Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(753)

Unified Diff: mojo/public/cpp/bindings/lib/sync_handle_watcher.h

Issue 1713203002: Mojo C++ bindings: support sync methods - part 2 (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: Created 4 years, 10 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
« no previous file with comments | « mojo/public/cpp/bindings/lib/router.cc ('k') | mojo/public/cpp/bindings/lib/sync_handle_watcher.cc » ('j') | no next file with comments »
Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
Index: mojo/public/cpp/bindings/lib/sync_handle_watcher.h
diff --git a/mojo/public/cpp/bindings/lib/sync_handle_watcher.h b/mojo/public/cpp/bindings/lib/sync_handle_watcher.h
new file mode 100644
index 0000000000000000000000000000000000000000..734a21289a5890f61fc6dfeb4bf30d2a059f95de
--- /dev/null
+++ b/mojo/public/cpp/bindings/lib/sync_handle_watcher.h
@@ -0,0 +1,73 @@
+// Copyright 2016 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.
+
+#ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_SYNC_HANDLE_WATCHER_H_
+#define MOJO_PUBLIC_CPP_BINDINGS_LIB_SYNC_HANDLE_WATCHER_H_
+
+#include <unordered_map>
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/message_loop/message_loop.h"
+#include "base/threading/thread_checker.h"
+#include "mojo/public/cpp/system/core.h"
+
+namespace mojo {
+namespace internal {
+
+// SyncHandleWatcher is used to support sync methods. While a sync call is
+// waiting for response, we would like incoming sync method requests on the same
+// thread to be able to reenter. We also would like master endpoints to continue
+// dispatching messages for associated endpoints on different threads.
+// Therefore, SyncHandleWatcher is used as thread-local storage to register all
+// handles that need to be watched while waiting for sync call responses.
+//
+// This class is not thread safe.
+class SyncHandleWatcher : public base::MessageLoop::DestructionObserver {
+ public:
+ // Returns a thread-local object.
+ static SyncHandleWatcher* current();
+
+ using HandleCallback = base::Callback<void(MojoResult)>;
+ bool RegisterHandle(const Handle& handle,
+ MojoHandleSignals handle_signals,
+ const HandleCallback& callback);
+
+ void UnregisterHandle(const Handle& handle);
+
+ // Waits on all the registered handles and runs callbacks synchronously for
+ // those ready handles.
+ // The method:
+ // - returns true when |*should_stop| is set to true;
+ // - returns false when either |caller_handle| is unregistered or any error
+ // occurs.
+ bool WatchAllHandles(const Handle& caller_handle, const bool* should_stop);
+
+ private:
+ struct HandleHasher {
+ size_t operator()(const Handle& handle) const {
+ return std::hash<uint32_t>()(static_cast<uint32_t>(handle.value()));
+ }
+ };
+ using HandleMap = std::unordered_map<Handle, HandleCallback, HandleHasher>;
+
+ SyncHandleWatcher();
+ ~SyncHandleWatcher() override;
+
+ // base::MessageLoop::DestructionObserver implementation:
+ void WillDestroyCurrentMessageLoop() override;
+
+ HandleMap handles_;
+
+ ScopedHandle wait_set_handle_;
+
+ base::ThreadChecker thread_checker_;
+
+ DISALLOW_COPY_AND_ASSIGN(SyncHandleWatcher);
+};
+
+} // namespace internal
+} // namespace mojo
+
+#endif // MOJO_PUBLIC_CPP_BINDINGS_LIB_SYNC_HANDLE_WATCHER_H_
« no previous file with comments | « mojo/public/cpp/bindings/lib/router.cc ('k') | mojo/public/cpp/bindings/lib/sync_handle_watcher.cc » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698