From bc78ce3534af86dde4cff218665fa3d0936ca685 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lukas=20H=C3=B6ppner?= <lukas.hoeppner@gmail.com>
Date: Wed, 12 Aug 2026 14:25:21 +0200
Subject: [PATCH] Refactor sleep handling and WASM task termination;
 consolidate platform-specific sleep functions and improve task cleanup logic

---
 core/include/nova64_internal.h |  10 ++++++++
 core/src/nova64_core.c         |  10 --------
 core/src/wasm_runner.c         |  44 ++++++++++++++-------------------
 simulator/sd/slot0/init.wasm   | Bin 139 -> 169 bytes
 software/build.bat             |   6 ++++-
 software/init.zig              |   2 +-
 6 files changed, 35 insertions(+), 37 deletions(-)

diff --git a/core/include/nova64_internal.h b/core/include/nova64_internal.h
index cbdd5b0..a4fdec3 100644
--- a/core/include/nova64_internal.h
+++ b/core/include/nova64_internal.h
@@ -9,4 +9,14 @@ const nova64_io_interface_t *nova64_get_io_interface(void);
 
 void nova64_log_scheduler_state(void);
 
+#if defined(_WIN32)
+#include <windows.h>
+#define nova64_host_sleep_ms(ms) Sleep(ms)
+#elif defined(__unix__) || defined(__APPLE__)
+#include <unistd.h>
+#define nova64_host_sleep_ms(ms) usleep((ms) * 1000)
+#else
+#define nova64_host_sleep_ms(ms) ((void)0)
+#endif
+
 #endif // NOVA64_INTERNAL_H
\ No newline at end of file
diff --git a/core/src/nova64_core.c b/core/src/nova64_core.c
index 1f05efd..9cfc4c4 100644
--- a/core/src/nova64_core.c
+++ b/core/src/nova64_core.c
@@ -20,16 +20,6 @@
 #include <time.h>
 #endif
 
-#if defined(_WIN32)
-#include <windows.h>
-#define nova64_host_sleep_ms(ms) Sleep(ms)
-#elif defined(__unix__) || defined(__APPLE__)
-#include <unistd.h>
-#define nova64_host_sleep_ms(ms) usleep((ms) * 1000)
-#else
-#define nova64_host_sleep_ms(ms) ((void)0)
-#endif
-
 volatile bool is_initialized = false;
 volatile bool shutdown_requested = false;
 static nova64_io_interface_t g_io_interface_storage;
diff --git a/core/src/wasm_runner.c b/core/src/wasm_runner.c
index 762952e..9856535 100644
--- a/core/src/wasm_runner.c
+++ b/core/src/wasm_runner.c
@@ -155,21 +155,21 @@ bool wasm_runner_start_program(
 void wasm_runner_terminate(void) {
   nova64_log("Stopping all WASM tasks...\n");
 
+  // 1. Send stop signal to all running WASM instances
   for (int i = 0; i < MAX_WASM_TASKS; i++) {
     if (g_wasm_slots[i].state == SLOT_RUNNING) {
       g_wasm_slots[i].state = SLOT_STOPPING;
       if (g_wasm_slots[i].module_inst) {
+        // Thread-safe: Only sets an abort flag internally in WAMR
         wasm_runtime_terminate(g_wasm_slots[i].module_inst);
       }
     }
   }
 
-  /* Wait a short grace period for tasks to exit on their own. */
-  const TickType_t grace = pdMS_TO_TICKS(2000);
-  TickType_t start = xTaskGetTickCount();
-  bool any_running = true;
-  while (any_running) {
-    any_running = false;
+  // 2. Wait with HOST-Sleep (NATIVE C / C# thread-safe!)
+  int timeout_ms = 2000;
+  while (timeout_ms > 0) {
+    bool any_running = false;
     for (int i = 0; i < MAX_WASM_TASKS; i++) {
       if (g_wasm_slots[i].state != SLOT_FREE) {
         any_running = true;
@@ -178,28 +178,22 @@ void wasm_runner_terminate(void) {
     }
 
     if (!any_running) {
-      break;
+      break; // All WASM tasks have terminated and cleaned up themselves!
     }
 
