1156956Sume#include <sys/cdefs.h> 2156956Sume__FBSDID("$FreeBSD$"); 3156956Sume 4156952Sume#include <port_before.h> 5156952Sume#ifdef DO_PTHREADS 6156952Sume#include <pthread.h> 7156956Sume#ifdef _LIBC 8156956Sume#include <pthread_np.h> 9156952Sume#endif 10156956Sume#endif 11156952Sume#include <errno.h> 12156952Sume#include <netdb.h> 13156952Sume#include <stdlib.h> 14156952Sume#include <string.h> 15156952Sume#include <resolv_mt.h> 16156952Sume#include <port_after.h> 17156952Sume 18156952Sume#ifdef DO_PTHREADS 19156952Sumestatic pthread_key_t key; 20156952Sumestatic int mt_key_initialized = 0; 21156952Sume 22156952Sumestatic int __res_init_ctx(void); 23156952Sumestatic void __res_destroy_ctx(void *); 24156952Sume 25156952Sume#if defined(sun) && !defined(__GNUC__) 26156952Sume#pragma init (_mtctxres_init) 27156952Sume#endif 28156952Sume#endif 29156952Sume 30156952Sumestatic mtctxres_t sharedctx; 31156952Sume 32156952Sume#ifdef DO_PTHREADS 33156952Sume/* 34156952Sume * Initialize the TSD key. By doing this at library load time, we're 35156952Sume * implicitly running without interference from other threads, so there's 36156952Sume * no need for locking. 37156952Sume */ 38156952Sumestatic void 39156952Sume_mtctxres_init(void) { 40156952Sume int pthread_keycreate_ret; 41156952Sume 42156952Sume pthread_keycreate_ret = pthread_key_create(&key, __res_destroy_ctx); 43156952Sume if (pthread_keycreate_ret == 0) 44156952Sume mt_key_initialized = 1; 45156952Sume} 46156952Sume#endif 47156952Sume 48156956Sume#ifndef _LIBC 49156952Sume/* 50156952Sume * To support binaries that used the private MT-safe interface in 51156952Sume * Solaris 8, we still need to provide the __res_enable_mt() 52156952Sume * and __res_disable_mt() entry points. They're do-nothing routines. 53156952Sume */ 54156952Sumeint 55156952Sume__res_enable_mt(void) { 56156952Sume return (-1); 57156952Sume} 58156952Sume 59156952Sumeint 60156952Sume__res_disable_mt(void) { 61156952Sume return (0); 62156952Sume} 63156956Sume#endif 64156952Sume 65156952Sume#ifdef DO_PTHREADS 66156952Sumestatic int 67156952Sume__res_init_ctx(void) { 68156952Sume 69156952Sume mtctxres_t *mt; 70156952Sume int ret; 71156952Sume 72156952Sume 73156952Sume if (pthread_getspecific(key) != 0) { 74156952Sume /* Already exists */ 75156952Sume return (0); 76156952Sume } 77156952Sume 78297790Spfg if ((mt = malloc(sizeof(mtctxres_t))) == NULL) { 79156952Sume errno = ENOMEM; 80156952Sume return (-1); 81156952Sume } 82156952Sume 83156952Sume memset(mt, 0, sizeof (mtctxres_t)); 84156952Sume 85156952Sume if ((ret = pthread_setspecific(key, mt)) != 0) { 86156952Sume free(mt); 87156952Sume errno = ret; 88156952Sume return (-1); 89156952Sume } 90156952Sume 91156952Sume return (0); 92156952Sume} 93156952Sume 94156952Sumestatic void 95156952Sume__res_destroy_ctx(void *value) { 96156952Sume 97297790Spfg free(value); 98156952Sume} 99156952Sume#endif 100156952Sume 101156952Sumemtctxres_t * 102156952Sume___mtctxres(void) { 103156952Sume#ifdef DO_PTHREADS 104156952Sume mtctxres_t *mt; 105156952Sume 106156956Sume#ifdef _LIBC 107156956Sume if (pthread_main_np() != 0) 108156956Sume return (&sharedctx); 109156956Sume#endif 110156956Sume 111156952Sume /* 112156952Sume * This if clause should only be executed if we are linking 113156952Sume * statically. When linked dynamically _mtctxres_init() should 114156952Sume * be called at binding time due the #pragma above. 115156952Sume */ 116156952Sume if (!mt_key_initialized) { 117156952Sume static pthread_mutex_t keylock = PTHREAD_MUTEX_INITIALIZER; 118165258Sume if (pthread_mutex_lock(&keylock) == 0) { 119165258Sume _mtctxres_init(); 120165258Sume (void) pthread_mutex_unlock(&keylock); 121165258Sume } 122156952Sume } 123156952Sume 124156952Sume /* 125156952Sume * If we have already been called in this thread return the existing 126156952Sume * context. Otherwise recreat a new context and return it. If 127156952Sume * that fails return a global context. 128156952Sume */ 129156952Sume if (mt_key_initialized) { 130297790Spfg if (((mt = pthread_getspecific(key)) != NULL) || 131156952Sume (__res_init_ctx() == 0 && 132297790Spfg (mt = pthread_getspecific(key)) != NULL)) { 133156952Sume return (mt); 134156952Sume } 135156952Sume } 136156952Sume#endif 137156952Sume return (&sharedctx); 138156952Sume} 139