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// Copyright 2008, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef SANDBOX_SRC_WIN2K_THREADPOOL_H__
#define SANDBOX_SRC_WIN2K_THREADPOOL_H__
#include <list>
#include <algorithm>
#include "sandbox/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_);
}
~Win2kThreadPool();
virtual bool RegisterWait(const void* client, HANDLE waitable_object,
CrossCallIPCCallback callback,
void* context);
virtual bool UnRegisterWaits(void* cookie);
// Returns the total number of non-released 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_EVIL_CONSTRUCTORS(Win2kThreadPool);
};
} // namespace sandbox
#endif // SANDBOX_SRC_WIN2K_THREADPOOL_H__
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