Merge "Initialize _nres only once" am: 24e0b57429 am: 5ffb5a6882
Original change: https://android-review.googlesource.com/c/platform/bionic/+/1534576
Change-Id: I17ae65cf42eddd4e9f8d22061fd0344a98c51c59
diff --git a/libc/dns/resolv/res_data.c b/libc/dns/resolv/res_data.c
index 9bc02e7..4f8df69 100644
--- a/libc/dns/resolv/res_data.c
+++ b/libc/dns/resolv/res_data.c
@@ -40,6 +40,7 @@
#include <ctype.h>
#include <netdb.h>
#include "resolv_private.h"
+#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@@ -82,11 +83,9 @@
int res_ourserver_p(const res_state, const struct sockaddr *);
-#define res_need_init() ((_nres.options & RES_INIT) == 0U)
+static pthread_once_t once_control = PTHREAD_ONCE_INIT;
-int
-res_init(void) {
- int rv;
+static void init_once(void) {
extern int __res_vinit(res_state, int);
#ifdef COMPAT__RES
/*
@@ -140,11 +139,21 @@
if (!_nres.id)
_nres.id = res_randomid();
- rv = __res_vinit(&_nres, 1);
+ __res_vinit(&_nres, 1);
#ifdef COMPAT__RES
__res_put_old_state(&_nres);
#endif
- return rv;
+}
+
+int
+res_init(void) {
+ pthread_once(&once_control, init_once);
+ return 0;
+}
+
+static res_state get_static_res_state() {
+ pthread_once(&once_control, init_once);
+ return &_nres;
}
void
@@ -159,10 +168,7 @@
void
fp_nquery(const u_char *msg, int len, FILE *file) {
- if (res_need_init() && res_init() == -1)
- return;
-
- res_pquery(&_nres, msg, len, file);
+ res_pquery(get_static_res_state(), msg, len, file);
}
int
@@ -175,11 +181,7 @@
u_char *buf, /* buffer to put query */
int buflen) /* size of buffer */
{
- if (res_need_init() && res_init() == -1) {
- RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
- return (-1);
- }
- return (res_nmkquery(&_nres, op, dname, class, type,
+ return (res_nmkquery(get_static_res_state(), op, dname, class, type,
data, datalen,
newrr_in, buf, buflen));
}
@@ -187,12 +189,7 @@
#ifdef _LIBRESOLV
int
res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
- if (res_need_init() && res_init() == -1) {
- RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
- return (-1);
- }
-
- return (res_nmkupdate(&_nres, rrecp_in, buf, buflen));
+ return (res_nmkupdate(get_static_res_state(), rrecp_in, buf, buflen));
}
#endif
@@ -202,11 +199,7 @@
u_char *answer, /* buffer to put answer */
int anslen) /* size of answer buffer */
{
- if (res_need_init() && res_init() == -1) {
- RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
- return (-1);
- }
- return (res_nquery(&_nres, name, class, type, answer, anslen));
+ return (res_nquery(get_static_res_state(), name, class, type, answer, anslen));
}
void
@@ -226,12 +219,7 @@
int
res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) {
- if (res_need_init() && res_init() == -1) {
- /* errno should have been set by res_init() in this case. */
- return (-1);
- }
-
- return (res_nsend(&_nres, buf, buflen, ans, anssiz));
+ return (res_nsend(get_static_res_state(), buf, buflen, ans, anssiz));
}
#ifdef _LIBRESOLV
@@ -239,12 +227,7 @@
res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key,
u_char *ans, int anssiz)
{
- if (res_need_init() && res_init() == -1) {
- /* errno should have been set by res_init() in this case. */
- return (-1);
- }
-
- return (res_nsendsigned(&_nres, buf, buflen, key, ans, anssiz));
+ return (res_nsendsigned(get_static_res_state(), buf, buflen, key, ans, anssiz));
}
#endif
@@ -256,12 +239,7 @@
#ifdef _LIBRESOLV
int
res_update(ns_updrec *rrecp_in) {
- if (res_need_init() && res_init() == -1) {
- RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
- return (-1);
- }
-
- return (res_nupdate(&_nres, rrecp_in, NULL));
+ return (res_nupdate(get_static_res_state(), rrecp_in, NULL));
}
#endif
@@ -271,12 +249,7 @@
u_char *answer, /* buffer to put answer */
int anslen) /* size of answer */
{
- if (res_need_init() && res_init() == -1) {
- RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
- return (-1);
- }
-
- return (res_nsearch(&_nres, name, class, type, answer, anslen));
+ return (res_nsearch(get_static_res_state(), name, class, type, answer, anslen));
}
int
@@ -286,12 +259,7 @@
u_char *answer, /* buffer to put answer */
int anslen) /* size of answer */
{
- if (res_need_init() && res_init() == -1) {
- RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
- return (-1);
- }
-
- return (res_nquerydomain(&_nres, name, domain,
+ return (res_nquerydomain(get_static_res_state(), name, domain,
class, type,
answer, anslen));
}