| // Copyright 2014 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 MOJO_EDK_EMBEDDER_SIMPLE_PLATFORM_SHARED_BUFFER_H_ |
| #define MOJO_EDK_EMBEDDER_SIMPLE_PLATFORM_SHARED_BUFFER_H_ |
| |
| #include <stddef.h> |
| |
| #include "mojo/edk/embedder/platform_shared_buffer.h" |
| #include "mojo/edk/system/system_impl_export.h" |
| #include "mojo/public/cpp/system/macros.h" |
| |
| namespace mojo { |
| namespace embedder { |
| |
| // A simple implementation of |PlatformSharedBuffer|. |
| class MOJO_SYSTEM_IMPL_EXPORT SimplePlatformSharedBuffer final |
| : public PlatformSharedBuffer { |
| public: |
| // Creates a shared buffer of size |num_bytes| bytes (initially zero-filled). |
| // |num_bytes| must be nonzero. Returns null on failure. |
| static SimplePlatformSharedBuffer* Create(size_t num_bytes); |
| |
| static SimplePlatformSharedBuffer* CreateFromPlatformHandle( |
| size_t num_bytes, |
| ScopedPlatformHandle platform_handle); |
| |
| // |PlatformSharedBuffer| implementation: |
| size_t GetNumBytes() const override; |
| scoped_ptr<PlatformSharedBufferMapping> Map(size_t offset, |
| size_t length) override; |
| bool IsValidMap(size_t offset, size_t length) override; |
| scoped_ptr<PlatformSharedBufferMapping> MapNoCheck(size_t offset, |
| size_t length) override; |
| ScopedPlatformHandle DuplicatePlatformHandle() override; |
| ScopedPlatformHandle PassPlatformHandle() override; |
| |
| private: |
| explicit SimplePlatformSharedBuffer(size_t num_bytes); |
| ~SimplePlatformSharedBuffer() override; |
| |
| // Implemented in simple_platform_shared_buffer_{posix,win}.cc: |
| |
| // This is called by |Create()| before this object is given to anyone. |
| bool Init(); |
| |
| // This is like |Init()|, but for |CreateFromPlatformHandle()|. (Note: It |
| // should verify that |platform_handle| is an appropriate handle for the |
| // claimed |num_bytes_|.) |
| bool InitFromPlatformHandle(ScopedPlatformHandle platform_handle); |
| |
| // The platform-dependent part of |Map()|; doesn't check arguments. |
| scoped_ptr<PlatformSharedBufferMapping> MapImpl(size_t offset, size_t length); |
| |
| const size_t num_bytes_; |
| |
| // This is set in |Init()|/|InitFromPlatformHandle()| and never modified |
| // (except by |PassPlatformHandle()|; see the comments above its declaration), |
| // hence does not need to be protected by a lock. |
| ScopedPlatformHandle handle_; |
| |
| MOJO_DISALLOW_COPY_AND_ASSIGN(SimplePlatformSharedBuffer); |
| }; |
| |
| // An implementation of |PlatformSharedBufferMapping|, produced by |
| // |SimplePlatformSharedBuffer|. |
| class MOJO_SYSTEM_IMPL_EXPORT SimplePlatformSharedBufferMapping |
| : public PlatformSharedBufferMapping { |
| public: |
| ~SimplePlatformSharedBufferMapping() override; |
| |
| void* GetBase() const override; |
| size_t GetLength() const override; |
| |
| private: |
| friend class SimplePlatformSharedBuffer; |
| |
| SimplePlatformSharedBufferMapping(void* base, |
| size_t length, |
| void* real_base, |
| size_t real_length) |
| : base_(base), |
| length_(length), |
| real_base_(real_base), |
| real_length_(real_length) {} |
| void Unmap(); |
| |
| void* const base_; |
| const size_t length_; |
| |
| void* const real_base_; |
| const size_t real_length_; |
| |
| MOJO_DISALLOW_COPY_AND_ASSIGN(SimplePlatformSharedBufferMapping); |
| }; |
| |
| } // namespace embedder |
| } // namespace mojo |
| |
| #endif // MOJO_EDK_EMBEDDER_SIMPLE_PLATFORM_SHARED_BUFFER_H_ |