// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef MOJO_CORE_CORE_H_
#define MOJO_CORE_CORE_H_
#include <memory>
#include <string>
#include <string_view>
#include <vector>
#include "base/functional/callback.h"
#include "base/memory/scoped_refptr.h"
#include "base/synchronization/lock.h"
#include "base/task/single_thread_task_runner.h"
#include "build/build_config.h"
#include "mojo/core/dispatcher.h"
#include "mojo/core/handle_signals_state.h"
#include "mojo/core/handle_table.h"
#include "mojo/core/node_controller.h"
#include "mojo/core/system_impl_export.h"
#include "mojo/public/c/system/buffer.h"
#include "mojo/public/c/system/data_pipe.h"
#include "mojo/public/c/system/invitation.h"
#include "mojo/public/c/system/message_pipe.h"
#include "mojo/public/c/system/platform_handle.h"
#include "mojo/public/c/system/quota.h"
#include "mojo/public/c/system/trap.h"
#include "mojo/public/c/system/types.h"
namespace mojo {
namespace core {
class PlatformSharedMemoryMapping;
// |Core| is an object that implements the Mojo system calls. All public methods
// are thread-safe.
class MOJO_SYSTEM_IMPL_EXPORT Core {
public:
Core();
Core(const Core&) = delete;
Core& operator=(const Core&) = delete;
virtual ~Core();
static Core* Get();
// Called exactly once, shortly after construction, and before any other
// methods are called on this object.
void SetIOTaskRunner(
scoped_refptr<base::SingleThreadTaskRunner> io_task_runner);
// Retrieves the NodeController for the current process.
NodeController* GetNodeController();
scoped_refptr<Dispatcher> GetDispatcher(MojoHandle handle);
scoped_refptr<Dispatcher> GetAndRemoveDispatcher(MojoHandle handle);
// Creates a message pipe endpoint with an unbound peer port returned in
// |*peer|. Useful for setting up cross-process bootstrap message pipes. The
// returned message pipe handle is usable immediately by the caller.
//
// The value returned in |*peer| may be passed along with a broker client
// invitation. See SendBrokerClientInvitation() below.
MojoHandle CreatePartialMessagePipe(ports::PortRef* peer);
// Like above but exchanges an existing ports::PortRef for a message pipe
// handle which wraps it.
MojoHandle CreatePartialMessagePipe(const ports::PortRef& port);
// Sends a broker client invitation to |target_process| over the connection
// medium in |connection_params|. The other end of the connection medium in
// |connection_params| can be used within the target process to call
// AcceptBrokerClientInvitation() and complete the process's admission into
// this process graph.
//
// |attached_ports| is a list of named port references to be attached to the
// invitation. An attached port can be claimed (as a message pipe handle) by
// the invitee.
void SendBrokerClientInvitation(
base::Process target_process,
ConnectionParams connection_params,
const std::vector<std::pair<std::string, ports::PortRef>>& attached_ports,
const ProcessErrorCallback& process_error_callback);
// Extracts a named message pipe endpoint from the broker client invitation
// accepted by this process. Must only be called after
// AcceptBrokerClientInvitation.
MojoHandle ExtractMessagePipeFromInvitation(const std::string& name);
// Called to connect to a peer process. This should be called only if there
// is no common ancestor for the processes involved within this mojo system.
// Both processes must call this function, each passing one end of a platform
// channel. |port| is a port to be merged with the remote peer's port, which
// it will provide via the same API.
//
// |connection_name| if non-empty guarantees that no other isolated
// connections exist in the calling process using the same name. This is
// useful for invitation endpoints that use a named server accepting multiple
// connections.
void ConnectIsolated(ConnectionParams connection_params,
const ports::PortRef& port,
std::string_view connection_name);
MojoHandle AddDispatcher(scoped_refptr<Dispatcher> dispatcher);
// Adds new dispatchers for non-message-pipe handles received in a message.
// |dispatchers| and |handles| should be the same size.
bool AddDispatchersFromTransit(
const std::vector<Dispatcher::DispatcherInTransit>& dispatchers,
MojoHandle* handles);
// Marks a set of handles as busy and acquires references to each of their
// dispatchers. The caller MUST eventually call ReleaseDispatchersForTransit()
// on the resulting |*dispatchers|. Note that |*dispatchers| contents are
// extended, not replaced, by this call.
MojoResult AcquireDispatchersForTransit(
const MojoHandle* handles,
size_t num_handles,
std::vector<Dispatcher::DispatcherInTransit>* dispatchers);
// Releases dispatchers previously acquired by
// |AcquireDispatchersForTransit()|. |in_transit| should be |true| if the
// caller has fully serialized every dispatcher in |dispatchers|, in which
// case this will close and remove their handles from the handle table.
