Use reentrant version of readdir. If the target platform does not support

the POSIX-like readdir_r, we fall back to readdir. In ZTS mode, this will
cause php_readdir_r calls to be serialized.

acinclude.m4

@@ -4,6 +4,36 @@ dnl This file contains local autoconf functions.
 
 sinclude(dynlib.m4)
 
+AC_DEFUN(PHP_POSIX_READDIR_R,[
+  AC_CACHE_CHECK(for type of readdir_r, ac_cv_what_readdir_r,[
+    AC_TRY_RUN([
+#include <sys/types.h>
+#include <dirent.h>
+
+main() {
+	DIR *dir;
+	struct dirent entry, *pentry;
+
+	dir = opendir("/");
+	if (!dir) 
+		exit(1);
+	if (readdir_r(dir, &entry, &pentry) == 0)
+		exit(0);
+	exit(1);
+}
+    ],[
+      ac_cv_what_readdir_r=POSIX
+    ],[
+      ac_cv_what_readdir_r=none
+    ],[
+      ac_cv_what_readdir_r=none
+   ])
+  ])
+  if test "$ac_cv_what_readdir_r" = "POSIX"; then
+    AC_DEFINE(HAVE_POSIX_READDIR_R,1,[whether you have POSIX readdir_r])
+  fi
+])
+
 AC_DEFUN(PHP_SHLIB_SUFFIX_NAME,[
   PHP_SUBST(SHLIB_SUFFIX_NAME)
   SHLIB_SUFFIX_NAME=so

configure.in

@@ -379,6 +379,7 @@ AC_FUNC_ALLOCA
 AC_BROKEN_SPRINTF
 PHP_DECLARED_TIMEZONE
 PHP_TIME_R_TYPE
+PHP_POSIX_READDIR_R
 
 dnl AIX keeps in_addr_t in /usr/include/netinet/in.h
 dnl AC_MSG_CHECKING(for in_addr_t)

ext/session/mod_files.c

@@ -154,7 +154,7 @@ static void _ps_files_open(ps_files *data, const char *key)
 static int _ps_files_cleanup_dir(const char *dirname, int maxlifetime)
 {
 	DIR *dir;
-	struct dirent *entry;
+	struct dirent *entry, dentry;
 	struct stat sbuf;
 	char buf[MAXPATHLEN];
 	time_t now;
@@ -168,7 +168,7 @@ static int _ps_files_cleanup_dir(const char *dirname, int maxlifetime)
 
 	time(&now);
 
-	while((entry = readdir(dir))) {
+	while (php_readdir_r(dir, &dentry, &entry) == 0 && entry) {
 		/* does the file start with our prefix? */
 		if (!strncmp(entry->d_name, FILE_PREFIX, sizeof(FILE_PREFIX) - 1) &&
 				/* create full path */

ext/standard/dir.c

@@ -273,14 +273,14 @@ PHP_FUNCTION(readdir)
 {
 	pval **id, **tmp, *myself;
 	php_dir *dirp;
-	struct dirent *direntp;
+	struct dirent entry;
+	struct dirent *result;
 	DIRLS_FETCH();
 
 	FETCH_DIRP();
-	
-	direntp = readdir(dirp->dir);
-	if (direntp) {
-		RETURN_STRINGL(direntp->d_name, strlen(direntp->d_name), 1);
+
+	if (php_readdir_r(dirp->dir, &entry, &result) == 0 && result) {
+		RETURN_STRINGL(result->d_name, strlen(result->d_name), 1);
 	}
 	RETURN_FALSE;
 }

main/php_reentrancy.h

@@ -22,6 +22,8 @@
 
 #include "php.h"
 
+#include <sys/types.h>
+#include <dirent.h>
 #include <time.h>
 
 /* currently, PHP does not check for these functions, but assumes
@@ -40,6 +42,13 @@
 #undef HAVE_GMTIME_R
 #endif
 
+#if defined(HAVE_POSIX_READDIR_R)
+#define php_readdir_r readdir_r
+#else
+PHPAPI int php_readdir_r(DIR *dirp, struct dirent *entry,
+		struct dirent **result);
+#endif
+
 #if !defined(HAVE_LOCALTIME_R) && defined(HAVE_LOCALTIME)
 #define PHP_NEED_REENTRANCY 1
 PHPAPI struct tm *php_localtime_r(const time_t *const timep, struct tm *p_tm);

main/reentrancy.c

@@ -17,7 +17,17 @@
  */
 
 
+#include <sys/types.h>
 #include <string.h>
+#include <errno.h>
+#ifdef HAVE_DIRENT_H
+#include <dirent.h>
+#endif
+
+#ifdef PHP_WIN32
+#define NEEDRDH 1
+#include "win32/readdir.h"
+#endif
 
 #include "php_reentrancy.h"
 #include "ext/standard/php_rand.h"                   /* for RAND_MAX */
@@ -27,6 +37,7 @@ enum {
 	CTIME_R,
 	ASCTIME_R,
 	GMTIME_R,
+	READDIR_R,
 	NUMBER_OF_LOCKS
 };
 
@@ -77,7 +88,37 @@ PHPAPI struct tm *php_gmtime_r(const time_t *const timep, struct tm *p_tm)
 }
 
 #endif
+
+#if !defined(HAVE_POSIX_READDIR_R)
+
+PHPAPI int php_readdir_r(DIR *dirp, struct dirent *entry, 
+		struct dirent **result)
+{
+	struct dirent *ptr;
+	int ret = 0;
+
+	local_lock(READDIR_R);
 	
+	errno = 0;
+	
+	ptr = readdir(dirp);
+	
+	if (!ptr && errno != 0)
+		ret = errno;
+
+	if (entry && ptr)
+		memcpy(entry, ptr, sizeof(*ptr));
+
+	if (result) 
+		*result = ptr;
+
+	local_unlock(READDIR_R);
+
+	return ret;
+}
+
+#endif
+
 #if !defined(HAVE_LOCALTIME_R) && defined(HAVE_LOCALTIME)
 
 PHPAPI struct tm *php_localtime_r(const time_t *const timep, struct tm *p_tm)