* thread.c (rb_thread_atfork, rb_thread_atfork_before_exec): do
  nothing unless working fork is available.
* thread_sync.c (rb_mutex_abandon_all): define only if working
  fork is available.
* thread_sync.c (rb_mutex_abandon_keeping_mutexes): ditto.
* thread_sync.c (rb_mutex_abandon_locking_mutex): ditto.
* thread_win32.c (gvl_init): never used.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@54960 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

  add_signal_thread_list.
* thread_pthread.c (unregister_ubf_list): renamed
  from remove_signal_thread_list.
* thread_pthread.c (ubf_wakeup_all_threads): renamed from
  ping_signal_thread_list.
* thread_pthread.c (ubf_wakeup_thread): renamed from
  ubf_select_each.
* thread_pthread.c (ubf_threads_empty): renamed from
  check_signal_thread_list().
* thread_pthread.c (ubf_list_lock): renamed from
  signal_thread_list_lock.

* thread_pthread.c (register_ubf_list): large simplification
  by using ccan/list.h.
  bonus: removed malloc() and exit(EXIT_FAILURE).
* thread_pthread.c (unregister_ubf_list): ditto.
* thread_pthread.c (ubf_threads_empty): ditto.
* thread_pthread.c (ubf_wakeup_all_threads): ditto.

* thread_pthread.c (print_signal_list): removed.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52818 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

Shutting down the timer thread now always closes pipes to free FDs.
In fact, we close the write ends of the pipes is done in the main
RubyVM to signal the timer thread shutdown.

To effectively close pipes, we implement userspace locks via
atomics to force the pipe closing thread to wait on any signal
handlers which may be waking up.

While we're at it, improve robustness during resource exhaustion and
allow it to limp along non-fatally if restarting a timer thread
fails.

This reverts r51268

Note: this change is tested with VM_CHECK_MODE 1 in vm_core.h

* process.c (close_unless_reserved): add extra check
  (dup2_with_divert): remove
  (redirect_dup2): use dup2 without divert
  (before_exec_non_async_signal_safe): adjust call + comment
  (rb_f_exec): stop timer thread for all OSes
  (rb_exec_without_timer_thread): remove
* eval.c (ruby_cleanup): adjust call
* thread.c (rb_thread_stop_timer_thread): always close pipes
* thread_pthread.c (struct timer_thread_pipe): add writing field,
    mark owner_process volatile for signal handlers
  (rb_thread_wakeup_timer_thread_fd): check valid FD
  (rb_thread_wakeup_timer_thread): set writing flag to prevent close
  (rb_thread_wakeup_timer_thread_low): ditto
  (CLOSE_INVALIDATE): new macro
  (close_invalidate): new function
  (close_communication_pipe): removed
  (setup_communication_pipe_internal): make errors non-fatal
  (setup_communication_pipe): ditto
  (thread_timer): close reading ends inside timer thread
  (rb_thread_create_timer_thread): make errors non-fatal
  (native_stop_timer_thread): close write ends only, always,
   wait for signal handlers to finish
  (rb_divert_reserved_fd): remove
* thread_win32.c (native_stop_timer_thread): adjust (untested)
  (rb_divert_reserved_fd): remove
* vm_core.h: adjust prototype

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51576 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

  with one of the timer thread FDs, the internal FD is diverted.
  [Bug #11336] [ruby-core:69886] [Bug #11350] [ruby-core:69961]
    
* process.c (dup2_with_divert): new function for the above purpose.
   
* thread_pthread.c (rb_divert_reserved_fd): new function for
  diverting reserved FD. If the given FD is the same as one of the
  reserved FDs, the reserved FD number is internally changed.
  It returns -1 when error. Otherwise, returns 0. It also returns
  0 if there is no need to change reserved FD number.

* thread_win32.c (rb_divert_reserved_fd): always returns 0 because
  of no reserved FDs.

* internal.h (rb_divert_reserved_fd): prototype declaration.
  It is Ruby internal use only.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51268 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

  set thread name visible with ps command on GNU/Linux.
  Ex. ps -o %c -L

* thread.c (thread_start_func_2): Call native_set_thread_name at
  beginning.
  (rb_thread_inspect_msg): Extract from rb_thread_inspect.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47670 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

* thread_pthread.c (timer_thread): add a flag to tell timer thread
  is created, since 0 may be a valid value as pthread_t.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46405 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

* thread_win32.c (rb_w32_stack_overflow_handler): use Structured
  Exception Handling by Addvectoredexceptionhandler() for machine
  stack overflow on mingw.
  This would be equivalent to the handling using __try and __exept
  on mswin introduced by r43748.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45947 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

* thread_{pthread,win32}.c (native_cond_timedwait): constify.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45890 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

* vm_core.h (rb_thread_struct): aggregate cpu stuff into a struct,
  so that a debugger can show its content at once.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44722 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

  test/ruby/test_exception.rb on Windows.
  wrap by __try and __exception statements on mswin to raise SIGSEGV
  when EXCEPTION_STACK_OVERFLOW is occurred, because MSVCRT doesn't
  handle the exception.
  however, (1) mingw-gcc doesn't support __try and __exception
  statements, and (2) we cannot retry SystemStackError after this
  change yet (maybe crashed) because SEH and longjmp() are too
  uncongenial.

* signal.c (check_stack_overflow, CHECK_STACK_OVERFLOW): now defined on
  Windows, too.

* thread_win32.c (ruby_stack_overflowed_p): ditto.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43748 b2dd03c8-39d4-4d8f-98ff-823fe69b080e