//
// If |in_transit| is false, this simply unmarks the dispatchers as busy,
// making them available for general use once again.
void ReleaseDispatchersForTransit(
const std::vector<Dispatcher::DispatcherInTransit>& dispatchers,
bool in_transit);
// Requests that the EDK tear itself down. |callback| will be called once
// the shutdown process is complete. Note that |callback| is always called
// asynchronously on the calling thread if said thread is running a message
// loop, and the calling thread must continue running a MessageLoop at least
// until the callback is called. If there is no running loop, the |callback|
// may be called from any thread. Beware!
void RequestShutdown(base::OnceClosure callback);
// ---------------------------------------------------------------------------
// The following methods are essentially implementations of the Mojo Core
// functions of the Mojo API, with the C interface translated to C++ by
// "mojo/core/embedder/entrypoints.cc". The best way to understand the
// contract of these methods is to look at the header files defining the
// corresponding API functions, referenced below.
// These methods correspond to the API functions defined in
// "mojo/public/c/system/functions.h":
MojoTimeTicks GetTimeTicksNow();
MojoResult Close(MojoHandle handle);
MojoResult QueryHandleSignalsState(MojoHandle handle,
MojoHandleSignalsState* signals_state);
MojoResult CreateTrap(MojoTrapEventHandler handler,
const MojoCreateTrapOptions* options,
MojoHandle* trap_handle);
MojoResult AddTrigger(MojoHandle trap_handle,
MojoHandle handle,
MojoHandleSignals signals,
MojoTriggerCondition condition,
uintptr_t context,
const MojoAddTriggerOptions* options);
MojoResult RemoveTrigger(MojoHandle trap_handle,
uintptr_t context,
const MojoRemoveTriggerOptions* options);
MojoResult ArmTrap(MojoHandle trap_handle,
const MojoArmTrapOptions* options,
uint32_t* num_blocking_events,
MojoTrapEvent* blocking_events);
MojoResult CreateMessage(const MojoCreateMessageOptions* options,
MojoMessageHandle* message_handle);
MojoResult DestroyMessage(MojoMessageHandle message_handle);
MojoResult SerializeMessage(MojoMessageHandle message_handle,
const MojoSerializeMessageOptions* options);
MojoResult ReserveMessageCapacity(MojoMessageHandle message_handle,
uint32_t payload_buffer_size,
uint32_t* buffer_size);
MojoResult AppendMessageData(MojoMessageHandle message_handle,
uint32_t additional_payload_size,
const MojoHandle* handles,
uint32_t num_handles,
const MojoAppendMessageDataOptions* options,
void** buffer,
uint32_t* buffer_size);
MojoResult GetMessageData(MojoMessageHandle message_handle,
const MojoGetMessageDataOptions* options,
void** buffer,
uint32_t* num_bytes,
MojoHandle* handles,
uint32_t* num_handles);
MojoResult SetMessageContext(MojoMessageHandle message_handle,
uintptr_t context,
MojoMessageContextSerializer serializer,
MojoMessageContextDestructor destructor,
const MojoSetMessageContextOptions* options);
MojoResult GetMessageContext(MojoMessageHandle message_handle,
const MojoGetMessageContextOptions* options,
uintptr_t* context);
// These methods correspond to the API functions defined in
// "mojo/public/c/system/message_pipe.h":
MojoResult CreateMessagePipe(const MojoCreateMessagePipeOptions* options,
MojoHandle* message_pipe_handle0,
MojoHandle* message_pipe_handle1);
MojoResult WriteMessage(MojoHandle message_pipe_handle,
MojoMessageHandle message_handle,
const MojoWriteMessageOptions* options);
MojoResult ReadMessage(MojoHandle message_pipe_handle,
const MojoReadMessageOptions* options,
MojoMessageHandle* message_handle);
MojoResult FuseMessagePipes(MojoHandle handle0,
MojoHandle handle1,
const MojoFuseMessagePipesOptions* options);
MojoResult NotifyBadMessage(MojoMessageHandle message_handle,
const char* error,
size_t error_num_bytes,
const MojoNotifyBadMessageOptions* options);
// These methods correspond to the API functions defined in
// "mojo/public/c/system/data_pipe.h":
MojoResult CreateDataPipe(const MojoCreateDataPipeOptions* options,
MojoHandle* data_pipe_producer_handle,
MojoHandle* data_pipe_consumer_handle);
MojoResult WriteData(MojoHandle data_pipe_producer_handle,
const void* elements,
uint32_t* num_bytes,
const MojoWriteDataOptions* options);
MojoResult BeginWriteData(MojoHandle data_pipe_producer_handle,
const MojoBeginWriteDataOptions* options,
void** buffer,
uint32_t* buffer_num_bytes);
MojoResult EndWriteData(MojoHandle data_pipe_producer_handle,
uint32_t num_bytes_written,
const MojoEndWriteDataOptions* options);
MojoResult ReadData(MojoHandle data_pipe_consumer_handle,
const MojoReadDataOptions* options,
void* elements,
uint32_t* num_bytes);
MojoResult BeginReadData(MojoHandle data_pipe_consumer_handle,
const MojoBeginReadDataOptions* options,
const void** buffer,
uint32_t* buffer_num_bytes);
MojoResult EndReadData(MojoHandle data_pipe_consumer_handle,
uint32_t num_bytes_read,
const MojoEndReadDataOptions* options);
// These methods correspond to the API functions defined in
// "mojo/public/c/system/buffer.h":
MojoResult CreateSharedBuffer(uint64_t num_bytes,
const MojoCreateSharedBufferOptions* options,
MojoHandle* shared_buffer_handle);
MojoResult DuplicateBufferHandle(
MojoHandle buffer_handle,
const MojoDuplicateBufferHandleOptions* options,
MojoHandle* new_buffer_handle);
MojoResult MapBuffer(MojoHandle buffer_handle,
uint64_t offset,
uint64_t num_bytes,
const MojoMapBufferOptions* options,
void** buffer);
MojoResult UnmapBuffer(void* buffer);
MojoResult GetBufferInfo(MojoHandle buffer_handle,
const MojoGetBufferInfoOptions* options,
MojoSharedBufferInfo* info);
// These methods correspond to the API functions defined in
// "mojo/public/c/system/platform_handle.h".
