Remove sandbox on Windows.

sandbox/win/src/sharedmem_ipc_client.h

-// Copyright (c) 2006-2008 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_SHAREDMEM_IPC_CLIENT_H__
-#define SANDBOX_SRC_SHAREDMEM_IPC_CLIENT_H__
-
-#include <stddef.h>
-#include <stdint.h>
-
-#include "sandbox/win/src/crosscall_params.h"
-#include "sandbox/win/src/sandbox.h"
-
-// IPC transport implementation that uses shared memory.
-// This is the client side
-//
-// The shared memory is divided on blocks called channels, and potentially
-// it can perform as many concurrent IPC calls as channels. The IPC over
-// each channel is strictly synchronous for the client.
-//
-// Each channel as a channel control section associated with. Each control
-// section has two kernel events (known as ping and pong) and a integer
-// variable that maintains a state
-//
-// this is the state diagram of a channel:
-//
-//                   locked                in service
-//     kFreeChannel---------->BusyChannel-------------->kAckChannel
-//          ^                                                 |
-//          |_________________________________________________|
-//                             answer ready
-//
-// The protocol is as follows:
-//   1) client finds a free channel: state = kFreeChannel
-//   2) does an atomic compare-and-swap, now state = BusyChannel
-//   3) client writes the data into the channel buffer
-//   4) client signals the ping event and waits (blocks) on the pong event
-//   5) eventually the server signals the pong event
-//   6) the client awakes and reads the answer from the same channel
-//   7) the client updates its InOut parameters with the new data from the
-//      shared memory section.
-//   8) the client atomically sets the state = kFreeChannel
-//
-//  In the shared memory the layout is as follows:
-//
-//    [ channel count    ]
-//    [ channel control 0]
-//    [ channel control 1]
-//    [ channel control N]
-//    [ channel buffer 0 ] 1024 bytes
-//    [ channel buffer 1 ] 1024 bytes
-//    [ channel buffer N ] 1024 bytes
-//
-// By default each channel buffer is 1024 bytes
-namespace sandbox {
-
-// the possible channel states as described above
-enum ChannelState {
-  // channel is free
-  kFreeChannel = 1,
-  // IPC in progress client side
-  kBusyChannel,
-  // IPC in progress server side
-  kAckChannel,
-  // not used right now
-  kReadyChannel,
-  // IPC abandoned by client side
-  kAbandonedChannel
-};
-
-// The next two constants control the time outs for the IPC.
-const DWORD kIPCWaitTimeOut1 = 1000;   // Milliseconds.
-const DWORD kIPCWaitTimeOut2 =   50;   // Milliseconds.
-
-// the channel control structure
-struct ChannelControl {
-  // points to be beginning of the channel buffer, where data goes
-  size_t channel_base;
-  // maintains the state from the ChannelState enumeration
-  volatile LONG state;
-  // the ping event is signaled by the client when the IPC data is ready on
-  // the buffer
-  HANDLE ping_event;
-  // the client waits on the pong event for the IPC answer back
-  HANDLE pong_event;
-  // the IPC unique identifier
-  uint32_t ipc_tag;
-};
-
-struct IPCControl {
-  // total number of channels available, some might be busy at a given time
-  size_t channels_count;
-  // handle to a shared mutex to detect when the server is dead
-  HANDLE server_alive;
-  // array of channel control structures
-  ChannelControl channels[1];
-};
-
-// the actual shared memory IPC implementation class. This object is designed
-// to be lightweight so it can be constructed on-site (at the calling place)
-// wherever an IPC call is needed.
-class SharedMemIPCClient {
- public:
-  // Creates the IPC client.
-  // as parameter it takes the base address of the shared memory
-  explicit SharedMemIPCClient(void* shared_mem);
-
-  // locks a free channel and returns the channel buffer memory base. This call
-  // blocks until there is a free channel
-  void* GetBuffer();
-
-  // releases the lock on the channel, for other to use. call this if you have
-  // called GetBuffer and you want to abort but have not called yet DoCall()
-  void FreeBuffer(void* buffer);
-
-  // Performs the actual IPC call.
-  // params: The blob of packed input parameters.
-  // answer: upon IPC completion, it contains the server answer to the IPC.
-  // If the return value is not SBOX_ERROR_CHANNEL_ERROR, the caller has to free
-  // the channel.
-  // returns ALL_OK if the IPC mechanism successfully delivered. You still need
-  // to check on the answer structure to see the actual IPC result.
-  ResultCode DoCall(CrossCallParams* params, CrossCallReturn* answer);
-
- private:
-  // Returns the index of the first free channel. It sets 'severe_failure'
-  // to true if there is an unrecoverable error that does not allow to
-  // find a channel.
-  size_t LockFreeChannel(bool* severe_failure);
-  // Return the channel index given the address of the buffer.
-  size_t ChannelIndexFromBuffer(const void* buffer);
-  IPCControl* control_;
-  // point to the first channel base
-  char* first_base_;
-};
-
-}  // namespace sandbox
-
-#endif  // SANDBOX_SRC_SHAREDMEM_IPC_CLIENT_H__