freertos spinlocks/portmux: Add combination unit tests & microbenchmarks

diff --git a/components/freertos/test/test_spinlocks.c b/components/freertos/test/test_spinlocks.c
new file mode 100644 (file)
index 0000000..2ddbb07
--- /dev/null
+++ b/components/freertos/test/test_spinlocks.c
@@ -0,0 +1,133 @@
+/*
+ Combined unit tests & benchmarking for spinlock "portMUX" functionality
+*/
+
+#include <esp_types.h>
+#include <stdio.h>
+#include "rom/ets_sys.h"
+
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "freertos/semphr.h"
+#include "freertos/queue.h"
+#include "freertos/xtensa_api.h"
+#include "unity.h"
+#include "soc/uart_reg.h"
+#include "soc/dport_reg.h"
+#include "soc/io_mux_reg.h"
+#include "soc/cpu.h"
+
+#define REPEAT_OPS 10000
+
+static uint32_t start, end;
+
+#define BENCHMARK_START() do {                  \
+        RSR(CCOUNT, start);                     \
+    } while(0)
+
+#define BENCHMARK_END(OPERATION) do {                       \
+        RSR(CCOUNT, end);                                           \
+        printf("%s took %d cycles/op (%d cycles for %d ops)\n",     \
+               OPERATION, (end - start)/REPEAT_OPS,                 \
+               (end - start), REPEAT_OPS);                          \
+    } while(0)
+
+TEST_CASE("portMUX spinlocks (no contention)", "[freertos]")
+{
+    portMUX_TYPE mux = portMUX_INITIALIZER_UNLOCKED;
+    BENCHMARK_START();
+
+    for (int i = 0; i < REPEAT_OPS; i++) {
+        portENTER_CRITICAL(&mux);
+        portEXIT_CRITICAL(&mux);
+    }
+    BENCHMARK_END("no contention lock");
+}
+
+TEST_CASE("portMUX recursive locks (no contention)", "[freertos]")
+{
+    portMUX_TYPE mux = portMUX_INITIALIZER_UNLOCKED;
+    BENCHMARK_START();
+
+    const int RECURSE_COUNT = 25;
+
+    for (int i = 0; i < REPEAT_OPS / RECURSE_COUNT; i++) {
+        for (int j = 0; j < RECURSE_COUNT; j++) {
+            portENTER_CRITICAL(&mux);
+        }
+        for (int j = 0; j < RECURSE_COUNT; j++) {
+            portEXIT_CRITICAL(&mux);
+        }
+    }
+    BENCHMARK_END("no contention recursive");
+}
+
+static volatile int shared_value;
+static portMUX_TYPE shared_mux;
+static xSemaphoreHandle done_sem;
+
+static void task_shared_value_increment(void *ignore)
+{
+    for (int i = 0; i < REPEAT_OPS; i++) {
+        portENTER_CRITICAL(&shared_mux);
+        shared_value++;
+        portEXIT_CRITICAL(&shared_mux);
+    }
+    xSemaphoreGive(done_sem);
+    vTaskDelete(NULL);
+}
+
+TEST_CASE("portMUX cross-core locking", "[freertos]")
+{
+    done_sem = xSemaphoreCreateCounting(2, 0);
+    vPortCPUInitializeMutex(&shared_mux);
+    shared_value = 0;
+
+    BENCHMARK_START();
+
+    xTaskCreatePinnedToCore(task_shared_value_increment, "INC0", 2048, NULL, UNITY_FREERTOS_PRIORITY + 1, NULL, UNITY_FREERTOS_CPU ? 0 : 1);
+    xTaskCreatePinnedToCore(task_shared_value_increment, "INC1", 2048, NULL, UNITY_FREERTOS_PRIORITY + 1, NULL, UNITY_FREERTOS_CPU);
+
+    for(int i = 0; i < 2; i++) {
+        if(!xSemaphoreTake(done_sem, 10000/portTICK_PERIOD_MS)) {
+            TEST_FAIL_MESSAGE("done_sem not released by test task");
+        }
+    }
+
+    BENCHMARK_END("cross-core incrementing");
+    vSemaphoreDelete(done_sem);
+
+    TEST_ASSERT_EQUAL_INT(REPEAT_OPS * 2, shared_value);
+}
+
+TEST_CASE("portMUX high contention", "[freertos]")
+{
+    const int TOTAL_TASKS = 8; /* half on each core */
+    done_sem = xSemaphoreCreateCounting(TOTAL_TASKS, 0);
+    vPortCPUInitializeMutex(&shared_mux);
+    shared_value = 0;
+
+    BENCHMARK_START();
+
+    for (int i = 0; i < TOTAL_TASKS / 2; i++) {
+        /* as each task has a higher priority than previous, expect
+           them to preempt the earlier created task, at least on the
+           other core (this core has the unity task, until that
+           blocks)... */
+        xTaskCreatePinnedToCore(task_shared_value_increment, "INC0", 2048, NULL, tskIDLE_PRIORITY + 1 + i, NULL, UNITY_FREERTOS_CPU ? 0 : 1);
+        xTaskCreatePinnedToCore(task_shared_value_increment, "INC1", 2048, NULL, tskIDLE_PRIORITY + 1 + i, NULL, UNITY_FREERTOS_CPU);
+    }
+
+    for(int i = 0; i < TOTAL_TASKS; i++) {
+        if(!xSemaphoreTake(done_sem, 10000/portTICK_PERIOD_MS)) {
+            TEST_FAIL_MESSAGE("done_sem not released by test task");
+        }
+    }
+
+    BENCHMARK_END("cross-core high contention");
+    vSemaphoreDelete(done_sem);
+
+    TEST_ASSERT_EQUAL_INT(REPEAT_OPS * TOTAL_TASKS, shared_value);
+}
+
+