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nptl: Handle spurious EINTR when thread cancellation is disabled (BZ#29029) 

Some Linux interfaces never restart after being interrupted by a signal
handler, regardless of the use of SA_RESTART [1].  It means that for
pthread cancellation, if the target thread disables cancellation with
pthread_setcancelstate and calls such interfaces (like poll or select),
it should not see spurious EINTR failures due the internal SIGCANCEL.

However recent changes made pthread_cancel to always sent the internal
signal, regardless of the target thread cancellation status or type.
To fix it, the previous semantic is restored, where the cancel signal
is only sent if the target thread has cancelation enabled in
asynchronous mode.

The cancel state and cancel type is moved back to cancelhandling
and atomic operation are used to synchronize between threads.  The
patch essentially revert the following commits:

  8c1c0aae20 nptl: Move cancel type out of cancelhandling
  2b51742531 nptl: Move cancel state out of cancelhandling
  26cfbb7162 nptl: Remove CANCELING_BITMASK

However I changed the atomic operation to follow the internal C11
semantic and removed the MACRO usage, it simplifies a bit the
resulting code (and removes another usage of the old atomic macros).

Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu,
and powerpc64-linux-gnu.

[1] https://man7.org/linux/man-pages/man7/signal.7.html

Reviewed-by: Florian Weimer <fweimer@redhat.com>
Tested-by: Aurelien Jarno <aurelien@aurel32.net>
This commit is contained in:
Adhemerval Zanella 2022-04-06 12:24:42 -03:00
parent 2376944b9e
commit 404656009b
15 changed files with 481 additions and 90 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
manual/process.texi
View File

@ -68,8 +68,7 @@ until the subprogram terminates before you can do anything else.
@c CLEANUP_HANDLER @ascuplugin @ascuheap @acsmem
@c libc_cleanup_region_start @ascuplugin @ascuheap @acsmem
@c pthread_cleanup_push_defer @ascuplugin @ascuheap @acsmem
@c __pthread_testcancel @ascuplugin @ascuheap @acsmem
@c CANCEL_ENABLED_AND_CANCELED ok
@c cancel_enabled_and_canceled @ascuplugin @ascuheap @acsmem
@c do_cancel @ascuplugin @ascuheap @acsmem
@c cancel_handler ok
@c kill syscall ok

2
nptl/allocatestack.c
View File

@ -119,8 +119,6 @@ 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;

52
nptl/cancellation.c
View File

@ -30,19 +30,26 @@ int
__pthread_enable_asynccancel (void)
{
struct pthread *self = THREAD_SELF;
int oldval = atomic_load_relaxed (&self->cancelhandling);
int oldval = THREAD_GETMEM (self, canceltype);
THREAD_SETMEM (self, canceltype, PTHREAD_CANCEL_ASYNCHRONOUS);
int ch = THREAD_GETMEM (self, cancelhandling);
if (self->cancelstate == PTHREAD_CANCEL_ENABLE
&& (ch & CANCELED_BITMASK)
&& !(ch & EXITING_BITMASK)
&& !(ch & TERMINATED_BITMASK))
while (1)
{
THREAD_SETMEM (self, result, PTHREAD_CANCELED);
__do_cancel ();
int newval = oldval | CANCELTYPE_BITMASK;
if (newval == oldval)
break;
if (atomic_compare_exchange_weak_acquire (&self->cancelhandling,
&oldval, newval))
{
if (cancel_enabled_and_canceled_and_async (newval))
{
self->result = PTHREAD_CANCELED;
__do_cancel ();
}
break;
}
}
return oldval;
@ -56,10 +63,29 @@ __pthread_disable_asynccancel (int oldtype)
{
/* If asynchronous cancellation was enabled before we do not have
anything to do. */
if (oldtype == PTHREAD_CANCEL_ASYNCHRONOUS)
if (oldtype & CANCELTYPE_BITMASK)
return;
struct pthread *self = THREAD_SELF;
self->canceltype = PTHREAD_CANCEL_DEFERRED;
int newval;
int oldval = atomic_load_relaxed (&self->cancelhandling);
do
{
newval = oldval & ~CANCELTYPE_BITMASK;
}
while (!atomic_compare_exchange_weak_acquire (&self->cancelhandling,
&oldval, newval));
/* We cannot return when we are being canceled. Upon return the
thread might be things which would have to be undone. The
following loop should loop until the cancellation signal is
delivered. */
while (__glibc_unlikely ((newval & (CANCELING_BITMASK | CANCELED_BITMASK))
== CANCELING_BITMASK))
{
futex_wait_simple ((unsigned int *) &self->cancelhandling, newval,
FUTEX_PRIVATE);
newval = atomic_load_relaxed (&self->cancelhandling);
}
}
libc_hidden_def (__pthread_disable_asynccancel)

