In debug mode, check work queue is empty, and the job counter matches

src/ammonite/core/threadManager.cpp

@@ -4,6 +4,7 @@
 #include <thread>
 
 #include "../types.hpp"
+#include "../utils/debug.hpp"
 
 #define MAX_EXTRA_THREADS 512
 
@@ -171,6 +172,31 @@ namespace ammonite {
         }
       }
 
+#ifdef DEBUG
+      bool debugCheckRemainingWork(bool verbose) {
+        bool issuesFound = false;
+
+        workQueueMutex.lock();
+        if (workQueue.size() != 0) {
+          issuesFound = true;
+          if (verbose) {
+            ammoniteInternalDebug << "WARNING: Work queue not empty" << std::endl;
+          }
+        }
+
+        if (workQueue.size() != (unsigned)jobCount) {
+          issuesFound = true;
+          if (verbose) {
+            ammoniteInternalDebug << "WARNING: Work queue size and job count don't match" \
+                                  << std::endl;
+          }
+        }
+        workQueueMutex.unlock();
+
+        return issuesFound;
+      }
+#endif
+
       //Finish work already in the queue and kill the threads
       void destroyThreadPool() {
         //Finish existing work and block new work from starting
@@ -187,6 +213,14 @@ namespace ammonite {
           threadPool[i].thread.join();
         }
 
+/* In debug mode, check that the queue is empty, and matches the job counter
+ - If it doesn't, it's not technically a bug, but in practice it will be, as work
+   that was expected to be finished wasn't
+*/
+#ifdef DEBUG
+        debugCheckRemainingWork(true);
+#endif
+
         //Reset remaining data
         delete[] threadPool;
         extraThreadCount = 0;

src/ammonite/core/threadManager.hpp

@@ -21,4 +21,14 @@ namespace ammonite {
   }
 }
 
+#ifdef DEBUG
+namespace ammonite {
+  namespace thread {
+    namespace internal {
+      bool debugCheckRemainingWork(bool verbose);
+    }
+  }
+}
+#endif
+
 #endif

src/threadDemo.cpp

@@ -12,7 +12,9 @@ static void shortTask(void*) {
 }
 
 int main() {
+  bool passed = true;
   ammonite::utils::Timer runTimer;
+
   if (ammonite::thread::internal::createThreadPool(0) == -1) {
     ammonite::utils::error << "Failed to create thread pool, exiting" << std::endl;
     return EXIT_FAILURE;
@@ -39,5 +41,13 @@ int main() {
 
   //Clean up and exit
   ammonite::thread::internal::destroyThreadPool();
-  return EXIT_SUCCESS;
+
+  //Check work queue is empty, and job counter is also 0 (debug mode)
+#ifdef DEBUG
+  if (ammonite::thread::internal::debugCheckRemainingWork(false)) {
+    passed = false;
+  }
+#endif
+
+  return passed ? EXIT_SUCCESS : EXIT_FAILURE;
 }