Closure Callbacks

Functions
bool	ccbSignalEvent (stvlist *cvars, stvlist *args)
bool	ccbSignalSharedEvent (stvlist *cvars, stvlist *args)
bool	ccbAdvanceTask (stvlist *cvars, stvlist *args)

Detailed Description

Provides ready-to-use closure callback functions for common operations like event signaling and task management. These functions are designed to work with the closure and closure chain systems (see Closures and Closure Chains).

These callbacks are particularly useful for deferred execution, event handling, and coordination between asynchronous operations. Each callback expects specific captured variables (cvars) as documented.

Example usage with closure chains:

SharedEvent *sev = sheventCreate();
cchain myChain = NULL;
 
// Attach callback that will signal and release the shared event when chain is called
// Acquire a reference to hand off to the callback
cchainAttach(&myChain, ccbSignalSharedEvent, stvar(ptr, sheventAcquire(sev)));
 
// Later, when chain is called, the event will be signaled and released
cchainCall(&myChain);
 
// Wait for event on another thread
eventWait(&sev->ev, timeForever);
sheventRelease(&sev);
 
cchainDestroy(&myChain);

Function Documentation

ccbAdvanceTask()

bool ccbAdvanceTask	(	stvlist *	cvars,
		stvlist *	args
	)

Advance a complex task

Closure callback that advances a ComplexTask given a weak reference. Acquires the task from the weak reference, advances it, then releases the task. If the weak reference is invalid (task destroyed), does nothing. Ignores call-time arguments.

This is useful for scheduling task advancement in response to events or callbacks.

Captured variables:

• cvar[0]: Weak(ComplexTask)* - Weak reference to the task to advance

Parameters

cvars	Captured variables containing weak task reference
args	Call-time arguments (ignored)

Returns

true on success, false if weak reference is NULL or task is destroyed

ccbSignalEvent()

bool ccbSignalEvent	(	stvlist *	cvars,
		stvlist *	args
	)

Signal an event

Closure callback that signals an Event. Expects the event pointer as the first captured variable (cvar). Ignores call-time arguments.

Captured variables:

• cvar[0]: Event* - Pointer to event to signal

Parameters

cvars	Captured variables containing Event pointer
args	Call-time arguments (ignored)

Returns

true on success, false if event pointer is NULL

ccbSignalSharedEvent()

bool ccbSignalSharedEvent	(	stvlist *	cvars,
		stvlist *	args
	)

Signal and release a shared event

Closure callback that signals a SharedEvent and then releases the reference. Expects the shared event pointer as the first captured variable. Ignores call-time arguments.

This is useful for one-time event notifications where the shared event reference should be released after signaling.

Captured variables:

• cvar[0]: SharedEvent* - Pointer to shared event to signal and release

Parameters

cvars	Captured variables containing SharedEvent pointer
args	Call-time arguments (ignored)

Returns

true on success, false if shared event pointer is NULL