@@ -25,7 +25,7 @@ include ../Makeconfig
bench-math := acos acosh asin asinh atan atanh cos cosh exp exp2 ffs ffsll \
log log2 modf pow rint sin sincos sinh sqrt tan tanh
-bench-pthread := pthread_once
+bench-pthread := pthread_once pthread_setcanceltype
bench := $(bench-math) $(bench-pthread)
@@ -547,4 +547,17 @@
# define atomic_delay() do { /* nothing */ } while (0)
#endif
+
+#ifndef atomic_read_after_write_dependent_barrier
+# define atomic_read_after_write_dependent_barrier() atomic_full_barrier ()
+#endif
+
+
+#ifndef atomic_write(mem, val)
+# define atomic_write(mem, val) \
+ do { \
+ *(mem) = (val); \
+ } while (0)
+#endif
+
#endif /* atomic.h */
@@ -31,28 +31,16 @@ __pthread_enable_asynccancel (void)
struct pthread *self = THREAD_SELF;
int oldval = THREAD_GETMEM (self, cancelhandling);
- while (1)
+ if ((oldval & CANCELTYPE_BITMASK) == 0)
{
- 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 (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval))
- {
- THREAD_SETMEM (self, result, PTHREAD_CANCELED);
- __do_cancel ();
- }
-
- break;
- }
-
- /* Prepare the next round. */
- oldval = curval;
+ /* Set the new value. */
+ THREAD_SETMEM_ATOMIC (self, cancel.type,
+ (char) PTHREAD_CANCEL_ASYNCHRONOUS);
+
+ /* Synchronize with pthread_cancel() */
+ atomic_read_after_write_dependent_barrier();
+
+ CANCELLATION_P (self);
}
return oldval;
@@ -69,22 +57,14 @@ __pthread_disable_asynccancel (int oldtype)
return;
struct pthread *self = THREAD_SELF;
- int newval;
-
- int oldval = THREAD_GETMEM (self, cancelhandling);
- while (1)
- {
- newval = oldval & ~CANCELTYPE_BITMASK;
+ /* Set the new value. */
+ THREAD_SETMEM_ATOMIC (self, cancel.type, (char) PTHREAD_CANCEL_DEFERRED);
- int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval,
- oldval);
- if (__glibc_likely (curval == oldval))
- break;
+ /* Synchronize with pthread_cancel() */
+ atomic_read_after_write_dependent_barrier();
- /* Prepare the next round. */
- oldval = curval;
- }
+ int newval = THREAD_GETMEM (self, cancelhandling);
/* We cannot return when we are being canceled. Upon return the
thread might be things which would have to be undone. The
@@ -35,19 +35,12 @@ __pthread_register_cancel_defer (__pthread_unwind_buf_t *buf)
/* 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;
- }
+ {
+ THREAD_SETMEM_ATOMIC (self, cancel.type, (char) PTHREAD_CANCEL_DEFERRED);
+
+ /* Synchronize with pthread_cancel() */
+ atomic_read_after_write_dependent_barrier();
+ }
ibuf->priv.data.canceltype = (cancelhandling & CANCELTYPE_BITMASK
? PTHREAD_CANCEL_ASYNCHRONOUS
@@ -72,19 +65,10 @@ __pthread_unregister_cancel_restore (__pthread_unwind_buf_t *buf)
&& ((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_ATOMIC (self, cancel.type, PTHREAD_CANCEL_ASYNCHRONOUS);
+
+ /* Synchronize with pthread_cancel() */
+ atomic_read_after_write_dependent_barrier();
CANCELLATION_P (self);
}
@@ -35,19 +35,12 @@ _pthread_cleanup_push_defer (buffer, routine, arg)
/* 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;
- }
+ {
+ THREAD_SETMEM_ATOMIC (self, cancel.type, (char) PTHREAD_CANCEL_DEFERRED);
+
+ /* Synchronize with pthread_cancel() */
+ atomic_read_after_write_dependent_barrier();
+ }
buffer->__canceltype = (cancelhandling & CANCELTYPE_BITMASK
? PTHREAD_CANCEL_ASYNCHRONOUS
@@ -72,19 +65,10 @@ _pthread_cleanup_pop_restore (buffer, execute)
&& ((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_ATOMIC (self, cancel.type, PTHREAD_CANCEL_ASYNCHRONOUS);
+
+ /* Synchronize with pthread_cancel() */
+ atomic_read_after_write_dependent_barrier();
CANCELLATION_P (self);
}
@@ -19,6 +19,7 @@
#ifndef _DESCR_H
#define _DESCR_H 1
+#include <endian.h>
#include <limits.h>
#include <sched.h>
#include <setjmp.h>
@@ -255,30 +256,63 @@ struct pthread
#define HAVE_CLEANUP_JMP_BUF
/* Flags determining processing of cancellation. */
