1*9525b14bSRao Shoaib /* 2*9525b14bSRao Shoaib * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 3*9525b14bSRao Shoaib * Use is subject to license terms. 4*9525b14bSRao Shoaib */ 5*9525b14bSRao Shoaib 6*9525b14bSRao Shoaib 7*9525b14bSRao Shoaib #include <port_before.h> 8*9525b14bSRao Shoaib #ifdef DO_PTHREADS 9*9525b14bSRao Shoaib #include <pthread.h> 10*9525b14bSRao Shoaib #endif 11*9525b14bSRao Shoaib #include <errno.h> 12*9525b14bSRao Shoaib #include <netdb.h> 13*9525b14bSRao Shoaib #include <stdlib.h> 14*9525b14bSRao Shoaib #include <string.h> 15*9525b14bSRao Shoaib #include <resolv_mt.h> 16*9525b14bSRao Shoaib #include <irs.h> 17*9525b14bSRao Shoaib #include <port_after.h> 18*9525b14bSRao Shoaib 19*9525b14bSRao Shoaib #ifdef DO_PTHREADS 20*9525b14bSRao Shoaib static pthread_key_t key; 21*9525b14bSRao Shoaib static int mt_key_initialized = 0; 22*9525b14bSRao Shoaib 23*9525b14bSRao Shoaib static int __res_init_ctx(void); 24*9525b14bSRao Shoaib static void __res_destroy_ctx(void *); 25*9525b14bSRao Shoaib 26*9525b14bSRao Shoaib #if defined(sun) && !defined(__GNUC__) 27*9525b14bSRao Shoaib #pragma init (_mtctxres_init) 28*9525b14bSRao Shoaib #endif 29*9525b14bSRao Shoaib #endif 30*9525b14bSRao Shoaib 31*9525b14bSRao Shoaib static mtctxres_t sharedctx; 32*9525b14bSRao Shoaib 33*9525b14bSRao Shoaib #ifdef DO_PTHREADS 34*9525b14bSRao Shoaib /* 35*9525b14bSRao Shoaib * Initialize the TSD key. By doing this at library load time, we're 36*9525b14bSRao Shoaib * implicitly running without interference from other threads, so there's 37*9525b14bSRao Shoaib * no need for locking. 38*9525b14bSRao Shoaib */ 39*9525b14bSRao Shoaib static void 40*9525b14bSRao Shoaib _mtctxres_init(void) { 41*9525b14bSRao Shoaib int pthread_keycreate_ret; 42*9525b14bSRao Shoaib 43*9525b14bSRao Shoaib pthread_keycreate_ret = pthread_key_create(&key, __res_destroy_ctx); 44*9525b14bSRao Shoaib if (pthread_keycreate_ret == 0) 45*9525b14bSRao Shoaib mt_key_initialized = 1; 46*9525b14bSRao Shoaib } 47*9525b14bSRao Shoaib #endif 48*9525b14bSRao Shoaib 49*9525b14bSRao Shoaib /* 50*9525b14bSRao Shoaib * To support binaries that used the private MT-safe interface in 51*9525b14bSRao Shoaib * Solaris 8, we still need to provide the __res_enable_mt() 52*9525b14bSRao Shoaib * and __res_disable_mt() entry points. They're do-nothing routines. 53*9525b14bSRao Shoaib */ 54*9525b14bSRao Shoaib int 55*9525b14bSRao Shoaib __res_enable_mt(void) { 56*9525b14bSRao Shoaib return (-1); 57*9525b14bSRao Shoaib } 58*9525b14bSRao Shoaib 59*9525b14bSRao Shoaib int 60*9525b14bSRao Shoaib __res_disable_mt(void) { 61*9525b14bSRao Shoaib return (0); 62*9525b14bSRao Shoaib } 63*9525b14bSRao Shoaib 64*9525b14bSRao Shoaib #ifdef DO_PTHREADS 65*9525b14bSRao Shoaib static int 66*9525b14bSRao Shoaib __res_init_ctx(void) { 67*9525b14bSRao Shoaib 