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#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <port_before.h>
#ifdef DO_PTHREADS
#include <pthread.h>
#ifdef _LIBC
#include <pthread_np.h>
#endif
#endif
#include <errno.h>
#include <netdb.h>
#include <stdlib.h>
#include <string.h>
#include <resolv_mt.h>
#include <port_after.h>
#ifdef DO_PTHREADS
static pthread_key_t key;
static int mt_key_initialized = 0;
static int __res_init_ctx(void);
static void __res_destroy_ctx(void *);
#if defined(sun) && !defined(__GNUC__)
#pragma init (_mtctxres_init)
#endif
#endif
static mtctxres_t sharedctx;
#ifdef DO_PTHREADS
/*
* Initialize the TSD key. By doing this at library load time, we're
* implicitly running without interference from other threads, so there's
* no need for locking.
*/
static void
_mtctxres_init(void) {
int pthread_keycreate_ret;
pthread_keycreate_ret = pthread_key_create(&key, __res_destroy_ctx);
if (pthread_keycreate_ret == 0)
mt_key_initialized = 1;
}
#endif
#ifndef _LIBC
/*
* To support binaries that used the private MT-safe interface in
* Solaris 8, we still need to provide the __res_enable_mt()
* and __res_disable_mt() entry points. They're do-nothing routines.
*/
int
__res_enable_mt(void) {
return (-1);
}
int
__res_disable_mt(void) {
return (0);
}
#endif
#ifdef DO_PTHREADS
static int
__res_init_ctx(void) {
mtctxres_t *mt;
int ret;
if (pthread_getspecific(key) != 0) {
/* Already exists */
return (0);
}
if ((mt = malloc(sizeof (mtctxres_t))) == 0) {
errno = ENOMEM;
return (-1);
}
memset(mt, 0, sizeof (mtctxres_t));
if ((ret = pthread_setspecific(key, mt)) != 0) {
free(mt);
errno = ret;
return (-1);
}
return (0);
}
static void
__res_destroy_ctx(void *value) {
mtctxres_t *mt = (mtctxres_t *)value;
if (mt != 0)
free(mt);
}
#endif
mtctxres_t *
___mtctxres(void) {
#ifdef DO_PTHREADS
mtctxres_t *mt;
#ifdef _LIBC
if (pthread_main_np() != 0)
return (&sharedctx);
#endif
/*
* This if clause should only be executed if we are linking
* statically. When linked dynamically _mtctxres_init() should
* be called at binding time due the #pragma above.
*/
if (!mt_key_initialized) {
static pthread_mutex_t keylock = PTHREAD_MUTEX_INITIALIZER;
if (pthread_mutex_lock(&keylock) == 0) {
_mtctxres_init();
(void) pthread_mutex_unlock(&keylock);
}
}
/*
* If we have already been called in this thread return the existing
* context. Otherwise recreat a new context and return it. If
* that fails return a global context.
*/
if (mt_key_initialized) {
if (((mt = pthread_getspecific(key)) != 0) ||
(__res_init_ctx() == 0 &&
(mt = pthread_getspecific(key)) != 0)) {
return (mt);
}
}
#endif
return (&sharedctx);
}
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