r22661: optimize the handling of directly triggered timed events:
- if someone adds a timed_event with a zero timeval
we now avoid serval gettimeofday() calls and the
event handler doesn't get the current time when it's
called, instead we also pass a zero timeval
- this also makes sure multiple timed events with a zero timeval
are processed in the order there're added.
the little benchmark shows that processing
2000000 directly timed events
is now much faster, while avoiding syscalls at all!
> time ./evtest (with the old code)
real 0m6.388s
user 0m1.740s
sys 0m4.632s
> time ./evtest (with the new code)
real 0m1.498s
user 0m1.496s
sys 0m0.004s
metze@SERNOX:~/devel/samba/4.0/samba4-ci/source> cat evtest.c
#include <stdio.h>
#include <stdint.h>
#include <sys/time.h>
#include <talloc.h>
#include <events.h>
static void dummy_fde_handler(struct event_context *ev_ctx, struct fd_event *fde,
uint16_t flags, void *private_data)
{
}
static void timeout_handler(struct event_context *ev, struct timed_event *te,
struct timeval tval, void *private_data)
{
uint32_t *countp = (uint32_t *)private_data;
(*countp)++;
if (*countp >
2000000) exit(0);
event_add_timed(ev, ev, tval, timeout_handler, countp);
}
int main(void)
{
struct event_context *ev;
struct timeval tval = { 0, 0 };
uint32_t count = 0;
ev = event_context_init(NULL);
event_add_fd(ev, ev, 0, 0, dummy_fde_handler, NULL);
event_add_timed(ev, ev, tval, timeout_handler, &count);
return event_loop_wait(ev);
}