[Mono-bugs] [Bug 28722][Nor] New - Thread crashes with garbage collection enabled
8 Aug 2002 10:32:09 -0000
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Changed by firstname.lastname@example.org.
--- shadow/28722 Thu Aug 8 06:32:09 2002
+++ shadow/28722.tmp.12797 Thu Aug 8 06:32:09 2002
@@ -0,0 +1,84 @@
+OS Details: SuSE Linux 8.0
+Summary: Thread crashes with garbage collection enabled
+Description of Problem:
+The following program creates an additional thread and waits for 10
+seconds while the background thread prints a sequence of numbers:
+ static int count;
+ static void Main()
+ Thread t1 = new Thread( new ThreadStart( Go ) );
+ static void Go()
+ while (true)
+ count += 1;
+Steps to reproduce the problem:
+1. mcs thread.cs
+2. mono thread.exe
+Prints the numbers 0, 1, ..., 19064 then reports
+** (process:21025): WARNING **: unhandled exception
+System.NullReferenceException: "A null value was found where an object
+instance was required"
+Once the exception message is printed, the program produces no further
+output. The program does not halt, however, until ten second interval has
+Prints the numbers 0, 1, ... until ten seconds elapses.
+How often does this happen?
+If I run the program with 'GC_DONT_GC=1 mono thread.exe' no such
+exceptions are reported: the program spews out numbers for ten seconds.
+We are having some idiopathic problems with Qt# in which some objects are
+mysteriously taking on the value null and random times during execution.
+This particularly comes up in some of the demo programs that do a large
+number of allocations. I think that the problems we're experiencing with
+Qt# might be related to the problems with the program above.