[email protected] | 8c197e50 | 2012-11-20 20:32:30 | [diff] [blame] | 1 | // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #ifndef REMOTING_BASE_SHARED_BUFFER_H_ |
| 6 | #define REMOTING_BASE_SHARED_BUFFER_H_ |
| 7 | |
| 8 | #include "base/basictypes.h" |
| 9 | #include "base/memory/ref_counted.h" |
| 10 | #include "base/process.h" |
| 11 | #include "base/shared_memory.h" |
| 12 | |
| 13 | namespace remoting { |
| 14 | |
| 15 | // Represents a memory buffer that can be shared between multiple processes. |
| 16 | // It is more or less a convenience wrapper around base::SharedMemory providing |
| 17 | // ref-counted lifetime management and unique buffer identifiers. |
| 18 | class SharedBuffer |
| 19 | : public base::RefCountedThreadSafe<SharedBuffer> { |
| 20 | public: |
| 21 | // Creates a new shared memory buffer of the given size and maps it to |
| 22 | // the memory of the calling process. If the operation fails for any reason, |
| 23 | // ptr() method will return NULL. This constructor set the identifier of this |
| 24 | // buffer to 0. |
| 25 | explicit SharedBuffer(uint32 size); |
| 26 | |
| 27 | // Opens an existing shared memory buffer and maps it to the memory of |
| 28 | // the calling process (in read only mode). If the operation fails for any |
| 29 | // reason, ptr() method will return NULL. |
[email protected] | ff72dd1 | 2012-11-27 05:18:25 | [diff] [blame^] | 30 | SharedBuffer(int id, base::SharedMemoryHandle handle, uint32 size); |
[email protected] | 8c197e50 | 2012-11-20 20:32:30 | [diff] [blame] | 31 | |
| 32 | // Opens an existing shared memory buffer created by a different process and |
| 33 | // maps it to the memory of the calling process (in read only mode). If |
| 34 | // the operation fails for any reason, ptr() method will return NULL. |
[email protected] | ff72dd1 | 2012-11-27 05:18:25 | [diff] [blame^] | 35 | SharedBuffer(int id, base::SharedMemoryHandle handle, |
[email protected] | 8c197e50 | 2012-11-20 20:32:30 | [diff] [blame] | 36 | base::ProcessHandle process, uint32 size); |
| 37 | |
| 38 | // Returns pointer to the beginning of the allocated data buffer. Returns NULL |
| 39 | // if the object initialization failed for any reason. |
| 40 | void* ptr() const { return shared_memory_.memory(); } |
| 41 | |
| 42 | // Returns handle of the shared memory section containing the allocated |
| 43 | // data buffer. |
| 44 | base::SharedMemoryHandle handle() const { return shared_memory_.handle(); } |
| 45 | |
[email protected] | ff72dd1 | 2012-11-27 05:18:25 | [diff] [blame^] | 46 | int id() const { return id_; } |
[email protected] | 8c197e50 | 2012-11-20 20:32:30 | [diff] [blame] | 47 | uint32 size() const { return size_; } |
| 48 | |
[email protected] | ff72dd1 | 2012-11-27 05:18:25 | [diff] [blame^] | 49 | void set_id(int id) { id_ = id; } |
[email protected] | 8c197e50 | 2012-11-20 20:32:30 | [diff] [blame] | 50 | |
| 51 | private: |
| 52 | friend class base::RefCountedThreadSafe<SharedBuffer>; |
| 53 | virtual ~SharedBuffer(); |
| 54 | |
| 55 | // Unique identifier of the buffer or 0 if ID hasn't been set. |
[email protected] | ff72dd1 | 2012-11-27 05:18:25 | [diff] [blame^] | 56 | int id_; |
[email protected] | 8c197e50 | 2012-11-20 20:32:30 | [diff] [blame] | 57 | |
| 58 | // Shared memory section backing up the buffer. |
| 59 | base::SharedMemory shared_memory_; |
| 60 | |
| 61 | // Size of the buffer in bytes. |
| 62 | uint32 size_; |
| 63 | |
| 64 | DISALLOW_COPY_AND_ASSIGN(SharedBuffer); |
| 65 | }; |
| 66 | |
| 67 | } // namespace remoting |
| 68 | |
| 69 | #endif // REMOTING_BASE_SHARED_BUFFER_H_ |