42
nptl/cleanup_defer.c
View File

@ -30,9 +30,22 @@ ___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);
/* Disable asynchronous cancellation for now. */
ibuf->priv.data.canceltype = THREAD_GETMEM (self, canceltype);
THREAD_SETMEM (self, canceltype, PTHREAD_CANCEL_DEFERRED);
int cancelhandling = atomic_load_relaxed (&self->cancelhandling);
if (__glibc_unlikely (cancelhandling & CANCELTYPE_BITMASK))
{
int newval;
do
{
newval = cancelhandling & ~CANCELTYPE_BITMASK;
}
while (!atomic_compare_exchange_weak_acquire (&self->cancelhandling,
&cancelhandling,
newval));
}
ibuf->priv.data.canceltype = (cancelhandling & CANCELTYPE_BITMASK
? PTHREAD_CANCEL_ASYNCHRONOUS
: PTHREAD_CANCEL_DEFERRED);
/* Store the new cleanup handler info. */
THREAD_SETMEM (self, cleanup_jmp_buf, (struct pthread_unwind_buf *) buf);
@ -54,9 +67,26 @@ ___pthread_unregister_cancel_restore (__pthread_unwind_buf_t *buf)
THREAD_SETMEM (self, cleanup_jmp_buf, ibuf->priv.data.prev);
THREAD_SETMEM (self, canceltype, ibuf->priv.data.canceltype);
if (ibuf->priv.data.canceltype == PTHREAD_CANCEL_ASYNCHRONOUS)
__pthread_testcancel ();
if (ibuf->priv.data.canceltype == PTHREAD_CANCEL_DEFERRED)
return;
int cancelhandling = atomic_load_relaxed (&self->cancelhandling);
if (cancelhandling & CANCELTYPE_BITMASK)
{
int newval;
do
{
newval = cancelhandling | CANCELTYPE_BITMASK;
}
while (!atomic_compare_exchange_weak_acquire (&self->cancelhandling,
&cancelhandling, newval));
if (cancel_enabled_and_canceled (cancelhandling))
{
self->result = PTHREAD_CANCELED;
__do_cancel ();
}
}
}
versioned_symbol (libc, ___pthread_unregister_cancel_restore,
__pthread_unregister_cancel_restore, GLIBC_2_34);

