fix debugger tracking of shared libraries on mips with PIE main program

[musl] / src / thread / pthread_mutex_timedlock.c

diff --git a/src/thread/pthread_mutex_timedlock.c b/src/thread/pthread_mutex_timedlock.c
index ae1e2c3..9279fc5 100644 (file)
--- a/src/thread/pthread_mutex_timedlock.c
+++ b/src/thread/pthread_mutex_timedlock.c
@@ -1,24 +1,92 @@
 #include "pthread_impl.h"
 
-int pthread_mutex_timedlock(pthread_mutex_t *m, const struct timespec *at)
+#define IS32BIT(x) !((x)+0x80000000ULL>>32)
+#define CLAMP(x) (int)(IS32BIT(x) ? (x) : 0x7fffffffU+((0ULL+(x))>>63))
+
+static int __futex4(volatile void *addr, int op, int val, const struct timespec *to)
+{
+#ifdef SYS_futex_time64
+       time_t s = to ? to->tv_sec : 0;
+       long ns = to ? to->tv_nsec : 0;
+       int r = -ENOSYS;
+       if (SYS_futex == SYS_futex_time64 || !IS32BIT(s))
+               r = __syscall(SYS_futex_time64, addr, op, val,
+                       to ? ((long long[]){s, ns}) : 0);
+       if (SYS_futex == SYS_futex_time64 || r!=-ENOSYS) return r;
+       to = to ? (void *)(long[]){CLAMP(s), ns} : 0;
+#endif
+       return __syscall(SYS_futex, addr, op, val, to);
+}
+
+static int pthread_mutex_timedlock_pi(pthread_mutex_t *restrict m, const struct timespec *restrict at)
 {
-       int r, t;
+       int type = m->_m_type;
+       int priv = (type & 128) ^ 128;
+       pthread_t self = __pthread_self();
+       int e;
+
+       if (!priv) self->robust_list.pending = &m->_m_next;
+
+       do e = -__futex4(&m->_m_lock, FUTEX_LOCK_PI|priv, 0, at);
+       while (e==EINTR);
+       if (e) self->robust_list.pending = 0;
+
+       switch (e) {
+       case 0:
+               /* Catch spurious success for non-robust mutexes. */
+               if (!(type&4) && ((m->_m_lock & 0x40000000) || m->_m_waiters)) {
+                       a_store(&m->_m_waiters, -1);
+                       __syscall(SYS_futex, &m->_m_lock, FUTEX_UNLOCK_PI|priv);
+                       self->robust_list.pending = 0;
+                       break;
+               }
+               /* Signal to trylock that we already have the lock. */
+               m->_m_count = -1;
+               return __pthread_mutex_trylock(m);
+       case ETIMEDOUT:
+               return e;
+       case EDEADLK:
+               if ((type&3) == PTHREAD_MUTEX_ERRORCHECK) return e;
+       }
+       do e = __timedwait(&(int){0}, 0, CLOCK_REALTIME, at, 1);
+       while (e != ETIMEDOUT);
+       return e;
+}
 
-       if (m->_m_type == PTHREAD_MUTEX_NORMAL && !a_cas(&m->_m_lock, 0, EBUSY))
+int __pthread_mutex_timedlock(pthread_mutex_t *restrict m, const struct timespec *restrict at)
+{
+       if ((m->_m_type&15) == PTHREAD_MUTEX_NORMAL
+           && !a_cas(&m->_m_lock, 0, EBUSY))
                return 0;
 
-       while ((r=pthread_mutex_trylock(m)) == EBUSY) {
-               if (!(r=m->_m_lock) || (r&0x40000000)) continue;
-               if ((m->_m_type&3) == PTHREAD_MUTEX_ERRORCHECK
-                && (r&0x1fffffff) == pthread_self()->tid)
+       int type = m->_m_type;
+       int r, t, priv = (type & 128) ^ 128;
+
+       r = __pthread_mutex_trylock(m);
+       if (r != EBUSY) return r;
+
+       if (type&8) return pthread_mutex_timedlock_pi(m, at);
+       
+       int spins = 100;
+       while (spins-- && m->_m_lock && !m->_m_waiters) a_spin();
+
+       while ((r=__pthread_mutex_trylock(m)) == EBUSY) {
+               r = m->_m_lock;
+               int own = r & 0x3fffffff;
+               if (!own && (!r || (type&4)))
+                       continue;
+               if ((type&3) == PTHREAD_MUTEX_ERRORCHECK
+                   && own == __pthread_self()->tid)
                        return EDEADLK;
 
                a_inc(&m->_m_waiters);
                t = r | 0x80000000;
                a_cas(&m->_m_lock, r, t);
-               r = __timedwait(&m->_m_lock, t, CLOCK_REALTIME, at, 0);
+               r = __timedwait(&m->_m_lock, t, CLOCK_REALTIME, at, priv);
                a_dec(&m->_m_waiters);
                if (r && r != EINTR) break;
        }
        return r;
 }
+
+weak_alias(__pthread_mutex_timedlock, pthread_mutex_timedlock);