68*9525b14bSRao Shoaib mtctxres_t *mt; 69*9525b14bSRao Shoaib int ret; 70*9525b14bSRao Shoaib 71*9525b14bSRao Shoaib 72*9525b14bSRao Shoaib if (pthread_getspecific(key) != 0) { 73*9525b14bSRao Shoaib /* Already exists */ 74*9525b14bSRao Shoaib return (0); 75*9525b14bSRao Shoaib } 76*9525b14bSRao Shoaib 77*9525b14bSRao Shoaib if ((mt = malloc(sizeof (mtctxres_t))) == 0) { 78*9525b14bSRao Shoaib errno = ENOMEM; 79*9525b14bSRao Shoaib return (-1); 80*9525b14bSRao Shoaib } 81*9525b14bSRao Shoaib 82*9525b14bSRao Shoaib memset(mt, 0, sizeof (mtctxres_t)); 83*9525b14bSRao Shoaib 84*9525b14bSRao Shoaib if ((ret = pthread_setspecific(key, mt)) != 0) { 85*9525b14bSRao Shoaib free(mt); 86*9525b14bSRao Shoaib errno = ret; 87*9525b14bSRao Shoaib return (-1); 88*9525b14bSRao Shoaib } 89*9525b14bSRao Shoaib 90*9525b14bSRao Shoaib return (0); 91*9525b14bSRao Shoaib } 92*9525b14bSRao Shoaib 93*9525b14bSRao Shoaib static void 94*9525b14bSRao Shoaib __res_destroy_ctx(void *value) { 95*9525b14bSRao Shoaib 96*9525b14bSRao Shoaib mtctxres_t *mt = (mtctxres_t *)value; 97*9525b14bSRao Shoaib 98*9525b14bSRao Shoaib if (mt != 0) 99*9525b14bSRao Shoaib free(mt); 100*9525b14bSRao Shoaib } 101*9525b14bSRao Shoaib #endif 102*9525b14bSRao Shoaib 103*9525b14bSRao Shoaib mtctxres_t * 104*9525b14bSRao Shoaib ___mtctxres(void) { 105*9525b14bSRao Shoaib #ifdef DO_PTHREADS 106*9525b14bSRao Shoaib mtctxres_t *mt; 107*9525b14bSRao Shoaib 108*9525b14bSRao Shoaib /* 109*9525b14bSRao Shoaib * This if clause should only be executed if we are linking 110*9525b14bSRao Shoaib * statically. When linked dynamically _mtctxres_init() should 111*9525b14bSRao Shoaib * be called at binding time due the #pragma above. 112*9525b14bSRao Shoaib */ 113*9525b14bSRao Shoaib if (!mt_key_initialized) { 114*9525b14bSRao Shoaib static pthread_mutex_t keylock = PTHREAD_MUTEX_INITIALIZER; 115*9525b14bSRao Shoaib if (pthread_mutex_lock(&keylock) == 0) { 116*9525b14bSRao Shoaib _mtctxres_init(); 117*9525b14bSRao Shoaib (void) pthread_mutex_unlock(&keylock); 118*9525b14bSRao Shoaib } 119*9525b14bSRao Shoaib } 120*9525b14bSRao Shoaib 121*9525b14bSRao Shoaib /* 122*9525b14bSRao Shoaib * If we have already been called in this thread return the existing 123*9525b14bSRao Shoaib * context. Otherwise recreat a new context and return it. If 124*9525b14bSRao Shoaib * that fails return a global context. 125*9525b14bSRao Shoaib */ 126*9525b14bSRao Shoaib if (mt_key_initialized) { 127*9525b14bSRao Shoaib if (((mt = pthread_getspecific(key)) != 0) || 128*9525b14bSRao Shoaib (__res_init_ctx() == 0 && 129*9525b14bSRao Shoaib (mt = pthread_getspecific(key)) != 0)) { 130*9525b14bSRao Shoaib return (mt); 131*9525b14bSRao Shoaib } 132*9525b14bSRao Shoaib } 133*9525b14bSRao Shoaib #endif 134*9525b14bSRao Shoaib return (&sharedctx); 135*9525b14bSRao Shoaib } 136