esp-idf/components/log/log_freertos.c

/*
 * SPDX-FileCopyrightText: 2015-2024 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/semphr.h"
#include "esp_compiler.h"
#include "esp_private/log_lock.h"

// Maximum time to wait for the mutex in a logging statement.
//
// We don't expect this to happen in most cases, as contention is low. The most likely case is if a
// log function is called from an ISR (technically caller should use the ISR-friendly logging macros but
// possible they use the normal one instead and disable the log type by tag).
#define MAX_MUTEX_WAIT_MS 10
#define MAX_MUTEX_WAIT_TICKS ((MAX_MUTEX_WAIT_MS + portTICK_PERIOD_MS - 1) / portTICK_PERIOD_MS)

static SemaphoreHandle_t s_log_mutex = NULL;

void esp_log_impl_lock(void)
{
    if (unlikely(!s_log_mutex)) {
        s_log_mutex = xSemaphoreCreateMutex();
    }
    if (unlikely(xTaskGetSchedulerState() == taskSCHEDULER_NOT_STARTED)) {
        return;
    }
    xSemaphoreTake(s_log_mutex, portMAX_DELAY);
}

bool esp_log_impl_lock_timeout(void)
{
    if (unlikely(!s_log_mutex)) {
        s_log_mutex = xSemaphoreCreateMutex();
    }
    if (unlikely(xTaskGetSchedulerState() == taskSCHEDULER_NOT_STARTED)) {
        return true;
    }
    return xSemaphoreTake(s_log_mutex, MAX_MUTEX_WAIT_TICKS) == pdTRUE;
}

void esp_log_impl_unlock(void)
{
    if (unlikely(xTaskGetSchedulerState() == taskSCHEDULER_NOT_STARTED)) {
        return;
    }
    xSemaphoreGive(s_log_mutex);
}