Руслан Бредун
test
Diff: mbed/platform/mbed_critical.h
- Revision:
- 12:406f75196a12
- Parent:
- 11:32eeb052cda5
- Child:
- 13:0c732e06d675
--- a/mbed/platform/mbed_critical.h Wed Aug 26 14:26:27 2020 +0530
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,437 +0,0 @@
-
-/*
- * Copyright (c) 2015-2016, ARM Limited, All Rights Reserved
- * SPDX-License-Identifier: Apache-2.0
- *
- * 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_UTIL_CRITICAL_H__
-#define __MBED_UTIL_CRITICAL_H__
-
-#include <stdbool.h>
-#include <stdint.h>
-#include <stddef.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/** \addtogroup platform */
-/** @{*/
-/**
- * \defgroup platform_critical critical section function
- * @{
- */
-
-/** Determine the current interrupts enabled state
- *
- * This function can be called to determine whether or not interrupts are currently enabled.
- * @note
- * NOTE:
- * This function works for both cortex-A and cortex-M, although the underlying implementation
- * differs.
- * @return true if interrupts are enabled, false otherwise
- */
-bool core_util_are_interrupts_enabled(void);
-
-/** Determine if this code is executing from an interrupt
- *
- * This function can be called to determine if the code is running on interrupt context.
- * @note
- * NOTE:
- * This function works for both cortex-A and cortex-M, although the underlying implementation
- * differs.
- * @return true if in an isr, false otherwise
- */
-bool core_util_is_isr_active(void);
-
-/** Mark the start of a critical section
- *
- * This function should be called to mark the start of a critical section of code.
- * @note
- * NOTES:
- * 1) The use of this style of critical section is targetted at C based implementations.
- * 2) These critical sections can be nested.
- * 3) The interrupt enable state on entry to the first critical section (of a nested set, or single
- * section) will be preserved on exit from the section.
- * 4) This implementation will currently only work on code running in privileged mode.
- */
-void core_util_critical_section_enter(void);
-
-/** Mark the end of a critical section
- *
- * This function should be called to mark the end of a critical section of code.
- * @note
- * NOTES:
- * 1) The use of this style of critical section is targetted at C based implementations.
- * 2) These critical sections can be nested.
- * 3) The interrupt enable state on entry to the first critical section (of a nested set, or single
- * section) will be preserved on exit from the section.
- * 4) This implementation will currently only work on code running in privileged mode.
- */
-void core_util_critical_section_exit(void);
-
-/**
- * Determine if we are currently in a critical section
- *
- * @return true if in a critical section, false otherwise.
- */
-bool core_util_in_critical_section(void);
-
-/**
- * A lock-free, primitive atomic flag.
- *
- * Emulate C11's atomic_flag. The flag is initially in an indeterminate state
- * unless explicitly initialized with CORE_UTIL_ATOMIC_FLAG_INIT.
- */
-typedef struct core_util_atomic_flag {
- uint8_t _flag;
-} core_util_atomic_flag;
-
-/**
- * Initializer for a core_util_atomic_flag.
- *
- * Example:
- * ~~~
- * core_util_atomic_flag in_progress = CORE_UTIL_ATOMIC_FLAG_INIT;
- * ~~~
- */
-#define CORE_UTIL_ATOMIC_FLAG_INIT { 0 }
-
-/**
- * Atomic test and set.
- *
- * Atomically tests then sets the flag to true, returning the previous value.
- *
- * @param flagPtr Target flag being tested and set.
- * @return The previous value.
- */
-bool core_util_atomic_flag_test_and_set(volatile core_util_atomic_flag *flagPtr);
-
-/**
- * Atomic clear.
- *
- * @param flagPtr Target flag being cleared.
- */
-void core_util_atomic_flag_clear(volatile core_util_atomic_flag *flagPtr);
-
-/**
- * Atomic compare and set. It compares the contents of a memory location to a
- * given value and, only if they are the same, modifies the contents of that
- * memory location to a given new value. This is done as a single atomic
- * operation. The atomicity guarantees that the new value is calculated based on
- * up-to-date information; if the value had been updated by another thread in
- * the meantime, the write would fail due to a mismatched expectedCurrentValue.
- *
- * Refer to https://en.wikipedia.org/wiki/Compare-and-set [which may redirect
- * you to the article on compare-and swap].
- *
- * @param ptr The target memory location.
- * @param[in,out] expectedCurrentValue A pointer to some location holding the
- * expected current value of the data being set atomically.
- * The computed 'desiredValue' should be a function of this current value.
- * @note: This is an in-out parameter. In the
- * failure case of atomic_cas (where the
- * destination isn't set), the pointee of expectedCurrentValue is
- * updated with the current value.
- * @param[in] desiredValue The new value computed based on '*expectedCurrentValue'.
- *
- * @return true if the memory location was atomically
- * updated with the desired value (after verifying
- * that it contained the expectedCurrentValue),
- * false otherwise. In the failure case,
- * exepctedCurrentValue is updated with the new
- * value of the target memory location.
