| // Copyright 2013 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_PUBLIC_SYSTEM_CORE_H_ |
| #define MOJO_PUBLIC_SYSTEM_CORE_H_ |
| |
| // Note: This header should be compilable as C. |
| |
| #include <stdint.h> |
| |
| #include "mojo/public/system/macros.h" |
| #include "mojo/public/system/system_export.h" |
| |
| // Types/constants ------------------------------------------------------------- |
| |
| // TODO(vtl): Notes: Use of undefined flags will lead to undefined behavior |
| // (typically they'll be ignored), not necessarily an error. |
| |
| // |MojoTimeTicks|: Used to specify time ticks. Value is in microseconds. |
| |
| typedef int64_t MojoTimeTicks; |
| |
| // |MojoHandle|: Handles to Mojo objects. |
| // |MOJO_HANDLE_INVALID| - A value that is never a valid handle. |
| |
| typedef uint32_t MojoHandle; |
| |
| #ifdef __cplusplus |
| const MojoHandle MOJO_HANDLE_INVALID = 0; |
| #else |
| #define MOJO_HANDLE_INVALID ((MojoHandle) 0) |
| #endif |
| |
| // |MojoResult|: Result codes for Mojo operations. Non-negative values are |
| // success codes; negative values are error/failure codes. |
| // |MOJO_RESULT_OK| - Not an error; returned on success. Note that positive |
| // |MojoResult|s may also be used to indicate success. |
| // |MOJO_RESULT_CANCELLED| - Operation was cancelled, typically by the caller. |
| // |MOJO_RESULT_UNKNOWN| - Unknown error (e.g., if not enough information is |
| // available for a more specific error). |
| // |MOJO_RESULT_INVALID_ARGUMENT| - Caller specified an invalid argument. This |
| // differs from |MOJO_RESULT_FAILED_PRECONDITION| in that the former |
| // indicates arguments that are invalid regardless of the state of the |
| // system. |
| // |MOJO_RESULT_DEADLINE_EXCEEDED| - Deadline expired before the operation |
| // could complete. |
| // |MOJO_RESULT_NOT_FOUND| - Some requested entity was not found (i.e., does |
| // not exist). |
| // |MOJO_RESULT_ALREADY_EXISTS| - Some entity or condition that we attempted |
| // to create already exists. |
| // |MOJO_RESULT_PERMISSION_DENIED| - The caller does not have permission to |
| // for the operation (use |MOJO_RESULT_RESOURCE_EXHAUSTED| for rejections |
| // caused by exhausting some resource instead). |
| // |MOJO_RESULT_RESOURCE_EXHAUSTED| - Some resource required for the call |
| // (possibly some quota) has been exhausted. |
| // |MOJO_RESULT_FAILED_PRECONDITION| - The system is not in a state required |
| // for the operation (use this if the caller must do something to rectify |
| // the state before retrying). |
| // |MOJO_RESULT_ABORTED| - The operation was aborted by the system, possibly |
| // due to a concurrency issue (use this if the caller may retry at a |
| // higher level). |
| // |MOJO_RESULT_OUT_OF_RANGE| - The operation was attempted past the valid |
| // range. Unlike |MOJO_RESULT_INVALID_ARGUMENT|, this indicates that the |
| // operation may be/become valid depending on the system state. (This |
| // error is similar to |MOJO_RESULT_FAILED_PRECONDITION|, but is more |
| // specific.) |
