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| #define DISPATCH_SOURCE_TYPE_DATA_ADD (&_dispatch_source_type_data_add) |
DISPATCH_SOURCE_TYPE_DATA_ADD A dispatch source that coalesces data obtained via calls to dispatch_source_merge_data(). An ADD is used to coalesce the data. The handle is unused (pass zero for now). The mask is unused (pass zero for now).
| #define DISPATCH_SOURCE_TYPE_DATA_OR (&_dispatch_source_type_data_or) |
DISPATCH_SOURCE_TYPE_DATA_OR A dispatch source that coalesces data obtained via calls to dispatch_source_merge_data(). A logical OR is used to coalesce the data. The handle is unused (pass zero for now). The mask is used to perform a logical AND with the value passed to dispatch_source_merge_data().
| #define DISPATCH_SOURCE_TYPE_MACH_RECV (&_dispatch_source_type_mach_recv) |
DISPATCH_SOURCE_TYPE_MACH_RECV A dispatch source that monitors a Mach port for pending messages. The handle is a Mach port with a receive right (mach_port_t). The mask is unused (pass zero for now).
| #define DISPATCH_SOURCE_TYPE_MACH_SEND (&_dispatch_source_type_mach_send) |
DISPATCH_SOURCE_TYPE_MACH_SEND A dispatch source that monitors a Mach port for dead name notifications (send right no longer has any corresponding receive right). The handle is a Mach port with a send or send-once right (mach_port_t). The mask is a mask of desired events from dispatch_source_mach_send_flags_t.
| #define DISPATCH_SOURCE_TYPE_PROC (&_dispatch_source_type_proc) |
DISPATCH_SOURCE_TYPE_PROC A dispatch source that monitors an external process for events defined by dispatch_source_proc_flags_t. The handle is a process identifier (pid_t). The mask is a mask of desired events from dispatch_source_proc_flags_t.
| #define DISPATCH_SOURCE_TYPE_READ (&_dispatch_source_type_read) |
DISPATCH_SOURCE_TYPE_READ A dispatch source that monitors a file descriptor for pending bytes available to be read. The handle is a file descriptor (int). The mask is unused (pass zero for now).
| #define DISPATCH_SOURCE_TYPE_SIGNAL (&_dispatch_source_type_signal) |
DISPATCH_SOURCE_TYPE_SIGNAL A dispatch source that monitors the current process for signals. The handle is a signal number (int). The mask is unused (pass zero for now).
| #define DISPATCH_SOURCE_TYPE_TIMER (&_dispatch_source_type_timer) |
DISPATCH_SOURCE_TYPE_TIMER A dispatch source that submits the event handler block based on a timer. The handle is unused (pass zero for now). The mask is unused (pass zero for now).
| #define DISPATCH_SOURCE_TYPE_VNODE (&_dispatch_source_type_vnode) |
DISPATCH_SOURCE_TYPE_VNODE A dispatch source that monitors a file descriptor for events defined by dispatch_source_vnode_flags_t. The handle is a file descriptor (int). The mask is a mask of desired events from dispatch_source_vnode_flags_t.
| #define DISPATCH_SOURCE_TYPE_WRITE (&_dispatch_source_type_write) |
DISPATCH_SOURCE_TYPE_WRITE A dispatch source that monitors a file descriptor for available buffer space to write bytes. The handle is a file descriptor (int). The mask is unused (pass zero for now).
Constants of this type represent the class of low-level system object that is being monitored by the dispatch source. Constants of this type are passed as a parameter to dispatch_source_create() and determine how the handle argument is interpreted (i.e. as a file descriptor, mach port, signal number, process identifer, etc.), and how the mask arugment is interpreted.
| anonymous enum |
| anonymous enum |
| DISPATCH_DECL | ( | dispatch_source | ) |
| void dispatch_source_cancel | ( | dispatch_source_t | source | ) |
dispatch_source_cancel
Asynchronously cancel the dispatch source, preventing any further invocation of its event handler block.
Cancellation prevents any further invocation of the event handler block for the specified dispatch source, but does not interrupt an event handler block that is already in progress.
The cancellation handler is submitted to the source's target queue once the the source's event handler has finished, indicating it is now safe to close the source's handle (i.e. file descriptor or mach port).
See dispatch_source_set_cancel_handler() for more information.
| source | The dispatch source to be canceled. The result of passing NULL in this parameter is undefined. |
| __DISPATCH_BEGIN_DECLS dispatch_source_t dispatch_source_create | ( | dispatch_source_type_t | type, |
| uintptr_t | handle, | ||
| unsigned long | mask, | ||
| dispatch_queue_t | queue | ||
| ) |
dispatch_source_create
Creates a new dispatch source to monitor low-level system objects and auto- matically submit a handler block to a dispatch queue in response to events.
