Pepper: Introduce ThreadAwareCallback.

ppapi/shared_impl/thread_aware_callback.cc

Index: ppapi/shared_impl/thread_aware_callback.cc
diff --git a/ppapi/shared_impl/thread_aware_callback.cc b/ppapi/shared_impl/thread_aware_callback.cc
new file mode 100644
index 0000000000000000000000000000000000000000..9b1063b3b2fd990835b734dec9618012060f830e
--- /dev/null
+++ b/ppapi/shared_impl/thread_aware_callback.cc
@@ -0,0 +1,63 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ppapi/shared_impl/thread_aware_callback.h"
+
+#include "base/callback.h"
+#include "base/logging.h"
+#include "ppapi/shared_impl/ppapi_globals.h"
+#include "ppapi/shared_impl/ppb_message_loop_shared.h"
+
+namespace ppapi {
+namespace internal {
+
+class ThreadAwareCallbackBase::Core : public base::RefCountedThreadSafe<Core> {
+ public:
+  Core() : aborted_(false) {
+  }
+
+  void MarkAsAborted() { aborted_ = true; }
+
+  void RunIfNotAborted(const base::Closure& closure) {
+    if (!aborted_)
+      CallWhileUnlocked(closure);
+  }
+
+ private:
+  friend class base::RefCountedThreadSafe<Core>;
+  ~Core() {
+  }
+
+  bool aborted_;
+};
+
+ThreadAwareCallbackBase::ThreadAwareCallbackBase()
+    : target_loop_(PpapiGlobals::Get()->GetCurrentMessageLoop()),
+      core_(new Core()) {
+  DCHECK(target_loop_.get());
+}
+
+ThreadAwareCallbackBase::~ThreadAwareCallbackBase() {
+  core_->MarkAsAborted();
+}
+
+// static
+bool ThreadAwareCallbackBase::HasTargetLoop() {
+  return !!PpapiGlobals::Get()->GetCurrentMessageLoop();
+}
+
+void ThreadAwareCallbackBase::InternalRunOnTargetThread(
+    const base::Closure& closure) {
+  if (target_loop_ != PpapiGlobals::Get()->GetCurrentMessageLoop()) {
+    target_loop_->PostClosure(
+        FROM_HERE,
+        RunWhileLocked(base::Bind(&Core::RunIfNotAborted, core_, closure)),
+        0);
+  } else {
+    CallWhileUnlocked(closure);
+  }
+}
+
+}  // namespace internal
+}  // namespace ppapi