| // |MOJO_RESULT_UNIMPLEMENTED| - The operation is not implemented, supported, |
| // or enabled. |
| // |MOJO_RESULT_INTERNAL| - Internal error: this should never happen and |
| // indicates that some invariant expected by the system has been broken. |
| // |MOJO_RESULT_UNAVAILABLE| - The operation is (temporarily) currently |
| // unavailable. The caller may simply retry the operation (possibly with a |
| // backoff). |
| // |MOJO_RESULT_DATA_LOSS| - Unrecoverable data loss or corruption. |
| // |MOJO_RESULT_BUSY| - One of the resources involved is currently being used |
| // (possibly on another thread) in a way that prevents the current |
| // operation from proceeding, e.g., if the other operation may result in |
| // the resource being invalidated. |
| // |
| // Note that positive values are also available as success codes. |
| // |
| // The codes from |MOJO_RESULT_OK| to |MOJO_RESULT_DATA_LOSS| come from |
| // Google3's canonical error codes. |
| // |
| // TODO(vtl): Add a |MOJO_RESULT_SHOULD_WAIT|. |
| |
| typedef int32_t MojoResult; |
| |
| #ifdef __cplusplus |
| const MojoResult MOJO_RESULT_OK = 0; |
| const MojoResult MOJO_RESULT_CANCELLED = -1; |
| const MojoResult MOJO_RESULT_UNKNOWN = -2; |
| const MojoResult MOJO_RESULT_INVALID_ARGUMENT = -3; |
| const MojoResult MOJO_RESULT_DEADLINE_EXCEEDED = -4; |
| const MojoResult MOJO_RESULT_NOT_FOUND = -5; |
| const MojoResult MOJO_RESULT_ALREADY_EXISTS = -6; |
| const MojoResult MOJO_RESULT_PERMISSION_DENIED = -7; |
| const MojoResult MOJO_RESULT_RESOURCE_EXHAUSTED = -8; |
| const MojoResult MOJO_RESULT_FAILED_PRECONDITION = -9; |
| const MojoResult MOJO_RESULT_ABORTED = -10; |
| const MojoResult MOJO_RESULT_OUT_OF_RANGE = -11; |
| const MojoResult MOJO_RESULT_UNIMPLEMENTED = -12; |
| const MojoResult MOJO_RESULT_INTERNAL = -13; |
| const MojoResult MOJO_RESULT_UNAVAILABLE = -14; |
| const MojoResult MOJO_RESULT_DATA_LOSS = -15; |
| const MojoResult MOJO_RESULT_BUSY = -16; |
| #else |
| #define MOJO_RESULT_OK ((MojoResult) 0) |
| #define MOJO_RESULT_CANCELLED ((MojoResult) -1) |
| #define MOJO_RESULT_UNKNOWN ((MojoResult) -2) |
| #define MOJO_RESULT_INVALID_ARGUMENT ((MojoResult) -3) |
| #define MOJO_RESULT_DEADLINE_EXCEEDED ((MojoResult) -4) |
| #define MOJO_RESULT_NOT_FOUND ((MojoResult) -5) |
| #define MOJO_RESULT_ALREADY_EXISTS ((MojoResult) -6) |
| #define MOJO_RESULT_PERMISSION_DENIED ((MojoResult) -7) |
| #define MOJO_RESULT_RESOURCE_EXHAUSTED ((MojoResult) -8) |
| #define MOJO_RESULT_FAILED_PRECONDITION ((MojoResult) -9) |
| #define MOJO_RESULT_ABORTED ((MojoResult) -10) |
| #define MOJO_RESULT_OUT_OF_RANGE ((MojoResult) -11) |
| #define MOJO_RESULT_UNIMPLEMENTED ((MojoResult) -12) |
| #define MOJO_RESULT_INTERNAL ((MojoResult) -13) |
| #define MOJO_RESULT_UNAVAILABLE ((MojoResult) -14) |
| #define MOJO_RESULT_DATA_LOSS ((MojoResult) -15) |
| #define MOJO_RESULT_BUSY ((MojoResult) -16) |
| #endif |
| |
| // |MojoDeadline|: Used to specify deadlines (timeouts), in microseconds (except |
| // for |MOJO_DEADLINE_INDEFINITE|). |
