Ticket #1054 (closed defect: fixed)

Opened 4 months ago

Last modified 1 month ago

ReadWriteMutex unittest can fail

Reported by:	fawzi	Assigned to:	sean
Priority:	major	Milestone:	0.99.8
Component:	Core Functionality	Version:	trunk
Keywords:	triage	Cc:

Description

The ReadWriteMutex? unit test checks that threads are really running in parallel, but the threads do very little operations, so especially if the system is a little busy the threadshave basically no overlap, and the test fails.

A simple fix is to replace the simple yiealds by a loop of yields

@@ -413,7 +415,8 @@
                     if( ++numReaders > maxReaders )
                         maxReaders = numReaders;
                 }
-                Thread.yield();
+               for (int i=0;i<1000;i++)
+                   Thread.yield();
                 synchronized( synInfo )
                 {
                     --numReaders;
@@ -474,7 +481,8 @@
                         if( ++numWriters > maxWriters )
                             maxWriters = numWriters;
                     }
-                    Thread.yield();
+                   for (int i=0;i<1000;i++)
+                      Thread.yield();
                     synchronized( synInfo )
                     {
                         --numWriters;

waiting a finite time would be even better.

Change History

04/17/08 06:27:02 changed by fawzi

sorry I messed up the previous patch. Anyway the idea is the correct one: make the single yield a loop.

Here is the correct patch

@@ -413,7 +415,8 @@
                     if( ++numReaders > maxReaders )
                         maxReaders = numReaders;
                 }
-                Thread.yield();
+               for (int i=0;i<1000;i++)
+                   Thread.yield();
                 synchronized( synInfo )
                 {
                     --numReaders;
@@ -454,7 +460,8 @@
                         if( ++numReaders > maxReaders )
                             maxReaders = numReaders;
                     }
-                    Thread.yield();
+                   for (int j=0;j<1000;j++)
+                       Thread.yield();
                     synchronized( synInfo )
                     {
                         --numReaders;
@@ -474,7 +481,8 @@
                         if( ++numWriters > maxWriters )
                             maxWriters = numWriters;
                     }
-                    Thread.yield();
+                   for (int j=0;j<1000;j++)
+                      Thread.yield();
                     synchronized( synInfo )
                     {
                         --numWriters;

Ticket Navigation

Ticket #1054 (closed defect: fixed)

ReadWriteMutex unittest can fail

Description

Change History

04/17/08 06:27:02 changed by fawzi

05/17/08 17:23:15 changed by larsivi

05/24/08 06:01:35 changed by larsivi

07/10/08 07:01:37 changed by larsivi

07/25/08 23:43:05 changed by sean

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