From: Bart Van Assche <bvanassche@acm.org>
Date: Sun, 30 Mar 2008 17:56:43 +0000 (+0000)
Subject: Introduced bm_test_and_clear().
X-Git-Tag: svn/VALGRIND_3_4_0~771
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=8d4a6c4012966758dad360686eff5fe3a0cc5f58;p=thirdparty%2Fvalgrind.git

Introduced bm_test_and_clear().

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@7824
---

diff --git a/exp-drd/drd_bitmap.c b/exp-drd/drd_bitmap.c
index 81424baf6c..03ed89bc60 100644
--- a/exp-drd/drd_bitmap.c
+++ b/exp-drd/drd_bitmap.c
@@ -477,6 +477,20 @@ void bm_clear_store(const struct bitmap* const bm,
   }
 }
 
+/** Clear bitmap bm starting at address a1 and up to but not including address
+ *  a2. Return True if and only if any of the addresses was set before
+ *  clearing.
+ */
+Bool bm_test_and_clear(const struct bitmap* const bm,
+                       const Addr a1, const Addr a2)
+{
+  Bool result;
+
+  result = bm_has_any_access(bm, a1, a2) != 0;
+  bm_clear(bm, a1, a2);
+  return result;
+}
+
 Bool bm_has_conflict_with(const struct bitmap* const bm,
                           const Addr a1, const Addr a2,
                           const BmAccessTypeT access_type)
diff --git a/exp-drd/drd_thread.c b/exp-drd/drd_thread.c
index 55bf0fd114..b8eb755ad0 100644
--- a/exp-drd/drd_thread.c
+++ b/exp-drd/drd_thread.c
@@ -670,10 +670,13 @@ void thread_stop_using_mem(const Addr a1, const Addr a2)
     for (p = s_threadinfo[i].first; p; p = p->next)
     {
       if (other_user == DRD_INVALID_THREADID
-          && i != s_drd_running_tid
-          && bm_has_any_access(p->bm, a1, a2))
+          && i != s_drd_running_tid)
       {
-        other_user = i;
+        if (UNLIKELY(bm_test_and_clear(p->bm, a1, a2)))
+        {
+          other_user = i;
+        }
+        continue;
       }
       bm_clear(p->bm, a1, a2);
     }
diff --git a/exp-drd/pub_drd_bitmap.h b/exp-drd/pub_drd_bitmap.h
index ede095e4ce..72470ace0a 100644
--- a/exp-drd/pub_drd_bitmap.h
+++ b/exp-drd/pub_drd_bitmap.h
@@ -84,6 +84,8 @@ void bm_clear_load(const struct bitmap* const bm,
                    const Addr a1, const Addr a2);
 void bm_clear_store(const struct bitmap* const bm,
                     const Addr a1, const Addr a2);
+Bool bm_test_and_clear(const struct bitmap* const bm,
+                       const Addr a1, const Addr a2);
 Bool bm_has_conflict_with(const struct bitmap* const bm,
                           const Addr a1, const Addr a2,
                           const BmAccessTypeT access_type);