| // |MOJO_DEADLINE_INDEFINITE| - Used to indicate "forever". |
| |
| typedef uint64_t MojoDeadline; |
| |
| #ifdef __cplusplus |
| const MojoDeadline MOJO_DEADLINE_INDEFINITE = static_cast<MojoDeadline>(-1); |
| #else |
| #define MOJO_DEADLINE_INDEFINITE = ((MojoDeadline) -1); |
| #endif |
| |
| // |MojoWaitFlags|: Used to specify the state of a handle to wait on (e.g., the |
| // ability to read or write to it). |
| // |MOJO_WAIT_FLAG_NONE| - No flags. |MojoWait()|, etc. will return |
| // |MOJO_RESULT_FAILED_PRECONDITION| if you attempt to wait on this. |
| // |MOJO_WAIT_FLAG_READABLE| - Can read (e.g., a message) from the handle. |
| // |MOJO_WAIT_FLAG_WRITABLE| - Can write (e.g., a message) to the handle. |
| // |MOJO_WAIT_FLAG_EVERYTHING| - All flags. |
| |
| typedef uint32_t MojoWaitFlags; |
| |
| #ifdef __cplusplus |
| const MojoWaitFlags MOJO_WAIT_FLAG_NONE = 0; |
| const MojoWaitFlags MOJO_WAIT_FLAG_READABLE = 1 << 0; |
| const MojoWaitFlags MOJO_WAIT_FLAG_WRITABLE = 1 << 1; |
| const MojoWaitFlags MOJO_WAIT_FLAG_EVERYTHING = ~0; |
| #else |
| #define MOJO_WAIT_FLAG_NONE ((MojoWaitFlags) 0) |
| #define MOJO_WAIT_FLAG_READABLE ((MojoWaitFlags) 1 << 0) |
| #define MOJO_WAIT_FLAG_WRITABLE ((MojoWaitFlags) 1 << 1) |
| #define MOJO_WAIT_FLAG_EVERYTHING (~((MojoWaitFlags) 0)) |
| #endif |
| |
| // Message pipe: |
| |
| // |MojoWriteMessageFlags|: Used to specify different modes to |
| // |MojoWriteMessage()|. |
| // |MOJO_WRITE_MESSAGE_FLAG_NONE| - No flags; default mode. |
| |
| typedef uint32_t MojoWriteMessageFlags; |
| |
| #ifdef __cplusplus |
| const MojoWriteMessageFlags MOJO_WRITE_MESSAGE_FLAG_NONE = 0; |
| #else |
| #define MOJO_WRITE_MESSAGE_FLAG_NONE ((MojoWriteMessageFlags) 0) |
| #endif |
| |
| // |MojoReadMessageFlags|: Used to specify different modes to |
| // |MojoReadMessage()|. |
| // |MOJO_READ_MESSAGE_FLAG_NONE| - No flags; default mode. |
| // |MOJO_READ_MESSAGE_FLAG_MAY_DISCARD| - If the message is unable to be read |
| // for whatever reason (e.g., the caller-supplied buffer is too small), |
| // discard the message (i.e., simply dequeue it). |
| |
| typedef uint32_t MojoReadMessageFlags; |
| |
| #ifdef __cplusplus |
| const MojoReadMessageFlags MOJO_READ_MESSAGE_FLAG_NONE = 0; |
| const MojoReadMessageFlags MOJO_READ_MESSAGE_FLAG_MAY_DISCARD = 1 << 0; |
| #else |
| #define MOJO_READ_MESSAGE_FLAG_NONE ((MojoReadMessageFlags) 0) |
| #define MOJO_READ_MESSAGE_FLAG_MAY_DISCARD ((MojoReadMessageFlags) 1 << 0) |
| #endif |
| |
| // Data pipe: |
| |
| // |MojoCreateDataPipeOptions|: Used to specify creation parameters for a data |
| // pipe to |MojoCreateDataPipe()|. |
| // |MojoCreateDataPipeOptionsFlags|: Used to specify different modes of |
| // operation. |
| // |MOJO_CREATE_DATA_PIPE_OPTIONS_FLAG_NONE|: No flags; default mode. |
| // |MOJO_CREATE_DATA_PIPE_OPTIONS_FLAG_MAY_DISCARD|: May discard data for |
| // whatever reason; best-effort delivery. In particular, if the capacity |
| // is reached, old data may be discard to make room for new data. |
| // |
| // |element_size * capacity_num_elements| must be less than 2^32 (i.e., it must |
