Merge pull request #26 from Andargor/master

Changed readdir to readdir_r for thread-safety

1 files changed, 85 insertions, 2 deletions

diff --git a/tinydir.h b/tinydir.h
index 01fdb39..e04fa41 100644..100755
--- a/tinydir.h
+++ b/tinydir.h
@@ -40,6 +40,7 @@ extern "C" {
 # include <dirent.h>
 # include <libgen.h>
 # include <sys/stat.h>
+# include <stddef.h>
 #endif
 
 
@@ -72,6 +73,61 @@ extern "C" {
 	#define _TINYDIR_FREE(_ptr)    free(_ptr)
 #endif //!defined(_TINYDIR_MALLOC)
 
+/* avoid warnings due to unused variables or parameters */
+#ifndef _MSC_VER
+	#if !defined(_TINYDIR_UNUSED)
+		#ifdef __GNUC__
+			#define _TINYDIR_UNUSED(x) _TINYDIR_UNUSED_ ## x __attribute__((__unused__))
+		#else
+			#define _TINYDIR_UNUSED(x) _TINYDIR_UNUSED_ ## x
+		#endif
+	#endif
+#endif
+
+#ifndef _MSC_VER
+ /*
+	The following authored by Ben Hutchings <ben@decadent.org.uk>
+	from https://womble.decadent.org.uk/readdir_r-advisory.html
+*/
+/* Calculate the required buffer size (in bytes) for directory       *
+ * entries read from the given directory handle.  Return -1 if this  *
+ * this cannot be done.                                              *
+ *                                                                   *
+ * This code does not trust values of NAME_MAX that are less than    *
+ * 255, since some systems (including at least HP-UX) incorrectly    *
+ * define it to be a smaller value.                                  *
+ *                                                                   *
+ * If you use autoconf, include fpathconf and dirfd in your          *
+ * AC_CHECK_FUNCS list.  Otherwise use some other method to detect   *
+ * and use them where available.                                     */
+
+static size_t dirent_buf_size(DIR * _TINYDIR_UNUSED(dirp))
+{
+    long name_max;
+    size_t name_end;
+	
+#   if defined(HAVE_FPATHCONF) && defined(HAVE_DIRFD) \
+       && defined(_PC_NAME_MAX)
+        name_max = fpathconf(dirfd(dirp), _PC_NAME_MAX);
+        if (name_max == -1)
+#           if defined(NAME_MAX)
+                name_max = (NAME_MAX > 255) ? NAME_MAX : 255;
+#           else
+                return (size_t)(-1);
+#           endif
+#   else
+#       if defined(NAME_MAX)
+            name_max = (NAME_MAX > 255) ? NAME_MAX : 255;
+#       else
+#           error "buffer size for readdir_r cannot be determined"
+#       endif
+#   endif
+    name_end = (size_t)offsetof(struct dirent, d_name) + name_max + 1;
+    return (name_end > sizeof(struct dirent)
+            ? name_end : sizeof(struct dirent));
+}
+#endif
+
 typedef struct
 {
 	char path[_TINYDIR_PATH_MAX];
@@ -98,6 +154,7 @@ typedef struct
 #else
 	DIR *_d;
 	struct dirent *_e;
+	struct dirent *_ep;
 #endif
 } tinydir_dir;
 
@@ -131,6 +188,11 @@ int _tinydir_file_cmp(const void *a, const void *b);
 _TINYDIR_FUNC
 int tinydir_open(tinydir_dir *dir, const char *path)
 {
+#ifndef _MSC_VER
+	int error;
+	int size;	/* using int size */
+#endif
+
 	if (dir == NULL || path == NULL || strlen(path) == 0)
 	{
 		errno = EINVAL;
@@ -148,6 +210,7 @@ int tinydir_open(tinydir_dir *dir, const char *path)
 	dir->_h = INVALID_HANDLE_VALUE;
 #else
 	dir->_d = NULL;
+	dir->_ep = NULL;
 #endif
 	tinydir_close(dir);
 
@@ -169,7 +232,15 @@ int tinydir_open(tinydir_dir *dir, const char *path)
 	/* read first file */
 	dir->has_next = 1;
 #ifndef _MSC_VER
-	dir->_e = readdir(dir->_d);
+	/* allocate dirent buffer for readdir_r */
+	size = dirent_buf_size(dir->_d); /* conversion to int */
+	if (size == -1) return -1;
+	dir->_ep = (struct dirent*)_TINYDIR_MALLOC(size);
+	if (dir->_ep == NULL) return -1;	
+
+	error = readdir_r(dir->_d, dir->_ep, &dir->_e);
+	if (error != 0) return -1;
+
 	if (dir->_e == NULL)
 	{
 		dir->has_next = 0;
@@ -276,12 +347,21 @@ void tinydir_close(tinydir_dir *dir)
 	}
 	dir->_d = NULL;
 	dir->_e = NULL;
+	if (dir->_ep != NULL)
+	{
+		_TINYDIR_FREE(dir->_ep);
+	}
+	dir->_ep = NULL;
 #endif
 }
 
 _TINYDIR_FUNC
 int tinydir_next(tinydir_dir *dir)
 {
+#ifndef _MSC_VER
+	int error;
+#endif
+	
 	if (dir == NULL)
 	{
 		errno = EINVAL;
@@ -296,7 +376,10 @@ int tinydir_next(tinydir_dir *dir)
 #ifdef _MSC_VER
 	if (FindNextFileA(dir->_h, &dir->_f) == 0)
 #else
-	dir->_e = readdir(dir->_d);
+	if (dir->_ep == NULL) return -1;
+	error = readdir_r(dir->_d, dir->_ep, &dir->_e);
+	if (error != 0) return -1;
+
 	if (dir->_e == NULL)
 #endif
 	{