1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/security/sandbox/win/src/win2k_threadpool.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,58 @@
1.4 +// Copyright (c) 2012 The Chromium Authors. All rights reserved.
1.5 +// Use of this source code is governed by a BSD-style license that can be
1.6 +// found in the LICENSE file.
1.7 +
1.8 +#ifndef SANDBOX_SRC_WIN2K_THREADPOOL_H_
1.9 +#define SANDBOX_SRC_WIN2K_THREADPOOL_H_
1.10 +
1.11 +#include <list>
1.12 +#include <algorithm>
1.13 +#include "sandbox/win/src/crosscall_server.h"
1.14 +
1.15 +namespace sandbox {
1.16 +
1.17 +// Win2kThreadPool a simple implementation of a thread provider as required
1.18 +// for the sandbox IPC subsystem. See sandbox\crosscall_server.h for the details
1.19 +// and requirements of this interface.
1.20 +//
1.21 +// Implementing the thread provider as a thread pool is desirable in the case
1.22 +// of shared memory IPC because it can generate a large number of waitable
1.23 +// events: as many as channels. A thread pool does not create a thread per
1.24 +// event, instead maintains a few idle threads but can create more if the need
1.25 +// arises.
1.26 +//
1.27 +// This implementation simply thunks to the nice thread pool API of win2k.
1.28 +class Win2kThreadPool : public ThreadProvider {
1.29 + public:
1.30 + Win2kThreadPool() {
1.31 + ::InitializeCriticalSection(&lock_);
1.32 + }
1.33 + virtual ~Win2kThreadPool();
1.34 +
1.35 + virtual bool RegisterWait(const void* cookie, HANDLE waitable_object,
1.36 + CrossCallIPCCallback callback,
1.37 + void* context);
1.38 +
1.39 + virtual bool UnRegisterWaits(void* cookie);
1.40 +
1.41 + // Returns the total number of wait objects associated with
1.42 + // the thread pool.
1.43 + size_t OutstandingWaits();
1.44 +
1.45 + private:
1.46 + // record to keep track of a wait and its associated cookie.
1.47 + struct PoolObject {
1.48 + const void* cookie;
1.49 + HANDLE wait;
1.50 + };
1.51 + // The list of pool wait objects.
1.52 + typedef std::list<PoolObject> PoolObjects;
1.53 + PoolObjects pool_objects_;
1.54 + // This lock protects the list of pool wait objects.
1.55 + CRITICAL_SECTION lock_;
1.56 + DISALLOW_COPY_AND_ASSIGN(Win2kThreadPool);
1.57 +};
1.58 +
1.59 +} // namespace sandbox
1.60 +
1.61 +#endif // SANDBOX_SRC_WIN2K_THREADPOOL_H_
