The Signal Manager provides the capabilities required for asynchronous communication. More...

Macros
#define	RTEMS_SIGNAL_0 0x00000001
	This signal set constant represents the bit in the signal set associated with signal 0.

#define	RTEMS_SIGNAL_1 0x00000002
	This signal set constant represents the bit in the signal set associated with signal 1.

#define	RTEMS_SIGNAL_2 0x00000004
	This signal set constant represents the bit in the signal set associated with signal 2.

#define	RTEMS_SIGNAL_3 0x00000008
	This signal set constant represents the bit in the signal set associated with signal 3.

#define	RTEMS_SIGNAL_4 0x00000010
	This signal set constant represents the bit in the signal set associated with signal 4.

#define	RTEMS_SIGNAL_5 0x00000020
	This signal set constant represents the bit in the signal set associated with signal 5.

#define	RTEMS_SIGNAL_6 0x00000040
	This signal set constant represents the bit in the signal set associated with signal 6.

#define	RTEMS_SIGNAL_7 0x00000080
	This signal set constant represents the bit in the signal set associated with signal 7.

#define	RTEMS_SIGNAL_8 0x00000100
	This signal set constant represents the bit in the signal set associated with signal 8.

#define	RTEMS_SIGNAL_9 0x00000200
	This signal set constant represents the bit in the signal set associated with signal 9.

#define	RTEMS_SIGNAL_10 0x00000400
	This signal set constant represents the bit in the signal set associated with signal 10.

#define	RTEMS_SIGNAL_11 0x00000800
	This signal set constant represents the bit in the signal set associated with signal 11.

#define	RTEMS_SIGNAL_12 0x00001000
	This signal set constant represents the bit in the signal set associated with signal 12.

#define	RTEMS_SIGNAL_13 0x00002000
	This signal set constant represents the bit in the signal set associated with signal 13.

#define	RTEMS_SIGNAL_14 0x00004000
	This signal set constant represents the bit in the signal set associated with signal 14.

#define	RTEMS_SIGNAL_15 0x00008000
	This signal set constant represents the bit in the signal set associated with signal 15.

#define	RTEMS_SIGNAL_16 0x00010000
	This signal set constant represents the bit in the signal set associated with signal 16.

#define	RTEMS_SIGNAL_17 0x00020000
	This signal set constant represents the bit in the signal set associated with signal 17.

#define	RTEMS_SIGNAL_18 0x00040000
	This signal set constant represents the bit in the signal set associated with signal 18.

#define	RTEMS_SIGNAL_19 0x00080000
	This signal set constant represents the bit in the signal set associated with signal 19.

#define	RTEMS_SIGNAL_20 0x00100000
	This signal set constant represents the bit in the signal set associated with signal 20.

#define	RTEMS_SIGNAL_21 0x00200000
	This signal set constant represents the bit in the signal set associated with signal 21.

#define	RTEMS_SIGNAL_22 0x00400000
	This signal set constant represents the bit in the signal set associated with signal 22.

#define	RTEMS_SIGNAL_23 0x00800000
	This signal set constant represents the bit in the signal set associated with signal 23.

#define	RTEMS_SIGNAL_24 0x01000000
	This signal set constant represents the bit in the signal set associated with signal 24.

#define	RTEMS_SIGNAL_25 0x02000000
	This signal set constant represents the bit in the signal set associated with signal 25.

#define	RTEMS_SIGNAL_26 0x04000000
	This signal set constant represents the bit in the signal set associated with signal 26.

#define	RTEMS_SIGNAL_27 0x08000000
	This signal set constant represents the bit in the signal set associated with signal 27.

#define	RTEMS_SIGNAL_28 0x10000000
	This signal set constant represents the bit in the signal set associated with signal 28.

#define	RTEMS_SIGNAL_29 0x20000000
	This signal set constant represents the bit in the signal set associated with signal 29.

#define	RTEMS_SIGNAL_30 0x40000000
	This signal set constant represents the bit in the signal set associated with signal 30.

#define	RTEMS_SIGNAL_31 0x80000000
	This signal set constant represents the bit in the signal set associated with signal 31.