41
nptl/descr.h
View File

@ -279,18 +279,27 @@ struct pthread
/* Flags determining processing of cancellation. */
int cancelhandling;
/* Bit set if cancellation is disabled. */
#define CANCELSTATE_BIT 0
#define CANCELSTATE_BITMASK (1 << CANCELSTATE_BIT)
/* Bit set if asynchronous cancellation mode is selected. */
#define CANCELTYPE_BIT 1
#define CANCELTYPE_BITMASK (1 << CANCELTYPE_BIT)
/* Bit set if canceling has been initiated. */
#define CANCELING_BIT 2
#define CANCELING_BITMASK (1 << CANCELING_BIT)
/* Bit set if canceled. */
#define CANCELED_BIT 3
#define CANCELED_BITMASK (0x01 << CANCELED_BIT)
#define CANCELED_BITMASK (1 << CANCELED_BIT)
/* Bit set if thread is exiting. */
#define EXITING_BIT 4
#define EXITING_BITMASK (0x01 << EXITING_BIT)
#define EXITING_BITMASK (1 << EXITING_BIT)
/* Bit set if thread terminated and TCB is freed. */
#define TERMINATED_BIT 5
#define TERMINATED_BITMASK (0x01 << TERMINATED_BIT)
#define TERMINATED_BITMASK (1 << TERMINATED_BIT)
/* Bit set if thread is supposed to change XID. */
#define SETXID_BIT 6
#define SETXID_BITMASK (0x01 << SETXID_BIT)
#define SETXID_BITMASK (1 << SETXID_BIT)
/* Flags. Including those copied from the thread attribute. */
int flags;
@ -390,14 +399,6 @@ struct pthread
/* Indicates whether is a C11 thread created by thrd_creat. */
bool c11;
/* Thread cancel state (PTHREAD_CANCEL_ENABLE or
PTHREAD_CANCEL_DISABLE). */
unsigned char cancelstate;
/* Thread cancel type (PTHREAD_CANCEL_DEFERRED or
PTHREAD_CANCEL_ASYNCHRONOUS). */
unsigned char canceltype;
/* Used in __pthread_kill_internal to detected a thread that has
exited or is about to exit. exit_lock must only be acquired
after blocking signals. */
@ -417,6 +418,22 @@ struct pthread
(sizeof (struct pthread) - offsetof (struct pthread, end_padding))
} __attribute ((aligned (TCB_ALIGNMENT)));
static inline bool
cancel_enabled_and_canceled (int value)
{
return (value & (CANCELSTATE_BITMASK | CANCELED_BITMASK | EXITING_BITMASK
| TERMINATED_BITMASK))
== CANCELED_BITMASK;
}
static inline bool
cancel_enabled_and_canceled_and_async (int value)
{
return ((value) & (CANCELSTATE_BITMASK | CANCELTYPE_BITMASK | CANCELED_BITMASK
| EXITING_BITMASK | TERMINATED_BITMASK))
== (CANCELTYPE_BITMASK | CANCELED_BITMASK);
}
/* This yields the pointer that TLS support code calls the thread pointer. */
#if TLS_TCB_AT_TP
# define TLS_TPADJ(pd) (pd)

39
nptl/libc-cleanup.c
View File

@ -26,9 +26,24 @@ __libc_cleanup_push_defer (struct _pthread_cleanup_buffer *buffer)
buffer->__prev = THREAD_GETMEM (self, cleanup);
int cancelhandling = atomic_load_relaxed (&self->cancelhandling);
/* Disable asynchronous cancellation for now. */
buffer->__canceltype = THREAD_GETMEM (self, canceltype);
THREAD_SETMEM (self, canceltype, PTHREAD_CANCEL_DEFERRED);
if (__glibc_unlikely (cancelhandling & CANCELTYPE_BITMASK))
{
int newval;
do
{
newval = cancelhandling & ~CANCELTYPE_BITMASK;
}
while (!atomic_compare_exchange_weak_acquire (&self->cancelhandling,
&cancelhandling,
newval));
}
buffer->__canceltype = (cancelhandling & CANCELTYPE_BITMASK
? PTHREAD_CANCEL_ASYNCHRONOUS
: PTHREAD_CANCEL_DEFERRED);
THREAD_SETMEM (self, cleanup, buffer);
}
@ -41,8 +56,22 @@ __libc_cleanup_pop_restore (struct _pthread_cleanup_buffer *buffer)
THREAD_SETMEM (self, cleanup, buffer->__prev);
THREAD_SETMEM (self, canceltype, buffer->__canceltype);
if (buffer->__canceltype == PTHREAD_CANCEL_ASYNCHRONOUS)
__pthread_testcancel ();
int cancelhandling = atomic_load_relaxed (&self->cancelhandling);
if (cancelhandling & CANCELTYPE_BITMASK)
{
int newval;
do
{
newval = cancelhandling | CANCELTYPE_BITMASK;
}
while (!atomic_compare_exchange_weak_acquire (&self->cancelhandling,
&cancelhandling, newval));
if (cancel_enabled_and_canceled (cancelhandling))
{
self->result = PTHREAD_CANCELED;
__do_cancel ();
}
}
}
libc_hidden_def (__libc_cleanup_pop_restore)

