factor cancellation cleanup push/pop out of futex __timedwait function

previously, the __timedwait function was optionally a cancellation
point depending on whether it was passed a pointer to a cleaup
function and context to register. as of now, only one caller actually
used such a cleanup function (and it may face removal soon); most
callers either passed a null pointer to disable cancellation or a
dummy cleanup function.

now, __timedwait is never a cancellation point, and __timedwait_cp is
the cancellable version. this makes the intent of the calling code
more obvious and avoids ugly dummy functions and long argument lists.

diff --git a/src/aio/aio_suspend.c b/src/aio/aio_suspend.c
index 2391d786524e75d183771d829945b4678108af41..dfa524bfaa922d2a61ecef3a27700afc775b50af 100644 (file)
--- a/src/aio/aio_suspend.c
+++ b/src/aio/aio_suspend.c
@@ -61,7 +61,7 @@ int aio_suspend(const struct aiocb *const cbs[], int cnt, const struct timespec
                        break;
                }
 
-               ret = __timedwait(pfut, expect, CLOCK_MONOTONIC, ts?&at:0, 0, 0, 1);
+               ret = __timedwait(pfut, expect, CLOCK_MONOTONIC, ts?&at:0, 1);
 
                if (ret) {
                        errno = ret==ETIMEDOUT ? EAGAIN : ret;

diff --git a/src/internal/pthread_impl.h b/src/internal/pthread_impl.h
index ae6e60b5ebc6d4bfd28ee9bb8adc136b8321d5dd..7e7baa9051e6183a1b49d7f0e0e6ba9d13b62b53 100644 (file)
--- a/src/internal/pthread_impl.h
+++ b/src/internal/pthread_impl.h
@@ -107,7 +107,8 @@ int __libc_sigprocmask(int, const sigset_t *, sigset_t *);
 void __lock(volatile int *);
 void __unmapself(void *, size_t);
 
-int __timedwait(volatile int *, int, clockid_t, const struct timespec *, void (*)(void *), void *, int);
+int __timedwait(volatile int *, int, clockid_t, const struct timespec *, int);
+int __timedwait_cp(volatile int *, int, clockid_t, const struct timespec *, int);
 void __wait(volatile int *, volatile int *, int, int);
 static inline void __wake(volatile void *addr, int cnt, int priv)
 {

diff --git a/src/thread/__timedwait.c b/src/thread/__timedwait.c
index 9b882b5a2005cf60a765c0f2dcfe839e0f1be4bc..13d8465a450552bf418f05ac06a3d81176c5b118 100644 (file)
--- a/src/thread/__timedwait.c
+++ b/src/thread/__timedwait.c
@@ -3,15 +3,15 @@
 #include <errno.h>
 #include "futex.h"
 #include "syscall.h"
+#include "pthread_impl.h"
 
 int __pthread_setcancelstate(int, int *);
 int __clock_gettime(clockid_t, struct timespec *);
 
-int __timedwait(volatile int *addr, int val,
-       clockid_t clk, const struct timespec *at,
-       void (*cleanup)(void *), void *arg, int priv)
+int __timedwait_cp(volatile int *addr, int val,
+       clockid_t clk, const struct timespec *at, int priv)
 {
-       int r, cs;
+       int r;
        struct timespec to, *top=0;
 
        if (priv) priv = 128;
@@ -28,15 +28,19 @@ int __timedwait(volatile int *addr, int val,
                top = &to;
        }
 
-       if (!cleanup) __pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
-       pthread_cleanup_push(cleanup, arg);
-
        r = -__syscall_cp(SYS_futex, addr, FUTEX_WAIT|priv, val, top);
        if (r == ENOSYS) r = -__syscall_cp(SYS_futex, addr, FUTEX_WAIT, val, top);
        if (r != EINTR && r != ETIMEDOUT && r != ECANCELED) r = 0;
 
-       pthread_cleanup_pop(0);
-       if (!cleanup) __pthread_setcancelstate(cs, 0);
+       return r;
+}
 
+int __timedwait(volatile int *addr, int val,
+       clockid_t clk, const struct timespec *at, int priv)
+{
+       int cs, r;
+       __pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
+       r = __timedwait_cp(addr, val, clk, at, priv);
+       __pthread_setcancelstate(cs, 0);
        return r;
 }

diff --git a/src/thread/pthread_cond_timedwait.c b/src/thread/pthread_cond_timedwait.c
index adf9c6e55d9303f723bb3bc53849de999533e987..f5fd08c099703dacd56950269adf3cdb616b45d2 100644 (file)
--- a/src/thread/pthread_cond_timedwait.c
+++ b/src/thread/pthread_cond_timedwait.c
@@ -64,10 +64,6 @@ enum {
        LEAVING,
 };
 
-static void dummy(void *arg)
-{
-}
-
 int __pthread_cond_timedwait(pthread_cond_t *restrict c, pthread_mutex_t *restrict m, const struct timespec *restrict ts)
 {
        struct waiter node = { 0 };
@@ -104,7 +100,7 @@ int __pthread_cond_timedwait(pthread_cond_t *restrict c, pthread_mutex_t *restri
 
