mbed_critical.h

00001 /*
00002  * Copyright (c) 2015-2019, ARM Limited, All Rights Reserved
00003  * SPDX-License-Identifier: Apache-2.0
00004  *
00005  * Licensed under the Apache License, Version 2.0 (the "License"); you may
00006  * not use this file except in compliance with the License.
00007  * You may obtain a copy of the License at
00008  *
00009  * http://www.apache.org/licenses/LICENSE-2.0
00010  *
00011  * Unless required by applicable law or agreed to in writing, software
00012  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
00013  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00014  * See the License for the specific language governing permissions and
00015  * limitations under the License.
00016  */
00017 
00018 #ifndef __MBED_UTIL_CRITICAL_H__
00019 #define __MBED_UTIL_CRITICAL_H__
00020 
00021 #include <stdbool.h>
00022 
00023 #ifdef __cplusplus
00024 extern "C" {
00025 #endif
00026 
00027 /** \addtogroup platform-public-api */
00028 /** @{*/
00029 /**
00030  * \defgroup platform_critical critical section function
00031  * @{
00032  */
00033 
00034 /** Determine the current interrupts enabled state
00035   *
00036   * This function can be called to determine whether or not interrupts are currently enabled.
00037   * @note
00038   * NOTE:
00039   * This function works for both cortex-A and cortex-M, although the underlying implementation
00040   * differs.
00041   * @return true if interrupts are enabled, false otherwise
00042   */
00043 bool core_util_are_interrupts_enabled(void);
00044 
00045 /** Determine if this code is executing from an interrupt
00046   *
00047   * This function can be called to determine if the code is running on interrupt context.
00048   * @note
00049   * NOTE:
00050   * This function works for both cortex-A and cortex-M, although the underlying implementation
00051   * differs.
00052   * @return true if in an isr, false otherwise
00053   */
00054 bool core_util_is_isr_active(void);
00055 
00056 /** Mark the start of a critical section
00057   *
00058   * This function should be called to mark the start of a critical section of code.
00059   * @note
00060   * NOTES:
00061   * 1) The use of this style of critical section is targetted at C based implementations.
00062   * 2) These critical sections can be nested.
00063   * 3) The interrupt enable state on entry to the first critical section (of a nested set, or single
00064   *    section) will be preserved on exit from the section.
00065   * 4) This implementation will currently only work on code running in privileged mode.
00066   */
00067 void core_util_critical_section_enter(void);
00068 
00069 /** Mark the end of a critical section
00070   *
00071   * This function should be called to mark the end of a critical section of code.
00072   * @note
00073   * NOTES:
00074   * 1) The use of this style of critical section is targetted at C based implementations.
00075   * 2) These critical sections can be nested.
00076   * 3) The interrupt enable state on entry to the first critical section (of a nested set, or single
00077   *    section) will be preserved on exit from the section.
00078   * 4) This implementation will currently only work on code running in privileged mode.
00079   */
00080 void core_util_critical_section_exit(void);
00081 
00082 /**
00083  * Determine if we are currently in a critical section
00084  *
00085  * @return true if in a critical section, false otherwise.
00086  */
00087 bool core_util_in_critical_section(void);
00088 
00089 /**@}*/
00090 
00091 /**@}*/
00092 
00093 #ifdef __cplusplus
00094 } // extern "C"
00095 #endif
00096 
00097 #endif // __MBED_UTIL_CRITICAL_H__