Dispatch sources are not reentrant. Any events received while the dispatch source is suspended or while the event handler block is currently executing will be coalesced and delivered after the dispatch source is resumed or the event handler block has returned.
Dispatch sources are created in a suspended state. After creating the source and setting any desired attributes (i.e. the handler, context, etc.), a call must be made to dispatch_resume() in order to begin event delivery.
| type | Declares the type of the dispatch source. Must be one of the defined dispatch_source_type_t constants. |
| handle | The underlying system handle to monitor. The interpretation of this argument is determined by the constant provided in the type parameter. |
| mask | A mask of flags specifying which events are desired. The interpretation of this argument is determined by the constant provided in the type parameter. |
| queue | The dispatch queue to which the event handler block will be submited. |
| unsigned long dispatch_source_get_data | ( | dispatch_source_t | source | ) |
dispatch_source_get_data
Returns pending data for the dispatch source.
This function is intended to be called from within the event handler block. The result of calling this function outside of the event handler callback is undefined.
| source | The result of passing NULL in this parameter is undefined. |
DISPATCH_SOURCE_TYPE_DATA_ADD: application defined data DISPATCH_SOURCE_TYPE_DATA_OR: application defined data DISPATCH_SOURCE_TYPE_MACH_SEND: dispatch_source_mach_send_flags_t DISPATCH_SOURCE_TYPE_MACH_RECV: n/a DISPATCH_SOURCE_TYPE_PROC: dispatch_source_proc_flags_t DISPATCH_SOURCE_TYPE_READ: estimated bytes available to read DISPATCH_SOURCE_TYPE_SIGNAL: number of signals delivered since the last handler invocation DISPATCH_SOURCE_TYPE_TIMER: number of times the timer has fired since the last handler invocation DISPATCH_SOURCE_TYPE_VNODE: dispatch_source_vnode_flags_t DISPATCH_SOURCE_TYPE_WRITE: estimated buffer space available
| uintptr_t dispatch_source_get_handle | ( | dispatch_source_t | source | ) |
dispatch_source_get_handle
Returns the underlying system handle associated with this dispatch source.
| source | The result of passing NULL in this parameter is undefined. |
DISPATCH_SOURCE_TYPE_DATA_ADD: n/a DISPATCH_SOURCE_TYPE_DATA_OR: n/a DISPATCH_SOURCE_TYPE_MACH_SEND: mach port (mach_port_t) DISPATCH_SOURCE_TYPE_MACH_RECV: mach port (mach_port_t) DISPATCH_SOURCE_TYPE_PROC: process identifier (pid_t) DISPATCH_SOURCE_TYPE_READ: file descriptor (int) DISPATCH_SOURCE_TYPE_SIGNAL: signal number (int) DISPATCH_SOURCE_TYPE_TIMER: n/a DISPATCH_SOURCE_TYPE_VNODE: file descriptor (int) DISPATCH_SOURCE_TYPE_WRITE: file descriptor (int)
| unsigned long dispatch_source_get_mask | ( | dispatch_source_t | source | ) |
dispatch_source_get_mask
Returns the mask of events monitored by the dispatch source.
| source | The result of passing NULL in this parameter is undefined. |
DISPATCH_SOURCE_TYPE_DATA_ADD: n/a DISPATCH_SOURCE_TYPE_DATA_OR: n/a DISPATCH_SOURCE_TYPE_MACH_SEND: dispatch_source_mach_send_flags_t DISPATCH_SOURCE_TYPE_MACH_RECV: n/a DISPATCH_SOURCE_TYPE_PROC: dispatch_source_proc_flags_t DISPATCH_SOURCE_TYPE_READ: n/a DISPATCH_SOURCE_TYPE_SIGNAL: n/a DISPATCH_SOURCE_TYPE_TIMER: n/a DISPATCH_SOURCE_TYPE_VNODE: dispatch_source_vnode_flags_t DISPATCH_SOURCE_TYPE_WRITE: n/a
| void dispatch_source_merge_data | ( | dispatch_source_t | source, |
| unsigned long | value | ||
| ) |
dispatch_source_merge_data
Merges data into a dispatch source of type DISPATCH_SOURCE_TYPE_DATA_ADD or DISPATCH_SOURCE_TYPE_DATA_OR and submits its event handler block to its target queue.
| source | The result of passing NULL in this parameter is undefined. |
| value | The value to coalesce with the pending data using a logical OR or an ADD as specified by the dispatch source type. A value of zero has no effect and will not result in the submission of the event handler block. |
| void dispatch_source_set_cancel_handler | ( | dispatch_source_t | source, |
| dispatch_block_t | cancel_handler | ||
| ) |
dispatch_source_set_cancel_handler
Sets the cancellation handler block for the given dispatch source.
