major improvements to temp file name generator

[musl] / src / temp / mktemp.c

diff --git a/src/temp/mktemp.c b/src/temp/mktemp.c
index 1078b9d..1462a16 100644 (file)
--- a/src/temp/mktemp.c
+++ b/src/temp/mktemp.c
@@ -4,28 +4,30 @@
 #include <fcntl.h>
 #include <unistd.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <errno.h>

+#include <time.h>
+#include <stdint.h>

 #include "libc.h"
 
 char *__mktemp(char *template)
 {
 #include "libc.h"
 
 char *__mktemp(char *template)
 {

-       static int lock;
-       static int index;
-       int l = strlen(template);
+       struct timespec ts;
+       size_t l = strlen(template);
+       int retries = 10000;
+       unsigned long r;

 
        if (l < 6 || strcmp(template+l-6, "XXXXXX")) {
                errno = EINVAL;
 
        if (l < 6 || strcmp(template+l-6, "XXXXXX")) {
                errno = EINVAL;

-               return NULL;
+               return 0;

        }
        }

-       LOCK(&lock);
-       for (; index < 1000000; index++) {
-               snprintf(template+l-6, 6, "%06d", index);
-               if (access(template, F_OK) != 0) {
-                       UNLOCK(&lock);
-                       return template;
-               }
+       clock_gettime(CLOCK_REALTIME, &ts);
+       r = ts.tv_nsec + (uintptr_t)&ts / 16 + (uintptr_t)template;
+       while (retries--) {
+               snprintf(template+l-6, 7, "%06lX", r & 0xffffff);
+               if (access(template, F_OK) < 0) return template;
+               r = r * 1103515245 + 12345;

        }
        }

-       UNLOCK(&lock);
-       return NULL;    
+       errno = EEXIST;
+       return 0;

 }
 
 weak_alias(__mktemp, mktemp);
 }
 
 weak_alias(__mktemp, mktemp);