can shut down executor at the end of exe now

MipImproving.sol

@@ -0,0 +1,50 @@
+Objective 1
+# Columns -1
+C0 1 0
+TM1 60 0
+ANM1 16 1
+UE1 600 2
+STM2 70 3
+ANM2 7 4
+STM3 70 6
+ANM3 7 7
+STM4 70 9
+ANM4 7 10
+UE4 200 11
+STM5 70 12
+ANM5 11 13
+STM6 74 15
+UE6 900 17
+Objective 1240500
+# Columns -14
+STM1 60 0
+ANM1 16 1
+UE1 600 2
+STM2 70 3
+ANM2 7 4
+STM3 70 6
+ANM3 7 7
+STM4 70 9
+ANM4 7 10
+UE4 200 11
+STM5 70 12
+ANM5 12 13
+STM6 75 15
+UE6 750 17
+Objective 1201500
+# Columns -15
+STM1 60 0
+ANM1 6 1
+STM2 60 3
+ANM2 6 4
+UE2 600 5
+STM3 60 6
+ANM3 16 7
+UE3 600 8
+STM4 70 9
+ANM4 7 10
+UE4 200 11
+STM5 70 12
+ANM5 12 13
+STM6 75 15
+UE6 750 17

app/RunHighs.cpp

@@ -16,7 +16,7 @@
 #include "lp_data/HighsRuntimeOptions.h"
 
 // uncomment if we will be shutting down task executor from exe
-// #include "parallel/HighsParallel.h"
+#include "parallel/HighsParallel.h"
 
 void reportModelStatsOrError(const HighsLogOptions& log_options,
                              const HighsStatus read_status,
@@ -102,7 +102,7 @@ int main(int argc, char** argv) {
 
   // Shut down task executor: wip 
   // Will be added as an option, as we should not detach in lib if this is used
-  // HighsTaskExecutor::shutdown(true);
+  HighsTaskExecutor::shutdown(true);
 
   return (int)run_status;
 }

src/parallel/HighsTaskExecutor.h

@@ -32,6 +32,7 @@ class HighsTaskExecutor {
   struct ExecutorHandle {
     HighsTaskExecutor* ptr{nullptr};
     bool isMain{false};
+    bool isStopped{false};
 
     void dispose();
     ~ExecutorHandle() { dispose(); }
@@ -137,8 +138,10 @@ class HighsTaskExecutor {
   void stopWorkerThreads(bool blocking = false) {
     // auto id = mainWorkerId.exchange(std::thread::id());
     // if (id == std::thread::id()) return;  // already been called
-    // does this happen?
-
+    auto &executorHandle = threadLocalExecutorHandle();
+    if(executorHandle.isStopped)
+      return;
+
     // now inject the null task as termination signal to every worker
     for (auto& workerDeque : workerDeques) {
       workerDeque->injectTaskAndNotify(nullptr);
@@ -147,19 +150,19 @@ class HighsTaskExecutor {
     // only block if called on main thread, otherwise deadlock may occur
     // if (blocking && std::this_thread::get_id() == id) {
     // threadLocalExecutorHandle();
-    if (blocking && threadLocalExecutorHandle().isMain) {
+    if (blocking && executorHandle.isStopped) {
       for (auto& workerThread : workerThreads) {
         workerThread.join();
       }
     } 
     else {
       for (auto& workerThread : workerThreads) {
-        // do not detach if shutdown() will be called from the driver code
-        // after we are done with the highs library
-        //workerThread.detach();
         workerThread.detach();
       }
     }
+
+    if (executorHandle.isMain)
+      executorHandle.isStopped = true;
   }
 
   static HighsSplitDeque* getThisWorkerDeque() {