* thread_pthread.c (ubf_select): call rb_thread_wakeup_timer_thread()
only when it is not timer_thread. [Bug #5757] [ruby-dev:44985]
patched by Tomoyuki Chikanaga.
* thread_pthread.c (ping_signal_thread_list): remove return value.
* thread_pthread.c (check_signal_thread_list): add a new function to
check if signal thread list is empty.
* thread_pthread.c (thread_timer): check signal thread list after
timer_thread_function(). main thread might be added into signal thread
list during timer_thread_function().
merge revision(s) r34038,34099:
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@34425 b2dd03c8-39d4-4d8f-98ff-823fe69b080e