thread_pool.rb in bixby-common-0.6.3

- old
+ new

@@ -30,11 +30,11 @@
 
     def enqueue(command, block=nil)
       logger.debug { "enqueue new task: #{command}" }
       @input_queue.push(Task.new(command, block))
       if command == :perform then
-        grow_pool
+        grow
       end
       nil
     end
 
     def perform(&block)
@@ -123,11 +123,10 @@
             remove_worker(worker)
             block.call if block
           end
 
           enqueue(:shutdown, callback)
-          @size -= 1
         end
       end
 
       nil
     end
@@ -163,12 +162,12 @@
         logger.debug "spawning new worker thread"
 
         exit_handler = lambda { |worker, reason|
           @lock.synchronize do
             if reason == :exception or (reason == :timeout && @size > @min_size) then
-              @size -= 1
               remove_worker(worker)
+              grow
               return true
             end
             false
           end
         }
@@ -177,28 +176,40 @@
         @size += 1
       end
     end
 
     # Grow the pool by one if we have more jobs than idle workers
-    def grow_pool
+    def grow
       @lock.synchronize do
+        prune
         logger.debug { "jobs: #{num_jobs}; busy: #{num_working}; idle: #{num_idle}" }
-        if @size < @max_size && num_jobs > 0 && num_jobs > num_idle then
+        if @size == 0 || (@size < @max_size && num_jobs > 0 && num_jobs > num_idle) then
           space = @max_size-@size
           jobs = num_jobs-num_idle
           needed = space < jobs ? space : jobs
+          needed = 1 if needed <= 0
           expand(needed)
         else
           logger.debug "NOT growing the pool!"
         end
       end
 
       nil
     end
 
+    # Remove any dead worker threads which may not have been cleaned up properly
+    # (via callback handler)
+    def prune
+      @lock.synchronize do
+        @workers.delete_if { |w| !w.alive? }
+        @size = @workers.size
+      end
+    end
+
     def remove_worker(worker)
       @lock.synchronize do
         @workers.delete(worker)
+        @size -= 1
       end
 
       nil
     end
   end