condwait_wrap.c

#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <dlfcn.h>
#include <pthread.h>

static int (*condwait_internal)(pthread_cond_t *cond, pthread_mutex_t *mutex);

void __attribute__ ((constructor)) init(void);

/* Library constructor */
void
init(void)
{

	condwait_internal = dlvsym(RTLD_NEXT, "pthread_cond_wait", "GLIBC_2.3.2");
}

int
pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
{
	int ret;

	printf("Calling func condwait with cond: %p, mutex: %p...",
	       cond, mutex);
	fflush(stdout);
	ret = condwait_internal(cond, mutex);
	printf("..got it!\n");

	return ret;
}