start of a thread safe queue

1 files changed, 109 insertions, 0 deletions

diff --git a/indra/llcommon/llthreadsafequeue.cpp b/indra/llcommon/llthreadsafequeue.cpp
new file mode 100644
index 0000000000..a7141605ef
--- /dev/null
+++ b/indra/llcommon/llthreadsafequeue.cpp
@@ -0,0 +1,109 @@
+/** 
+ * @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 <apr_pools.h>
+#include <apr_queue.h>
+#include "llthreadsafequeue.h"
+
+
+
+// LLThreadSafeQueueImplementation
+//-----------------------------------------------------------------------------
+
+
+LLThreadSafeQueueImplementation::LLThreadSafeQueueImplementation(apr_pool_t * pool, unsigned int capacity):
+	mOwnsPool(pool == 0),
+	mPool(pool),
+	mQueue(0)
+{
+	if(mOwnsPool) {
+		apr_status_t status = apr_pool_create(&mPool, 0);
+		if(status != APR_SUCCESS) throw LLThreadSafeQueueError("failed to allocate pool");
+	} else {
+		; // No op.
+	}
+	
+	apr_status_t status = apr_queue_create(&mQueue, capacity, mPool);
+	if(status != APR_SUCCESS) throw LLThreadSafeQueueError("failed to allocate queue");
+}
+
+
+LLThreadSafeQueueImplementation::~LLThreadSafeQueueImplementation()
+{
+	if(mOwnsPool && (mPool != 0)) apr_pool_destroy(mPool);
+	if(mQueue != 0) {
+		if(apr_queue_size(mQueue) != 0) llwarns << 
+			"terminating queue which still contains elements;" << 
+			"memory will be leaked" << LL_ENDL;
+		apr_queue_term(mQueue);
+	}
+}
+
+
+void LLThreadSafeQueueImplementation::pushFront(void * element)
+{
+	apr_status_t status = apr_queue_push(mQueue, element);
+	
+	if(status == APR_EINTR) {
+		throw LLThreadSafeQueueInterrupt();
+	} else if(status != APR_SUCCESS) {
+		throw LLThreadSafeQueueError("push failed");
+	} else {
+		; // Success.
+	}
+}
+
+
+bool LLThreadSafeQueueImplementation::tryPushFront(void * element){
+	return apr_queue_trypush(mQueue, element) == APR_SUCCESS;
+}
+
+
+void * LLThreadSafeQueueImplementation::popBack(void)
+{
+	void * element;
+	apr_status_t status = apr_queue_pop(mQueue, &element);
+
+	if(status == APR_EINTR) {
+		throw LLThreadSafeQueueInterrupt();
+	} else if(status != APR_SUCCESS) {
+		throw LLThreadSafeQueueError("pop failed");
+	} else {
+		return element;
+	}
+}
+
+
+bool LLThreadSafeQueueImplementation::tryPopBack(void *& element)
+{
+	return apr_queue_trypop(mQueue, &element) == APR_SUCCESS;
+}
+
+
+size_t LLThreadSafeQueueImplementation::size()
+{
+	return apr_queue_size(mQueue);
+}