From 592a4295befa7459f493332b9ee38d526ff3bd05 Mon Sep 17 00:00:00 2001 From: Konstantin Kondrashov Date: Wed, 3 Apr 2019 12:18:20 +0800 Subject: [PATCH] newlib: Fix adjtime Fixed adjtime function: While using the adjtime() function, the time correction accumulated an error when reading the time frequently (using gettimeofday). --- components/newlib/test/test_time.c | 148 +++++++++++++++++------------ components/newlib/time.c | 2 +- 2 files changed, 88 insertions(+), 62 deletions(-) diff --git a/components/newlib/test/test_time.c b/components/newlib/test/test_time.c index 4a55b303e..fc10ac2a1 100644 --- a/components/newlib/test/test_time.c +++ b/components/newlib/test/test_time.c @@ -204,97 +204,123 @@ TEST_CASE("test for no interlocking adjtime, gettimeofday and settimeofday funct } #ifndef CONFIG_FREERTOS_UNICORE -static xSemaphoreHandle gettime_start_sema; -static xSemaphoreHandle adjtime_continue_sema; -static void adjtimeTask(void *pvParameters) -{ - const uint64_t adjtime_us = 2000000000; // 2000 sec - struct timeval delta = {.tv_sec = adjtime_us / 1000000, .tv_usec = 900000}; - struct timeval outdelta; - struct timeval tv_time; - int shift = 1; - int cycle = 0; +#define ADJTIME_CORRECTION_FACTOR 6 +static int64_t result_adjtime_correction_us[2]; + +static void get_time_task(void *pvParameters) +{ + xSemaphoreHandle *sema = (xSemaphoreHandle *) pvParameters; + struct timeval tv_time; // although exit flag is set in another task, checking (exit_flag == false) is safe while (exit_flag == false) { gettimeofday(&tv_time, NULL); - uint64_t start_time_us = (uint64_t)tv_time.tv_sec * 1000000L + tv_time.tv_usec; - - ++cycle; - if (shift > 3000) { - shift = 1; - } - int i_shift = shift++; - - xSemaphoreGive(gettime_start_sema); - while (--i_shift) { - __asm__ __volatile__ ("nop": : : "memory"); - }; - adjtime(&delta, &outdelta); - xSemaphoreTake(adjtime_continue_sema, portMAX_DELAY); - - gettimeofday(&tv_time, NULL); - uint64_t end_time_us = (uint64_t)tv_time.tv_sec * 1000000L + tv_time.tv_usec; - - if (!(start_time_us < end_time_us) || (end_time_us - start_time_us > adjtime_us) - || (end_time_us - start_time_us > 300) || (end_time_us - start_time_us < 30)) { - printf("ERROR: start_time_us %lld usec.\n", start_time_us); - printf("ERROR: end_time_us %lld usec.\n", end_time_us); - printf("ERROR: dt %lld usec.\n", end_time_us - start_time_us); - printf("ERROR: cycle %d\n", cycle); - printf("ERROR: shift %d\n", shift); - TEST_FAIL_MESSAGE("The time is corrupted due to the lack of locks for the adjtime function."); - } } - xSemaphoreGive(adjtime_continue_sema); - xSemaphoreGive(gettime_start_sema); + xSemaphoreGive(*sema); vTaskDelete(NULL); } -static void gettimeofdayTask(void *pvParameters) +static void start_measure(int64_t* sys_time, int64_t* real_time) { struct timeval tv_time; + *real_time = esp_timer_get_time(); + gettimeofday(&tv_time, NULL); + *sys_time = (int64_t)tv_time.tv_sec * 1000000L + tv_time.tv_usec; +} +static void end_measure(int64_t* sys_time, int64_t* real_time) +{ + struct timeval tv_time; + gettimeofday(&tv_time, NULL); + *real_time = esp_timer_get_time(); + *sys_time = (int64_t)tv_time.tv_sec * 1000000L + tv_time.tv_usec; +} + +static int64_t calc_correction(const char* tag, int64_t* sys_time, int64_t* real_time) +{ + int64_t dt_real_time_us = real_time[1] - real_time[0]; + int64_t dt_sys_time_us = sys_time[1] - sys_time[0]; + int64_t calc_correction_us = dt_real_time_us >> ADJTIME_CORRECTION_FACTOR; + int64_t real_correction_us = dt_sys_time_us - dt_real_time_us; + int64_t error_us = calc_correction_us - real_correction_us; + printf("%s: dt_real_time = %lli us, dt_sys_time = %lli us, calc_correction = %lli us, error = %lli us\n", + tag, dt_real_time_us, dt_sys_time_us, calc_correction_us, error_us); + + TEST_ASSERT_TRUE(dt_sys_time_us > 0 && dt_real_time_us > 0); + TEST_ASSERT_INT_WITHIN(100, 0, error_us); + return real_correction_us; +} + +static void measure_time_task(void *pvParameters) +{ + struct timeval tv_time; + int64_t real_time_us[2]; + int64_t sys_time_us[2]; + int64_t delay_us = 2 * 1000000; // 2 sec + xSemaphoreHandle *sema = (xSemaphoreHandle *) pvParameters; + gettimeofday(&tv_time, NULL); + start_measure(&sys_time_us[0], &real_time_us[0]); // although exit flag is set in another task, checking (exit_flag == false) is safe while (exit_flag == false) { - xSemaphoreTake(gettime_start_sema, portMAX_DELAY); - gettimeofday(&tv_time, NULL); - xSemaphoreGive(adjtime_continue_sema); + ets_delay_us(delay_us); + + end_measure(&sys_time_us[1], &real_time_us[1]); + result_adjtime_correction_us[1] += calc_correction("measure", sys_time_us, real_time_us); + + sys_time_us[0] = sys_time_us[1]; + real_time_us[0] = real_time_us[1]; } - xSemaphoreGive(adjtime_continue_sema); - xSemaphoreGive(gettime_start_sema); + xSemaphoreGive(*sema); vTaskDelete(NULL); } -TEST_CASE("test for thread safety adjtime and gettimeofday functions", "[newlib]") +TEST_CASE("test time adjustment happens linearly", "[newlib][timeout=35]") { + int64_t real_time_us[2]; + int64_t sys_time_us[2]; + exit_flag = false; - struct timeval tv_time = { .tv_sec = 1520000000, .tv_usec = 0 }; + struct timeval tv_time = {.tv_sec = 1550000000, .tv_usec = 0}; TEST_ASSERT_EQUAL(0, settimeofday(&tv_time, NULL)); - gettime_start_sema = xSemaphoreCreateBinary(); - adjtime_continue_sema = xSemaphoreCreateBinary(); + struct timeval delta = {.tv_sec = 2000, .tv_usec = 900000}; + adjtime(&delta, NULL); + gettimeofday(&tv_time, NULL); - printf("CPU0 and CPU1. Tasks run: 1 - adjtimeTask, 2 - gettimeofdayTask\n"); - xTaskCreatePinnedToCore(adjtimeTask, "adjtimeTask", 2048, NULL, UNITY_FREERTOS_PRIORITY - 1, NULL, 0); - xTaskCreatePinnedToCore(gettimeofdayTask, "gettimeofdayTask", 2048, NULL, UNITY_FREERTOS_PRIORITY - 1, NULL, 1); + xSemaphoreHandle exit_sema[2]; + for (int i = 0; i < 2; ++i) { + exit_sema[i] = xSemaphoreCreateBinary(); + result_adjtime_correction_us[i] = 0; + } - printf("start wait for 10 seconds\n"); - vTaskDelay(10000 / portTICK_PERIOD_MS); + start_measure(&sys_time_us[0], &real_time_us[0]); + + xTaskCreatePinnedToCore(get_time_task, "get_time_task", 2048, &exit_sema[0], UNITY_FREERTOS_PRIORITY - 1, NULL, 0); + xTaskCreatePinnedToCore(measure_time_task, "measure_time_task", 2048, &exit_sema[1], UNITY_FREERTOS_PRIORITY - 1, NULL, 1); + + printf("start waiting for 30 seconds\n"); + vTaskDelay(30000 / portTICK_PERIOD_MS); // set exit flag to let thread exit exit_flag = true; - vTaskDelay(2000 / portTICK_PERIOD_MS); - if (!xSemaphoreTake(gettime_start_sema, 1000 / portTICK_PERIOD_MS)) { - TEST_FAIL_MESSAGE("gettime_start_semaphore not released by test task"); + for (int i = 0; i < 2; ++i) { + if (!xSemaphoreTake(exit_sema[i], 2100/portTICK_PERIOD_MS)) { + TEST_FAIL_MESSAGE("exit_sema not released by test task"); + } } - if (!xSemaphoreTake(adjtime_continue_sema, 1000 / portTICK_PERIOD_MS)) { - TEST_FAIL_MESSAGE("adjtime_continue_semaphore not released by test task"); + + end_measure(&sys_time_us[1], &real_time_us[1]); + result_adjtime_correction_us[0] = calc_correction("main", sys_time_us, real_time_us); + + int64_t delta_us = result_adjtime_correction_us[0] - result_adjtime_correction_us[1]; + printf("\nresult of adjtime correction: %lli us, %lli us. delta = %lli us\n", result_adjtime_correction_us[0], result_adjtime_correction_us[1], delta_us); + TEST_ASSERT_INT_WITHIN(100, 0, delta_us); + + for (int i = 0; i < 2; ++i) { + vSemaphoreDelete(exit_sema[i]); } - vSemaphoreDelete(gettime_start_sema); - vSemaphoreDelete(adjtime_continue_sema); } #endif diff --git a/components/newlib/time.c b/components/newlib/time.c index 892ab2ff8..948c80a31 100644 --- a/components/newlib/time.c +++ b/components/newlib/time.c @@ -132,7 +132,7 @@ static uint64_t adjust_boot_time() // and the correction will be equal to (1_000_000us >> 6) = 15_625 us. // The minimum possible correction step can be (64us >> 6) = 1us. // Example: if the time error is 1 second, then it will be compensate for 1 sec / 0,015625 = 64 seconds. - int64_t correction = (since_boot - adjtime_start) >> ADJTIME_CORRECTION_FACTOR; + int64_t correction = (since_boot >> ADJTIME_CORRECTION_FACTOR) - (adjtime_start >> ADJTIME_CORRECTION_FACTOR); if (correction > 0) { adjtime_start = since_boot; if (adjtime_total_correction < 0) {