| // fit into a 32-bit unsigned integer). |
| // TODO(vtl): Finish this. |
| typedef uint32_t MojoCreateDataPipeOptionsFlags; |
| |
| #ifdef __cplusplus |
| const MojoCreateDataPipeOptionsFlags |
| MOJO_CREATE_DATA_PIPE_OPTIONS_FLAG_NONE = 0; |
| const MojoCreateDataPipeOptionsFlags |
| MOJO_CREATE_DATA_PIPE_OPTIONS_FLAG_MAY_DISCARD = 1 << 0; |
| #else |
| #define MOJO_CREATE_DATA_PIPE_OPTIONS_FLAG_NONE \ |
| ((MojoCreateDataPipeOptionsFlags) 0) |
| #define MOJO_CREATE_DATA_PIPE_OPTIONS_FLAG_MAY_DISCARD \ |
| ((MojoCreateDataPipeOptionsFlags) 1 << 0) |
| #endif |
| |
| struct MojoCreateDataPipeOptions { |
| size_t struct_size; // Set to the size of this structure. |
| MojoCreateDataPipeOptionsFlags flags; |
| uint32_t element_size; // Must be nonzero. |
| uint32_t capacity_num_elements; // Zero means "default"/automatic. |
| }; |
| |
| // |MojoWriteDataFlags|: Used to specify different modes to |MojoWriteData()| |
| // and |MojoBeginWriteData()|. |
| // |MOJO_WRITE_DATA_FLAG_NONE| - No flags; default mode. |
| // |MOJO_WRITE_DATA_FLAG_ALL_OR_NOTHING| - Write either all the elements |
| // requested or none of them. |
| |
| typedef uint32_t MojoWriteDataFlags; |
| |
| #ifdef __cplusplus |
| const MojoWriteDataFlags MOJO_WRITE_DATA_FLAG_NONE = 0; |
| const MojoWriteDataFlags MOJO_WRITE_DATA_FLAG_ALL_OR_NONE = 1 << 0; |
| #else |
| #define MOJO_WRITE_DATA_FLAG_NONE ((MojoWriteDataFlags) 0) |
| #define MOJO_WRITE_DATA_FLAG_ALL_OR_NONE ((MojoWriteDataFlags) 1 << 0) |
| #endif |
| |
| // |MojoReadDataFlags|: Used to specify different modes to |MojoReadData()| and |
| // |MojoBeginReadData()|. |
| // |MOJO_READ_DATA_FLAG_NONE| - No flags; default mode. |
| // |MOJO_READ_DATA_FLAG_ALL_OR_NONE| - Read (or discard) either the requested |
| // number of elements or none. |
| // |MOJO_READ_DATA_FLAG_DISCARD| - Discard (up to) the requested number of |
| // elements. |
| // |MOJO_READ_DATA_FLAG_QUERY| - Query the number of elements available to |
| // read. For use with |MojoReadData()| only. Mutually exclusive with |
| // |MOJO_READ_DATA_FLAG_DISCARD| and |MOJO_READ_DATA_FLAG_ALL_OR_NONE| is |
| // ignored if this flag is set. |
| |
| typedef uint32_t MojoReadDataFlags; |
| |
| #ifdef __cplusplus |
| const MojoReadDataFlags MOJO_READ_DATA_FLAG_NONE = 0; |
| const MojoReadDataFlags MOJO_READ_DATA_FLAG_ALL_OR_NONE = 1 << 0; |
| const MojoReadDataFlags MOJO_READ_DATA_FLAG_DISCARD = 1 << 1; |
| const MojoReadDataFlags MOJO_READ_DATA_FLAG_QUERY = 1 << 2; |
| #else |
| #define MOJO_READ_DATA_FLAG_NONE ((MojoReadDataFlags) 0) |
| #define MOJO_READ_DATA_FLAG_ALL_OR_NONE ((MojoReadDataFlags) 1 << 0) |
| #define MOJO_READ_DATA_FLAG_DISCARD ((MojoReadDataFlags) 1 << 1) |
| #define MOJO_READ_DATA_FLAG_QUERY ((MojoReadDataFlags) 1 << 2) |
| #endif |
| |
| // Functions ------------------------------------------------------------------- |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| // Platform-dependent monotonically increasing tick count representing "right |
| // now." The resolution of this clock is ~1-15ms. Resolution varies depending |
