summary: Test for bz549813 (dl_close() race with C++ destructor)
description: |
    Bug summary: dl_close() race with C++ destructor
    Bugzilla link: https://bugzilla.redhat.com/show_bug.cgi?id=549813

    Description:

    This looks like a dup of

    http://sources.redhat.com/bugzilla/show_bug.cgi?id=654


    Create a pthread in the library init. In fini, cancel the pthread and then join. If the main thread does a dlclose(), the program hangs at pthread_join(). 
    It is stuck in a futex. I tried the testcase from http://sources.redhat.com/bugzilla/show_bug.cgi?id=654 and that fails too. 

    One thing that may be relevant is that if dlopen is called with RTLD_NODELETE, pthread_join will not hang.


    main program->

    #include <stdio.h> 
    #include <dlfcn.h> 

    int main(int argc, char *argv[]) {
    	void *handle;

    	handle =  dlopen("tiny.so",RTLD_NOW);
    	if (handle) 
    		printf("loaded shared library\n");
    	else {
    		printf("could not load shared library\n");
    		return (-1);
    	}	
    	sleep(1);
    	dlclose(handle);

    }

    the lib ->

    #include <pthread.h>
    #include <stdio.h>
    #include <unistd.h>
    #include <stdlib.h>
    #include <signal.h>
    pthread_t t;


    void *F(void *arg) {

    	int old;
    	if (pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, &old) == 0) {
    		printf("> cancelability enabled.\n");
    	}
    	else {
    		printf("> could not set cancelability\n");
    		return (0);
    	}

    	sleep(2);
    } /*end F */

    int _init_rick (void) {

    printf("in init\n");
        if (pthread_create(&t, NULL, (void *(*)(void *)) F, NULL) == 0) 
    	printf("started thread\n");
    else
    	printf("could not start thread\n");

    } /* end _init_rick */

    int _fini_rick (void) {

    	printf("in fini\n");

    	printf("canceling thread\n");
    	if (pthread_cancel(t) == 0)
    		printf("canceled thread\n");
    	else
    		printf("could not cancel thread \n");
    	
    	printf("joining thread\n");
    	if (pthread_join(t, NULL) == 0)
    		printf("joined with thread\n");
    	else
    		printf("could not join with thread\n");


    } /* end _fini_rick */
contact: Petr Muller <pmuller@redhat.com>
component:
  - glibc
test: ./runtest.sh
framework: beakerlib
recommend:
  - glibc
duration: 30m
link:
  - relates: https://bugzilla.redhat.com/show_bug.cgi?id=549813
extra-summary: /tools/glibc/Regression/bz549813-dl-close-race-with-C-destructor
extra-task: /tools/glibc/Regression/bz549813-dl-close-race-with-C-destructor