1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef MOJO_EMBEDDER_EMBEDDER_H_ 6 #define MOJO_EMBEDDER_EMBEDDER_H_ 7 8 #include "base/callback.h" 9 #include "base/memory/ref_counted.h" 10 #include "base/task_runner.h" 11 #include "mojo/embedder/scoped_platform_handle.h" 12 #include "mojo/public/cpp/system/core.h" 13 #include "mojo/system/system_impl_export.h" 14 15 namespace mojo { 16 namespace embedder { 17 18 // Must be called first to initialize the (global, singleton) system. 19 MOJO_SYSTEM_IMPL_EXPORT void Init(); 20 21 // Creates a new "channel", returning a handle to the bootstrap message pipe on 22 // that channel. |platform_handle| should be an OS-dependent handle to one side 23 // of a suitable bidirectional OS "pipe" (e.g., a file descriptor to a socket on 24 // POSIX, a handle to a named pipe on Windows); this "pipe" should be connected 25 // and ready for operation (e.g., to be written to or read from). 26 // |io_thread_task_runner| should be a |TaskRunner| for the thread on which the 27 // "channel" will run (read data and demultiplex). 28 // 29 // On completion, it will run |callback| with a pointer to a |ChannelInfo| 30 // (which is meant to be opaque to the embedder). If 31 // |callback_thread_task_runner| is non-null, it the callback will be posted to 32 // that task runner. Otherwise, it will be run on the I/O thread directly. 33 // 34 // Returns an invalid |MOJO_HANDLE_INVALID| on error. Note that this will happen 35 // only if, e.g., the handle table is full (operation of the channel begins 36 // asynchronously and if, e.g., the other end of the "pipe" is closed, this will 37 // report an error to the returned handle in the usual way). 38 // 39 // Notes: The handle returned is ready for use immediately, with messages 40 // written to it queued. E.g., it would be perfectly valid for a message to be 41 // immediately written to the returned handle and the handle closed, all before 42 // the channel has begun operation on the IO thread. In this case, the channel 43 // is expected to connect as usual, send the queued message, and report that the 44 // handle was closed to the other side. (This message may well contain another 45 // handle, so there may well still be message pipes "on" this channel.) 46 // 47 // TODO(vtl): Figure out channel teardown. 48 struct ChannelInfo; 49 typedef base::Callback<void(ChannelInfo*)> DidCreateChannelCallback; 50 MOJO_SYSTEM_IMPL_EXPORT ScopedMessagePipeHandle CreateChannel( 51 ScopedPlatformHandle platform_handle, 52 scoped_refptr<base::TaskRunner> io_thread_task_runner, 53 DidCreateChannelCallback callback, 54 scoped_refptr<base::TaskRunner> callback_thread_task_runner); 55 56 MOJO_SYSTEM_IMPL_EXPORT void DestroyChannelOnIOThread( 57 ChannelInfo* channel_info); 58 59 // Creates a |MojoHandle| that wraps the given |PlatformHandle| (taking 60 // ownership of it). This |MojoHandle| can then, e.g., be passed through message 61 // pipes. Note: This takes ownership (and thus closes) |platform_handle| even on 62 // failure, which is different from what you'd expect from a Mojo API, but it 63 // makes for a more convenient embedder API. 64 MOJO_SYSTEM_IMPL_EXPORT MojoResult CreatePlatformHandleWrapper( 65 ScopedPlatformHandle platform_handle, 66 MojoHandle* platform_handle_wrapper_handle); 67 // Retrieves the |PlatformHandle| that was wrapped into a |MojoHandle| (using 68 // |CreatePlatformHandleWrapper()| above). Note that the |MojoHandle| must still 69 // be closed separately. 70 MOJO_SYSTEM_IMPL_EXPORT MojoResult PassWrappedPlatformHandle( 71 MojoHandle platform_handle_wrapper_handle, 72 ScopedPlatformHandle* platform_handle); 73 74 } // namespace embedder 75 } // namespace mojo 76 77 #endif // MOJO_EMBEDDER_EMBEDDER_H_ 78
