BUPT-OS
/
libevl
4
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

tests: stax-lock: stax should be unlocked before leaving a thread 

Make sure we always drop the stax before exiting the test thread,
otherwise we might deadlock contenders. Replace the async cancellation
with a synchronous exit condition.

Signed-off-by: Philippe Gerum <rpm@xenomai.org>
This commit is contained in:
Philippe Gerum 2020-02-21 18:20:14 +01:00
parent f5ad0e320f
commit b60f9257e5
1 changed files with 19 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
tests/stax-lock.c
View File

@ -40,9 +40,11 @@ static atomic_t presence_mask;
static atomic_t counter_proof;
static sig_atomic_t done;
static bool verbose;
static int timeout_secs = 5; /* Default to 5s runtime. */
static int timeout_secs = 3; /* Default to 5s runtime. */
static void *test_thread(void *arg)
{
@ -80,7 +82,11 @@ static void *test_thread(void *arg)
invalid = 0xAAAAAAAA;
}
for (;;) {
/*
* Do not pthread_cancel() the lock owner, this would block
* contenders indefinitely.
*/
while (!done) {
if (atomic_read(&presence_mask) & invalid)
atomic_add_return(&counter_proof, 1);
@ -180,8 +186,15 @@ int main(int argc, char *argv[])
return 1;
}
/* Detect the hectic driver, check whether the stax locking
* interface is present.
/*
* CAUTION: this test uses an internal interface of the
* 'hectic' driver in order to test the stax mechanism. This
* interface is enabling the caller to do something wrong and
* nasty, i.e. holding a stax across the kernel/user space
* boundary. This is only for the purpose of testing this
* mechanism, this is bad, applications should never do this,
* ever. IOW, a stax should be held while in kernel space
* exclusively, always released before returning to user.
*/
drvfd = open("/dev/hectic", O_RDONLY);
if (drvfd < 0)
@ -228,11 +241,10 @@ int main(int argc, char *argv[])
alarm(timeout_secs);
sigwait(&sigmask, &sig);
done = true;
for (n = 0; n < STAX_CONCURRENCY; n++) {
pthread_cancel(tids[n]);
for (n = 0; n < STAX_CONCURRENCY; n++)
pthread_join(tids[n], NULL);
}
/*
* We must have observed at least conflicting access outside