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

R=sky@chromium.org

Review URL: https://codereview.chromium.org/298273005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@273082 0039d316-1c4b-4281-b951-d872f2087c98

10 files changed, 161 insertions, 136 deletions

diff --git a/mojo/mojo_public.gypi b/mojo/mojo_public.gypi
index 166d8da..1caa854 100644
--- a/mojo/mojo_public.gypi
+++ b/mojo/mojo_public.gypi
@@ -29,6 +29,7 @@
         'public/c/system/core.h',
         'public/c/system/functions.h',
         'public/c/system/macros.h',
+        'public/c/system/message_pipe.h',
         'public/c/system/system_export.h',
         'public/c/system/types.h',
         'public/platform/native/system_thunks.cc',
diff --git a/mojo/public/c/system/core.h b/mojo/public/c/system/core.h
index 199d918..9531494 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:
 
diff --git a/mojo/public/c/system/functions.h b/mojo/public/c/system/functions.h
index fa2bd06..a0330fe 100644
--- a/mojo/public/c/system/functions.h
+++ b/mojo/public/c/system/functions.h
@@ -14,6 +14,10 @@
 #include "mojo/public/c/system/system_export.h"
 #include "mojo/public/c/system/types.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 // Note: Pointer parameters that are labelled "optional" may be null (at least
 // under some circumstances). Non-const pointer parameters are also labeled
 // "in", "out", or "in/out", to indicate how they are used. (Note that how/if
@@ -21,10 +25,6 @@
 // operation's success/failure. E.g., a separate |flags| parameter may control
 // whether a given "in/out" parameter is used for input, output, or both.)
 
-#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.
diff --git a/mojo/public/c/system/message_pipe.h b/mojo/public/c/system/message_pipe.h
new file mode 100644
index 0000000..ffedd9e
--- /dev/null
+++ b/mojo/public/c/system/message_pipe.h
@@ -0,0 +1,146 @@
+// 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.
+
+// This file contains types/constants and functions specific to message pipes.
+
+// Note: This header should be compilable as C.
+
+#ifndef MOJO_PUBLIC_C_SYSTEM_MESSAGE_PIPE_H_
+#define MOJO_PUBLIC_C_SYSTEM_MESSAGE_PIPE_H_
+
+#include "mojo/public/c/system/system_export.h"
+#include "mojo/public/c/system/types.h"
+
+// |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
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Note: See the comment in functions.h about the meaning of the "optional"
+// label for pointer parameters.
+
+// 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);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // MOJO_PUBLIC_C_SYSTEM_MESSAGE_PIPE_H_
diff --git a/mojo/system/core.h b/mojo/system/core.h
index e97c61b..60c15db 100644
--- a/mojo/system/core.h
+++ b/mojo/system/core.h
@@ -10,6 +10,7 @@
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/lock.h"
 #include "mojo/public/c/system/core.h"
+#include "mojo/public/c/system/message_pipe.h"
 #include "mojo/public/c/system/types.h"
 #include "mojo/system/handle_table.h"
 #include "mojo/system/mapping_table.h"
diff --git a/mojo/system/dispatcher.h b/mojo/system/dispatcher.h
index c96dba8..eb26291 100644
--- a/mojo/system/dispatcher.h
+++ b/mojo/system/dispatcher.h
@@ -17,6 +17,8 @@
 #include "mojo/embedder/platform_handle.h"
 #include "mojo/embedder/platform_handle_vector.h"
 #include "mojo/public/c/system/core.h"
+#include "mojo/public/c/system/message_pipe.h"
+#include "mojo/public/c/system/types.h"
 #include "mojo/system/system_impl_export.h"
 
 namespace mojo {
diff --git a/mojo/system/local_message_pipe_endpoint.h b/mojo/system/local_message_pipe_endpoint.h
index d30f54b..fdc3211 100644
--- a/mojo/system/local_message_pipe_endpoint.h
+++ b/mojo/system/local_message_pipe_endpoint.h
@@ -7,7 +7,6 @@
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
-#include "mojo/public/c/system/core.h"
 #include "mojo/system/message_in_transit_queue.h"
 #include "mojo/system/message_pipe_endpoint.h"
 #include "mojo/system/system_impl_export.h"
diff --git a/mojo/system/message_pipe.h b/mojo/system/message_pipe.h
index 10668da..ca0155d 100644
--- a/mojo/system/message_pipe.h
+++ b/mojo/system/message_pipe.h
@@ -11,7 +11,8 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/lock.h"
-#include "mojo/public/c/system/core.h"
+#include "mojo/public/c/system/message_pipe.h"
+#include "mojo/public/c/system/types.h"
 #include "mojo/system/dispatcher.h"
 #include "mojo/system/message_in_transit.h"
 #include "mojo/system/message_pipe_endpoint.h"
diff --git a/mojo/system/message_pipe_endpoint.h b/mojo/system/message_pipe_endpoint.h
index 46a67e1..331d7af 100644
--- a/mojo/system/message_pipe_endpoint.h
+++ b/mojo/system/message_pipe_endpoint.h
@@ -12,7 +12,8 @@
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
-#include "mojo/public/c/system/core.h"
+#include "mojo/public/c/system/message_pipe.h"
+#include "mojo/public/c/system/types.h"
 #include "mojo/system/dispatcher.h"
 #include "mojo/system/message_in_transit.h"
 #include "mojo/system/system_impl_export.h"
diff --git a/mojo/system/proxy_message_pipe_endpoint.h b/mojo/system/proxy_message_pipe_endpoint.h
index 28b634d..f3e9b1d 100644
--- a/mojo/system/proxy_message_pipe_endpoint.h
+++ b/mojo/system/proxy_message_pipe_endpoint.h
@@ -10,7 +10,6 @@
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
-#include "mojo/public/c/system/core.h"
 #include "mojo/system/message_in_transit.h"
 #include "mojo/system/message_in_transit_queue.h"
 #include "mojo/system/message_pipe_endpoint.h"