106
nptl/pthread_cancel.c
View File

@ -42,18 +42,29 @@ sigcancel_handler (int sig, siginfo_t *si, void *ctx)
struct pthread *self = THREAD_SELF;
int ch = atomic_load_relaxed (&self->cancelhandling);
/* Cancelation not enabled, not cancelled, or already exitting. */
if (self->cancelstate == PTHREAD_CANCEL_DISABLE
|| (ch & CANCELED_BITMASK) == 0
|| (ch & EXITING_BITMASK) != 0)
return;
int oldval = atomic_load_relaxed (&self->cancelhandling);
while (1)
{
/* We are canceled now. When canceled by another thread this flag
is already set but if the signal is directly send (internally or
from another process) is has to be done here. */
int newval = oldval | CANCELING_BITMASK | CANCELED_BITMASK;
/* Set the return value. */
THREAD_SETMEM (self, result, PTHREAD_CANCELED);
/* Make sure asynchronous cancellation is still enabled. */
if (self->canceltype == PTHREAD_CANCEL_ASYNCHRONOUS)
__do_cancel ();
if (oldval == newval || (oldval & EXITING_BITMASK) != 0)
/* Already canceled or exiting. */
break;
if (atomic_compare_exchange_weak_acquire (&self->cancelhandling,
&oldval, newval))
{
self->result = PTHREAD_CANCELED;
/* Make sure asynchronous cancellation is still enabled. */
if ((oldval & CANCELTYPE_BITMASK) != 0)
/* Run the registered destructors and terminate the thread. */
__do_cancel ();
}
}
}
int
@ -92,29 +103,70 @@ __pthread_cancel (pthread_t th)
}
#endif
int oldch = atomic_fetch_or_acquire (&pd->cancelhandling, CANCELED_BITMASK);
if ((oldch & CANCELED_BITMASK) != 0)
return 0;
/* Some syscalls are never restarted after being interrupted by a signal
handler, regardless of the use of SA_RESTART (they always fail with
EINTR). So pthread_cancel cannot send SIGCANCEL unless the cancellation
is enabled and set as asynchronous (in this case the cancellation will
be acted in the cancellation handler instead by the syscall wrapper).
Otherwise the target thread is set as 'cancelling' (CANCELING_BITMASK)
by atomically setting 'cancelhandling' and the cancelation will be acted
upon on next cancellation entrypoing in the target thread.
if (pd == THREAD_SELF)
It also requires to atomically check if cancellation is enabled and
asynchronous, so both cancellation state and type are tracked on
'cancelhandling'. */
int result = 0;
int oldval = atomic_load_relaxed (&pd->cancelhandling);
int newval;
do
{
/* A single-threaded process should be able to kill itself, since there
is nothing in the POSIX specification that says that it cannot. So
we set multiple_threads to true so that cancellation points get
executed. */
THREAD_SETMEM (THREAD_SELF, header.multiple_threads, 1);
newval = oldval | CANCELING_BITMASK | CANCELED_BITMASK;
if (oldval == newval)
break;
/* If the cancellation is handled asynchronously just send a
signal. We avoid this if possible since it's more
expensive. */
if (cancel_enabled_and_canceled_and_async (newval))
{
/* Mark the cancellation as "in progress". */
int newval2 = oldval | CANCELING_BITMASK;
if (!atomic_compare_exchange_weak_acquire (&pd->cancelhandling,
&oldval, newval2))
continue;
if (pd == THREAD_SELF)
/* This is not merely an optimization: An application may
call pthread_cancel (pthread_self ()) without calling
pthread_create, so the signal handler may not have been
set up for a self-cancel. */
{
pd->result = PTHREAD_CANCELED;
if ((newval & CANCELTYPE_BITMASK) != 0)
__do_cancel ();
}
else
/* The cancellation handler will take care of marking the
thread as canceled. */
result = __pthread_kill_internal (th, SIGCANCEL);
break;
}
/* A single-threaded process should be able to kill itself, since
there is nothing in the POSIX specification that says that it
cannot. So we set multiple_threads to true so that cancellation
points get executed. */
THREAD_SETMEM (THREAD_SELF, header.multiple_threads, 1);
#ifndef TLS_MULTIPLE_THREADS_IN_TCB
__libc_multiple_threads = 1;
#endif
THREAD_SETMEM (pd, result, PTHREAD_CANCELED);
if (pd->cancelstate == PTHREAD_CANCEL_ENABLE
&& pd->canceltype == PTHREAD_CANCEL_ASYNCHRONOUS)
__do_cancel ();
return 0;
}
while (!atomic_compare_exchange_weak_acquire (&pd->cancelhandling, &oldval,
newval));
return __pthread_kill_internal (th, SIGCANCEL);
return result;
}
versioned_symbol (libc, __pthread_cancel, pthread_cancel, GLIBC_2_34);

