diff options
Diffstat (limited to 'src/thread')
| -rw-r--r-- | src/thread/__lock.c | 4 | ||||
| -rw-r--r-- | src/thread/pthread_create.c | 8 |
2 files changed, 7 insertions, 5 deletions
diff --git a/src/thread/__lock.c b/src/thread/__lock.c index 5b9b144e..60eece49 100644 --- a/src/thread/__lock.c +++ b/src/thread/__lock.c @@ -18,9 +18,11 @@ void __lock(volatile int *l) { - if (!libc.threaded) return; + int need_locks = libc.need_locks; + if (!need_locks) return; /* fast path: INT_MIN for the lock, +1 for the congestion */ int current = a_cas(l, 0, INT_MIN + 1); + if (need_locks < 0) libc.need_locks = 0; if (!current) return; /* A first spin loop, for medium congestion. */ for (unsigned i = 0; i < 10; ++i) { diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c index 6a3b0c21..6bdfb44f 100644 --- a/src/thread/pthread_create.c +++ b/src/thread/pthread_create.c @@ -118,8 +118,8 @@ _Noreturn void __pthread_exit(void *result) * until the lock is released, which only happens after SYS_exit * has been called, via the exit futex address pointing at the lock. * This needs to happen after any possible calls to LOCK() that might - * skip locking if libc.threads_minus_1 is zero. */ - libc.threads_minus_1--; + * skip locking if process appears single-threaded. */ + if (!--libc.threads_minus_1) libc.need_locks = -1; self->next->prev = self->prev; self->prev->next = self->next; self->prev = self->next = self; @@ -339,7 +339,7 @@ int __pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict att ~(1UL<<((SIGCANCEL-1)%(8*sizeof(long)))); __tl_lock(); - libc.threads_minus_1++; + if (!libc.threads_minus_1++) libc.need_locks = 1; ret = __clone((c11 ? start_c11 : start), stack, flags, args, &new->tid, TP_ADJ(new), &__thread_list_lock); /* All clone failures translate to EAGAIN. If explicit scheduling @@ -363,7 +363,7 @@ int __pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict att new->next->prev = new; new->prev->next = new; } else { - libc.threads_minus_1--; + if (!--libc.threads_minus_1) libc.need_locks = 0; } __tl_unlock(); __restore_sigs(&set); |