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| author | Rich Felker <dalias@aerifal.cx> | 2020-10-14 19:07:27 -0400 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2020-10-14 20:27:12 -0400 |
| commit | 85e16aec51c343f64601b70a6081def69b9f87bc (patch) | |
| tree | d802c54aba2c459c46dd1eba4f5d8e78d3c5fcd8 | |
| parent | 6ae2568bc2367b4d47e0ea1cb043fd56e697912f (diff) | |
| download | musl-85e16aec51c343f64601b70a6081def69b9f87bc.zip musl-85e16aec51c343f64601b70a6081def69b9f87bc.tar.gz musl-85e16aec51c343f64601b70a6081def69b9f87bc.tar.bz2 | |
drop use of pthread_once in timer_create
this makes the code slightly smaller and eliminates timer_create from
relevance to possible future changes to multithreaded fork.
the barrier of a_store isn't technically needed here, but a_store is
used anyway for internal consistency of the memory model.
| -rw-r--r-- | src/time/timer_create.c | 17 |
1 files changed, 7 insertions, 10 deletions
diff --git a/src/time/timer_create.c b/src/time/timer_create.c index 2b1ea17..5ddfda2 100644 --- a/src/time/timer_create.c +++ b/src/time/timer_create.c @@ -2,6 +2,7 @@ #include <setjmp.h> #include <limits.h> #include "pthread_impl.h" +#include "atomic.h" struct ksigevent { union sigval sigev_value; @@ -32,14 +33,6 @@ static void cleanup_fromsig(void *p) longjmp(p, 1); } -static void install_handler() -{ - struct sigaction sa = { - .sa_handler = SIG_DFL, - }; - __libc_sigaction(SIGTIMER, &sa, 0); -} - static void *start(void *arg) { pthread_t self = __pthread_self(); @@ -66,7 +59,7 @@ static void *start(void *arg) int timer_create(clockid_t clk, struct sigevent *restrict evp, timer_t *restrict res) { - static pthread_once_t once = PTHREAD_ONCE_INIT; + volatile static int init = 0; pthread_t td; pthread_attr_t attr; int r; @@ -90,7 +83,11 @@ int timer_create(clockid_t clk, struct sigevent *restrict evp, timer_t *restrict *res = (void *)(intptr_t)timerid; break; case SIGEV_THREAD: - pthread_once(&once, install_handler); + if (!init) { + struct sigaction sa = { .sa_handler = SIG_DFL }; + __libc_sigaction(SIGTIMER, &sa, 0); + a_store(&init, 1); + } if (evp->sigev_notify_attributes) attr = *evp->sigev_notify_attributes; else |