- int cancelhandling;
+ union {
+ int cancelhandling;
+ struct {
+ char state;
+ char type;
+ } cancel;
+ };
+#if BYTE_ORDER == LITTLE_ENDIAN
/* Bit set if cancellation is disabled. */
#define CANCELSTATE_BIT 0
-#define CANCELSTATE_BITMASK (0x01 << CANCELSTATE_BIT)
/* Bit set if asynchronous cancellation mode is selected. */
-#define CANCELTYPE_BIT 1
-#define CANCELTYPE_BITMASK (0x01 << CANCELTYPE_BIT)
+#define CANCELTYPE_BIT 8
/* Bit set if canceling has been initiated. */
-#define CANCELING_BIT 2
-#define CANCELING_BITMASK (0x01 << CANCELING_BIT)
+#define CANCELING_BIT 16
/* Bit set if canceled. */
-#define CANCELED_BIT 3
-#define CANCELED_BITMASK (0x01 << CANCELED_BIT)
+#define CANCELED_BIT 17
/* Bit set if thread is exiting. */
-#define EXITING_BIT 4
-#define EXITING_BITMASK (0x01 << EXITING_BIT)
+#define EXITING_BIT 18
/* Bit set if thread terminated and TCB is freed. */
-#define TERMINATED_BIT 5
-#define TERMINATED_BITMASK (0x01 << TERMINATED_BIT)
+#define TERMINATED_BIT 19
/* Bit set if thread is supposed to change XID. */
-#define SETXID_BIT 6
+#define SETXID_BIT 20
+#else
+#if BYTE_ORDER == BIG_ENDIAN
+ /* Bit set if cancellation is disabled. */
+#define CANCELSTATE_BIT 24
+ /* Bit set if asynchronous cancellation mode is selected. */
+#define CANCELTYPE_BIT 16
+#else /* BYTE_ORDER == PDP_ENDIAN */
+ /* Bit set if cancellation is disabled. */
+#define CANCELSTATE_BIT 16
+ /* Bit set if asynchronous cancellation mode is selected. */
+#define CANCELTYPE_BIT 24
+#endif
+ /* Bit set if canceling has been initiated. */
+#define CANCELING_BIT 0
+ /* Bit set if canceled. */
+#define CANCELED_BIT 1
+ /* Bit set if thread is exiting. */
+#define EXITING_BIT 2
+ /* Bit set if thread terminated and TCB is freed. */
+#define TERMINATED_BIT 3
+ /* Bit set if thread is supposed to change XID. */
+#define SETXID_BIT 4
+#endif
+#define CANCELSTATE_BITMASK (0x01 << CANCELSTATE_BIT)
+#define CANCELTYPE_BITMASK (0x01 << CANCELTYPE_BIT)
+#define CANCELING_BITMASK (0x01 << CANCELING_BIT)
+#define CANCELED_BITMASK (0x01 << CANCELED_BIT)
+#define EXITING_BITMASK (0x01 << EXITING_BIT)
+#define TERMINATED_BITMASK (0x01 << TERMINATED_BIT)
#define SETXID_BITMASK (0x01 << SETXID_BIT)
/* Mask for the rest. Helps the compiler to optimize. */
-#define CANCEL_RESTMASK 0xffffff80
+#define CANCEL_RESTMASK \
+ ( ~((int) (CANCELSTATE_BITMASK | CANCELTYPE_BITMASK | CANCELING_BITMASK | \
+ CANCELED_BITMASK | EXITING_BITMASK | TERMINATED_BITMASK | \
+ SETXID_BITMASK)) )
#define CANCEL_ENABLED_AND_CANCELED(value) \
(((value) & (CANCELSTATE_BITMASK | CANCELED_BITMASK | EXITING_BITMASK \
@@ -57,6 +57,12 @@
#define PTHREAD_MUTEX_NOTRECOVERABLE (INT_MAX - 1)
+/* Same as THREAD_SETMEM, but the member offset can be non-constant. */
+#ifndef THREAD_SETMEM_ATOMIC
+# define THREAD_SETMEM_ATOMIC THREAD_SETMEM
+#endif
+
+
/* Internal mutex type value. */
enum
{
@@ -34,37 +34,30 @@ __pthread_setcancelstate (state, oldstate)
self = THREAD_SELF;
int oldval = THREAD_GETMEM (self, cancelhandling);
- while (1)
+
+ int prev_state = ((oldval & CANCELSTATE_BITMASK) ? PTHREAD_CANCEL_DISABLE :
+ PTHREAD_CANCEL_ENABLE);
+
+ /* Store the old value. */
+ if (oldstate != NULL)
+ *oldstate = prev_state;
+
+ /* Avoid doing unnecessary work. */
+ if (state != prev_state)
{
- int newval = (state == PTHREAD_CANCEL_DISABLE
- ? oldval | CANCELSTATE_BITMASK
- : oldval & ~CANCELSTATE_BITMASK);
-
- /* Store the old value. */
- if (oldstate != NULL)
- *oldstate = ((oldval & CANCELSTATE_BITMASK)
- ? PTHREAD_CANCEL_DISABLE : PTHREAD_CANCEL_ENABLE);
-
- /* 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 (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval))
- __do_cancel ();
-
- break;
- }
-
- /* Prepare for the next round. */
- oldval = curval;
+ /* Set the new value. */
+ THREAD_SETMEM_ATOMIC (self, cancel.state, (char) state);
