| /* |
| * Copyright (c) 2012-2014 Wind River Systems, Inc. |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| /** |
| * @file |
| * |
| * @brief measure time from ISR to a rescheduled thread |
| * |
| * This file contains test that measures time to switch from an interrupt |
| * handler to executing a thread after rescheduling. In other words, execution |
| * after interrupt handler resume in a different thread than the one which got |
| * interrupted. |
| */ |
| |
| #include <zephyr.h> |
| #include <irq_offload.h> |
| |
| #include "timestamp.h" |
| #include "utils.h" |
| |
| #include <arch/cpu.h> |
| |
| static u32_t timestamp; |
| |
| |
| K_SEM_DEFINE(INTSEMA, 0, 1); |
| K_ALERT_DEFINE(EVENT0, NULL, 10); |
| |
| /** |
| * |
| * @brief Test ISR used to measure best case interrupt latency |
| * |
| * The interrupt handler gets the second timestamp. |
| * |
| * @return N/A |
| */ |
| static void latency_test_isr(void *unused) |
| { |
| ARG_UNUSED(unused); |
| |
| k_alert_send(&EVENT0); |
| timestamp = TIME_STAMP_DELTA_GET(0); |
| } |
| |
| /** |
| * |
| * @brief Software interrupt generating thread |
| * |
| * Lower priority thread that, when it starts, it waits for a semaphore. When |
| * it gets it, released by the main thread, sets up the interrupt handler and |
| * generates the software interrupt |
| * |
| * @return 0 on success |
| */ |
| void int_thread(void) |
| { |
| k_sem_take(&INTSEMA, K_FOREVER); |
| irq_offload(latency_test_isr, NULL); |
| k_thread_suspend(k_current_get()); |
| } |
| |
| |
| K_THREAD_DEFINE(int_thread_id, 512, |
| (k_thread_entry_t) int_thread, NULL, NULL, NULL, |
| 11, 0, K_NO_WAIT); |
| |
| /** |
| * |
| * @brief The test main function |
| * |
| * @return 0 on success |
| */ |
| int int_to_thread_evt(void) |
| { |
| PRINT_FORMAT(" 2 - Measure time from ISR to executing a different thread" |
| " (rescheduled)"); |
| TICK_SYNCH(); |
| k_sem_give(&INTSEMA); |
| k_alert_recv(&EVENT0, K_FOREVER); |
| timestamp = TIME_STAMP_DELTA_GET(timestamp); |
| PRINT_FORMAT(" switch time is %u tcs = %u nsec", |
| timestamp, SYS_CLOCK_HW_CYCLES_TO_NS(timestamp)); |
| return 0; |
| } |