Configure threads to not abort on exceptions (#484)

* Configure all threads to not abort on exceptions

This solves long outstanding issue: #396.
This happens, because some applications or gems do overwrite global setting of `Thread.abort_on_exception=` which is by default set to `false`.
This leads to application process to exit and making the spring unable to recover from that.

* Use rescue blocks instead of `abort_on_exception=`

* Rescue PTY

* Use `Spring.failsafe_thread`

* Add CHANGELOG

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 1.7.2
+
+* Use `Spring.failsafe_thread` to prevent threads from aborting process due to `Thread.abort_on_exception` when set to `true`
+
 ## 1.7.1
 
 * Specify absolute path to spring binfile when starting the server

lib/spring/application.rb

@@ -306,7 +306,7 @@ def wait(pid, streams, client)
       @mutex.synchronize { @waiting << pid }
 
       # Wait in a separate thread so we can run multiple commands at once
-      Thread.new {
+      Spring.failsafe_thread {
         begin
           _, status = Process.wait2 pid
           log "#{pid} exited with #{status.exitstatus}"
@@ -320,7 +320,7 @@ def wait(pid, streams, client)
         end
       }
 
-      Thread.new {
+      Spring.failsafe_thread {
         while signal = client.gets.chomp
           begin
             Process.kill(signal, -Process.getpgid(pid))

lib/spring/application_manager.rb

@@ -116,7 +116,7 @@ def start_child(preload = false)
     def start_wait_thread(pid, child)
       Process.detach(pid)
 
-      Thread.new {
+      Spring.failsafe_thread {
         # The recv can raise an ECONNRESET, killing the thread, but that's ok
         # as if it does we're no longer interested in the child
         loop do

lib/spring/boot.rb

@@ -6,3 +6,5 @@
 require "spring/process_title_updater"
 require "spring/json"
 require "spring/watcher"
+require "spring/failsafe_thread"
+

lib/spring/failsafe_thread.rb

@@ -0,0 +1,14 @@
+require 'thread'
+
+module Spring
+  class << self
+    def failsafe_thread
+      Thread.new {
+        begin
+          yield
+        rescue
+        end
+      }
+    end
+  end
+end

lib/spring/process_title_updater.rb

@@ -10,7 +10,7 @@ class ProcessTitleUpdater
     def self.run(&block)
       updater = new(&block)
 
-      Thread.new {
+      Spring.failsafe_thread {
         $0 = updater.value
         loop { $0 = updater.next }
       }

lib/spring/server.rb

@@ -106,7 +106,7 @@ def shutdown
         end
       end
 
-      @applications.values.map { |a| Thread.new { a.stop } }.map(&:join)
+      @applications.values.map { |a| Spring.failsafe_thread { a.stop } }.map(&:join)
     end
 
     def write_pidfile