MojoResult WrapPlatformHandle(const MojoPlatformHandle* platform_handle,
const MojoWrapPlatformHandleOptions* options,
MojoHandle* mojo_handle);
MojoResult UnwrapPlatformHandle(
MojoHandle mojo_handle,
const MojoUnwrapPlatformHandleOptions* options,
MojoPlatformHandle* platform_handle);
MojoResult WrapPlatformSharedMemoryRegion(
const MojoPlatformHandle* platform_handles,
uint32_t num_platform_handles,
uint64_t size,
const MojoSharedBufferGuid* guid,
MojoPlatformSharedMemoryRegionAccessMode access_mode,
const MojoWrapPlatformSharedMemoryRegionOptions* options,
MojoHandle* mojo_handle);
MojoResult UnwrapPlatformSharedMemoryRegion(
MojoHandle mojo_handle,
const MojoUnwrapPlatformSharedMemoryRegionOptions* options,
MojoPlatformHandle* platform_handles,
uint32_t* num_platform_handles,
uint64_t* size,
MojoSharedBufferGuid* guid,
MojoPlatformSharedMemoryRegionAccessMode* access_mode);
// Invitation API.
MojoResult CreateInvitation(const MojoCreateInvitationOptions* options,
MojoHandle* invitation_handle);
MojoResult AttachMessagePipeToInvitation(
MojoHandle invitation_handle,
const void* name,
uint32_t name_num_bytes,
const MojoAttachMessagePipeToInvitationOptions* options,
MojoHandle* message_pipe_handle);
MojoResult ExtractMessagePipeFromInvitation(
MojoHandle invitation_handle,
const void* name,
uint32_t name_num_bytes,
const MojoExtractMessagePipeFromInvitationOptions* options,
MojoHandle* message_pipe_handle);
MojoResult SendInvitation(
MojoHandle invitation_handle,
const MojoPlatformProcessHandle* process_handle,
const MojoInvitationTransportEndpoint* transport_endpoint,
MojoProcessErrorHandler error_handler,
uintptr_t error_handler_context,
const MojoSendInvitationOptions* options);
MojoResult AcceptInvitation(
const MojoInvitationTransportEndpoint* transport_endpoint,
const MojoAcceptInvitationOptions* options,
MojoHandle* invitation_handle);
// Quota API.
MojoResult SetQuota(MojoHandle handle,
MojoQuotaType type,
uint64_t limit,
const MojoSetQuotaOptions* options);
MojoResult QueryQuota(MojoHandle handle,
MojoQuotaType type,
const MojoQueryQuotaOptions* options,
uint64_t* limit,
uint64_t* usage);
MojoResult SetDefaultProcessErrorHandler(
MojoDefaultProcessErrorHandler handler,
const MojoSetDefaultProcessErrorHandlerOptions* options);
void GetActiveHandlesForTest(std::vector<MojoHandle>* handles);
private:
// Used to pass ownership of our NodeController over to the IO thread in the
// event that we're torn down before said thread.
static void PassNodeControllerToIOThread(
std::unique_ptr<NodeController> node_controller);
// Guards node_controller_.
//
// TODO(rockot): Consider removing this. It's only needed because we
// initialize node_controller_ lazily and that may happen on any thread.
// Otherwise it's effectively const and shouldn't need to be guarded.
//
// We can get rid of lazy initialization if we defer Mojo initialization far
// enough that zygotes don't do it. The zygote can't create a NodeController.
base::Lock node_controller_lock_;
// This is lazily initialized on first access. Always use GetNodeController()
// to access it.
std::unique_ptr<NodeController> node_controller_;
// The default callback to invoke, if any, when a process error is reported
// but cannot be associated with a specific process.
ProcessErrorCallback default_process_error_callback_;
std::unique_ptr<HandleTable> handles_;
base::Lock mapping_table_lock_; // Protects |mapping_table_|.
using MappingTable =
std::unordered_map<void*, std::unique_ptr<PlatformSharedMemoryMapping>>;
MappingTable mapping_table_;
};
} // namespace core
} // namespace mojo
#endif // MOJO_CORE_CORE_H_