Fixed handling childTid in cThread to avoid possible race conditions

3 files changed, 12 insertions, 4 deletions

diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index e42fb982..e13b6c08 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -188,6 +188,7 @@ Stefan Huelswitt <huels@iname.com>
  for reporting a bug in setting the title in the replay display of the "Classic VDR"
  skin in case a shorter title is set after a longer one
  for fixing handling of pmAudioOnlyBlack
+ for pointing out possible race conditions in handling childTid in cThread
 
 Ulrich Röder <roeder@efr-net.de>
  for pointing out that there are channels that have a symbol rate higher than
diff --git a/HISTORY b/HISTORY
index 271353bd..767b1fd7 100644
--- a/HISTORY
+++ b/HISTORY
@@ -3159,3 +3159,5 @@ Video Disk Recorder Revision History
   overhead in the firmware (thanks to Werner Fink).
 - Now checking available OSD memory at runtime (thanks to Oliver Endriss).
 - Fixed some typos in the Makefile's 'font' target (thanks to Olaf Titz).
+- Fixed handling childTid in cThread to avoid possible race conditions (thanks
+  to Stefan Huelswitt for pointing this out).
diff --git a/thread.c b/thread.c
index 080be0e0..7045e5ad 100644
--- a/thread.c
+++ b/thread.c
@@ -4,7 +4,7 @@
  * See the main source file 'vdr.c' for copyright information and
  * how to reach the author.
  *
- * $Id: thread.c 1.36 2004/10/31 09:54:02 kls Exp $
+ * $Id: thread.c 1.37 2004/11/20 16:21:14 kls Exp $
  */
 
 #include "thread.h"
@@ -233,12 +233,15 @@ void *cThread::StartThread(cThread *Thread)
 
 bool cThread::Start(void)
 {
+  Lock();
   if (!childTid) {
      parentTid = pthread_self();
-     pthread_create(&childTid, NULL, (void *(*) (void *))&StartThread, (void *)this);
-     pthread_detach(childTid); // auto-reap
-     pthread_setschedparam(childTid, SCHED_RR, 0);
+     pthread_t Tid;
+     pthread_create(&Tid, NULL, (void *(*) (void *))&StartThread, (void *)this);
+     pthread_detach(Tid); // auto-reap
+     pthread_setschedparam(Tid, SCHED_RR, 0);
      }
+  Unlock();
   return true; //XXX return value of pthread_create()???
 }
 
@@ -277,10 +280,12 @@ void cThread::Cancel(int WaitSeconds)
             }
         esyslog("ERROR: thread %ld won't end (waited %d seconds) - cancelling it...", childTid, WaitSeconds);
         }
+     Lock();
      if (childTid) {
         pthread_cancel(childTid);
         childTid = 0;
         }
+     Unlock();
      }
 }