ev_pop(S)
ev_pop --
pop the next event off the queue
Syntax
cc . . . -levent
#include <sys/types.h>
#include <sys/param.h>
#include <sys/sysmacros.h>
#include <sys/page.h>
#include <sys/event.h>
#include <mouse.h>
int ev_pop()
Description
ev_pop
clears the next event off the queue and returns the number of events
that were lost due to queue overrun since the last ev_pop call.
An event queue must have been opened with ev_init and
ev_open.
After an application is done with an event, the event is popped off
the queue. The queue is of fixed size, so if events are not popped
fast enough some might be lost due to overrun.
A counter maintains the number of lost events.
When ev_pop is called, it clears the top
event off of the queue, clears the counter and returns the number of
lost events.
This should always be zero, unless
a program stops reading its event queue.
If the queue is empty, ev_pop returns -1.
When ev_pop is called, the most recent pointer returned
by ev_read must be considered invalid, since that storage
may be overwritten by the event driver.
Diagnostics
ev_pop
returns -1 if there is not an open event queue. It returns
-2 if there is nothing to pop because the queue is empty.
See also
ev_block(S),
ev_close(S),
ev_count(S),
ev_flush(S),
ev_getdev(S),
ev_getemask(S),
ev_gindev(S),
ev_init(S),
ev_open(S),
ev_read(S),
ev_resume(S),
ev_setemask(S),
ev_suspend(S)
Standards conformance
ev_pop is not part of any currently supported standard;
it is an extension of AT&T System V provided by the Santa Cruz Operation.
© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003