Bruce Momjian wrote:
> > I did a cvs update, make, then rebuilt and tested thread_test. I ran it
> > about 120 times and got "GETHOSTBYNAME_THREADSAFE=yes" almost all of the
> > time. I got "GETHOSTBYNAME_THREADSAFE=no" three times. The other two were
> > always "yes".
>
> Yep, I can reproduce this on BSD/OS too, so it must be something wrong
> with my program. I see:
>
> $ for X in `jot 1000`; do thread_test |grep -10 '=no' && echo $X;
> done|less
> Make sure you have added any needed 'THREAD_CPPFLAGS' and 'THREAD_LIBS'
> defines to your template/$port file before compiling this program.
>
> Add this to your template/$port file:
>
> STRERROR_THREADSAFE=yes
> GETPWUID_THREADSAFE=no
> GETHOSTBYNAME_THREADSAFE=no
> 919
>
> I bet the problem is that I am accessing thread-specific pointers after
> the thread exits. It is possible thread 1 completes before thread2 gets
> to the getpwuid and gethostbyname tests, and then reuses the
> thread-specific pointer. Let me work on a patch and email it to you in
> a few minutes.
OK, new patch applied that causes all threads to wait until the parent
checks their thread-specific pointers. I ran 1000 tests and all passed.
Hopefully it will good for you too.
--
Bruce Momjian | http://candle.pha.pa.us
pgman@candle.pha.pa.us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
Index: src/tools/thread/thread_test.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/tools/thread/thread_test.c,v
retrieving revision 1.12
diff -c -c -r1.12 thread_test.c
*** src/tools/thread/thread_test.c 5 Apr 2004 02:22:14 -0000 1.12
--- src/tools/thread/thread_test.c 5 Apr 2004 05:40:13 -0000
***************
*** 40,45 ****
--- 40,48 ----
volatile int errno1_set = 0;
volatile int errno2_set = 0;
+ volatile int thread1_done = 0;
+ volatile int thread2_done = 0;
+
char *strerror_p1;
char *strerror_p2;
***************
*** 49,57 ****
struct hostent *hostent_p1;
struct hostent *hostent_p2;
! pthread_mutex_t singlethread_lock1 = PTHREAD_MUTEX_INITIALIZER;
! pthread_mutex_t singlethread_lock2 = PTHREAD_MUTEX_INITIALIZER;
!
int main(int argc, char *argv[])
{
pthread_t thread1,
--- 52,59 ----
struct hostent *hostent_p1;
struct hostent *hostent_p2;
! pthread_mutex_t init_mutex = PTHREAD_MUTEX_INITIALIZER;
!
int main(int argc, char *argv[])
{
pthread_t thread1,
***************
*** 73,82 ****
Make sure you have added any needed 'THREAD_CPPFLAGS' and 'THREAD_LIBS'\n\
defines to your template/$port file before compiling this program.\n\n"
);
pthread_create(&thread1, NULL, (void * (*)(void *)) func_call_1, NULL);
pthread_create(&thread2, NULL, (void * (*)(void *)) func_call_2, NULL);
! pthread_join(thread1, NULL);
! pthread_join(thread2, NULL);
printf("Add this to your template/$port file:\n\n");
--- 75,89 ----
Make sure you have added any needed 'THREAD_CPPFLAGS' and 'THREAD_LIBS'\n\
defines to your template/$port file before compiling this program.\n\n"
);
+
+ /* Hold lock until we are ready for the child threads to exit. */
+ pthread_mutex_lock(&init_mutex);
+
pthread_create(&thread1, NULL, (void * (*)(void *)) func_call_1, NULL);
pthread_create(&thread2, NULL, (void * (*)(void *)) func_call_2, NULL);
!
! while (thread1_done == 0 || thread2_done == 0)
! getpid(); /* force system call */
printf("Add this to your template/$port file:\n\n");
***************
*** 94,100 ****
--- 101,112 ----
printf("GETHOSTBYNAME_THREADSAFE=yes\n");
else
printf("GETHOSTBYNAME_THREADSAFE=no\n");
+
+ pthread_mutex_unlock(&init_mutex); /* let children exit */
+ pthread_join(thread1, NULL); /* clean up children */
+ pthread_join(thread2, NULL);
+
return 0;
}
***************
*** 110,116 ****
fprintf(stderr, "could not generate failure for create file in /tmp, exiting\n");
exit(1);
}
! /* wait for other thread to set errno */
errno1_set = 1;
while (errno2_set == 0)
getpid(); /* force system call */
--- 122,132 ----
fprintf(stderr, "could not generate failure for create file in /tmp, exiting\n");
exit(1);
}
! /*
! * Wait for other thread to set errno.
! * We can't use thread-specific locking here because it might
! * affect errno.
! */
errno1_set = 1;
while (errno2_set == 0)
getpid(); /* force system call */
***************
*** 144,149 ****
--- 160,169 ----
printf("Your gethostbyname() changes the static memory area between calls\n");
hostent_p1 = NULL; /* force thread-safe failure report */
}
+
+ thread1_done = 1;
+ pthread_mutex_lock(&init_mutex); /* wait for parent to test */
+ pthread_mutex_unlock(&init_mutex);
}
***************
*** 157,163 ****
fprintf(stderr, "Read-only open succeeded without create, exiting\n");
exit(1);
}
! /* wait for other thread to set errno */
errno2_set = 1;
while (errno1_set == 0)
getpid(); /* force system call */
--- 177,187 ----
fprintf(stderr, "Read-only open succeeded without create, exiting\n");
exit(1);
}
! /*
! * Wait for other thread to set errno.
! * We can't use thread-specific locking here because it might
! * affect errno.
! */
errno2_set = 1;
while (errno1_set == 0)
getpid(); /* force system call */
***************
*** 191,194 ****
--- 215,222 ----
printf("Your gethostbyname() changes the static memory area between calls\n");
hostent_p2 = NULL; /* force thread-safe failure report */
}
+
+ thread2_done = 1;
+ pthread_mutex_lock(&init_mutex); /* wait for parent to test */
+ pthread_mutex_unlock(&init_mutex);
}
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