freertos: Add unit test for deleting task which may be blocking

components/freertos/test/test_freertos_task_delete.c

@@ -2,9 +2,8 @@
  * Test backported deletion behavior by creating tasks of various affinities and
  * check if the task memory is freed immediately under the correct conditions.
  *
- * The behavior of vTaskDelete() has been backported form FreeRTOS v9.0.0. This
- * results in the immediate freeing of task memory and the immediate execution
- * of deletion callbacks under the following conditions...
+ * The behavior of vTaskDelete() results in the immediate freeing of task memory
+ * and the immediate execution of deletion callbacks under the following conditions...
  * - When deleting a task that is not currently running on either core
  * - When deleting a task that is pinned to the same core (with respect to
  *   the core that calls vTaskDelete()
@@ -16,6 +15,7 @@
 
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
+#include "freertos/semphr.h"
 #include "esp_heap_caps.h"
 
 #include "unity.h"
@@ -84,3 +84,71 @@ TEST_CASE("FreeRTOS Delete Tasks", "[freertos]")
     }
 
 }
+
+
+typedef struct {
+    SemaphoreHandle_t sem;
+    volatile bool deleted; // Check the deleted task doesn't keep running after being deleted
+} tsk_blocks_param_t;
+
+/* Task blocks as often as possible
+   (two or more of these can share the same semaphore and "juggle" it around)
+*/
+static void tsk_blocks_frequently(void *param)
+{
+    tsk_blocks_param_t *p = (tsk_blocks_param_t *)param;
+    SemaphoreHandle_t sem = p->sem;
+    srand(xTaskGetTickCount() ^ (int)xTaskGetCurrentTaskHandle());
+    while (1) {
+        assert(!p->deleted);
+        esp_rom_delay_us(rand() % 10);
+        assert(!p->deleted);
+        xSemaphoreTake(sem, portMAX_DELAY);
+        assert(!p->deleted);
+        esp_rom_delay_us(rand() % 10);
+        assert(!p->deleted);
+        xSemaphoreGive(sem);
+    }
+}
+
+TEST_CASE("FreeRTOS Delete Blocked Tasks", "[freertos]")
+{
+    TaskHandle_t blocking_tasks[portNUM_PROCESSORS + 1]; // one per CPU, plus one unpinned task
+    tsk_blocks_param_t params[portNUM_PROCESSORS + 1] = { 0 };
+
+    unsigned before = heap_caps_get_free_size(MALLOC_CAP_8BIT);
+    printf("Free memory at start %u\n", before);
+
+    /* Any bugs will depend on relative timing of destroying the tasks, so create & delete many times.
+
+       Stop early if it looks like some resources have not been properly cleaned up.
+
+       (1000 iterations takes about 9 seconds on ESP32 dual core)
+     */
+    for(unsigned iter = 0; iter < 1000; iter++) {
+        // Create everything
+        SemaphoreHandle_t sem = xSemaphoreCreateMutex();
+        for(unsigned i = 0; i < portNUM_PROCESSORS + 1; i++) {
+            params[i].deleted = false;
+            params[i].sem = sem;
+
+            TEST_ASSERT_EQUAL(pdTRUE,
+                              xTaskCreatePinnedToCore(tsk_blocks_frequently, "tsk_block", 4096, &params[i],
+                                                      UNITY_FREERTOS_PRIORITY - 1, &blocking_tasks[i],
+                                                      i < portNUM_PROCESSORS ? i : tskNO_AFFINITY));
+        }
+
+        vTaskDelay(5); // Let the tasks juggle the mutex for a bit
+
+        for(unsigned i = 0; i < portNUM_PROCESSORS + 1; i++) {
+            vTaskDelete(blocking_tasks[i]);
+            params[i].deleted = true;
+        }
+        vTaskDelay(4); // Yield to the idle task for cleanup
+
+        vSemaphoreDelete(sem);
+
+        // Check we haven't leaked resources yet
+        TEST_ASSERT_GREATER_OR_EQUAL(before - 256, heap_caps_get_free_size(MALLOC_CAP_8BIT));
+    }
+}