| // on hardware/operating system configuration. |
| MOJO_SYSTEM_EXPORT MojoTimeTicks MojoGetTimeTicksNow(); |
| |
| // Closes the given |handle|. |
| // |
| // Returns: |
| // |MOJO_RESULT_OK| on success. |
| // |MOJO_RESULT_INVALID_ARGUMENT| if |handle| is not a valid handle. |
| // |
| // Concurrent operations on |handle| may succeed (or fail as usual) if they |
| // happen before the close, be cancelled with result |MOJO_RESULT_CANCELLED| if |
| // they properly overlap (this is likely the case with |MojoWait()|, etc.), or |
| // fail with |MOJO_RESULT_INVALID_ARGUMENT| if they happen after. |
| MOJO_SYSTEM_EXPORT MojoResult MojoClose(MojoHandle handle); |
| |
| // Waits on the given handle until the state indicated by |flags| is satisfied |
| // or until |deadline| has passed. |
| // |
| // Returns: |
| // |MOJO_RESULT_OK| if some flag in |flags| was satisfied (or is already |
| // satisfied). |
| // |MOJO_RESULT_INVALID_ARGUMENT| if |handle| is not a valid handle (e.g., if |
| // it has already been closed). |
| // |MOJO_RESULT_DEADLINE_EXCEEDED| if the deadline has passed without any of |
| // the flags being satisfied. |
| // |MOJO_RESULT_FAILED_PRECONDITION| if it is or becomes impossible that any |
| // flag in |flags| will ever be satisfied. |
| // |
| // If there are multiple waiters (on different threads, obviously) waiting on |
| // the same handle and flag and that flag becomes set, all waiters will be |
| // awoken. |
| MOJO_SYSTEM_EXPORT MojoResult MojoWait(MojoHandle handle, |
| MojoWaitFlags flags, |
| MojoDeadline deadline); |
| |
| // Waits on |handles[0]|, ..., |handles[num_handles-1]| for at least one of them |
| // to satisfy the state indicated by |flags[0]|, ..., |flags[num_handles-1]|, |
| // respectively, or until |deadline| has passed. |
| // |
| // Returns: |
| // The index |i| (from 0 to |num_handles-1|) if |handle[i]| satisfies |
| // |flags[i]|. |
| // |MOJO_RESULT_INVALID_ARGUMENT| if some |handle[i]| is not a valid handle |
| // (e.g., if it has already been closed). |
| // |MOJO_RESULT_DEADLINE_EXCEEDED| if the deadline has passed without any of |
| // handles satisfying any of its flags. |
| // |MOJO_RESULT_FAILED_PRECONDITION| if it is or becomes impossible that SOME |
| // |handle[i]| will ever satisfy any of its flags |flags[i]|. |
| MOJO_SYSTEM_EXPORT MojoResult MojoWaitMany(const MojoHandle* handles, |
| const MojoWaitFlags* flags, |
| uint32_t num_handles, |
| MojoDeadline deadline); |
| |
| // Message pipe: |
| |
| // Creates a message pipe, which is a bidirectional communication channel for |
| // framed data (i.e., messages). Messages can contain plain data and/or Mojo |
| // handles. On success, |*message_pipe_handle_0| and |*message_pipe_1| are set |
| // to handles for the two endpoints (ports) for the message pipe. |
| // |
| // Returns: |
| // |MOJO_RESULT_OK| on success. |
| // |MOJO_RESULT_INVALID_ARGUMENT| if |message_pipe_handle_0| and/or |
| // |message_pipe_handle_1| do not appear to be valid pointers. |