- *
- * pseudocode:
- * function cas(p : pointer to int, old : pointer to int, new : int) returns bool {
- * if *p != *old {
- * *old = *p
- * return false
- * }
- * *p = new
- * return true
- * }
- *
- * @note: In the failure case (where the destination isn't set), the value
- * pointed to by expectedCurrentValue is instead updated with the current value.
- * This property helps writing concise code for the following incr:
- *
- * function incr(p : pointer to int, a : int) returns int {
- * done = false
- * value = *p // This fetch operation need not be atomic.
- * while not done {
- * done = atomic_cas(p, &value, value + a) // *value gets updated automatically until success
- * }
- * return value + a
- * }
- *
- * @note: This corresponds to the C11 "atomic_compare_exchange_strong" - it
- * always succeeds if the current value is expected, as per the pseudocode
- * above; it will not spuriously fail as "atomic_compare_exchange_weak" may.
- */
-bool core_util_atomic_cas_u8(volatile uint8_t *ptr, uint8_t *expectedCurrentValue, uint8_t desiredValue);
-
-/**
- * Atomic compare and set. It compares the contents of a memory location to a
- * given value and, only if they are the same, modifies the contents of that
- * memory location to a given new value. This is done as a single atomic
- * operation. The atomicity guarantees that the new value is calculated based on
- * up-to-date information; if the value had been updated by another thread in
- * the meantime, the write would fail due to a mismatched expectedCurrentValue.
- *
- * Refer to https://en.wikipedia.org/wiki/Compare-and-set [which may redirect
- * you to the article on compare-and swap].
- *
- * @param ptr The target memory location.
- * @param[in,out] expectedCurrentValue A pointer to some location holding the
- * expected current value of the data being set atomically.
- * The computed 'desiredValue' should be a function of this current value.
- * @note: This is an in-out parameter. In the
- * failure case of atomic_cas (where the
- * destination isn't set), the pointee of expectedCurrentValue is
- * updated with the current value.
- * @param[in] desiredValue The new value computed based on '*expectedCurrentValue'.
- *
- * @return true if the memory location was atomically
- * updated with the desired value (after verifying
- * that it contained the expectedCurrentValue),
- * false otherwise. In the failure case,
- * exepctedCurrentValue is updated with the new
- * value of the target memory location.
- *
- * pseudocode:
- * function cas(p : pointer to int, old : pointer to int, new : int) returns bool {
- * if *p != *old {
- * *old = *p
- * return false
- * }
- * *p = new
- * return true
- * }
- *
- * @note: In the failure case (where the destination isn't set), the value
- * pointed to by expectedCurrentValue is instead updated with the current value.
- * This property helps writing concise code for the following incr:
- *
- * function incr(p : pointer to int, a : int) returns int {
- * done = false
- * value = *p // This fetch operation need not be atomic.
- * while not done {
- * done = atomic_cas(p, &value, value + a) // *value gets updated automatically until success
- * }
- * return value + a
- * }
- *
- * @note: This corresponds to the C11 "atomic_compare_exchange_strong" - it
- * always succeeds if the current value is expected, as per the pseudocode
- * above; it will not spuriously fail as "atomic_compare_exchange_weak" may.
- */
-bool core_util_atomic_cas_u16(volatile uint16_t *ptr, uint16_t *expectedCurrentValue, uint16_t desiredValue);
-
-/**
- * Atomic compare and set. It compares the contents of a memory location to a
- * given value and, only if they are the same, modifies the contents of that
- * memory location to a given new value. This is done as a single atomic
- * operation. The atomicity guarantees that the new value is calculated based on
- * up-to-date information; if the value had been updated by another thread in
- * the meantime, the write would fail due to a mismatched expectedCurrentValue.
- *
- * Refer to https://en.wikipedia.org/wiki/Compare-and-set [which may redirect
- * you to the article on compare-and swap].
- *
- * @param ptr The target memory location.
- * @param[in,out] expectedCurrentValue A pointer to some location holding the
- * expected current value of the data being set atomically.
- * The computed 'desiredValue' should be a function of this current value.
- * @note: This is an in-out parameter. In the
- * failure case of atomic_cas (where the
- * destination isn't set), the pointee of expectedCurrentValue is
- * updated with the current value.
- * @param[in] desiredValue The new value computed based on '*expectedCurrentValue'.
- *
- * @return true if the memory location was atomically
- * updated with the desired value (after verifying
- * that it contained the expectedCurrentValue),
- * false otherwise. In the failure case,
- * exepctedCurrentValue is updated with the new
- * value of the target memory location.
- *
- * pseudocode:
- * function cas(p : pointer to int, old : pointer to int, new : int) returns bool {
- * if *p != *old {
- * *old = *p
- * return false
- * }
- * *p = new
- * return true
- * }
- *
- * @note: In the failure case (where the destination isn't set), the value
- * pointed to by expectedCurrentValue is instead updated with the current value.
