1 files changed, 330 insertions, 0 deletions
diff --git a/indra/llcommon/llthread.cpp b/indra/llcommon/llthread.cpp
new file mode 100644
index 0000000000..bd2dd7c8f5
--- /dev/null
+++ b/indra/llcommon/llthread.cpp
@@ -0,0 +1,330 @@
+/** 
+ * @file llthread.cpp
+ *
+ * Copyright (c) 2004-$CurrentYear$, Linden Research, Inc.
+ * $License$
+ */
+
+#include "linden_common.h"
+#include "llapr.h"
+
+#include "llthread.h"
+
+#include "lltimer.h"
+
+#if LL_LINUX
+#include <sched.h>
+#endif
+
+//----------------------------------------------------------------------------
+// Usage:
+// void run_func(LLThread* thread)
+// {
+// }
+// LLThread* thread = new LLThread();
+// thread->run(run_func);
+// ...
+// thread->setQuitting();
+// while(!timeout)
+// {
+//   if (thread->isStopped())
+//   {
+//     delete thread;
+//     break;
+//   }
+// }
+// 
+//----------------------------------------------------------------------------
+
+//
+// Handed to the APR thread creation function
+//
+void *APR_THREAD_FUNC LLThread::staticRun(apr_thread_t *apr_threadp, void *datap)
+{
+	LLThread *threadp = (LLThread *)datap;
+
+	// Set thread state to running
+	threadp->mStatus = RUNNING;
+
+	// 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(const std::string& name, apr_pool_t *poolp) :
+	mPaused(FALSE),
+	mName(name),
+	mAPRThreadp(NULL),
+	mStatus(STOPPED)
+{
+	// Thread creation probably CAN be paranoid about APR being initialized, if necessary
+	if (poolp)
+	{
+		mIsLocalPool = FALSE;
+		mAPRPoolp = poolp;
+	}
+	else
+	{
+		mIsLocalPool = TRUE;
+		apr_pool_create(&mAPRPoolp, NULL); // Create a subpool for this thread
+	}
+	mRunCondition = new LLCondition(mAPRPoolp);
+}
+
+
+LLThread::~LLThread()
+{
+	// 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::~LLThread() exiting thread before clean exit!" << llendl;
+			return;
+		}
+		mAPRThreadp = NULL;
+	}
+
+	delete mRunCondition;
+	
+	if (mIsLocalPool)
+	{
+		apr_pool_destroy(mAPRPoolp);
+	}
+}
+
+
+void LLThread::start()
+{
+	apr_thread_create(&mAPRThreadp, NULL, staticRun, (void *)this, mAPRPoolp);	
+
+	// We won't bother joining
+	apr_thread_detach(mAPRThreadp);
+}
+
+//============================================================================
+// 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 = 1;		// Does not need to be atomic since this is only set/unset from the main thread
+	}	
+}
+
+void LLThread::unpause()
+{
+	if (mPaused)
+	{
+		mPaused = 0;
+	}
+
+	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();
+}
+
+//============================================================================
+
+bool LLThread::isQuitting() const
+{
+	return (QUITTING == mStatus);
+}
+
+
+bool LLThread::isStopped() const
+{
+	return (STOPPED == mStatus);
+}
+
+
+void LLThread::setQuitting()
+{
+	mRunCondition->lock();
+	if (mStatus == RUNNING)
+	{
+		mStatus = QUITTING;
+	}
+	mRunCondition->unlock();
+	wake();
+}
+
+
+// static
+void LLThread::yield()
+{
+#if LL_LINUX
+	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();
+	}
+}
+
+//============================================================================
+
+LLMutex::LLMutex(apr_pool_t *poolp) :
+	mAPRMutexp(NULL)
+{
+	if (poolp)
+	{
+		mIsLocalPool = FALSE;
+		mAPRPoolp = poolp;
+	}
+	else
+	{
+		mIsLocalPool = TRUE;
+		apr_pool_create(&mAPRPoolp, NULL); // Create a subpool for this thread
+	}
+	apr_thread_mutex_create(&mAPRMutexp, APR_THREAD_MUTEX_DEFAULT, mAPRPoolp);
+}
+
+
+LLMutex::~LLMutex()
+{
+#if _DEBUG
+	llassert(!isLocked()); // better not be locked!
+#endif
+	apr_thread_mutex_destroy(mAPRMutexp);
+	mAPRMutexp = NULL;
+	if (mIsLocalPool)
+	{
+		apr_pool_destroy(mAPRPoolp);
+	}
+}
+
+
+void LLMutex::lock()
+{
+	apr_thread_mutex_lock(mAPRMutexp);
+}
+
+void LLMutex::unlock()
+{
+	apr_thread_mutex_unlock(mAPRMutexp);
+}
+
+bool LLMutex::isLocked()
+{
+	apr_status_t status = apr_thread_mutex_trylock(mAPRMutexp);
+	if (APR_STATUS_IS_EBUSY(status))
+	{
+		return true;
+	}
+	else
+	{
+		apr_thread_mutex_unlock(mAPRMutexp);
+		return false;
+	}
+}
+
+//============================================================================
+
+LLCondition::LLCondition(apr_pool_t *poolp) :
+	LLMutex(poolp)
+{
+	// base class (LLMutex) has already ensured that mAPRPoolp is set up.
+
+	apr_thread_cond_create(&mAPRCondp, mAPRPoolp);
+}
+
+
+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);
+}
+