phoenix-firestorm/indra/llcommon/llthread.cpp

461 lines
9.9 KiB
C++

/**
* @file llthread.cpp
*
* $LicenseInfo:firstyear=2004&license=viewerlgpl$
* Second Life Viewer Source Code
* Copyright (C) 2010, Linden Research, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License only.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
* $/LicenseInfo$
*/
#include "linden_common.h"
#include "llapr.h"
#include "apr_portable.h"
#include "llthread.h"
#include "lltimer.h"
#if LL_LINUX || LL_SOLARIS
#include <sched.h>
#endif
#if !LL_DARWIN
U32 ll_thread_local local_thread_ID = 0;
#endif
U32 LLThread::sIDIter = 0;
//----------------------------------------------------------------------------
// Usage:
// void run_func(LLThread* thread)
// {
// }
// LLThread* thread = new LLThread();
// thread->run(run_func);
// ...
// thread->setQuitting();
// while(!timeout)
// {
// if (thread->isStopped())
// {
// delete thread;
// break;
// }
// }
//
//----------------------------------------------------------------------------
LL_COMMON_API void assert_main_thread()
{
static U32 s_thread_id = LLThread::currentID();
if (LLThread::currentID() != s_thread_id)
{
llerrs << "Illegal execution outside main thread." << llendl;
}
}
//
// Handed to the APR thread creation function
//
void *APR_THREAD_FUNC LLThread::staticRun(apr_thread_t *apr_threadp, void *datap)
{
LLThread *threadp = (LLThread *)datap;
#if !LL_DARWIN
local_thread_ID = threadp->mID;
#endif
// Create a thread local data.
LLThreadLocalData::create(threadp);
// Run the user supplied function
threadp->run();
//llinfos << "LLThread::staticRun() Exiting: " << threadp->mName << llendl;
// We're done with the run function, this thread is done executing now.
threadp->mStatus = STOPPED;
return NULL;
}
LLThread::LLThread(std::string const& name) :
mPaused(false),
mName(name),
mAPRThreadp(NULL),
mStatus(STOPPED),
mThreadLocalData(NULL)
{
mID = ++sIDIter; //flaw: assume this is called only in the main thread!
mRunCondition = new LLCondition;
}
LLThread::~LLThread()
{
shutdown();
}
void LLThread::shutdown()
{
// Warning! If you somehow call the thread destructor from itself,
// the thread will die in an unclean fashion!
if (mAPRThreadp)
{
if (!isStopped())
{
// The thread isn't already stopped
// First, set the flag that indicates that we're ready to die
setQuitting();
//llinfos << "LLThread::~LLThread() Killing thread " << mName << " Status: " << mStatus << llendl;
// Now wait a bit for the thread to exit
// It's unclear whether I should even bother doing this - this destructor
// should netver get called unless we're already stopped, really...
S32 counter = 0;
const S32 MAX_WAIT = 600;
while (counter < MAX_WAIT)
{
if (isStopped())
{
break;
}
// Sleep for a tenth of a second
ms_sleep(100);
yield();
counter++;
}
}
if (!isStopped())
{
// This thread just wouldn't stop, even though we gave it time
//llwarns << "LLThread::shutdown() exiting thread before clean exit!" << llendl;
// Put a stake in its heart.
apr_thread_exit(mAPRThreadp, -1);
return;
}
mAPRThreadp = NULL;
}
delete mRunCondition;
mRunCondition = 0;
}
void LLThread::start()
{
llassert(isStopped());
// Set thread state to running
mStatus = RUNNING;
apr_status_t status =
apr_thread_create(&mAPRThreadp, NULL, staticRun, (void *)this, tldata().mRootPool());
if(status == APR_SUCCESS)
{
// We won't bother joining
apr_thread_detach(mAPRThreadp);
}
else
{
mStatus = STOPPED;
llwarns << "failed to start thread " << mName << llendl;
ll_apr_warn_status(status);
}
}
//============================================================================
// Called from MAIN THREAD.
// Request that the thread pause/resume.
// The thread will pause when (and if) it calls checkPause()
void LLThread::pause()
{
if (!mPaused)
{
// this will cause the thread to stop execution as soon as checkPause() is called
mPaused = true; // Does not need to be atomic since this is only set/unset from the main thread
}
}
void LLThread::unpause()
{
if (mPaused)
{
mPaused = false;
}
wake(); // wake up the thread if necessary
}
// virtual predicate function -- returns true if the thread should wake up, false if it should sleep.
bool LLThread::runCondition(void)
{
// by default, always run. Handling of pause/unpause is done regardless of this function's result.
return true;
}
//============================================================================
// Called from run() (CHILD THREAD).