+
+ /* Synchronize with pthread_cancel() */
+ atomic_read_after_write_dependent_barrier();
+
+ int newval = THREAD_GETMEM (self, cancelhandling);
+
+ if (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval))
+ {
+ THREAD_SETMEM (self, result, PTHREAD_CANCELED);
+ __do_cancel ();
+ }
}
return 0;
@@ -34,40 +34,30 @@ __pthread_setcanceltype (type, oldtype)
self = THREAD_SELF;
int oldval = THREAD_GETMEM (self, cancelhandling);
- while (1)
+
+ int prev_type = ((oldval & CANCELTYPE_BITMASK) ? PTHREAD_CANCEL_ASYNCHRONOUS :
+ PTHREAD_CANCEL_DEFERRED);
+
+ /* Store the old value. */
+ if (oldtype != NULL)
+ *oldtype = prev_type;
+
+ /* Avoid doing unnecessary work. */
+ if (type != prev_type)
{
- 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 (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval))
- {
- THREAD_SETMEM (self, result, PTHREAD_CANCELED);
- __do_cancel ();
- }
-
- break;
- }
-
- /* Prepare for the next round. */
- oldval = curval;
+ /* Set the new value. */
+ THREAD_SETMEM_ATOMIC (self, cancel.type, (char) type);
+
+ /* Synchronize with pthread_cancel() */
+ atomic_read_after_write_dependent_barrier();
+
+ int newval = THREAD_GETMEM (self, cancelhandling);
+
+ if (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval))
+ {
+ THREAD_SETMEM (self, result, PTHREAD_CANCELED);
+ __do_cancel ();
+ }
}
return 0;
@@ -129,6 +129,8 @@ register struct pthread *__thread_self __asm__("%g7");
descr->member[idx]
#define THREAD_SETMEM(descr, member, value) \
descr->member = (value)
+#define THREAD_SETMEM_ATOMIC(descr, member, value) \
+ atomic_write(&(descr)->(member), (value))
#define THREAD_SETMEM_NC(descr, member, idx, value) \
descr->member[idx] = (value)
@@ -173,6 +173,15 @@ volatile unsigned char __sparc32_atomic_locks[64]
__sparc32_atomic_do_unlock (__acev_memp); \
__acev_ret; })
+#define __v7_write(mem, value) \
+ do { \
+ __typeof (mem) __acev_memp = (mem); \
+ \
+ __sparc32_atomic_do_lock (__acev_memp); \
+ *__acev_memp = (value); \
+ __sparc32_atomic_do_unlock (__acev_memp); \
+ } while (0)
+
/* Special versions, which guarantee that top 8 bits of all values
are cleared and use those bits as the ldstub lock. */
#define __v7_compare_and_exchange_val_24_acq(mem, newval, oldval) \
@@ -234,6 +243,9 @@ volatile unsigned char __sparc32_atomic_locks[64]
# define atomic_read_barrier() atomic_full_barrier ()
# define atomic_write_barrier() atomic_full_barrier ()
+# define atomic_write(mem, value) \
+ __v7_write (mem, value)
+
#else
/* In libc.a/libpthread.a etc. we don't know if we'll be run on
@@ -349,6 +361,16 @@ extern uint64_t _dl_hwcap __attribute__((weak));
__asm __volatile ("" : : : "memory"); \
} while (0)
+# define atomic_write(mem, val) \
+ do { \
+ int __acev_wret; \
+ if (__atomic_is_v9) \
+ *(mem) = (val); \
+ else \
+ __v7_write (mem, val); \
+ } while (0)
+
+
#endif
#include <sysdep.h>
new file mode 100644
@@ -0,0 +1,57 @@
+/* Measure memchr functions.
+ Copyright (C) 2013-2014 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <assert.h>
+#include <errno.h>
+#include <error.h>
+#include <pthread.h>
+#include <stdio.h>
+#include "bench-timing.h"
+
+#define INNER_LOOP_ITERS 64
+
+int
+do_test (int argc, char *argv[])
+{
+ size_t i, iters = INNER_LOOP_ITERS;
+ timing_t start, stop, cur;
+ int res = pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
+ if (res)
+ {
+ error (0, 0, "Wrong result in function pthread_setcanceltype %d 0", res);
+ return 1;
+ }
+
+ TIMING_NOW (start);
+ for (i = 0; i < iters; ++i)
+ {
+ pthread_setcanceltype (PTHREAD_CANCEL_DEFERRED, NULL);
+ pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
+ }
+ TIMING_NOW (stop);
+
+ TIMING_DIFF (cur, start, stop);
+
+ TIMING_PRINT_MEAN ((double) cur, (double) iters);
+
+ putchar ('\n');
+
+ return 0;
+}
+
+#include "../test-skeleton.c"