| // |MOJO_RESULT_RESOURCE_EXHAUSTED| if a process/system/quota/etc. limit has |
| // been reached. |
| // |
| // TODO(vtl): Add an options struct pointer argument. |
| MOJO_SYSTEM_EXPORT MojoResult MojoCreateMessagePipe( |
| MojoHandle* message_pipe_handle_0, |
| MojoHandle* message_pipe_handle_1); |
| |
| // Writes a message to the message pipe endpoint given by |message_pipe_handle|, |
| // with message data specified by |bytes| of size |num_bytes| and attached |
| // handles specified by |handles| of count |num_handles|, and options specified |
| // by |flags|. If there is no message data, |bytes| may be null, in which case |
| // |num_bytes| must be zero. If there are no attached handles, |handles| may be |
| // null, in which case |num_handles| must be zero. |
| // |
| // If handles are attached, on success the handles will no longer be valid (the |
| // receiver will receive equivalent, but logically different, handles). Handles |
| // to be sent should not be in simultaneous use (e.g., on another thread). |
| // |
| // Returns: |
| // |MOJO_RESULT_OK| on success (i.e., the message was enqueued). |
| // |MOJO_RESULT_INVALID_ARGUMENT| if some argument was invalid (e.g., if |
| // |message_pipe_handle| is not a valid handle, or some of the |
| // requirements above are not satisfied). |
| // |MOJO_RESULT_RESOURCE_EXHAUSTED| if some system limit has been reached, or |
| // the number of handles to send is too large (TODO(vtl): reconsider the |
| // latter case). |
| // |MOJO_RESULT_FAILED_PRECONDITION| if the other endpoint has been closed. |
| // Note that closing an endpoint is not necessarily synchronous (e.g., |
| // across processes), so this function may be succeed even if the other |
| // endpoint has been closed (in which case the message would be dropped). |
| // |MOJO_RESULT_BUSY| if some handle to be sent is currently in use. |
| // |
| // TODO(vtl): Add a notion of capacity for message pipes, and return |
| // |MOJO_RESULT_SHOULD_WAIT| if the message pipe is full. |
| MOJO_SYSTEM_EXPORT MojoResult MojoWriteMessage(MojoHandle message_pipe_handle, |
| const void* bytes, |
| uint32_t num_bytes, |
| const MojoHandle* handles, |
| uint32_t num_handles, |
| MojoWriteMessageFlags flags); |
| |
| // Reads a message from the message pipe endpoint given by |
| // |message_pipe_handle|; also usable to query the size of the next message or |
| // discard the next message. |bytes|/|*num_bytes| indicate the buffer/buffer |
| // size to receive the message data (if any) and |handles|/|*num_handles| |
| // indicate the buffer/maximum handle count to receive the attached handles (if |
| // any). |
| // |
| // |num_bytes| and |num_handles| are optional "in-out" parameters. If non-null, |
| // on return |*num_bytes| and |*num_handles| will usually indicate the number |
| // of bytes and number of attached handles in the "next" message, respectively, |
| // whether that message was read or not. (If null, the number of bytes/handles |
| // is treated as zero.) |
| // |
| // If |bytes| is null, then |*num_bytes| must be zero, and similarly for |