7
nptl/pthread_join_common.c
View File

@ -57,12 +57,9 @@ __pthread_clockjoin_ex (pthread_t threadid, void **thread_return,
if ((pd == self
|| (self->joinid == pd
&& (pd->cancelhandling
& (CANCELED_BITMASK | EXITING_BITMASK
& (CANCELING_BITMASK | CANCELED_BITMASK | EXITING_BITMASK
| TERMINATED_BITMASK)) == 0))
&& !(self->cancelstate == PTHREAD_CANCEL_ENABLE
&& (pd->cancelhandling & (CANCELED_BITMASK | EXITING_BITMASK
| TERMINATED_BITMASK))
== CANCELED_BITMASK))
&& !cancel_enabled_and_canceled (self->cancelhandling))
/* This is a deadlock situation. The threads are waiting for each
other to finish. Note that this is a "may" error. To be 100%
sure we catch this error we would have to lock the data

26
nptl/pthread_setcancelstate.c
View File

@ -30,9 +30,29 @@ __pthread_setcancelstate (int state, int *oldstate)
self = THREAD_SELF;
if (oldstate != NULL)
*oldstate = self->cancelstate;
self->cancelstate = state;
int oldval = atomic_load_relaxed (&self->cancelhandling);
while (1)
{
int newval = (state == PTHREAD_CANCEL_DISABLE
? oldval | CANCELSTATE_BITMASK
: oldval & ~CANCELSTATE_BITMASK);
if (oldstate != NULL)
*oldstate = ((oldval & CANCELSTATE_BITMASK)
? PTHREAD_CANCEL_DISABLE : PTHREAD_CANCEL_ENABLE);
if (oldval == newval)
break;
if (atomic_compare_exchange_weak_acquire (&self->cancelhandling,
&oldval, newval))
{
if (cancel_enabled_and_canceled_and_async (newval))
__do_cancel ();
break;
}
}
return 0;
}

