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Cygwin: testsuite: Busy-wait in cancel3 and cancel5 

These tests async thread cancellation of a thread that doesn't have any
cancellation points.

Unfortunately, since 2b165a45 the async cancellation silently fails when
the thread is inside the kernel function Sleep(), so it just exits
normally after 10 seconds. (See the commentary in pthread::cancel() in
thread.cc, where it checks if the target thread is inside the kernel,
and silently converts the cancellation into a deferred one)

Work around this by busy-waiting rather than Sleep()ing for 10 seconds.

This is still somewhat fragile: the async cancel could still fail, if it
happens to occur while we're inside the kernel function that time()
calls.

v2:
Do nothing more efficiently

Signed-off-by: Jon Turney <jon.turney@dronecode.org.uk>
This commit is contained in:
Jon Turney 2023-07-10 19:04:58 +01:00
parent 7d50e65a84
commit e867f8c3e8
No known key found for this signature in database
GPG Key ID: C7C86F0370285C81
2 changed files with 36 additions and 12 deletions
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24
winsup/testsuite/winsup.api/pthread/cancel3.c
View File

@ -75,11 +75,22 @@ mythread(void * arg)
assert(pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL) == 0);
/*
* We wait up to 10 seconds, waking every 0.1 seconds,
* for a cancelation to be applied to us.
* We wait up to 10 seconds for a cancelation to be applied to us.
*/
for (bag->count = 0; bag->count < 100; bag->count++)
Sleep(100);
for (bag->count = 0; bag->count < 10; bag->count++)
{
/* Busy wait to avoid Sleep(), since we can't asynchronous cancel inside a
kernel function. (This is still somewhat fragile as if the async cancel
can fail if it happens to occur while we're inside the kernel function
that time() calls...) */
time_t start = time(NULL);
while ((time(NULL) - start) < 1)
{
int i;
for (i = 0; i < 1E7; i++)
__asm__ volatile ("pause":::);
}
}
return result;
}
@ -149,10 +160,11 @@ main()
if (fail)
{
fprintf(stderr, "Thread %d: started %d: count %d\n",
fprintf(stderr, "Thread %d: started %d: count %d: result %d \n",
i,
threadbag[i].started,
threadbag[i].count);
threadbag[i].count,
result);
}
failed = (failed || fail);
}

24
winsup/testsuite/winsup.api/pthread/cancel5.c
View File

@ -76,11 +76,22 @@ mythread(void * arg)
assert(pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL) == 0);
/*
* We wait up to 10 seconds, waking every 0.1 seconds,
* for a cancelation to be applied to us.
* We wait up to 10 seconds for a cancelation to be applied to us.
*/
for (bag->count = 0; bag->count < 100; bag->count++)
Sleep(100);
for (bag->count = 0; bag->count < 10; bag->count++)
{
/* Busy wait to avoid Sleep(), since we can't asynchronous cancel inside a
kernel function. (This is still somewhat fragile as if the async cancel
can fail if it happens to occur while we're inside the kernel function
that time() calls...) */
time_t start = time(NULL);
while ((time(NULL) - start) < 1)
{
int i;
for (i = 0; i < 1E7; i++)
__asm__ volatile ("pause":::);
}
}
return result;
}
@ -148,10 +159,11 @@ main()
if (fail)
{
fprintf(stderr, "Thread %d: started %d: count %d\n",
fprintf(stderr, "Thread %d: started %d: count %d: result %d\n",
i,
threadbag[i].started,
threadbag[i].count);
threadbag[i].count,
result);
}
failed = (failed || fail);
}