From f97aaf70db67da69e40a79cd0c60303cd613c016 Mon Sep 17 00:00:00 2001
From: ngoto <ngoto@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Tue, 15 Dec 2015 16:03:00 +0000
Subject: * lib/webrick/utils.rb (WEBrick::Utils::TimeoutHandler): Acquire  
 TimeoutMutex only when accessing @timeout_info for avoiding   potential
 deadlock. [Bug #11742] [ruby-dev:49387]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53134 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 lib/webrick/utils.rb | 43 ++++++++++++++++++++++---------------------
 1 file changed, 22 insertions(+), 21 deletions(-)

(limited to 'lib/webrick')

diff --git a/lib/webrick/utils.rb b/lib/webrick/utils.rb
index dc7ce508ea..654d9dea95 100644
--- a/lib/webrick/utils.rb
+++ b/lib/webrick/utils.rb
@@ -135,24 +135,22 @@ module WEBrick
       # +time+:: Timeout in seconds
       # +exception+:: Exception to raise when timeout elapsed
       def TimeoutHandler.register(seconds, exception)
-        TimeoutMutex.synchronize{
-          instance.register(Thread.current, Time.now + seconds, exception)
-        }
+        instance.register(Thread.current, Time.now + seconds, exception)
       end
 
       ##
       # Cancels the timeout handler +id+
       def TimeoutHandler.cancel(id)
-        TimeoutMutex.synchronize{
-          instance.cancel(Thread.current, id)
-        }
+        instance.cancel(Thread.current, id)
       end
 
       ##
       # Creates a new TimeoutHandler.  You should use ::register and ::cancel
       # instead of creating the timeout handler directly.
       def initialize
-        @timeout_info = Hash.new
+        TimeoutMutex.synchronize{
+          @timeout_info = Hash.new
+        }
         @watcher = Thread.start{
           to_interrupt = []
           while true
@@ -185,11 +183,9 @@ module WEBrick
       ##
       # Interrupts the timeout handler +id+ and raises +exception+
       def interrupt(thread, id, exception)
-        TimeoutMutex.synchronize{
-          if cancel(thread, id) && thread.alive?
-            thread.raise(exception, "execution timeout")
-          end
-        }
+        if cancel(thread, id) && thread.alive?
+          thread.raise(exception, "execution timeout")
+        end
       end
 
       ##
@@ -198,8 +194,11 @@ module WEBrick
       # +time+:: Timeout in seconds
       # +exception+:: Exception to raise when timeout elapsed
       def register(thread, time, exception)
-        @timeout_info[thread] ||= Array.new
-        @timeout_info[thread] << (info = [time, exception])
+        info = nil
+        TimeoutMutex.synchronize{
+          @timeout_info[thread] ||= Array.new
+          @timeout_info[thread] << (info = [time, exception])
+        }
         begin
           @watcher.wakeup
         rescue ThreadError
@@ -210,14 +209,16 @@ module WEBrick
       ##
       # Cancels the timeout handler +id+
       def cancel(thread, id)
-        if ary = @timeout_info[thread]
-          ary.delete_if{|info| info.object_id == id }
-          if ary.empty?
-            @timeout_info.delete(thread)
+        TimeoutMutex.synchronize{
+          if ary = @timeout_info[thread]
+            ary.delete_if{|info| info.object_id == id }
+            if ary.empty?
+              @timeout_info.delete(thread)
+            end
+            return true
           end
-          return true
-        end
-        return false
+          return false
+        }
       end
     end
 
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