diff options
Diffstat (limited to 'include/io/channel.h')
| -rw-r--r-- | include/io/channel.h | 69 |
1 files changed, 30 insertions, 39 deletions
diff --git a/include/io/channel.h b/include/io/channel.h index 229bf36910..5f9dbaab65 100644 --- a/include/io/channel.h +++ b/include/io/channel.h @@ -81,9 +81,11 @@ struct QIOChannel { Object parent; unsigned int features; /* bitmask of QIOChannelFeatures */ char *name; - AioContext *ctx; + AioContext *read_ctx; Coroutine *read_coroutine; + AioContext *write_ctx; Coroutine *write_coroutine; + bool follow_coroutine_ctx; #ifdef _WIN32 HANDLE event; /* For use with GSource on Win32 */ #endif @@ -140,8 +142,9 @@ struct QIOChannelClass { int whence, Error **errp); void (*io_set_aio_fd_handler)(QIOChannel *ioc, - AioContext *ctx, + AioContext *read_ctx, IOHandler *io_read, + AioContext *write_ctx, IOHandler *io_write, void *opaque); int (*io_flush)(QIOChannel *ioc, @@ -499,6 +502,21 @@ int qio_channel_set_blocking(QIOChannel *ioc, Error **errp); /** + * qio_channel_set_follow_coroutine_ctx: + * @ioc: the channel object + * @enabled: whether or not to follow the coroutine's AioContext + * + * If @enabled is true, calls to qio_channel_yield() use the current + * coroutine's AioContext. Usually this is desirable. + * + * If @enabled is false, calls to qio_channel_yield() use the global iohandler + * AioContext. This is may be used by coroutines that run in the main loop and + * do not wish to respond to I/O during nested event loops. This is the + * default for compatibility with code that is not aware of AioContexts. + */ +void qio_channel_set_follow_coroutine_ctx(QIOChannel *ioc, bool enabled); + +/** * qio_channel_close: * @ioc: the channel object * @errp: pointer to a NULL-initialized error object @@ -704,41 +722,6 @@ GSource *qio_channel_add_watch_source(QIOChannel *ioc, GMainContext *context); /** - * qio_channel_attach_aio_context: - * @ioc: the channel object - * @ctx: the #AioContext to set the handlers on - * - * Request that qio_channel_yield() sets I/O handlers on - * the given #AioContext. If @ctx is %NULL, qio_channel_yield() - * uses QEMU's main thread event loop. - * - * You can move a #QIOChannel from one #AioContext to another even if - * I/O handlers are set for a coroutine. However, #QIOChannel provides - * no synchronization between the calls to qio_channel_yield() and - * qio_channel_attach_aio_context(). - * - * Therefore you should first call qio_channel_detach_aio_context() - * to ensure that the coroutine is not entered concurrently. Then, - * while the coroutine has yielded, call qio_channel_attach_aio_context(), - * and then aio_co_schedule() to place the coroutine on the new - * #AioContext. The calls to qio_channel_detach_aio_context() - * and qio_channel_attach_aio_context() should be protected with - * aio_context_acquire() and aio_context_release(). - */ -void qio_channel_attach_aio_context(QIOChannel *ioc, - AioContext *ctx); - -/** - * qio_channel_detach_aio_context: - * @ioc: the channel object - * - * Disable any I/O handlers set by qio_channel_yield(). With the - * help of aio_co_schedule(), this allows moving a coroutine that was - * paused by qio_channel_yield() to another context. - */ -void qio_channel_detach_aio_context(QIOChannel *ioc); - -/** * qio_channel_yield: * @ioc: the channel object * @condition: the I/O condition to wait for @@ -785,8 +768,9 @@ void qio_channel_wait(QIOChannel *ioc, /** * qio_channel_set_aio_fd_handler: * @ioc: the channel object - * @ctx: the AioContext to set the handlers on + * @read_ctx: the AioContext to set the read handler on or NULL * @io_read: the read handler + * @write_ctx: the AioContext to set the write handler on or NULL * @io_write: the write handler * @opaque: the opaque value passed to the handler * @@ -794,10 +778,17 @@ void qio_channel_wait(QIOChannel *ioc, * be used by channel implementations to forward the handlers * to another channel (e.g. from #QIOChannelTLS to the * underlying socket). + * + * When @read_ctx is NULL, don't touch the read handler. When @write_ctx is + * NULL, don't touch the write handler. Note that setting the read handler + * clears the write handler, and vice versa, if they share the same AioContext. + * Therefore the caller must pass both handlers together when sharing the same + * AioContext. */ void qio_channel_set_aio_fd_handler(QIOChannel *ioc, - AioContext *ctx, + AioContext *read_ctx, IOHandler *io_read, + AioContext *write_ctx, IOHandler *io_write, void *opaque); |