JDK-8369631 : Assess and remedy any unsafe usage of the sr_semaphore Semaphore in the Posix signal code
  • Type: Bug
  • Component: hotspot
  • Sub-Component: runtime
  • Affected Version: 8
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2025-10-13
  • Updated: 2025-10-20
  • Resolved: 2025-10-20
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JDK 26
26 masterFixed
Related Reports
Causes :  
JDK-8370207 - Test sun/misc/SunMiscSignalTest.java crashes after JDK-8369631
Relates :  
JDK-8361462 - JVM crashed with assert(ret == 0) failed: Failed to wait on semaphore
Description
As discussed in JDK-8361462, static Semaphores are potentially unsafe if accessed during VM termination. The suspend/resume code (for event sampling) in signals_posix.cpp declares:

// suspend/resume support
#if defined(__APPLE__)
  static OSXSemaphore sr_semaphore;
#else
  static PosixSemaphore sr_semaphore;
#endif

It is very difficult to establish with certainty that we could not be utilising this semaphore around VM termination, so it is safest to fix the problem. The signal code already has another lazily initialization `Semaphore*` so we can easily change the `sr_semaphore` as well.
Comments
Changeset: 680414d0 Branch: master Author: David Holmes <dholmes@openjdk.org> Date: 2025-10-20 00:07:08 +0000 URL: https://git.openjdk.org/jdk/commit/680414d0f9ab75d888bcb284cc494124a01a388f
20-10-2025
A pull request was submitted for review. Branch: master URL: https://git.openjdk.org/jdk/pull/27762 Date: 2025-10-13 06:52:32 +0000
13-10-2025