/* * Copyright (c) 2012-2013 Apple Inc. All rights reserved. * * @APPLE_APACHE_LICENSE_HEADER_START@ * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * * @APPLE_APACHE_LICENSE_HEADER_END@ */ /* * IMPORTANT: This header file describes INTERNAL interfaces to libdispatch * which are subject to change in future releases of Mac OS X. Any applications * relying on these interfaces WILL break. */ #ifndef __DISPATCH_MACH_PRIVATE__ #define __DISPATCH_MACH_PRIVATE__ #ifndef __DISPATCH_INDIRECT__ #error "Please #include <dispatch/dispatch.h> instead of this file directly." #include <dispatch/base.h> // for HeaderDoc #endif __BEGIN_DECLS #if DISPATCH_MACH_SPI #include <mach/mach.h> /*! * @functiongroup Dispatch Mach Channel SPI * * IMPORTANT: This is Libsystem-internal SPI not intended for general use and * is subject to change at any time without warning. */ /*! * @typedef dispatch_mach_t * A dispatch mach channel asynchronously recevives and sends mach messages. */ DISPATCH_DECL(dispatch_mach); /*! * @typedef dispatch_mach_reason_t * Reasons for a mach channel handler to be invoked. * * @const DISPATCH_MACH_CONNECTED * The channel has been connected. The first handler invocation on a channel * after calling dispatch_mach_connect() will have this reason. * * @const DISPATCH_MACH_MESSAGE_RECEIVED * A message was received, it is passed in the message parameter. * * @const DISPATCH_MACH_MESSAGE_SENT * A message was sent, it is passed in the message parameter (so that associated * resources can be disposed of). * * @const DISPATCH_MACH_MESSAGE_SEND_FAILED * A message failed to be sent, it is passed in the message parameter (so that * associated resources can be disposed of), along with the error code from * mach_msg(). * * @const DISPATCH_MACH_MESSAGE_NOT_SENT * A message was not sent due to the channel being canceled or reconnected, it * is passed in the message parameter (so that associated resources can be * disposed of). * * @const DISPATCH_MACH_BARRIER_COMPLETED * A barrier block has finished executing. * * @const DISPATCH_MACH_DISCONNECTED * The channel has been disconnected by a call to dispatch_mach_reconnect() or * dispatch_mach_cancel(), an empty message is passed in the message parameter * (so that associated port rights can be disposed of). * The message header will contain either a remote port with a previously * connected send right, or a local port with a previously connected receive * right (if the channel was canceled), or a local port with a receive right * that was being monitored for a direct reply to a message previously sent to * the channel (if no reply was received). * * @const DISPATCH_MACH_CANCELED * The channel has been canceled. */ DISPATCH_ENUM(dispatch_mach_reason, unsigned long, DISPATCH_MACH_CONNECTED = 1, DISPATCH_MACH_MESSAGE_RECEIVED, DISPATCH_MACH_MESSAGE_SENT, DISPATCH_MACH_MESSAGE_SEND_FAILED, DISPATCH_MACH_MESSAGE_NOT_SENT, DISPATCH_MACH_BARRIER_COMPLETED, DISPATCH_MACH_DISCONNECTED, DISPATCH_MACH_CANCELED, DISPATCH_MACH_REASON_LAST, /* unused */ ); /*! * @typedef dispatch_mach_trailer_t * Trailer type of mach message received by dispatch mach channels */ typedef mach_msg_context_trailer_t dispatch_mach_trailer_t; /*! * @constant DISPATCH_MACH_RECEIVE_MAX_INLINE_MESSAGE_SIZE * Maximum size of a message that can be received inline by a dispatch mach * channel, reception of larger messages requires an extra roundtrip through * the kernel. */ #define DISPATCH_MACH_RECEIVE_MAX_INLINE_MESSAGE_SIZE \ ((PAGE_SIZE > 0x1000 ? 1 : 3) * PAGE_SIZE - \ sizeof(dispatch_mach_trailer_t)) /*! * @typedef dispatch_mach_msg_t * A dispatch mach message encapsulates messages received or sent with dispatch * mach channels. */ DISPATCH_DECL(dispatch_mach_msg); /*! * @typedef dispatch_mach_msg_destructor_t * Dispatch mach message object destructors. * * @const DISPATCH_MACH_MSG_DESTRUCTOR_DEFAULT * Message buffer storage is internal to the object, if a buffer is supplied * during object creation, its contents are copied. * * @const DISPATCH_MACH_MSG_DESTRUCTOR_FREE * Message buffer will be deallocated with free(3). * * @const DISPATCH_MACH_MSG_DESTRUCTOR_FREE * Message buffer will be deallocated with vm_deallocate. */ DISPATCH_ENUM(dispatch_mach_msg_destructor, unsigned int, DISPATCH_MACH_MSG_DESTRUCTOR_DEFAULT = 0, DISPATCH_MACH_MSG_DESTRUCTOR_FREE, DISPATCH_MACH_MSG_DESTRUCTOR_VM_DEALLOCATE, ); /*! * @function dispatch_mach_msg_create * Creates a dispatch mach message object, either with a newly allocated message * buffer of given size, or from an existing message buffer that will be * deallocated with the specified destructor when the object is released. * * If a non-NULL reference to a pointer is provided in 'msg_ptr', it is filled * with the location of the (possibly newly allocated) message buffer. * * It is the responsibility of the application to ensure that it does not modify * the underlying message