After excellently quick correction of pthread_kill when the argument
signal is zero
(by cgf), I have found another problem related to signal handling. The
code in attachment
demonstrates it ( because of pthread_kill, it must be run with
cygwin1-20080213.dll and newer ).
It seams that signal handlers for signals like SIGSEGV, SIGFPE are
called only once,
and the default handler is called for the second time the signal occures
in the process.
I'm not sure if the example is reasonable (e.g. pthread_exit in signal
handler...),
but works as expected on linux.
Output from the example compiled and run in linux:
Starting SIGSEGV1...
tid1=b7f1abb0
Sigaction success, errno = 0
Join1 ---> Result: 0, xx=8
Ret. value ---> Result: 8, xx=8
Good thread create ---> Result: 0, xx=8
Starting SIGSEGV2...
tid2=b7519bb0
Sigaction success, errno = 0
<--------------------------- this is the end in cygwin (crash info
message)------------
xx=9
Join2 ---> Result: 0, xx=9
Ret. value ---> Result: 9, xx=9
#include <signal.h>
#include <pthread.h>
#include <errno.h>
volatile static int xx=7;
void SHandler(int sig)
{
xx++;
pthread_exit((void*)xx);
return;
}
void* Thread1(void *arg)
{
struct sigaction actions;
int *a=0;
memset(&actions, 0, sizeof(actions));
sigemptyset(&actions.sa_mask);
sigaddset(&actions.sa_mask, SIGSEGV);
sleep(1);
actions.sa_handler = SHandler;
actions.sa_flags = 0;
if (sigaction(SIGSEGV,&actions, NULL))
printf("Sigaction ERROR !!!, errno = %d\n", errno);
else
printf("Sigaction success, errno = %d\n", errno);
sleep(5);
// induce SIGSEGV...
*a=5;
}
void* OKThread(void *arg)
{
sleep(30);
}
static void printrc( char *name, int rc)
{
printf("%-20s ---> Result: %d, xx=%d\n", name, rc, xx);
}
int main()
{
pthread_t tid,tid2;
int rc;
printf("Starting SIGSEGV1...\n");
pthread_create(&tid, NULL, Thread1, (void*)1);
printf("tid1=%x\n", tid);
while (pthread_kill(tid, 0) !=ESRCH)
sleep(1);
printrc("Join1",pthread_join(tid,(void**)&rc));
printrc("Ret. value", rc);
printrc("Good thread create",pthread_create(&tid, NULL, OKThread,
NULL));
printf("Starting SIGSEGV2...\n");
pthread_create(&tid2, NULL, Thread1, (void*)2);
printf("tid2=%x\n", tid2);
while (pthread_kill(tid2, 0) !=ESRCH)
sleep(1);
printf("xx=%d\n",xx);
printrc("Join2",pthread_join(tid2,(void**)&rc));
printrc("Ret. value", rc);
return 0;
}
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