Libc-1439.100.3.tar.gz

[apple/libc.git] / stdlib / FreeBSD / getenv.c

diff --git a/stdlib/FreeBSD/getenv.c b/stdlib/FreeBSD/getenv.c
index 47b60dfab1c9f9a56de038c3c16c14bf1998b1ba..c012578ad46397d6fc448f3e67ca030638cde988 100644 (file)
--- a/stdlib/FreeBSD/getenv.c
+++ b/stdlib/FreeBSD/getenv.c
@@ -33,15 +33,18 @@ static char sccsid[] = "@(#)getenv.c        8.1 (Berkeley) 6/4/93";
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD: src/lib/libc/stdlib/getenv.c,v 1.8 2007/05/01 16:02:41 ache Exp $");
 
+#include <os/lock_private.h>
 #include <stdlib.h>
 #include <stddef.h>
 #include <string.h>
 #include <crt_externs.h>
 
-__private_extern__ char *__findenv(const char *, int *, char **);
+__private_extern__ char *__findenv_locked(const char *, int *, char **);
+__private_extern__ void __environ_lock(void);
+__private_extern__ void __environ_unlock(void);
 
 /*
- * __findenv --
+ * __findenv_locked --
  *     Returns pointer to value associated with name, if any, else NULL.
  *     Sets offset to be the offset of the name/value combination in the
  *     environmental array, for use by setenv(3) and unsetenv(3).
@@ -50,7 +53,7 @@ __private_extern__ char *__findenv(const char *, int *, char **);
  *     This routine *should* be a static; don't use it.
  */
 __private_extern__ char *
-__findenv(name, offset, environ)
+__findenv_locked(name, offset, environ)
        const char *name;
        int *offset;
        char **environ;
@@ -76,6 +79,24 @@ __findenv(name, offset, environ)
        return (NULL);
 }
 
+static os_unfair_lock __environ_lock_obj = OS_UNFAIR_LOCK_INIT;
+__private_extern__ void
+__environ_lock(void)
+{
+       os_unfair_lock_lock_with_options(
+                       &__environ_lock_obj, OS_UNFAIR_LOCK_DATA_SYNCHRONIZATION);
+}
+__private_extern__ void
+__environ_unlock(void)
+{
+       os_unfair_lock_unlock(&__environ_lock_obj);
+}
+__private_extern__ void
+__environ_lock_fork_child(void)
+{
+       __environ_lock_obj = OS_UNFAIR_LOCK_INIT;
+}
+
 /*
  * _getenvp -- SPI using an arbitrary pointer to string array (the array must
  * have been created with malloc) and an env state, created by _allocenvstate().
@@ -84,9 +105,12 @@ __findenv(name, offset, environ)
 char *
 _getenvp(const char *name, char ***envp, void *state __unused)
 {
+       // envp is passed as an argument, so the lock is not protecting everything
        int offset;
-
-       return (__findenv(name, &offset, *envp));
+       __environ_lock();
+       char *result = (__findenv_locked(name, &offset, *envp));
+       __environ_unlock();
+       return result;
 }
 
 /*
@@ -98,6 +122,8 @@ getenv(name)
        const char *name;
 {
        int offset;
-
-       return (__findenv(name, &offset, *_NSGetEnviron()));
+       __environ_lock();
+       char *result = __findenv_locked(name, &offset, *_NSGetEnviron());
+       __environ_unlock();
+       return result;
 }