buffer once the dispatch mach message object is passed * to other dispatch mach API. * * @param msg The message buffer to create the message object from. * If 'destructor' is DISPATCH_MACH_MSG_DESTRUCTOR_DEFAULT, * this argument may be NULL to leave the newly allocated * message buffer zero-initialized. * @param size The size of the message buffer. * Must be >= sizeof(mach_msg_header_t) * @param destructor The destructor to use to deallocate the message buffer * when the object is released. * @param msg_ptr A pointer to a pointer variable to be filled with the * location of the (possibly newly allocated) message * buffer, or NULL. * @result A newly created dispatch mach message object. */ __OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_7_0) DISPATCH_EXPORT DISPATCH_MALLOC DISPATCH_RETURNS_RETAINED DISPATCH_WARN_RESULT DISPATCH_NOTHROW dispatch_mach_msg_t dispatch_mach_msg_create(mach_msg_header_t *msg, size_t size, dispatch_mach_msg_destructor_t destructor, mach_msg_header_t **msg_ptr); /*! * @function dispatch_mach_msg_get_msg * Returns the message buffer underlying a dispatch mach message object. * * @param message The dispatch mach message object to query. * @param size_ptr A pointer to a size_t variable to be filled with the * size of the message buffer, or NULL. * @result Pointer to message buffer underlying the object. */ __OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_7_0) DISPATCH_EXPORT DISPATCH_NONNULL1 DISPATCH_NOTHROW mach_msg_header_t* dispatch_mach_msg_get_msg(dispatch_mach_msg_t message, size_t *size_ptr); #ifdef __BLOCKS__ /*! * @typedef dispatch_mach_handler_t * Prototype of dispatch mach channel handler blocks. * * @param reason Reason the handler was invoked. * @param message Message object that was sent or received. * @param error Mach error code for the send operation. */ typedef void (^dispatch_mach_handler_t)(dispatch_mach_reason_t reason, dispatch_mach_msg_t message, mach_error_t error); /*! * @function dispatch_mach_create * Create a dispatch mach channel to asynchronously receive and send mach * messages. * * The specified handler will be called with the corresponding reason parameter * for each message received and for each message that was successfully sent, * that failed to be sent, or was not sent; as well as when a barrier block * has completed, or when channel connection, reconnection or cancellation has * taken effect. * * Dispatch mach channels are created in a disconnected state, they must be * connected via dispatch_mach_connect() to begin receiving and sending * messages. * * @param label * An optional string label to attach to the channel. The string is not copied, * if it is non-NULL it must point to storage that remains valid for the * lifetime of the channel object. May be NULL. * * @param queue * The target queue of the channel, where the handler and barrier blocks will * be submitted. * * @param handler * The handler block to submit when a message has been sent or received. * * @result * The newly created dispatch mach channel. */ __OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_6_0) DISPATCH_EXPORT DISPATCH_MALLOC DISPATCH_RETURNS_RETAINED DISPATCH_WARN_RESULT DISPATCH_NONNULL3 DISPATCH_NOTHROW dispatch_mach_t dispatch_mach_create(const char *label, dispatch_queue_t queue, dispatch_mach_handler_t handler); #endif /*! * @typedef dispatch_mach_handler_function_t * Prototype of dispatch mach channel handler functions. * * @param context Application-defined context parameter. * @param reason Reason the handler was invoked. * @param message Message object that was sent or received. * @param error Mach error code for the send operation. */ typedef void (*dispatch_mach_handler_function_t)(void *context, dispatch_mach_reason_t reason, dispatch_mach_msg_t message, mach_error_t error); /*! * @function dispatch_mach_create_f * Create a dispatch mach channel to asynchronously receive and send mach * messages. * * The specified handler will be called with the corresponding reason parameter * for each message received and for each message that was successfully sent, * that failed to be sent, or was not sent; as well as when a barrier block * has completed, or when channel connection, reconnection or cancellation has * taken effect. * * Dispatch mach channels are created in a disconnected state, they must be * connected via dispatch_mach_connect() to begin receiving and sending * messages. * * @param label * An optional string label to attach to the channel. The string is not copied, * if it is non-NULL it must point to storage that remains valid for the * lifetime of the channel object. May be NULL. * * @param queue * The target queue of the channel, where the handler and barrier blocks will * be submitted. * * @param context * The application-defined context to pass to the handler. * * @param handler * The handler function to submit when a message has been