Security-57031.20.26.tar.gz

[apple/security.git] / Security / libsecurity_utilities / lib / dispatch.cpp

diff --git a/Security/libsecurity_utilities/lib/dispatch.cpp b/Security/libsecurity_utilities/lib/dispatch.cpp
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+/*
+ * Copyright (c) 2014 Apple Inc. All Rights Reserved.
+ * 
+ * @APPLE_LICENSE_HEADER_START@
+ * 
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ * 
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+//
+// dispatch - libdispatch wrapper
+//
+#include "dispatch.h"
+#include <security_utilities/errors.h>
+
+namespace Security {
+namespace Dispatch {
+
+ExceptionAwareEnqueuing::ExceptionAwareEnqueuing()
+: mExceptionPending(false)
+{ }
+
+void ExceptionAwareEnqueuing::enqueueWithDispatcher(void (^dispatcher)(dispatch_block_t), dispatch_block_t block)
+{
+       if (mExceptionPending)
+               return;
+
+       dispatcher(^{
+               if (mExceptionPending)
+                       return;
+               try {
+                       block();
+               } catch (...) {
+                       StLock<Mutex> _(mLock);
+                       mExceptionPending = true;
+                       mException = std::current_exception();
+               }
+       });
+}
+
+void ExceptionAwareEnqueuing::throwPendingException()
+{
+       if (mExceptionPending) {
+               mExceptionPending = false;
+               std::rethrow_exception(mException);
+       }
+}
+
+
+
+Queue::Queue(const char *label, bool concurrent, dispatch_qos_class_t qos_class)
+{
+       dispatch_queue_attr_t attr = concurrent ? DISPATCH_QUEUE_CONCURRENT : DISPATCH_QUEUE_SERIAL;
+       attr = dispatch_queue_attr_make_with_qos_class(attr, qos_class, 0);
+       mQueue = dispatch_queue_create(label, attr);
+}
+
+Queue::~Queue()
+{
+       dispatch_barrier_sync(mQueue, ^{});
+       dispatch_release(mQueue);
+}
+
+void Queue::enqueue(dispatch_block_t block)
+{
+       enqueuing.enqueueWithDispatcher(^(dispatch_block_t block){ dispatch_async(mQueue, block); }, block);
+}
+
+void Queue::wait()
+{
+       dispatch_barrier_sync(mQueue, ^{});
+       enqueuing.throwPendingException();
+}
+
+
+
+Group::Group()
+{
+       mGroup = dispatch_group_create();
+}
+
+Group::~Group()
+{
+       dispatch_group_wait(mGroup, DISPATCH_TIME_FOREVER);
+       dispatch_release(mGroup);
+}
+
+void Group::enqueue(dispatch_queue_t queue, dispatch_block_t block)
+{
+       enqueuing.enqueueWithDispatcher(^(dispatch_block_t block){ dispatch_group_async(mGroup, queue, block); }, block);
+}
+
+void Group::wait()
+{
+       dispatch_group_wait(mGroup, DISPATCH_TIME_FOREVER);
+       enqueuing.throwPendingException();
+}
+
+
+
+Semaphore::Semaphore(long count) {
+       mSemaphore = dispatch_semaphore_create(count);
+}
+
+Semaphore::Semaphore(Semaphore& semaphore)
+: mSemaphore(semaphore.mSemaphore)
+{
+       dispatch_retain(mSemaphore);
+}
+
+Semaphore::~Semaphore() {
+       dispatch_release(mSemaphore);
+}
+
+bool Semaphore::signal() {
+       return dispatch_semaphore_signal(mSemaphore) == 0;
+}
+
+bool Semaphore::wait(dispatch_time_t timeout) {
+       return dispatch_semaphore_wait(mSemaphore, timeout) == 0;
+}
+
+
+// Transfer ownership of held resource.
+SemaphoreWait::SemaphoreWait(SemaphoreWait &originalWait)
+: mSemaphore(originalWait.mSemaphore), mAcquired(originalWait.mAcquired)
+{
+       originalWait.mAcquired = false;
+}
+
+SemaphoreWait::SemaphoreWait(Semaphore &semaphore, dispatch_time_t timeout)
+: mSemaphore(semaphore)
+{
+       mAcquired = mSemaphore.wait(timeout);
+}
+
+SemaphoreWait::~SemaphoreWait()
+{
+       if (mAcquired)
+               mSemaphore.signal();
+}
+
+
+} // end namespace Dispatch
+} // end namespace Security