-    if ((xTaskGetTickCount() - start) > grace) {
-      /* Force-delete any remaining FreeRTOS tasks */
-      for (int i = 0; i < MAX_WASM_TASKS; i++) {
-        if (g_wasm_slots[i].state != SLOT_FREE &&
-            g_wasm_slots[i].freertos_handle != NULL) {
-          nova64_log("Force-deleting WASM task %d\n", i);
-          vTaskDelete(g_wasm_slots[i].freertos_handle);
-          g_wasm_slots[i].freertos_handle = NULL;
-        }
-        /* Mark slot free even if we couldn't fully clean up module state to
-         * avoid blocking shutdown; it's better to free the native thread. */
-        g_wasm_slots[i].module_inst = NULL;
-        g_wasm_slots[i].exec_env = NULL;
-        g_wasm_slots[i].state = SLOT_FREE;
-      }
-      break;
-    }
+    // IMPORTANT: Use Host-Sleep, NEVER use vTaskDelay on the C# thread!
+    nova64_host_sleep_ms(10);
+    timeout_ms -= 10;
+  }
 
-    vTaskDelay(pdMS_TO_TICKS(10));
+  // 3. If after 2s a task is still hanging: ONLY clean up flags,
+  //    NEVER call vTaskDelete from outside!
+  for (int i = 0; i < MAX_WASM_TASKS; i++) {
+    if (g_wasm_slots[i].state != SLOT_FREE) {
+      nova64_log("Warning: Task slot %d failed to exit gracefully.\n", i);
+      g_wasm_slots[i].state = SLOT_FREE;
+      g_wasm_slots[i].freertos_handle = NULL;
+    }
   }
 
   nova64_log("All WASM tasks successfully stopped.\n");
diff --git a/simulator/sd/slot0/init.wasm b/simulator/sd/slot0/init.wasm
index aa6716760102ebfe7c3047074d7ec456d6eccd49..f70185274749ffd0ce74997ce7be6e3a30fe0aa7 100644
GIT binary patch
delta 97
zcmeBXT*+w5kXW3{$iTqB$ibArSkI8az`&%<#Fm#|mS|?e1)<_|^3xd@pkh2wvC7QU
koRo>`h7wF%vW(IU%nptX4F?(+1R8*V!O=*dabkut0A)WJ8vp<R

delta 67
zcmZ3<*v+WUkXW3{$iTqB$ibArSkI8az`!KR$d;F1mS|?e1)<_|^3x~U8VWFSi82Z^
SFgrLlG#qGP5NMd#rVIezln=oG

diff --git a/software/build.bat b/software/build.bat
index 19ae4d5..44ff2ef 100644
--- a/software/build.bat
+++ b/software/build.bat
@@ -1,4 +1,8 @@
+pushd "%~dp0"
+
 @REM tinygo build -o ../simulator/sd/slot0/init.wasm -target wasm-unknown init.go
 
 @REM zig build-exe init.zig -target wasm32-freestanding -fno-entry -O ReleaseSmall -femit-bin=../simulator/sd/slot0/init.wasm
-zig build-exe init.zig -target wasm32-freestanding -O ReleaseSmall -femit-bin=../simulator/sd/slot0/init.wasm
\ No newline at end of file
+zig build-exe init.zig -target wasm32-freestanding -O ReleaseSmall -femit-bin=../simulator/sd/slot0/init.wasm
+
+popd
\ No newline at end of file
diff --git a/software/init.zig b/software/init.zig
index dddf0cd..9a3e489 100644
--- a/software/init.zig
+++ b/software/init.zig
@@ -5,7 +5,7 @@ pub fn main() void {
     while (true) {
         nova64.log("Hello from Zig!");
         // nova64.yield();
-        // nova64.sleep(1000);
+        nova64.sleep(50);
     }
 }