Bug #15263: [PATCH] vm_trace.c (postponed_job_register): only hit main thread

• Status: Open
• Priority: Normal
• Assignee: ko1 (Koichi Sasada)
• Target version: -
• Backport: 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN

[normalperson (Eric Wong)]

vm_trace.c (postponed_job_register): only hit main thread

Since postponed_job_register may be called in a signal handler,
only the main thread is safe to touch as other threads may
become invalid.  Furthermore, the problem with trap interrupt
being lost during ec_switch [Bug #14939] also applies to the
postponed job and timer interrupts, so we need to preserve all
three interrupts in ec_switch.

Note: A minor problem is a possible crash during/after
  ruby_vm_destruct if postponed jobs are registered.

  The correct and performant fix would be to leak memory at exit
  for `vm' and `vm->main_thread'.  free(3) slows down short-lived
  scripts, as does unregistering signal handlers.

* vm_trace.c (postponed_job_register): only hit main thread
* cont.c (ec_switch): preserve postponed and timer interrupt flags, too