assuan: Use exponential decay for first 1s of spinlock.

* common/asshelp.c (wait_for_sock): instead of checking the socket
every second, we check 10 times in the first second (with exponential
decay).
--

This cuts the wall clock time for the standard test suite roughly by
half.

GnuPG-bug-id: 3490
Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
This commit is contained in:
Daniel Kahn Gillmor 2017-11-08 16:26:40 +01:00
parent 0471ff9d3b
commit 149041b0b9
1 changed files with 26 additions and 5 deletions

View File

@ -310,14 +310,32 @@ unlock_spawning (lock_spawn_t *lock, const char *name)
static gpg_error_t
wait_for_sock (int secs, const char *name, const char *sockname, int verbose, assuan_context_t ctx, int *did_success_msg)
{
int i;
gpg_error_t err = 0;
for (i=0; i < secs; i++)
int target_us = secs * 1000000;
int elapsed_us = 0;
/*
* 977us * 1024 = just a little more than 1s.
* so we will double this timeout 10 times in the first
* second, and then switch over to 1s checkins.
*/
int next_sleep_us = 977;
int lastalert = secs+1;
int secsleft;
while (elapsed_us < target_us)
{
if (verbose)
log_info (_("waiting for the %s to come up ... (%ds)\n"),
name, secs - i);
gnupg_sleep (1);
{
secsleft = (target_us - elapsed_us)/1000000;
if (secsleft < lastalert)
{
log_info (_("waiting for the %s to come up ... (%ds)\n"),
name, secsleft);
lastalert = secsleft;
}
}
gnupg_usleep (next_sleep_us);
elapsed_us += next_sleep_us;
err = assuan_socket_connect (ctx, sockname, 0, 0);
if (!err)
{
@ -329,6 +347,9 @@ wait_for_sock (int secs, const char *name, const char *sockname, int verbose, as
}
break;
}
next_sleep_us *= 2;
if (next_sleep_us > 1000000)
next_sleep_us = 1000000;
}
return err;
}