Resources: Allow res_free(NULL) and res_detach(NULL)

[libucw.git] / ucw / semaphore.h

diff --git a/ucw/semaphore.h b/ucw/semaphore.h
index fa2e0ee473d58318e59bc3683d22eb33d94a8895..a2bc8959118f84d66eee67a6b976a5a75511ad06 100644 (file)
--- a/ucw/semaphore.h
+++ b/ucw/semaphore.h
@@ -16,6 +16,9 @@
 
 #include <unistd.h>
 #include <stdio.h>
+#include <errno.h>
+
+#include "ucw/fastbuf.h" // For the temp_file_name
 
 /* In Darwin, sem_init() is unfortunately not implemented and the guide
  * recommends emulating it using sem_open().  */
@@ -23,10 +26,15 @@
 static inline sem_t *
 sem_alloc(void)
 {
-  static uns cnt = 0;
-  char buf[20];
-  sprintf(buf, "tmp/sem-%d-%d", getpid(), cnt++);
-  sem_t *sem = sem_open(buf, O_CREAT, 0777, 0);
+  char buf[TEMP_FILE_NAME_LEN];
+  int mode, retry = 10;
+  sem_t *sem;
+  do
+    {
+      temp_file_name(buf, &mode);
+      sem = sem_open(buf, mode | O_CREAT, 0777, 0);
+    }
+  while (sem == (sem_t*) SEM_FAILED && errno == EEXIST && retry --);
   ASSERT(sem != (sem_t*) SEM_FAILED);
   return sem;
 }