jemalloc/src/mutex.c

#define	JEMALLOC_MUTEX_C_
#include "jemalloc/internal/jemalloc_internal.h"

/******************************************************************************/
/* Data. */

#ifdef JEMALLOC_LAZY_LOCK
bool isthreaded = false;
#endif

#ifdef JEMALLOC_LAZY_LOCK
static void	pthread_create_once(void);
#endif

/******************************************************************************/
/*
 * We intercept pthread_create() calls in order to toggle isthreaded if the
 * process goes multi-threaded.
 */

#ifdef JEMALLOC_LAZY_LOCK
static int (*pthread_create_fptr)(pthread_t *__restrict, const pthread_attr_t *,
    void *(*)(void *), void *__restrict);

static void
pthread_create_once(void)
{

	pthread_create_fptr = dlsym(RTLD_NEXT, "pthread_create");
	if (pthread_create_fptr == NULL) {
		malloc_write4("<jemalloc>",
		    ": Error in dlsym(RTLD_NEXT, \"pthread_create\")\n", "",
		    "");
		abort();
	}

	isthreaded = true;
}

JEMALLOC_ATTR(visibility("default"))
int
pthread_create(pthread_t *__restrict thread,
    const pthread_attr_t *__restrict attr, void *(*start_routine)(void *),
    void *__restrict arg)
{
	static pthread_once_t once_control = PTHREAD_ONCE_INIT;

	pthread_once(&once_control, pthread_create_once);

	return (pthread_create_fptr(thread, attr, start_routine, arg));
}
#endif

/******************************************************************************/

bool
malloc_mutex_init(malloc_mutex_t *mutex)
{
	pthread_mutexattr_t attr;

	if (pthread_mutexattr_init(&attr) != 0)
		return (true);
	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ADAPTIVE_NP);
	if (pthread_mutex_init(mutex, &attr) != 0) {
		pthread_mutexattr_destroy(&attr);
		return (true);
	}
	pthread_mutexattr_destroy(&attr);

	return (false);
}