res_send: use a temp buffer if caller's buffer is under 512 bytes

[musl] / src / thread / pthread_mutexattr_setprotocol.c

diff --git a/src/thread/pthread_mutexattr_setprotocol.c b/src/thread/pthread_mutexattr_setprotocol.c
index 511cc32..8b80c1c 100644 (file)
--- a/src/thread/pthread_mutexattr_setprotocol.c
+++ b/src/thread/pthread_mutexattr_setprotocol.c
@@ -1,24 +1,23 @@
 #include "pthread_impl.h"
 #include "syscall.h"
 
-static pthread_once_t check_pi_once;
-static int check_pi_result;
-
-static void check_pi()
-{
-       volatile int lk = 0;
-       check_pi_result = -__syscall(SYS_futex, &lk, FUTEX_LOCK_PI, 0, 0);
-}
+static volatile int check_pi_result = -1;
 
 int pthread_mutexattr_setprotocol(pthread_mutexattr_t *a, int protocol)
 {
+       int r;
        switch (protocol) {
        case PTHREAD_PRIO_NONE:
                a->__attr &= ~8;
                return 0;
        case PTHREAD_PRIO_INHERIT:
-               pthread_once(&check_pi_once, check_pi);
-               if (check_pi_result) return check_pi_result;
+               r = check_pi_result;
+               if (r < 0) {
+                       volatile int lk = 0;
+                       r = -__syscall(SYS_futex, &lk, FUTEX_LOCK_PI, 0, 0);
+                       a_store(&check_pi_result, r);
+               }
+               if (r) return r;
                a->__attr |= 8;
                return 0;
        case PTHREAD_PRIO_PROTECT: