Merge pull request #3519 from DataDog/ivoanjo/prof-9136-remote-worker…

…-thread-leak

[PROF-9136] Fix rare remote configuration worker thread leak

lib/datadog/core/remote/worker.rb

@@ -10,8 +10,8 @@ def initialize(interval:, &block)
           @thr = nil
 
           @starting = false
-          @stopping = false
           @started = false
+          @stopped = false
 
           @interval = interval
           raise ArgumentError, 'can not initialize a worker without a block' unless block
@@ -24,6 +24,11 @@ def start
 
           acquire_lock
 
+          if @stopped
+            Datadog.logger.debug('remote worker: refusing to restart after previous stop')
+            return
+          end
+
           return if @starting || @started
 
           @starting = true
@@ -46,8 +51,6 @@ def stop
 
           acquire_lock
 
-          @stopping = true
-
           thread = @thr
 
           if thread
@@ -56,8 +59,8 @@ def stop
           end
 
           @started = false
-          @stopping = false
           @thr = nil
+          @stopped = true
 
           Datadog.logger.debug { 'remote worker stopped' }
         ensure

spec/datadog/core/remote/worker_spec.rb

@@ -67,6 +67,16 @@
 
       expect(worker.instance_variable_get(:@thr).thread_variable_get(:fork_safe)).to be true
     end
+
+    it 'does not restart the worker after being stopped once' do
+      worker.start
+      expect(worker.instance_variable_get(:@started)).to be true
+
+      worker.stop
+
+      worker.start
+      expect(worker.instance_variable_get(:@started)).to be false
+    end
   end
 
   describe '#stop' do