sent or received. * * @result * The newly created dispatch mach channel. */ __OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_6_0) DISPATCH_EXPORT DISPATCH_MALLOC DISPATCH_RETURNS_RETAINED DISPATCH_WARN_RESULT DISPATCH_NONNULL4 DISPATCH_NOTHROW dispatch_mach_t dispatch_mach_create_f(const char *label, dispatch_queue_t queue, void *context, dispatch_mach_handler_function_t handler); /*! * @function dispatch_mach_connect * Connect a mach channel to the specified receive and send rights. * * This function must only be called once during the lifetime of a channel, it * will initiate message reception and perform any already submitted message * sends or barrier operations. * * @param channel * The mach channel to connect. * * @param receive * The receive right to associate with the channel. May be MACH_PORT_NULL. * * @param send * The send right to associate with the channel. May be MACH_PORT_NULL. * * @param checkin * An optional message object encapsulating the initial check-in message to send * upon channel connection. The check-in message is sent immediately before the * first message submitted via dispatch_mach_send(). The message object will be * retained until the initial send operation is complete (or not peformed due * to channel cancellation or reconnection) and the channel handler has * returned. May be NULL. */ __OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_6_0) DISPATCH_EXPORT DISPATCH_NONNULL1 DISPATCH_NOTHROW void dispatch_mach_connect(dispatch_mach_t channel, mach_port_t receive, mach_port_t send, dispatch_mach_msg_t checkin); /*! * @function dispatch_mach_reconnect * Reconnect a mach channel to the specified send right. * * Disconnects the channel from the current send right, interrupts any pending * message sends (and returns the messages as unsent), and reconnects the * channel to a new send right. * * The application must wait for the channel handler to be invoked with * DISPATCH_MACH_DISCONNECTED before releasing the previous send right. * * @param channel * The mach channel to reconnect. * * @param send * The new send right to associate with the channel. May be MACH_PORT_NULL. * * @param checkin * An optional message object encapsulating the initial check-in message to send * upon channel reconnection. The check-in message is sent immediately before * the first message submitted via dispatch_mach_send() after this function * returns. The message object will be retained until the initial send operation * is complete (or not peformed due to channel cancellation or reconnection) * and the channel handler has returned. May be NULL. */ __OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_6_0) DISPATCH_EXPORT DISPATCH_NONNULL1 DISPATCH_NOTHROW void dispatch_mach_reconnect(dispatch_mach_t channel, mach_port_t send, dispatch_mach_msg_t checkin); /*! * @function dispatch_mach_cancel * Cancel a mach channel, preventing any further messages from being sent or * received. * * The application must wait for the channel handler to be invoked with * DISPATCH_MACH_DISCONNECTED before releasing the underlying send and receive * rights. * * Note: explicit cancellation of mach channels is required, no implicit * cancellation takes place on release of the last application reference * to the channel object. Failure to cancel will cause the channel and * its associated resources to be leaked. * * @param channel * The mach channel to cancel. */ __OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_6_0) DISPATCH_EXPORT DISPATCH_NONNULL_ALL DISPATCH_NOTHROW void dispatch_mach_cancel(dispatch_mach_t channel); /*! * @function dispatch_mach_send * Asynchronously send a message encapsulated in a dispatch mach message object * to the specified mach channel. * * Unless the message is being sent to a send-once right (as determined by the * presence of MACH_MSG_TYPE_MOVE_SEND_ONCE in the message header remote bits), * the message header remote port is set to the channel send right before the * send operation is performed. * * If the message expects a direct reply (as determined by the presence of * MACH_MSG_TYPE_MAKE_SEND_ONCE in the message header local bits) the receive * right specified in the message header local port will be monitored until a * reply message (or a send-once notification) is received, or the channel is * canceled. Hence the application must wait for the channel handler to be * invoked with a DISPATCH_MACH_DISCONNECTED message before releasing that * receive right. * * If the message send operation is attempted but the channel is canceled * before the send operation succesfully completes, the message returned to the * channel handler with DISPATCH_MACH_MESSAGE_NOT_SENT may be the result of a * pseudo-receive operation. If the message expected a direct reply, the * receive right originally specified in the message header local port will * returned in a DISPATCH_MACH_DISCONNECTED message. * * @param