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// 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.
#include <map>
#include <unordered_map>
#include "base/callback.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/synchronization/waitable_event.h"
#include "base/threading/thread_checker.h"
#include "mojo/public/cpp/bindings/bindings_export.h"
#include "mojo/public/cpp/system/core.h"
#include "mojo/public/cpp/system/wait_set.h"
namespace mojo {
// SyncHandleRegistry is a thread-local storage to register handles that want to
// be watched together.
// This class is not thread safe.
class MOJO_CPP_BINDINGS_EXPORT SyncHandleRegistry
: public base::RefCounted<SyncHandleRegistry> {
// Returns a thread-local object.
static scoped_refptr<SyncHandleRegistry> current();
using HandleCallback = base::Callback<void(MojoResult)>;
bool RegisterHandle(const Handle& handle,
MojoHandleSignals handle_signals,
const HandleCallback& callback);
void UnregisterHandle(const Handle& handle);
// Registers a |base::WaitableEvent| which can be used to wake up
// Wait() before any handle signals. |event| is not owned, and if it signals
// during Wait(), |callback| is invoked. Returns |true| if registered
// successfully or |false| if |event| was already registered.
bool RegisterEvent(base::WaitableEvent* event, const base::Closure& callback);
void UnregisterEvent(base::WaitableEvent* event);
// Waits on all the registered handles and events and runs callbacks
// synchronously for any that become ready.
// The method:
// - returns true when any element of |should_stop| is set to true;
// - returns false when any error occurs.
bool Wait(const bool* should_stop[], size_t count);
friend class base::RefCounted<SyncHandleRegistry>;
WaitSet wait_set_;
std::map<Handle, HandleCallback> handles_;
std::map<base::WaitableEvent*, base::Closure> events_;
base::ThreadChecker thread_checker_;
} // namespace mojo