#include "pthread_impl.h"
-static int vmlock[2];
-
-void __vm_lock(int inc)
-{
- for (;;) {
- int v = vmlock[0];
- if (inc*v < 0) __wait(vmlock, vmlock+1, v, 1);
- else if (a_cas(vmlock, v, v+inc)==v) break;
- }
-}
-
-void __vm_unlock(void)
-{
- if (vmlock[0]>0) a_dec(vmlock);
- else a_inc(vmlock);
- if (vmlock[1]) __wake(vmlock, 1, 1);
-}
-
static int pshared_barrier_wait(pthread_barrier_t *b)
{
int limit = (b->_b_limit & INT_MAX) + 1;
__wait(&b->_b_count, &b->_b_waiters2, v, 0);
}
- __vm_lock(+1);
+ __vm_lock();
/* Ensure all threads have a vm lock before proceeding */
if (a_fetch_add(&b->_b_count, -1)==1-limit) {
struct instance
{
- int count;
- int last;
- int waiters;
- int finished;
+ volatile int count;
+ volatile int last;
+ volatile int waiters;
+ volatile int finished;
};
int pthread_barrier_wait(pthread_barrier_t *b)
/* First thread to enter the barrier becomes the "instance owner" */
if (!inst) {
struct instance new_inst = { 0 };
- int spins = 10000;
+ int spins = 200;
b->_b_inst = inst = &new_inst;
a_store(&b->_b_lock, 0);
if (b->_b_waiters) __wake(&b->_b_lock, 1, 1);
a_spin();
a_inc(&inst->finished);
while (inst->finished == 1)
- __syscall(SYS_futex, &inst->finished, FUTEX_WAIT,1,0);
+ __syscall(SYS_futex,&inst->finished,FUTEX_WAIT|FUTEX_PRIVATE,1,0) != -ENOSYS
+ || __syscall(SYS_futex,&inst->finished,FUTEX_WAIT,1,0);
return PTHREAD_BARRIER_SERIAL_THREAD;
}