From 2178202d8f86301c34edcbf5f77e5af7731f0aca Mon Sep 17 00:00:00 2001
From: "Joshua T. Mckinney" <joshmckin@gmail.com>
Date: Sun, 15 May 2016 22:11:26 -0500
Subject: [PATCH] detect forks

---
 HISTORY.md          |  3 ++-
 README.md           | 29 +----------------------------
 lib/hot_tub/pool.rb | 41 +++++++++++------------------------------
 3 files changed, 14 insertions(+), 59 deletions(-)

diff --git a/HISTORY.md b/HISTORY.md
index aafeb4a..c17c847 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -5,11 +5,12 @@ Head
 =======
 - None yet.
 
-1.0.1
+1.1.0
 =======
 - Close orphan clients outside of synchonize
 - Freeze alarm message
 - Detect dead resources and reap
+- Detect fork
 
 1.0.0
 =======
diff --git a/README.md b/README.md
index bbc1091..641ec1c 100644
--- a/README.md
+++ b/README.md
@@ -140,35 +140,8 @@ a lambda that accepts the client as an argument or symbol representing a method
 
 ## Forking
 
-HotTub's `#reset!` methods close all idle connections, prevents connections in use from returning
-to the pool and attempts to close orphaned connections as they attempt to return.
+HotTub::Pool automatically detects forks and drains the pool, so no additional "after fork" code is required.
 
-    # Puma
-    on_worker_boot do
-
-      # If you let HotTub manage all your connections
-      HotTub.reset!
-
-      # If you have your own HotTub::Sessions
-      MY_SESSIONS.reset!
-
-      # If you have any one-off pools
-      MY_POOL.reset!
-
-    end
-
-    # Unicorn
-    before_fork do |server, worker|
-
-      # If you let HotTub manage all your connections
-      HotTub.reset!
-
-      # If you have your own HotTub::Sessions
-      MY_SESSIONS.reset!
-
-      # If you have any one-off pools
-      MY_POOL.reset!
-    end
 
 
 ## Contributing to HotTub
diff --git a/lib/hot_tub/pool.rb b/lib/hot_tub/pool.rb
index 2d9db25..6bc21e4 100644
--- a/lib/hot_tub/pool.rb
+++ b/lib/hot_tub/pool.rb
@@ -116,12 +116,15 @@ def initialize(opts={},&client_block)
 
       @never_block      = (@max_size == 0)
 
+      @pid              = Process.pid
+
       at_exit {shutdown!} unless @sessions_key
     end
 
     # Preform an operations with a client/connection.
     # Requires a block that receives the client.
     def run
+      drain! if forked?
       clnt = pop
       yield clnt
     ensure
@@ -158,48 +161,22 @@ def drain!
         ensure
           @_out.clear
           @_pool.clear
+          @pid = Process.pid
           @cond.broadcast
         end
       end
       nil
     end
     alias :close! :drain!
-
-    # Reset the pool.
-    # or if shutdown allow threads to quickly finish their work
-    # Clients from the previous pool will not return to pool.
-    def reset!
-      HotTub.logger.info "[HotTub] Resetting pool #{@name}!" if HotTub.logger
-      @mutex.synchronize do
-        begin
-          while clnt = @_pool.pop
-            close_client(clnt)
-          end
-        ensure
-          @_out.clear
-          @_pool.clear
-          @cond.broadcast
-        end
-      end
-      nil
-    end
+    alias :reset! :drain!
 
     # Kills the reaper and drains the pool.
     def shutdown!
       HotTub.logger.info "[HotTub] Shutting down pool #{@name}!" if HotTub.logger
       @shutdown = true
       kill_reaper if @reaper
-      @mutex.synchronize do
-        begin
-          while clnt = @_pool.pop
-            close_client(clnt)
-          end
-        ensure
-          @_out.clear
-          @_pool.clear
-          @cond.broadcast
-        end
-      end
+      drain!
+      @shutdown = false
       nil
     end
 
@@ -250,6 +227,10 @@ def max_size=max_size
       @max_size = max_size
     end
 
+    def forked?
+      @pid != Process.pid
+    end
+
     private
 
     ALARM_MESSAGE = "Could not fetch a free client in time. Consider increasing your pool size.".freeze