diff options
| -rw-r--r-- | nptl/allocatestack.c | 1 | ||||
| -rw-r--r-- | nptl/cancellation.c | 51 | ||||
| -rw-r--r-- | nptl/cleanup_defer.c | 46 | ||||
| -rw-r--r-- | nptl/descr.h | 14 | ||||
| -rw-r--r-- | nptl/libc-cleanup.c | 44 | ||||
| -rw-r--r-- | nptl/pthread_cancel.c | 6 | ||||
| -rw-r--r-- | nptl/pthread_setcanceltype.c | 42 | ||||
| -rw-r--r-- | sysdeps/nptl/dl-tls_init_tp.c | 1 |
8 files changed, 35 insertions, 170 deletions
diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c index 54e95ba..9be6c42 100644 --- a/nptl/allocatestack.c +++ b/nptl/allocatestack.c @@ -161,6 +161,7 @@ get_cached_stack (size_t *sizep, void **memp) /* Cancellation handling is back to the default. */ result->cancelhandling = 0; result->cancelstate = PTHREAD_CANCEL_ENABLE; + result->canceltype = PTHREAD_CANCEL_DEFERRED; result->cleanup = NULL; result->setup_failed = 0; diff --git a/nptl/cancellation.c b/nptl/cancellation.c index ce00603..0596278 100644 --- a/nptl/cancellation.c +++ b/nptl/cancellation.c @@ -31,31 +31,19 @@ int __pthread_enable_asynccancel (void) { struct pthread *self = THREAD_SELF; - int oldval = THREAD_GETMEM (self, cancelhandling); - while (1) - { - int newval = oldval | CANCELTYPE_BITMASK; - - if (newval == oldval) - break; - - int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval, - oldval); - if (__glibc_likely (curval == oldval)) - { - if (self->cancelstate == PTHREAD_CANCEL_ENABLE - && CANCEL_CANCELED_AND_ASYNCHRONOUS (newval)) - { - THREAD_SETMEM (self, result, PTHREAD_CANCELED); - __do_cancel (); - } + int oldval = THREAD_GETMEM (self, canceltype); + THREAD_SETMEM (self, canceltype, PTHREAD_CANCEL_ASYNCHRONOUS); - break; - } + int ch = THREAD_GETMEM (self, cancelhandling); - /* Prepare the next round. */ - oldval = curval; + if (self->cancelstate == PTHREAD_CANCEL_ENABLE + && (ch & CANCELED_BITMASK) + && !(ch & EXITING_BITMASK) + && !(ch & TERMINATED_BITMASK)) + { + THREAD_SETMEM (self, result, PTHREAD_CANCELED); + __do_cancel (); } return oldval; @@ -69,25 +57,10 @@ __pthread_disable_asynccancel (int oldtype) { /* If asynchronous cancellation was enabled before we do not have anything to do. */ - if (oldtype & CANCELTYPE_BITMASK) + if (oldtype == PTHREAD_CANCEL_ASYNCHRONOUS) return; struct pthread *self = THREAD_SELF; - int newval; - - int oldval = THREAD_GETMEM (self, cancelhandling); - - while (1) - { - newval = oldval & ~CANCELTYPE_BITMASK; - - int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval, - oldval); - if (__glibc_likely (curval == oldval)) - break; - - /* Prepare the next round. */ - oldval = curval; - } + self->canceltype = PTHREAD_CANCEL_DEFERRED; } libc_hidden_def (__pthread_disable_asynccancel) diff --git a/nptl/cleanup_defer.c b/nptl/cleanup_defer.c index 873ab00..7e858d0 100644 --- a/nptl/cleanup_defer.c +++ b/nptl/cleanup_defer.c @@ -31,27 +31,9 @@ ___pthread_register_cancel_defer (__pthread_unwind_buf_t *buf) ibuf->priv.data.prev = THREAD_GETMEM (self, cleanup_jmp_buf); ibuf->priv.data.cleanup = THREAD_GETMEM (self, cleanup); - int cancelhandling = THREAD_GETMEM (self, cancelhandling); - /* Disable asynchronous cancellation for now. */ - if (__glibc_unlikely (cancelhandling & CANCELTYPE_BITMASK)) - while (1) - { - int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, - cancelhandling - & ~CANCELTYPE_BITMASK, - cancelhandling); - if (__glibc_likely (curval == cancelhandling)) - /* Successfully replaced the value. */ - break; - - /* Prepare for the next round. */ - cancelhandling = curval; - } - - ibuf->priv.data.canceltype = (cancelhandling & CANCELTYPE_BITMASK - ? PTHREAD_CANCEL_ASYNCHRONOUS - : PTHREAD_CANCEL_DEFERRED); + ibuf->priv.data.canceltype = THREAD_GETMEM (self, canceltype); + THREAD_SETMEM (self, canceltype, PTHREAD_CANCEL_DEFERRED); /* Store the new cleanup handler info. */ THREAD_SETMEM (self, cleanup_jmp_buf, (struct pthread_unwind_buf *) buf); @@ -73,27 +55,9 @@ ___pthread_unregister_cancel_restore (__pthread_unwind_buf_t *buf) THREAD_SETMEM (self, cleanup_jmp_buf, ibuf->priv.data.prev); - int cancelhandling; - if (ibuf->priv.data.canceltype != PTHREAD_CANCEL_DEFERRED - && ((cancelhandling = THREAD_GETMEM (self, cancelhandling)) - & CANCELTYPE_BITMASK) == 0) - { - while (1) - { - int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, - cancelhandling - | CANCELTYPE_BITMASK, - cancelhandling); - if (__glibc_likely (curval == cancelhandling)) - /* Successfully replaced the value. */ - break; - - /* Prepare for the next round. */ - cancelhandling = curval; - } - - __pthread_testcancel (); - } + THREAD_SETMEM (self, canceltype, ibuf->priv.data.canceltype); + if (ibuf->priv.data.canceltype == PTHREAD_CANCEL_ASYNCHRONOUS) + __pthread_testcancel (); } versioned_symbol (libc, ___pthread_unregister_cancel_restore, __pthread_unregister_cancel_restore, GLIBC_2_34); diff --git a/nptl/descr.h b/nptl/descr.h index 35f5330..c85778d 100644 --- a/nptl/descr.h +++ b/nptl/descr.h @@ -277,9 +277,6 @@ struct pthread /* Flags determining processing of cancellation. */ int cancelhandling; - /* Bit set if asynchronous cancellation mode is selected. */ -#define CANCELTYPE_BIT 1 -#define CANCELTYPE_BITMASK (0x01 << CANCELTYPE_BIT) /* Bit set if canceled. */ #define CANCELED_BIT 3 #define CANCELED_BITMASK (0x01 << CANCELED_BIT) @@ -292,13 +289,6 @@ struct pthread /* Bit set if thread is supposed to change XID. */ #define SETXID_BIT 6 #define SETXID_BITMASK (0x01 << SETXID_BIT) - /* Mask for the rest. Helps the compiler to optimize. */ -#define CANCEL_RESTMASK 0xffffff80 - -#define CANCEL_CANCELED_AND_ASYNCHRONOUS(value) \ - (((value) & (CANCELTYPE_BITMASK | CANCELED_BITMASK \ - | EXITING_BITMASK | CANCEL_RESTMASK | TERMINATED_BITMASK)) \ - == (CANCELTYPE_BITMASK | CANCELED_BITMASK)) /* Flags. Including those copied from the thread attribute. */ int flags; @@ -402,6 +392,10 @@ struct pthread PTHREAD_CANCEL_DISABLE). */ unsigned char cancelstate; + /* Thread cancel type (PTHREAD_CANCEL_DEFERRED or + PTHREAD_CANCEL_ASYNCHRONOUS). */ + unsigned char canceltype; + /* Used on strsignal. */ struct tls_internal_t tls_state; diff --git a/nptl/libc-cleanup.c b/nptl/libc-cleanup.c index 6286b8b..180d15b 100644 --- a/nptl/libc-cleanup.c +++ b/nptl/libc-cleanup.c @@ -27,27 +27,9 @@ __libc_cleanup_push_defer (struct _pthread_cleanup_buffer *buffer) buffer->__prev = THREAD_GETMEM (self, cleanup); - int cancelhandling = THREAD_GETMEM (self, cancelhandling); - /* Disable asynchronous cancellation for now. */ - if (__glibc_unlikely (cancelhandling & CANCELTYPE_BITMASK)) - while (1) - { - int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, - cancelhandling - & ~CANCELTYPE_BITMASK, - cancelhandling); - if (__glibc_likely (curval == cancelhandling)) - /* Successfully replaced the value. */ - break; - - /* Prepare for the next round. */ - cancelhandling = curval; - } - - buffer->__canceltype = (cancelhandling & CANCELTYPE_BITMASK - ? PTHREAD_CANCEL_ASYNCHRONOUS - : PTHREAD_CANCEL_DEFERRED); + buffer->__canceltype = THREAD_GETMEM (self, canceltype); + THREAD_SETMEM (self, canceltype, PTHREAD_CANCEL_DEFERRED); THREAD_SETMEM (self, cleanup, buffer); } @@ -60,26 +42,8 @@ __libc_cleanup_pop_restore (struct _pthread_cleanup_buffer *buffer) THREAD_SETMEM (self, cleanup, buffer->__prev); - int cancelhandling; - if (__builtin_expect (buffer->__canceltype != PTHREAD_CANCEL_DEFERRED, 0) - && ((cancelhandling = THREAD_GETMEM (self, cancelhandling)) - & CANCELTYPE_BITMASK) == 0) - { - while (1) - { - int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, - cancelhandling - | CANCELTYPE_BITMASK, - cancelhandling); - if (__glibc_likely (curval == cancelhandling)) - /* Successfully replaced the value. */ - break; - - /* Prepare for the next round. */ - cancelhandling = curval; - } - + THREAD_SETMEM (self, canceltype, buffer->__canceltype); + if (buffer->__canceltype == PTHREAD_CANCEL_ASYNCHRONOUS) __pthread_testcancel (); - } } libc_hidden_def (__libc_cleanup_pop_restore) diff --git a/nptl/pthread_cancel.c b/nptl/pthread_cancel.c index f4f0836..de4659a 100644 --- a/nptl/pthread_cancel.c +++ b/nptl/pthread_cancel.c @@ -53,7 +53,7 @@ sigcancel_handler (int sig, siginfo_t *si, void *ctx) /* Set the return value. */ THREAD_SETMEM (self, result, PTHREAD_CANCELED); /* Make sure asynchronous cancellation is still enabled. */ - if ((ch & CANCELTYPE_BITMASK) != 0) + if (self->canceltype == PTHREAD_CANCEL_ASYNCHRONOUS) __do_cancel (); } @@ -104,8 +104,8 @@ __pthread_cancel (pthread_t th) #endif THREAD_SETMEM (pd, result, PTHREAD_CANCELED); - if ((oldch & CANCELSTATE_BITMASK) == 0 - && (oldch & CANCELTYPE_BITMASK) != 0) + if (pd->cancelstate == PTHREAD_CANCEL_ENABLE + && pd->canceltype == PTHREAD_CANCEL_ASYNCHRONOUS) __do_cancel (); return 0; } diff --git a/nptl/pthread_setcanceltype.c b/nptl/pthread_setcanceltype.c index ae5df1d..e7b24ae 100644 --- a/nptl/pthread_setcanceltype.c +++ b/nptl/pthread_setcanceltype.c @@ -29,43 +29,11 @@ __pthread_setcanceltype (int type, int *oldtype) volatile struct pthread *self = THREAD_SELF; - int oldval = THREAD_GETMEM (self, cancelhandling); - while (1) - { - int newval = (type == PTHREAD_CANCEL_ASYNCHRONOUS - ? oldval | CANCELTYPE_BITMASK - : oldval & ~CANCELTYPE_BITMASK); - - /* Store the old value. */ - if (oldtype != NULL) - *oldtype = ((oldval & CANCELTYPE_BITMASK) - ? PTHREAD_CANCEL_ASYNCHRONOUS : PTHREAD_CANCEL_DEFERRED); - - /* Avoid doing unnecessary work. The atomic operation can - potentially be expensive if the memory has to be locked and - remote cache lines have to be invalidated. */ - if (oldval == newval) - break; - - /* Update the cancel handling word. This has to be done - atomically since other bits could be modified as well. */ - int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval, - oldval); - if (__glibc_likely (curval == oldval)) - { - if (self->cancelstate == PTHREAD_CANCEL_ENABLE - && CANCEL_CANCELED_AND_ASYNCHRONOUS (newval)) - { - THREAD_SETMEM (self, result, PTHREAD_CANCELED); - __do_cancel (); - } - - break; - } - - /* Prepare for the next round. */ - oldval = curval; - } + if (oldtype != NULL) + *oldtype = self->canceltype; + self->canceltype = type; + if (type == PTHREAD_CANCEL_ASYNCHRONOUS) + __pthread_testcancel (); return 0; } diff --git a/sysdeps/nptl/dl-tls_init_tp.c b/sysdeps/nptl/dl-tls_init_tp.c index 378b26a..b7b3bb1 100644 --- a/sysdeps/nptl/dl-tls_init_tp.c +++ b/sysdeps/nptl/dl-tls_init_tp.c @@ -96,4 +96,5 @@ __tls_init_tp (void) THREAD_SETMEM (pd, stackblock_size, (size_t) __libc_stack_end); THREAD_SETMEM (pd, cancelstate, PTHREAD_CANCEL_ENABLE); + THREAD_SETMEM (pd, canceltype, PTHREAD_CANCEL_DEFERRED); } |