channel * The mach channel to which to send the message. * * @param message * The message object encapsulating the message to send. The object will be * retained until the send operation is complete and the channel handler has * returned. The storage underlying the message object may be modified by the * send operation. * * @param options * Additional send options to pass to mach_msg() when performing the send * operation. */ __OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_6_0) DISPATCH_EXPORT DISPATCH_NONNULL1 DISPATCH_NONNULL2 DISPATCH_NOTHROW void dispatch_mach_send(dispatch_mach_t channel, dispatch_mach_msg_t message, mach_msg_option_t options); #ifdef __BLOCKS__ /*! * @function dispatch_mach_send_barrier * Submit a send barrier to the specified mach channel. Messages submitted to * the channel before the barrier will be sent before the barrier block is * executed, and messages submitted to the channel after the barrier will only * be sent once the barrier block has completed and the channel handler * invocation for the barrier has returned. * * @param channel * The mach channel to which to submit the barrier. * * @param barrier * The barrier block to submit to the channel target queue. */ __OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_6_0) DISPATCH_EXPORT DISPATCH_NONNULL_ALL DISPATCH_NOTHROW void dispatch_mach_send_barrier(dispatch_mach_t channel, dispatch_block_t barrier); #endif /*! * @function dispatch_mach_send_barrier_f * Submit a send barrier to the specified mach channel. Messages submitted to * the channel before the barrier will be sent before the barrier block is * executed, and messages submitted to the channel after the barrier will only * be sent once the barrier block has completed and the channel handler * invocation for the barrier has returned. * * @param channel * The mach channel to which to submit the barrier. * * @param context * The application-defined context parameter to pass to the function. * * @param barrier * The barrier function to submit to the channel target queue. */ __OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_6_0) DISPATCH_EXPORT DISPATCH_NONNULL1 DISPATCH_NONNULL3 DISPATCH_NOTHROW void dispatch_mach_send_barrier_f(dispatch_mach_t channel, void *context, dispatch_function_t barrier); #ifdef __BLOCKS__ /*! * @function dispatch_mach_receive_barrier * Submit a receive barrier to the specified mach channel. Channel handlers for * messages received by the channel after the receive barrier has been * submitted will only be invoked once the barrier block has completed and the * channel handler invocation for the barrier has returned. * * @param channel * The mach channel to which to submit the receive barrier. * * @param barrier * The barrier block to submit to the channel target queue. */ __OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_6_0) DISPATCH_EXPORT DISPATCH_NONNULL_ALL DISPATCH_NOTHROW void dispatch_mach_receive_barrier(dispatch_mach_t channel, dispatch_block_t barrier); #endif /*! * @function dispatch_mach_receive_barrier_f * Submit a receive barrier to the specified mach channel. Channel handlers for * messages received by the channel after the receive barrier has been * submitted will only be invoked once the barrier block has completed and the * channel handler invocation for the barrier has returned. * * @param channel * The mach channel to which to submit the receive barrier. * * @param context * The application-defined context parameter to pass to the function. * * @param barrier * The barrier function to submit to the channel target queue. */ __OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_6_0) DISPATCH_EXPORT DISPATCH_NONNULL1 DISPATCH_NONNULL3 DISPATCH_NOTHROW void dispatch_mach_receive_barrier_f(dispatch_mach_t channel, void *context, dispatch_function_t barrier); /*! * @function dispatch_mach_get_checkin_port * Returns the port specified in the message header remote port of the check-in * message passed to the most recent invocation of dispatch_mach_connect() or * dispatch_mach_reconnect() for the provided mach channel (irrespective of the * completion of the (re)connect or check-in operations in question). * * Returns MACH_PORT_NULL if dispatch_mach_connect() has not yet been called or * if the most recently specified check-in message was NULL, and MACH_PORT_DEAD * if the channel has been canceled. * * It is the responsibility of the application to ensure that the port * specified in a check-in message remains valid at the time this function is * called. * * @param channel * The mach channel to query. * * @result * The most recently specified check-in port for the channel. */ __OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_6_0) DISPATCH_EXPORT DISPATCH_NONNULL_ALL DISPATCH_NOTHROW mach_port_t dispatch_mach_get_checkin_port(dispatch_mach_t channel); #endif // DISPATCH_MACH_SPI __END_DECLS #endif