Reland of Split iOS sdk in to separate targets

webrtc/sdk/objc/Framework/Classes/Common/RTCDispatcher.m

Index: webrtc/sdk/objc/Framework/Classes/Common/RTCDispatcher.m
diff --git a/webrtc/sdk/objc/Framework/Classes/Common/RTCDispatcher.m b/webrtc/sdk/objc/Framework/Classes/Common/RTCDispatcher.m
new file mode 100644
index 0000000000000000000000000000000000000000..530e51a3c94bc812425e5c00696245781f5d819d
--- /dev/null
+++ b/webrtc/sdk/objc/Framework/Classes/Common/RTCDispatcher.m
@@ -0,0 +1,61 @@
+/*
+ *  Copyright 2015 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#import "RTCDispatcher+Private.h"
+
+static dispatch_queue_t kAudioSessionQueue = nil;
+static dispatch_queue_t kCaptureSessionQueue = nil;
+
+@implementation RTCDispatcher
+
++ (void)initialize {
+  static dispatch_once_t onceToken;
+  dispatch_once(&onceToken, ^{
+    kAudioSessionQueue = dispatch_queue_create(
+        "org.webrtc.RTCDispatcherAudioSession",
+        DISPATCH_QUEUE_SERIAL);
+    kCaptureSessionQueue = dispatch_queue_create(
+        "org.webrtc.RTCDispatcherCaptureSession",
+        DISPATCH_QUEUE_SERIAL);
+  });
+}
+
++ (void)dispatchAsyncOnType:(RTCDispatcherQueueType)dispatchType
+                      block:(dispatch_block_t)block {
+  dispatch_queue_t queue = [self dispatchQueueForType:dispatchType];
+  dispatch_async(queue, block);
+}
+
++ (BOOL)isOnQueueForType:(RTCDispatcherQueueType)dispatchType {
+  dispatch_queue_t targetQueue = [self dispatchQueueForType:dispatchType];
+  const char* targetLabel = dispatch_queue_get_label(targetQueue);
+  const char* currentLabel = dispatch_queue_get_label(DISPATCH_CURRENT_QUEUE_LABEL);
+
+  NSAssert(strlen(targetLabel) > 0, @"Label is required for the target queue.");
+  NSAssert(strlen(currentLabel) > 0, @"Label is required for the current queue.");
+
+  return strcmp(targetLabel, currentLabel) == 0;
+}
+
+#pragma mark - Private
+
++ (dispatch_queue_t)dispatchQueueForType:(RTCDispatcherQueueType)dispatchType {
+  switch (dispatchType) {
+    case RTCDispatcherTypeMain:
+      return dispatch_get_main_queue();
+    case RTCDispatcherTypeCaptureSession:
+      return kCaptureSessionQueue;
+    case RTCDispatcherTypeAudioSession:
+      return kAudioSessionQueue;
+  }
+}
+
+@end
+