Only update the global tid_count once

Normally, the tid_count is initialized only once at the beginning of the
application.  The only exception is the pattern in the unit test where
isc_loopmgr is repeatedly created and torn down and each creation of
isc_loopmgr_t calls isc__tid_initcount() with the previous value.

ThreadSanitizer sees that as write operation on unprotected memory are
reports this as data race even though the value has not really changed.

This has been fixed by skipping the tid_count value update on repeated
calls.

diff --git a/lib/isc/tid.c b/lib/isc/tid.c
index ce385abeb7fd4e519a960ffa3ab8fa5b87015da7..9550908a2204bbc8effc439280e591144eaaf971 100644 (file)
--- a/lib/isc/tid.c
+++ b/lib/isc/tid.c
@@ -11,7 +11,6 @@
  * information regarding copyright ownership.
  */
 
-#include <stdlib.h>
 #include <sys/types.h>
 #include <unistd.h>
 
@@ -45,7 +44,9 @@ void
 isc__tid_initcount(isc_tid_t count) {
        REQUIRE(tid_count == 0 || tid_count == count);
        REQUIRE(count < ISC_TID_MAX);
-       tid_count = count;
+       if (tid_count == 0) {
+               tid_count = count;
+       }
 }
 
 /**