// 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.
#ifndef SANDBOX_SRC_WIN2K_THREADPOOL_H_
#define SANDBOX_SRC_WIN2K_THREADPOOL_H_
#include <list>
#include <algorithm>
#include "sandbox/win/src/crosscall_server.h"
namespace sandbox {
// Win2kThreadPool a simple implementation of a thread provider as required
// for the sandbox IPC subsystem. See sandbox\crosscall_server.h for the details
// and requirements of this interface.
//
// Implementing the thread provider as a thread pool is desirable in the case
// of shared memory IPC because it can generate a large number of waitable
// events: as many as channels. A thread pool does not create a thread per
// event, instead maintains a few idle threads but can create more if the need
// arises.
//
// This implementation simply thunks to the nice thread pool API of win2k.
class Win2kThreadPool : public ThreadProvider {
public:
Win2kThreadPool() {
::InitializeCriticalSection(&lock_);
}
virtual ~Win2kThreadPool();
virtual bool RegisterWait(const void* cookie, HANDLE waitable_object,
CrossCallIPCCallback callback,
void* context);
virtual bool UnRegisterWaits(void* cookie);
// Returns the total number of wait objects associated with
// the thread pool.
size_t OutstandingWaits();
private:
// record to keep track of a wait and its associated cookie.
struct PoolObject {
const void* cookie;
HANDLE wait;
};
// The list of pool wait objects.
typedef std::list<PoolObject> PoolObjects;
PoolObjects pool_objects_;
// This lock protects the list of pool wait objects.
CRITICAL_SECTION lock_;
DISALLOW_COPY_AND_ASSIGN(Win2kThreadPool);
};
} // namespace sandbox
#endif // SANDBOX_SRC_WIN2K_THREADPOOL_H_