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// 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_CORE_SHARED_BUFFER_DISPATCHER_H_
#define MOJO_CORE_SHARED_BUFFER_DISPATCHER_H_
#include <stddef.h>
#include <stdint.h>
#include <utility>
#include "base/macros.h"
#include "base/memory/platform_shared_memory_region.h"
#include "mojo/core/dispatcher.h"
#include "mojo/core/system_impl_export.h"
namespace mojo {
namespace core {
class NodeController;
class PlatformSharedMemoryMapping;
class MOJO_SYSTEM_IMPL_EXPORT SharedBufferDispatcher final : public Dispatcher {
public:
// The default options to use for |MojoCreateSharedBuffer()|. (Real uses
// should obtain this via |ValidateCreateOptions()| with a null |in_options|;
// this is exposed directly for testing convenience.)
static const MojoCreateSharedBufferOptions kDefaultCreateOptions;
// Validates and/or sets default options for |MojoCreateSharedBufferOptions|.
// If non-null, |in_options| must point to a struct of at least
// |in_options->struct_size| bytes. |out_options| must point to a (current)
// |MojoCreateSharedBufferOptions| and will be entirely overwritten on success
// (it may be partly overwritten on failure).
static MojoResult ValidateCreateOptions(
const MojoCreateSharedBufferOptions* in_options,
MojoCreateSharedBufferOptions* out_options);
// Static factory method: |validated_options| must be validated (obviously).
// On failure, |*result| will be left as-is.
// TODO(vtl): This should probably be made to return a scoped_refptr and have
// a MojoResult out parameter instead.
static MojoResult Create(
const MojoCreateSharedBufferOptions& validated_options,
NodeController* node_controller,
uint64_t num_bytes,
scoped_refptr<SharedBufferDispatcher>* result);
// Create a |SharedBufferDispatcher| from |shared_buffer|.
static MojoResult CreateFromPlatformSharedMemoryRegion(
base::subtle::PlatformSharedMemoryRegion region,
scoped_refptr<SharedBufferDispatcher>* result);
// The "opposite" of SerializeAndClose(). Called by Dispatcher::Deserialize().
static scoped_refptr<SharedBufferDispatcher> Deserialize(
const void* bytes,
size_t num_bytes,
const ports::PortName* ports,
size_t num_ports,
PlatformHandle* platform_handles,
size_t num_handles);
// Passes the underlying PlatformSharedMemoryRegion. This dispatcher must be
// closed after calling this function.
base::subtle::PlatformSharedMemoryRegion PassPlatformSharedMemoryRegion();
// NOTE: This is not thread-safe. Definitely never use it outside of tests.
base::subtle::PlatformSharedMemoryRegion& GetRegionForTesting() {
return region_;
}
// Dispatcher:
Type GetType() const override;
MojoResult Close() override;
MojoResult DuplicateBufferHandle(
const MojoDuplicateBufferHandleOptions* options,
scoped_refptr<Dispatcher>* new_dispatcher) override;
MojoResult MapBuffer(
uint64_t offset,
uint64_t num_bytes,
std::unique_ptr<PlatformSharedMemoryMapping>* mapping) override;
MojoResult GetBufferInfo(MojoSharedBufferInfo* info) override;
void StartSerialize(uint32_t* num_bytes,
uint32_t* num_ports,
uint32_t* num_platform_handles) override;
bool EndSerialize(void* destination,
ports::PortName* ports,
PlatformHandle* handles) override;
bool BeginTransit() override;
void CompleteTransitAndClose() override;
void CancelTransit() override;
private:
explicit SharedBufferDispatcher(
base::subtle::PlatformSharedMemoryRegion region);
~SharedBufferDispatcher() override;
static scoped_refptr<SharedBufferDispatcher> CreateInternal(
base::subtle::PlatformSharedMemoryRegion region);
// Validates and/or sets default options for
// |MojoDuplicateBufferHandleOptions|. If non-null, |in_options| must point to
// a struct of at least |in_options->struct_size| bytes. |out_options| must
// point to a (current) |MojoDuplicateBufferHandleOptions| and will be
// entirely overwritten on success (it may be partly overwritten on failure).
static MojoResult ValidateDuplicateOptions(
const MojoDuplicateBufferHandleOptions* in_options,
MojoDuplicateBufferHandleOptions* out_options);
// Guards access to the fields below.
base::Lock lock_;
bool in_transit_ = false;
base::subtle::PlatformSharedMemoryRegion region_;
DISALLOW_COPY_AND_ASSIGN(SharedBufferDispatcher);
};
} // namespace core
} // namespace mojo
#endif // MOJO_CORE_SHARED_BUFFER_DISPATCHER_H_