| // |handles| and |*num_handles|. |
| // |
| // Partial reads are NEVER done. Either a full read is done and |MOJO_RESULT_OK| |
| // returned, or the read is NOT done and |MOJO_RESULT_RESOURCE_EXHAUSTED| is |
| // returned (if |MOJO_READ_MESSAGE_FLAG_MAY_DISCARD| was set, the message is |
| // also discarded in this case). |
| // |
| // Returns: |
| // |MOJO_RESULT_OK| on success (i.e., a message was actually read). |
| // |MOJO_RESULT_INVALID_ARGUMENT| if some argument was invalid. |
| // |MOJO_RESULT_NOT_FOUND| if no message was available to be read (TODO(vtl): |
| // change this to |MOJO_RESULT_SHOULD_WAIT|). |
| // |MOJO_RESULT_FAILED_PRECONDITION| if the other endpoint has been closed. |
| // |MOJO_RESULT_RESOURCE_EXHAUSTED| if one of the buffers to receive the |
| // message/attached handles (|bytes|/|*num_bytes| or |
| // |handles|/|*num_handles|) was too small. (TODO(vtl): Reconsider this |
| // error code; should distinguish this from the hitting-system-limits |
| // case.) |
| MOJO_SYSTEM_EXPORT MojoResult MojoReadMessage(MojoHandle message_pipe_handle, |
| void* bytes, |
| uint32_t* num_bytes, |
| MojoHandle* handles, |
| uint32_t* num_handles, |
| MojoReadMessageFlags flags); |
| |
| // Data pipe: |
| // TODO(vtl): Moar docs. |
| |
| MOJO_SYSTEM_EXPORT MojoResult MojoCreateDataPipe( |
| const struct MojoCreateDataPipeOptions* options, |
| MojoHandle* data_pipe_producer_handle, |
| MojoHandle* data_pipe_consumer_handle); |
| |
| MOJO_SYSTEM_EXPORT MojoResult MojoWriteData( |
| MojoHandle data_pipe_producer_handle, |
| const void* elements, |
| uint32_t* num_elements, |
| MojoWriteDataFlags flags); |
| |
| // TODO(vtl): Note to self: |buffer_num_elements| is an "in-out" parameter: |
| // on the "in" side, |*buffer_num_elements| is the number requested; on success, |
| // on the "out" side, it's the number available (which may be GREATER or LESS |
| // than the number requested; if the "all-or-nothing" flag is set, it's AT LEAST |
| // the number requested). |
| MOJO_SYSTEM_EXPORT MojoResult MojoBeginWriteData( |
| MojoHandle data_pipe_producer_handle, |
| void** buffer, |
| uint32_t* buffer_num_elements, |
| MojoWriteDataFlags flags); |
| |
| MOJO_SYSTEM_EXPORT MojoResult MojoEndWriteData( |
| MojoHandle data_pipe_producer_handle, |
| uint32_t num_elements_written); |
| |
| // TODO(vtl): Note to self: If |MOJO_READ_DATA_FLAG_QUERY| is set, then |
| // |elements| must be null (and nothing will be read). |
| MOJO_SYSTEM_EXPORT MojoResult MojoReadData( |
| MojoHandle data_pipe_consumer_handle, |
| void* elements, |
| uint32_t* num_elements, |
| MojoReadDataFlags flags); |
| |
| MOJO_SYSTEM_EXPORT MojoResult MojoBeginReadData( |
| MojoHandle data_pipe_consumer_handle, |
| const void** buffer, |
| uint32_t* buffer_num_elements, |
| MojoReadDataFlags flags); |
| |
| MOJO_SYSTEM_EXPORT MojoResult MojoEndReadData( |
| MojoHandle data_pipe_consumer_handle, |
| uint32_t num_elements_read); |
| |
| #ifdef __cplusplus |
| } // extern "C" |
| #endif |
| |
| #endif // MOJO_PUBLIC_SYSTEM_CORE_H_ |