Thread safety

With default configuration, library is not thread safe. This means whenever it is used with operating system, user must resolve it with care.

Library has locking mechanism support for thread safety, which needs to be enabled manually.

Tip

To enable thread-safety support, parameter LWOW_CFG_OS must be set to 1. Please check Configuration for more information about other options.

After thread-safety features has been enabled, it is necessary to implement 4 low-level system functions.

Tip

System function template example is available in lwow/src/system/ folder.

Example code for CMSIS-OS V2

Note

Check System functions section for function description

System functions for CMSIS-OS based operating system
 1/**
 2 * \file            lwow_sys_cmsis_os.c
 3 * \brief           System functions for CMSIS-OS based operating system
 4 */
 5
 6/*
 7 * Copyright (c) 2020 Tilen MAJERLE
 8 *
 9 * Permission is hereby granted, free of charge, to any person
10 * obtaining a copy of this software and associated documentation
11 * files (the "Software"), to deal in the Software without restriction,
12 * including without limitation the rights to use, copy, modify, merge,
13 * publish, distribute, sublicense, and/or sell copies of the Software,
14 * and to permit persons to whom the Software is furnished to do so,
15 * subject to the following conditions:
16 *
17 * The above copyright notice and this permission notice shall be
18 * included in all copies or substantial portions of the Software.
19 *
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
21 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
22 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
23 * AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
24 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
25 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
26 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
27 * OTHER DEALINGS IN THE SOFTWARE.
28 *
29 * This file is part of LwOW - Lightweight onewire library.
30 *
31 * Author:          Tilen MAJERLE <tilen@majerle.eu>
32 * Version:         v3.0.2
33 */
34#include "system/lwow_sys.h"
35
36#if LWOW_CFG_OS && !__DOXYGEN__
37
38#include "cmsis_os.h"
39
40uint8_t
41lwow_sys_mutex_create(LWOW_CFG_OS_MUTEX_HANDLE* m, void* arg) {
42    LWOW_UNUSED(arg);
43    const osMutexAttr_t attr = {
44        .attr_bits = osMutexRecursive,
45        .name = "lwow_mutex",
46    };
47    return (*m = osMutexNew(&attr)) != NULL;
48}
49
50uint8_t
51lwow_sys_mutex_delete(LWOW_CFG_OS_MUTEX_HANDLE* m, void* arg) {
52    LWOW_UNUSED(arg);
53    return osMutexDelete(*m) == osOK;
54}
55
56uint8_t
57lwow_sys_mutex_wait(LWOW_CFG_OS_MUTEX_HANDLE* m, void* arg) {
58    LWOW_UNUSED(arg);
59    return osMutexAcquire(*m, osWaitForever) == osOK;
60}
61
62uint8_t
63lwow_sys_mutex_release(LWOW_CFG_OS_MUTEX_HANDLE* m, void* arg) {
64    LWOW_UNUSED(arg);
65    return osMutexRelease(*m) == osOK;
66}
67
68#endif /* LWOW_CFG_OS && !__DOXYGEN__ */