check interrupts at each frame pop timing.

Asynchronous events such as signal trap, finalization timing,
thread switching and so on are managed by "interrupt_flag".
Ruby's threads check this flag periodically and if a thread
does not check this flag, above events doesn't happen.

This checking is CHECK_INTS() (related) macro and it is placed
at some places (laeve instruction and so on). However, at the end
of C methods, C blocks (IMEMO_IFUNC) etc there are no checking
and it can introduce uninterruptible thread.

To modify this situation, we decide to place CHECK_INTS() at
vm_pop_frame(). It increases interrupt checking points.
[Bug #16366]

This patch can introduce unexpected events...

1 files changed, 3 insertions, 0 deletions

diff --git a/spec/ruby/core/thread/raise_spec.rb b/spec/ruby/core/thread/raise_spec.rb
index 38571854ef..88a96d5f4e 100644
--- a/spec/ruby/core/thread/raise_spec.rb
+++ b/spec/ruby/core/thread/raise_spec.rb
@@ -138,11 +138,14 @@ describe "Thread#raise on a running thread" do
   end
 
   it "can go unhandled" do
+    q = Queue.new
     t = Thread.new do
       Thread.current.report_on_exception = false
+      q << true
       loop { Thread.pass }
     end
 
+    q.pop # wait for `report_on_exception = false`.
     t.raise
     -> { t.value }.should raise_error(RuntimeError)
   end