31
nptl/pthread_setcanceltype.c
View File

@ -28,11 +28,32 @@ __pthread_setcanceltype (int type, int *oldtype)
volatile struct pthread *self = THREAD_SELF;
if (oldtype != NULL)
*oldtype = self->canceltype;
self->canceltype = type;
if (type == PTHREAD_CANCEL_ASYNCHRONOUS)
__pthread_testcancel ();
int oldval = atomic_load_relaxed (&self->cancelhandling);
while (1)
{
int newval = (type == PTHREAD_CANCEL_ASYNCHRONOUS
? oldval | CANCELTYPE_BITMASK
: oldval & ~CANCELTYPE_BITMASK);
if (oldtype != NULL)
*oldtype = ((oldval & CANCELTYPE_BITMASK)
? PTHREAD_CANCEL_ASYNCHRONOUS : PTHREAD_CANCEL_DEFERRED);
if (oldval == newval)
break;
if (atomic_compare_exchange_weak_acquire (&self->cancelhandling,
&oldval, newval))
{
if (cancel_enabled_and_canceled_and_async (newval))
{
THREAD_SETMEM (self, result, PTHREAD_CANCELED);
__do_cancel ();
}
break;
}
}
return 0;
}

9
nptl/pthread_testcancel.c
View File

@ -23,13 +23,10 @@ void
___pthread_testcancel (void)
{
struct pthread *self = THREAD_SELF;
int cancelhandling = THREAD_GETMEM (self, cancelhandling);
if (self->cancelstate == PTHREAD_CANCEL_ENABLE
&& (cancelhandling & CANCELED_BITMASK)
&& !(cancelhandling & EXITING_BITMASK)
&& !(cancelhandling & TERMINATED_BITMASK))
int cancelhandling = atomic_load_relaxed (&self->cancelhandling);
if (cancel_enabled_and_canceled (cancelhandling))
{
THREAD_SETMEM (self, result, PTHREAD_CANCELED);
self->result = PTHREAD_CANCELED;
__do_cancel ();
}
}

3
sysdeps/nptl/dl-tls_init_tp.c
View File

@ -128,7 +128,4 @@ __tls_init_tp (void)
It will be bigger than it actually is, but for unwind.c/pt-longjmp.c
purposes this is good enough. */
THREAD_SETMEM (pd, stackblock_size, (size_t) __libc_stack_end);
THREAD_SETMEM (pd, cancelstate, PTHREAD_CANCEL_ENABLE);
THREAD_SETMEM (pd, canceltype, PTHREAD_CANCEL_DEFERRED);
}

2
sysdeps/nptl/pthreadP.h
View File

@ -275,7 +275,7 @@ __do_cancel (void)
struct pthread *self = THREAD_SELF;
/* Make sure we get no more cancellations. */
THREAD_ATOMIC_BIT_SET (self, cancelhandling, EXITING_BIT);
atomic_bit_set (&self->cancelhandling, EXITING_BIT);
__pthread_unwind ((__pthread_unwind_buf_t *)
THREAD_GETMEM (self, cleanup_jmp_buf));

1
sysdeps/pthread/Makefile
View File

@ -69,6 +69,7 @@ tests += tst-cnd-basic tst-mtx-trylock tst-cnd-broadcast \
tst-cancel12 tst-cancel13 tst-cancel14 tst-cancel15 tst-cancel16 \
tst-cancel18 tst-cancel19 tst-cancel20 tst-cancel21 \
tst-cancel22 tst-cancel23 tst-cancel26 tst-cancel27 tst-cancel28 \
tst-cancel29 \
tst-cleanup0 tst-cleanup1 tst-cleanup2 tst-cleanup3 \
tst-clock1 \
tst-cond-except \