The cancellation handler (if specified) will be submitted to the source's target queue in response to a call to dispatch_source_cancel() once the system has released all references to the source's underlying handle and the source's event handler block has returned.
IMPORTANT: A cancellation handler is required for file descriptor and mach port based sources in order to safely close the descriptor or destroy the port. Closing the descriptor or port before the cancellation handler may result in a race condition. If a new descriptor is allocated with the same value as the recently closed descriptor while the source's event handler is still running, the event handler may read/write data to the wrong descriptor.
| source | The dispatch source to modify. The result of passing NULL in this parameter is undefined. |
| handler | The cancellation handler block to submit to the source's target queue. |
| void dispatch_source_set_cancel_handler_f | ( | dispatch_source_t | source, |
| dispatch_function_t | cancel_handler | ||
| ) |
dispatch_source_set_cancel_handler_f
Sets the cancellation handler function for the given dispatch source.
See dispatch_source_set_cancel_handler() for more details.
| source | The dispatch source to modify. The result of passing NULL in this parameter is undefined. |
| handler | The cancellation handler function to submit to the source's target queue. The context parameter passed to the event handler function is the current context of the dispatch source at the time the handler call is made. |
| void dispatch_source_set_event_handler | ( | dispatch_source_t | source, |
| dispatch_block_t | handler | ||
| ) |
dispatch_source_set_event_handler
Sets the event handler block for the given dispatch source.
| source | The dispatch source to modify. The result of passing NULL in this parameter is undefined. |
| handler | The event handler block to submit to the source's target queue. |
| void dispatch_source_set_event_handler_f | ( | dispatch_source_t | source, |
| dispatch_function_t | handler | ||
| ) |
dispatch_source_set_event_handler_f
Sets the event handler function for the given dispatch source.
| source | The dispatch source to modify. The result of passing NULL in this parameter is undefined. |
| handler | The event handler function to submit to the source's target queue. The context parameter passed to the event handler function is the current context of the dispatch source at the time the handler call is made. The result of passing NULL in this parameter is undefined. |
| void dispatch_source_set_timer | ( | dispatch_source_t | source, |
| dispatch_time_t | start, | ||
| uint64_t | interval, | ||
| uint64_t | leeway | ||
| ) |
dispatch_source_set_timer
Sets a start time, interval, and leeway value for a timer source.
Calling this function has no effect if the timer source has already been canceled.
The start time argument also determines which clock will be used for the timer. If the start time is DISPATCH_TIME_NOW or created with dispatch_time() then the timer is based on mach_absolute_time(). Otherwise, if the start time of the timer is created with dispatch_walltime() then the timer is based on gettimeofday(3).
| start | The start time of the timer. See dispatch_time() and dispatch_walltime() for more information. |
| interval | The nanosecond interval for the timer. |
| leeway | A hint given to the system by the application for the amount of leeway, in nanoseconds, that the system may defer the timer in order to align with other system activity for improved system performance or power consumption. (For example, an application might perform a periodic task every 5 minutes, with a leeway of up to 30 seconds.) Note that some latency is to be expected for all timers even when a leeway value of zero is specified. |
| long dispatch_source_testcancel | ( | dispatch_source_t | source | ) |
dispatch_source_testcancel
Tests whether the given dispatch source has been canceled.
| source | The dispatch source to be tested. The result of passing NULL in this parameter is undefined. |
| struct dispatch_source_type_s _dispatch_source_type_data_add |
| struct dispatch_source_type_s _dispatch_source_type_data_or |
| struct dispatch_source_type_s _dispatch_source_type_mach_recv |
| struct dispatch_source_type_s _dispatch_source_type_mach_send |
| struct dispatch_source_type_s _dispatch_source_type_proc |
| struct dispatch_source_type_s _dispatch_source_type_read |
| struct dispatch_source_type_s _dispatch_source_type_signal |
| struct dispatch_source_type_s _dispatch_source_type_timer |
| struct dispatch_source_type_s _dispatch_source_type_vnode |
| struct dispatch_source_type_s _dispatch_source_type_write |