        __pthread_setcancelstate(PTHREAD_CANCEL_MASKED, &cs);
 
-       do e = __timedwait(fut, seq, clock, ts, dummy, 0, !shared);
+       do e = __timedwait_cp(fut, seq, clock, ts, !shared);
        while (*fut==seq && (!e || e==EINTR));
        if (e == EINTR) e = 0;
 

diff --git a/src/thread/pthread_join.c b/src/thread/pthread_join.c
index 19e6b54861169f9ea7046672632c56f0a0981c2b..b4ff33a5e0ebbf1ca00c7b4c0a94cf3934eb7d06 100644 (file)
--- a/src/thread/pthread_join.c
+++ b/src/thread/pthread_join.c
@@ -3,15 +3,11 @@
 
 int __munmap(void *, size_t);
 
-static void dummy(void *p)
-{
-}
-
 int __pthread_join(pthread_t t, void **res)
 {
        int tmp;
        pthread_testcancel();
-       while ((tmp = t->tid)) __timedwait(&t->tid, tmp, 0, 0, dummy, 0, 0);
+       while ((tmp = t->tid)) __timedwait_cp(&t->tid, tmp, 0, 0, 0);
        if (res) *res = t->result;
        if (t->map_base) __munmap(t->map_base, t->map_size);
        return 0;

diff --git a/src/thread/pthread_mutex_timedlock.c b/src/thread/pthread_mutex_timedlock.c
index 16241eeb2938636109d030e2c9bc25635e669e2a..0a240e7913418bd86a48c02977c6733e8e49c0f8 100644 (file)
--- a/src/thread/pthread_mutex_timedlock.c
+++ b/src/thread/pthread_mutex_timedlock.c
@@ -24,7 +24,7 @@ int __pthread_mutex_timedlock(pthread_mutex_t *restrict m, const struct timespec
                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, 0, priv);
+               r = __timedwait(&m->_m_lock, t, CLOCK_REALTIME, at, priv);
                a_dec(&m->_m_waiters);
                if (r && r != EINTR) break;
        }

diff --git a/src/thread/pthread_rwlock_timedrdlock.c b/src/thread/pthread_rwlock_timedrdlock.c
index ea50da4a9e026d88780b9ecc72c880cb80fc4267..0d5d0d6c05fe8fe5c93999d45dbd76b47ee860b1 100644 (file)
--- a/src/thread/pthread_rwlock_timedrdlock.c
+++ b/src/thread/pthread_rwlock_timedrdlock.c
@@ -15,7 +15,7 @@ int pthread_rwlock_timedrdlock(pthread_rwlock_t *restrict rw, const struct times
                t = r | 0x80000000;
                a_inc(&rw->_rw_waiters);
                a_cas(&rw->_rw_lock, r, t);
-               r = __timedwait(&rw->_rw_lock, t, CLOCK_REALTIME, at, 0, 0, rw->_rw_shared^128);
+               r = __timedwait(&rw->_rw_lock, t, CLOCK_REALTIME, at, rw->_rw_shared^128);
                a_dec(&rw->_rw_waiters);
                if (r && r != EINTR) return r;
        }

diff --git a/src/thread/pthread_rwlock_timedwrlock.c b/src/thread/pthread_rwlock_timedwrlock.c
index 8d04f561e6e7744305e87306db46ee968becdb8a..7f26dad1f5915e8cf5f81f6a39e9695a071d5005 100644 (file)
--- a/src/thread/pthread_rwlock_timedwrlock.c
+++ b/src/thread/pthread_rwlock_timedwrlock.c
@@ -15,7 +15,7 @@ int pthread_rwlock_timedwrlock(pthread_rwlock_t *restrict rw, const struct times
                t = r | 0x80000000;
                a_inc(&rw->_rw_waiters);
                a_cas(&rw->_rw_lock, r, t);
-               r = __timedwait(&rw->_rw_lock, t, CLOCK_REALTIME, at, 0, 0, rw->_rw_shared^128);
+               r = __timedwait(&rw->_rw_lock, t, CLOCK_REALTIME, at, rw->_rw_shared^128);
                a_dec(&rw->_rw_waiters);
                if (r && r != EINTR) return r;
        }

diff --git a/src/thread/sem_timedwait.c b/src/thread/sem_timedwait.c
index 288991d4d64b71a7084297cb34da26e37e763930..a7488df7daa1484519ea3d53b81390487298b76c 100644 (file)
--- a/src/thread/sem_timedwait.c
+++ b/src/thread/sem_timedwait.c
@@ -19,8 +19,9 @@ int sem_timedwait(sem_t *restrict sem, const struct timespec *restrict at)
                int r;
                a_inc(sem->__val+1);
                a_cas(sem->__val, 0, -1);
-               r = __timedwait(sem->__val, -1, CLOCK_REALTIME, at, cleanup, sem->__val+1, sem->__val[2]);
-               a_dec(sem->__val+1);
+               pthread_cleanup_push(cleanup, sem->__val+1);
+               r = __timedwait_cp(sem->__val, -1, CLOCK_REALTIME, at, sem->__val[2]);
+               pthread_cleanup_pop(1);
                if (r && r != EINTR) {
                        errno = r;
                        return -1;