207
sysdeps/pthread/tst-cancel29.c Normal file
View File

@ -0,0 +1,207 @@
/* Check if a thread that disables cancellation and which call functions
that might be interrupted by a signal do not see the internal SIGCANCEL.
Copyright (C) 2022 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
<https://www.gnu.org/licenses/>. */
#include <array_length.h>
#include <errno.h>
#include <inttypes.h>
#include <poll.h>
#include <support/check.h>
#include <support/support.h>
#include <support/temp_file.h>
#include <support/xthread.h>
#include <sys/socket.h>
#include <signal.h>
#include <stdio.h>
#include <unistd.h>
/* On Linux some interfaces are never restarted after being interrupted by
a signal handler, regardless of the use of SA_RESTART. It means that
if asynchronous cancellation is not enabled, the pthread_cancel can not
set the internal SIGCANCEL otherwise the interface might see a spurious
EINTR failure. */
static pthread_barrier_t b;
/* Cleanup handling test. */
static int cl_called;
static void
cl (void *arg)
{
++cl_called;
}
static void *
tf_sigtimedwait (void *arg)
{
pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, NULL);
xpthread_barrier_wait (&b);
int r;
pthread_cleanup_push (cl, NULL);
sigset_t mask;
sigemptyset (&mask);
r = sigtimedwait (&mask, NULL, &(struct timespec) { 0, 250000000 });
if (r != -1)
return (void*) -1;
if (errno != EAGAIN)
return (void*) -2;
pthread_cleanup_pop (0);
return NULL;
}
static void *
tf_poll (void *arg)
{
pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, NULL);
xpthread_barrier_wait (&b);
int r;
pthread_cleanup_push (cl, NULL);
r = poll (NULL, 0, 250);
if (r != 0)
return (void*) -1;
pthread_cleanup_pop (0);
return NULL;
}
static void *
tf_ppoll (void *arg)
{
pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, NULL);
xpthread_barrier_wait (&b);
int r;
pthread_cleanup_push (cl, NULL);
r = ppoll (NULL, 0, &(struct timespec) { 0, 250000000 }, NULL);
if (r != 0)
return (void*) -1;
pthread_cleanup_pop (0);
return NULL;
}
static void *
tf_select (void *arg)
{
pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, NULL);
xpthread_barrier_wait (&b);
int r;
pthread_cleanup_push (cl, NULL);
r = select (0, NULL, NULL, NULL, &(struct timeval) { 0, 250000 });
if (r != 0)
return (void*) -1;
pthread_cleanup_pop (0);
return NULL;
}
static void *
tf_pselect (void *arg)
{
pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, NULL);
xpthread_barrier_wait (&b);
int r;
pthread_cleanup_push (cl, NULL);
r = pselect (0, NULL, NULL, NULL, &(struct timespec) { 0, 250000000 }, NULL);
if (r != 0)
return (void*) -1;
pthread_cleanup_pop (0);
return NULL;
}
static void *
tf_clock_nanosleep (void *arg)
{
pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, NULL);
xpthread_barrier_wait (&b);
int r;
pthread_cleanup_push (cl, NULL);
r = clock_nanosleep (CLOCK_REALTIME, 0, &(struct timespec) { 0, 250000000 },
NULL);
if (r != 0)
return (void*) -1;
pthread_cleanup_pop (0);
return NULL;
}
struct cancel_test_t
{
const char *name;
void * (*cf) (void *);
} tests[] =
{
{ "sigtimedwait", tf_sigtimedwait, },
{ "poll", tf_poll, },
{ "ppoll", tf_ppoll, },
{ "select", tf_select, },
{ "pselect", tf_pselect , },
{ "clock_nanosleep", tf_clock_nanosleep, },
};
static int
do_test (void)
{
for (int i = 0; i < array_length (tests); i++)
{
xpthread_barrier_init (&b, NULL, 2);
cl_called = 0;
pthread_t th = xpthread_create (NULL, tests[i].cf, NULL);
xpthread_barrier_wait (&b);
struct timespec ts = { .tv_sec = 0, .tv_nsec = 100000000 };
while (nanosleep (&ts, &ts) != 0)
continue;
xpthread_cancel (th);
void *status = xpthread_join (th);
if (status != NULL)
printf ("test '%s' failed: %" PRIdPTR "\n", tests[i].name,
(intptr_t) status);
TEST_VERIFY (status == NULL);
xpthread_barrier_destroy (&b);
TEST_COMPARE (cl_called, 0);
printf ("in-time cancel test of '%s' successful\n", tests[i].name);
}
return 0;
}
#include <support/test-driver.c>