JDK-4252694 : Solaris Hotspot VM ignores breakpoints on java.lang.Thread.resume
  • Type: Bug
  • Component: vm-legacy
  • Sub-Component: jvmdi
  • Affected Version: 1.3.0
  • Priority: P4
  • Status: Closed
  • Resolution: Duplicate
  • OS: generic
  • CPU: generic
  • Submitted: 1999-07-08
  • Updated: 2000-05-19
  • Resolved: 2000-05-19
Related Reports
Duplicate :  
JDK-4337667 - crash (sig 11) on second invocation of a breakpoint
Description
When running the current JDWP implementation under the hotspot vm, the following message is printed at startup. 

HotSpot VM warning: Ignoring breakpoint on java.lang.Thread.resume

The breakpoint on Thread.resume is an important part of the JDWP implementation that helps avoid race conditions when suspending and resuming multiple threads. As I recall, this was done during Hotspot JVMDI development for performance reasons, but it really should be removed in the production release. (And if there are performance problems with setting a breakpoint at VM startup, they should be addressed as well.)
Comments
EVALUATION Ignoroing breakpoints of resume was a hack done in HotSpot 1.0 because we did not have fast breakpointing implemented. This has been fixed in Sparc version of HotSpot 2.0 and will merge into Kestrel. Gordon Hirsch is working on Win32 implementation. daniel.daugherty@Eng 2000-05-18 The fix for 4337667 enables fast breakpoints on the Win32 platform. They were already enabled on the Solaris Production Release platform. When fast breakpoints are used, this code is never executed. I'm closing this bug as a duplicate of 4337667 since that fix obsoletes this code. All of the !UseFastBreakpoints code needs to be removed in the Ladybird timeframe.
11-06-2004