleCount;
nsCOMPtr<nsIThreadPoolListener> mListener;
bool mShutdown;
nsCString mName;
nsThreadPoolNaming mThreadNaming;
};
#define NS_THREADPOOL_CID \
{ /* 547ec2a8-315e-4ec4-888e-6e4264fe90eb */ \
0x547ec2a8, \
0x315e, \
0x4ec4, \
{0x88, 0x8e, 0x6e, 0x42, 0x64, 0xfe, 0x90, 0xeb} \
}
#endif // nsThreadPool_h__