Typedefs
typedef void	rtems_asr
	This type defines the return type of routines which are used to process asynchronous signals.

typedef uint32_t	rtems_signal_set
	This integer type represents a bit field which can hold exactly 32 individual signals.

typedef rtems_asr(*	rtems_asr_entry) (rtems_signal_set)
	This type defines the prototype of routines which are used to process asynchronous signals.

Functions
rtems_status_code	rtems_signal_catch (rtems_asr_entry asr_handler, rtems_mode mode_set)
	Establishes an asynchronous signal routine (ASR) for the calling task.

rtems_status_code	rtems_signal_send (rtems_id id, rtems_signal_set signal_set)
	Sends the signal set to the task.

Detailed Description

The Signal Manager provides the capabilities required for asynchronous communication.

Typedef Documentation

◆ rtems_asr

typedef void rtems_asr

This type defines the return type of routines which are used to process asynchronous signals.

Notes: This type can be used to document asynchronous signal routines in the source code.

Function Documentation

◆ rtems_signal_catch()

rtems_status_code rtems_signal_catch	(	rtems_asr_entry	asr_handler,
		rtems_mode	mode_set
	)

Establishes an asynchronous signal routine (ASR) for the calling task.

Parameters

asr_handler	is the handler to process an asynchronous signal set.
mode_set	is the task mode while an asynchronous signal set is processed by the handler. See rtems_task_mode().

This directive establishes an asynchronous signal routine (ASR) for the calling task. The asr_handler parameter specifies the entry point of the ASR. A task may have at most one handler installed at a time. The most recently installed handler is used. When asr_handler is NULL, the ASR for the calling task is invalidated and all pending signals are cleared. Any signals sent to a task with an invalid ASR are discarded. The mode_set parameter specifies the execution mode for the ASR. This execution mode supersedes the task's execution mode while the ASR is executing.

Return values

RTEMS_SUCCESSFUL	The requested operation was successful.
RTEMS_NOT_IMPLEMENTED	The RTEMS_NO_PREEMPT was set in `mode_set` and the system configuration had no implementation for this mode.
RTEMS_NOT_IMPLEMENTED	The RTEMS_INTERRUPT_LEVEL() was set to a positive level in `mode_set` and the system configuration had no implementation for this mode.

Notes

It is strongly recommended to disable ASR processing during ASR processing by setting RTEMS_NO_ASR in mode_set, otherwise a recursion may happen during ASR processing. Uncontrolled recursion may lead to stack overflows.

Using the same mutex (in particular a recursive mutex) in normal task context and during ASR processing may result in undefined behaviour.

Asynchronous signal handlers can access thread-local storage (TLS). When thread-local storage is shared between normal task context and ASR processing, it may be protected by disabled interrupts.

Constraints

The following constraints apply to this directive:

The directive may be called from within task context.
The directive will not cause the calling task to be preempted.

◆ rtems_signal_send()

rtems_status_code rtems_signal_send	(	rtems_id	id,
		rtems_signal_set	signal_set
	)

Sends the signal set to the task.

Parameters

id	is the identifier of the target task to receive the signal set.
signal_set	is the signal set to send.

This directive sends the signal set, signal_set, to the target task identified by id.

If a caller sends a signal set to a task with an invalid ASR, then an error code is returned to the caller. If a caller sends a signal set to a task whose ASR is valid but disabled, then the signal set will be caught and left pending for the ASR to process when it is enabled. If a caller sends a signal set to a task with an ASR that is both valid and enabled, then the signal set is caught and the ASR will execute the next time the task is dispatched to run.

Return values

RTEMS_SUCCESSFUL	The requested operation was successful.
RTEMS_INVALID_NUMBER	The `signal_set` parameter was 0.
RTEMS_INVALID_ID	There was no task associated with the identifier specified by `id`.
RTEMS_NOT_DEFINED	The target task had no valid ASR installed.

Notes

Sending a signal set to a task has no effect on that task's state. If a signal set is sent to a blocked task, then the task will remain blocked and the signals will be processed when the task becomes the running task.

Sending a signal set to a global task which does not reside on the local node will generate a request telling the remote node to send the signal set to the specified task.