Mojo: Move message pipe types/constants/functions from mojo/public/c/system/core.h to .../message_p…

mojo/public/c/system/core.h

Index: mojo/public/c/system/core.h
diff --git a/mojo/public/c/system/core.h b/mojo/public/c/system/core.h
index 199d91891c134dae5494f0dd7848eff69dd98a78..9531494708bb51370a351a528735a51c114afe3c 100644
--- a/mojo/public/c/system/core.h
+++ b/mojo/public/c/system/core.h
@@ -7,10 +7,9 @@
 #ifndef MOJO_PUBLIC_C_SYSTEM_CORE_H_
 #define MOJO_PUBLIC_C_SYSTEM_CORE_H_
 
-#include <stdint.h>
-
 #include "mojo/public/c/system/functions.h"
 #include "mojo/public/c/system/macros.h"
+#include "mojo/public/c/system/message_pipe.h"
 #include "mojo/public/c/system/system_export.h"
 #include "mojo/public/c/system/types.h"
 
@@ -18,37 +17,6 @@
 
 // TODO(vtl): Split these into their own header files.
 
-// 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
@@ -207,105 +175,12 @@ const MojoMapBufferFlags MOJO_MAP_BUFFER_FLAG_NONE = 0;
 
 // Functions -------------------------------------------------------------------
 
-// Note: See the comment in functions.h about the meaning of the "optional"
-// label for pointer parameters.
-
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-// 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_handle0| and |*message_pipe_handle1| 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_handle0| and/or
-//       |message_pipe_handle1| 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_handle0,  // Out.
-    MojoHandle* message_pipe_handle1);  // Out.
-
-// 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,  // Optional.
-    uint32_t num_bytes,
-    const MojoHandle* handles,  // Optional.
-    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_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_RESULT_SHOULD_WAIT| if no message was available to be read.
-MOJO_SYSTEM_EXPORT MojoResult MojoReadMessage(
-    MojoHandle message_pipe_handle,
-    void* bytes,  // Optional out.
-    uint32_t* num_bytes,  // Optional in/out.
-    MojoHandle* handles,  // Optional out.
-    uint32_t* num_handles,  // Optional in/out.
-    MojoReadMessageFlags flags);
+// Note: See the comment in functions.h about the meaning of the "optional"
+// label for pointer parameters.
 
 // Data pipe: