Folks,
While investigating an issue started at
http://www.open-mpi.org/community/lists/users/2014/10/25562.php
i found that it is mandatory to compile with -D_REENTRANT on Solaris (10
and 11)
(otherwise errno is not per thread specific, and the pmix thread
silently misinterpret EAGAIN or EWOULDBLOCK and that
leads to random behaviour, that generally terminates the application)
This is a bug / unexpected side effect introduced by me in commit
b1c4daa9567c7647318b9b673698c2251264f22e
on a RedHat 6 like server, this is not necessary.
on aix and/or freebsd, it might be necessary to compile with
-D_THREAD_SAFE in order to get a correct behaviour.
i wrote the simple attached program in order to check the correct
behavior with/without -D_REENTRANT or -D_THREAD_SAFE.
one option is to add automatically test this in
config/opal_config_pthreads.m4,
an other option is to hardcode this for the required OS.
Paul, since you have access to many platforms, could you please run this
test with and without -D_REENTRANT / -D_THREAD_SAFE
and tell me where the program produces incorrect behaviour (output is
KO...) without the flag ?
Thanks in advance,
Gilles
#include <errno.h>
#include <unistd.h>
#include <pthread.h>
#include <stdio.h>
static void * fn (void * arg) {
if (errno == 1) {
return (void *)-1;
}
read(0, NULL, 0);
if (errno != 0) {
return (void *)-2;
}
errno = 2;
return NULL;
}
int main (int argc, char *argv[]) {
pthread_t t;
void *s = NULL;
errno = 1;
if (pthread_create(&t, NULL, fn, NULL) < 0) {
perror ("pthread_create ");
return 1;
}
if (pthread_join(t, &s) < 0) {
perror ("pthread_join ");
return 2;
}
if (NULL != s) {
fprintf(stderr, "KO: error 3 (%ld)\n", (long)s);
return 3;
} else if (2 == errno) {
fprintf(stderr, "KO: error 4 (%ld)\n", (long)s);
return 4;
} else {
fprintf(stderr, "OK\n");
return 0;
}
}
