Fix windows thd, I think

src/core/lib/gprpp/thd_windows.cc

@@ -48,6 +48,7 @@ struct thd_info {
   void (*body)(void* arg); /* body of a thread */
   void* arg;               /* argument to a thread */
   HANDLE join_event;       /* the join event */
+  bool joinable;           /* whether it is joinable */
 };
 
 thread_local struct thd_info* g_thd_info;
@@ -55,7 +56,8 @@ thread_local struct thd_info* g_thd_info;
 class ThreadInternalsWindows
     : public grpc_core::internal::ThreadInternalsInterface {
  public:
-  ThreadInternalsWindows(void (*thd_body)(void* arg), void* arg, bool* success)
+  ThreadInternalsWindows(void (*thd_body)(void* arg), void* arg, bool* success,
+                         const grpc_core::Thread::Options& options)
       : started_(false) {
     gpr_mu_init(&mu_);
     gpr_cv_init(&ready_);
@@ -65,25 +67,37 @@ class ThreadInternalsWindows
     info_->thread = this;
     info_->body = thd_body;
     info_->arg = arg;
-
+    info_->join_event = nullptr;
+    info_->joinable = options.joinable();
+    if (info_->joinable) {
       info_->join_event = CreateEvent(nullptr, FALSE, FALSE, nullptr);
       if (info_->join_event == nullptr) {
         gpr_free(info_);
         *success = false;
-    } else {
+        return;
-      handle = CreateThread(
+      }
-          nullptr, 64 * 1024,
+    }
+    handle = CreateThread(nullptr, 64 * 1024,
                           [](void* v) WIN_LAMBDA -> DWORD {
                             g_thd_info = static_cast<thd_info*>(v);
                             gpr_mu_lock(&g_thd_info->thread->mu_);
                             while (!g_thd_info->thread->started_) {
-              gpr_cv_wait(&g_thd_info->thread->ready_, &g_thd_info->thread->mu_,
+                              gpr_cv_wait(&g_thd_info->thread->ready_,
+                                          &g_thd_info->thread->mu_,
                                           gpr_inf_future(GPR_CLOCK_MONOTONIC));
                             }
                             gpr_mu_unlock(&g_thd_info->thread->mu_);
+                            if (!g_thd_info->joinable) {
+                              grpc_core::Delete(g_thd_info->thread);
+                              g_thd_info->thread = nullptr;
+                            }
                             g_thd_info->body(g_thd_info->arg);
+                            if (g_thd_info->joinable) {
                               BOOL ret = SetEvent(g_thd_info->join_event);
                               GPR_ASSERT(ret);
+                            } else {
+                              gpr_free(g_thd_info);
+                            }
                             return 0;
                           },
                           info_, 0, nullptr);
@@ -95,7 +109,6 @@ class ThreadInternalsWindows
       *success = true;
     }
   }
-  }
 
   ~ThreadInternalsWindows() override {
     gpr_mu_destroy(&mu_);
@@ -117,7 +130,9 @@ class ThreadInternalsWindows
 
  private:
   void destroy_thread() {
+    if (info_ != nullptr && info_->joinable) {
       CloseHandle(info_->join_event);
+    }
     gpr_free(info_);
   }
 
@@ -132,9 +147,10 @@ class ThreadInternalsWindows
 namespace grpc_core {
 
 Thread::Thread(const char* thd_name, void (*thd_body)(void* arg), void* arg,
-               bool* success) {
+               bool* success, const Options& options) : options_(options) {
   bool outcome = false;
-  impl_ = grpc_core::New<ThreadInternalsWindows>(thd_body, arg, &outcome);
+  impl_ =
+      grpc_core::New<ThreadInternalsWindows>(thd_body, arg, &outcome, options);
   if (outcome) {
     state_ = ALIVE;
   } else {