// Stop thread execution if requested until unpaused.
void LLThread::checkPause()
{
mRunCondition->lock();
// This is in a while loop because the pthread API allows for spurious wakeups.
while(shouldSleep())
{
mRunCondition->wait(); // unlocks mRunCondition
// mRunCondition is locked when the thread wakes up
}
mRunCondition->unlock();
}
//============================================================================
void LLThread::setQuitting()
{
mRunCondition->lock();
if (mStatus == RUNNING)
{
mStatus = QUITTING;
}
mRunCondition->unlock();
wake();
}
// static
U32 LLThread::currentID()
{
return (U32)apr_os_thread_current();
}
// static
void LLThread::yield()
{
#if LL_LINUX || LL_SOLARIS
sched_yield(); // annoyingly, apr_thread_yield is a noop on linux...
#else
apr_thread_yield();
#endif
}
void LLThread::wake()
{
mRunCondition->lock();
if(!shouldSleep())
{
mRunCondition->signal();
}
mRunCondition->unlock();
}
void LLThread::wakeLocked()
{
if(!shouldSleep())
{
mRunCondition->signal();
}
}
#ifdef SHOW_ASSERT
// This allows the use of llassert(is_main_thread()) to assure the current thread is the main thread.
static apr_os_thread_t main_thread_id;
LL_COMMON_API bool is_main_thread(void) { return apr_os_thread_equal(main_thread_id, apr_os_thread_current()); }
#endif
// The thread private handle to access the LLThreadLocalData instance.
apr_threadkey_t* LLThreadLocalData::sThreadLocalDataKey;
//static
void LLThreadLocalData::init(void)
{
// Only do this once.
if (sThreadLocalDataKey)
{
return;
}
apr_status_t status = apr_threadkey_private_create(&sThreadLocalDataKey, &LLThreadLocalData::destroy, LLAPRRootPool::get()());
ll_apr_assert_status(status); // Or out of memory, or system-imposed limit on the
// total number of keys per process {PTHREAD_KEYS_MAX}
// has been exceeded.
// Create the thread-local data for the main thread (this function is called by the main thread).
LLThreadLocalData::create(NULL);
#ifdef SHOW_ASSERT
// This function is called by the main thread.
main_thread_id = apr_os_thread_current();
#endif
}
// This is called once for every thread when the thread is destructed.
//static
void LLThreadLocalData::destroy(void* thread_local_data)
{
delete static_cast<LLThreadLocalData*>(thread_local_data);
}
//static
void LLThreadLocalData::create(LLThread* threadp)
{
LLThreadLocalData* new_tld = new LLThreadLocalData;
if (threadp)
{
threadp->mThreadLocalData = new_tld;
}
apr_status_t status = apr_threadkey_private_set(new_tld, sThreadLocalDataKey);
llassert_always(status == APR_SUCCESS);
}
//static
LLThreadLocalData& LLThreadLocalData::tldata(void)
{
if (!sThreadLocalDataKey)
{
LLThreadLocalData::init();
}
void* data;
apr_status_t status = apr_threadkey_private_get(&data, sThreadLocalDataKey);
llassert_always(status == APR_SUCCESS);
return *static_cast<LLThreadLocalData*>(data);
}
//============================================================================
LLCondition::LLCondition(LLAPRPool& parent) : LLMutex(parent)
{
apr_thread_cond_create(&mAPRCondp, mPool());
}
LLCondition::~LLCondition()
{
apr_thread_cond_destroy(mAPRCondp);
mAPRCondp = NULL;
}
void LLCondition::wait()
{
apr_thread_cond_wait(mAPRCondp, mAPRMutexp);
}
void LLCondition::signal()
{
apr_thread_cond_signal(mAPRCondp);
}
void LLCondition::broadcast()
{
apr_thread_cond_broadcast(mAPRCondp);
}
//============================================================================
LLMutexBase::LLMutexBase() :
mLockingThread(NO_THREAD),
mCount(0)
{
}
void LLMutexBase::lock()
{
#if LL_DARWIN
if (mLockingThread == LLThread::currentID())
#else
if (mLockingThread == local_thread_ID)
#endif
{ //redundant lock
mCount++;
return;
}
apr_thread_mutex_lock(mAPRMutexp);
#if LL_DARWIN
mLockingThread = LLThread::currentID();
#else
mLockingThread = local_thread_ID;
#endif
}
void LLMutexBase::unlock()
{
if (mCount > 0)
{ //not the root unlock
mCount--;
return;
}
mLockingThread = NO_THREAD;
apr_thread_mutex_unlock(mAPRMutexp);
}
//----------------------------------------------------------------------------
//static
LLMutex* LLThreadSafeRefCount::sMutex = 0;
//static
void LLThreadSafeRefCount::initThreadSafeRefCount()
{
if (!sMutex)
{
sMutex = new LLMutex;
}
}
//static
void LLThreadSafeRefCount::cleanupThreadSafeRefCount()
{
delete sMutex;
sMutex = NULL;
}
//----------------------------------------------------------------------------
LLThreadSafeRefCount::LLThreadSafeRefCount() :
mRef(0)
{
}
LLThreadSafeRefCount::~LLThreadSafeRefCount()
{
if (mRef != 0)
{
llerrs << "deleting non-zero reference" << llendl;
}
}
//============================================================================
LLResponder::~LLResponder()
{
}
//============================================================================