test test test
Diff: snake-test/mbed/hal/critical_section_api.h
- Revision:
- 0:e4c5e6ec922e
diff -r 000000000000 -r e4c5e6ec922e snake-test/mbed/hal/critical_section_api.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/snake-test/mbed/hal/critical_section_api.h Mon May 25 19:06:11 2020 +0000 @@ -0,0 +1,107 @@ +/** \addtogroup hal */ +/** @{*/ +/* mbed Microcontroller Library + * Copyright (c) 2006-2017 ARM Limited + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +#ifndef MBED_CRITICAL_SECTION_API_H +#define MBED_CRITICAL_SECTION_API_H + +#include <stdbool.h> + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * \defgroup hal_critical Critical Section HAL functions + * @{ + */ + +/** + * Mark the start of a critical section + * + * This function will be called by core_util_critical_section_enter() each time + * the application requests to enter a critical section. The purpose of the + * critical section is to ensure mutual-exclusion synchronisation of the + * processor by preventing any change in processor control, the default + * behaviour requires storing the state of interrupts in the system before + * disabling them. + * + * The critical section code supports nesting. When a thread has entered a + * critical section it can make additional calls to + * core_util_critical_section_enter() without deadlocking itself. The critical + * section driver API tracks the number of nested calls to the critical section. + * The critical section will only be exited when + * core_util_critical_section_exit() has been called once for each time it + * entered the critical section. + * + * On the first call to enter a critical section this function MUST store the + * state of any interrupts or other application settings it will modify to + * facilitate the critical section. + * + * Each successive call to enter the critical section MUST ignore storing or + * modifying any application state. + * + * The default implementation of this function which will save the current state + * of interrupts before disabling them. This implementation can be found in + * mbed_critical_section_api.c. This behaviour is can be overridden on a per + * platform basis by providing a different implementation within the correct + * targets directory. + */ +void hal_critical_section_enter(void); + + +/** Mark the end of a critical section. + * + * The purpose of this function is to restore any state that was modified upon + * entering the critical section, allowing other threads or interrupts to change + * the processor control. + * + * This function will be called once by core_util_critical_section_exit() per + * critical section on last call to exit. When called, the application MUST + * restore the saved interrupt/application state that was saved when entering + * the critical section. + * + * There is a default implementation of this function, it will restore the state + * of interrupts that were previously saved when hal_critical_section_enter was + * first called, this implementation can be found in + * mbed_critical_section_api.c. This behaviour is overridable by providing a + * different function implementation within the correct targets directory. + */ +void hal_critical_section_exit(void); + + +/** Determine if the application is currently running in a critical section + * + * The purpose of this function is to inform the caller whether or not the + * application is running in a critical section. This is done by checking if + * the current interrupt state has been saved in the underlying implementation, + * this could also be done by checking the state of the interrupts at the time + * of calling. + * + * @return True if running in a critical section, false if not. + */ +bool hal_in_critical_section(void); + + +/**@}*/ + +#ifdef __cplusplus +} +#endif + +#endif // MBED_CRITICAL_SECTION_API_H + +/** @}*/