Properly wait between failed wait attempts to avoid busy loop

npatwardhan · May 23, 2020 · cf3cce3 · cf3cce3
1 parent 788d95c
commit cf3cce3
Showing 1 changed file with 9 additions and 3 deletions.
diff --git a/lib/parallel/forkmanager.rb b/lib/parallel/forkmanager.rb
@@ -153,7 +153,10 @@ def start(identification = nil, *args, &run_block)
       while @max_procs.nonzero? && @processes.length >= @max_procs
         on_wait
         arg = (defined? @on_wait_period && !@on_wait_period.nil?) ? Process::WNOHANG : nil
-        wait_one_child(arg)
+        kid = wait_one_child(arg)
+        if kid == 0 || kid == -1
+          sleep @waitpid_blocking_sleep
+        end
       end
 
       wait_children
@@ -343,10 +346,13 @@ def wait_one_child(par)
     # forked. This is a blocking wait.
     #
     def wait_all_children
-      until @processes.keys.empty?
+      until @processes.empty?
         on_wait
         arg = (defined? @on_wait_period and !@on_wait_period.nil?) ? Process::WNOHANG : nil
-        wait_one_child(arg)
+        kid = wait_one_child(arg)
+        if kid == 0 || kid == -1
+          sleep @waitpid_blocking_sleep
+        end
       end
     rescue Errno::ECHILD
       # do nothing.