- * This property helps writing concise code for the following incr:
- *
- * function incr(p : pointer to int, a : int) returns int {
- * done = false
- * value = *p // This fetch operation need not be atomic.
- * while not done {
- * done = atomic_cas(p, &value, value + a) // *value gets updated automatically until success
- * }
- * return value + a
- *
- * @note: This corresponds to the C11 "atomic_compare_exchange_strong" - it
- * always succeeds if the current value is expected, as per the pseudocode
- * above; it will not spuriously fail as "atomic_compare_exchange_weak" may.
- * }
- */
-bool core_util_atomic_cas_u32(volatile uint32_t *ptr, uint32_t *expectedCurrentValue, uint32_t desiredValue);
-
-/**
- * Atomic compare and set. It compares the contents of a memory location to a
- * given value and, only if they are the same, modifies the contents of that
- * memory location to a given new value. This is done as a single atomic
- * operation. The atomicity guarantees that the new value is calculated based on
- * up-to-date information; if the value had been updated by another thread in
- * the meantime, the write would fail due to a mismatched expectedCurrentValue.
- *
- * Refer to https://en.wikipedia.org/wiki/Compare-and-set [which may redirect
- * you to the article on compare-and swap].
- *
- * @param ptr The target memory location.
- * @param[in,out] expectedCurrentValue A pointer to some location holding the
- * expected current value of the data being set atomically.
- * The computed 'desiredValue' should be a function of this current value.
- * @note: This is an in-out parameter. In the
- * failure case of atomic_cas (where the
- * destination isn't set), the pointee of expectedCurrentValue is
- * updated with the current value.
- * @param[in] desiredValue The new value computed based on '*expectedCurrentValue'.
- *
- * @return true if the memory location was atomically
- * updated with the desired value (after verifying
- * that it contained the expectedCurrentValue),
- * false otherwise. In the failure case,
- * exepctedCurrentValue is updated with the new
- * value of the target memory location.
- *
- * pseudocode:
- * function cas(p : pointer to int, old : pointer to int, new : int) returns bool {
- * if *p != *old {
- * *old = *p
- * return false
- * }
- * *p = new
- * return true
- * }
- *
- * @note: In the failure case (where the destination isn't set), the value
- * pointed to by expectedCurrentValue is instead updated with the current value.
- * This property helps writing concise code for the following incr:
- *
- * function incr(p : pointer to int, a : int) returns int {
- * done = false
- * value = *p // This fetch operation need not be atomic.
- * while not done {
- * done = atomic_cas(p, &value, value + a) // *value gets updated automatically until success
- * }
- * return value + a
- * }
- *
- * @note: This corresponds to the C11 "atomic_compare_exchange_strong" - it
- * always succeeds if the current value is expected, as per the pseudocode
- * above; it will not spuriously fail as "atomic_compare_exchange_weak" may.
- */
-bool core_util_atomic_cas_ptr(void *volatile *ptr, void **expectedCurrentValue, void *desiredValue);
-
-/**
- * Atomic increment.
- * @param valuePtr Target memory location being incremented.
- * @param delta The amount being incremented.
- * @return The new incremented value.
- */
-uint8_t core_util_atomic_incr_u8(volatile uint8_t *valuePtr, uint8_t delta);
-
-/**
- * Atomic increment.
- * @param valuePtr Target memory location being incremented.
- * @param delta The amount being incremented.
- * @return The new incremented value.
- */
-uint16_t core_util_atomic_incr_u16(volatile uint16_t *valuePtr, uint16_t delta);
-
-/**
- * Atomic increment.
- * @param valuePtr Target memory location being incremented.
- * @param delta The amount being incremented.
- * @return The new incremented value.
- */
-uint32_t core_util_atomic_incr_u32(volatile uint32_t *valuePtr, uint32_t delta);
-
-/**
- * Atomic increment.
- * @param valuePtr Target memory location being incremented.
- * @param delta The amount being incremented in bytes.
- * @return The new incremented value.
- *
- * @note The type of the pointer argument is not taken into account
- * and the pointer is incremented by bytes.
- */
-void *core_util_atomic_incr_ptr(void *volatile *valuePtr, ptrdiff_t delta);
-
-/**
- * Atomic decrement.
- * @param valuePtr Target memory location being decremented.
- * @param delta The amount being decremented.
- * @return The new decremented value.
- */
-uint8_t core_util_atomic_decr_u8(volatile uint8_t *valuePtr, uint8_t delta);
-
-/**
- * Atomic decrement.
- * @param valuePtr Target memory location being decremented.
- * @param delta The amount being decremented.
- * @return The new decremented value.
- */
-uint16_t core_util_atomic_decr_u16(volatile uint16_t *valuePtr, uint16_t delta);
-
-/**
- * Atomic decrement.
- * @param valuePtr Target memory location being decremented.
- * @param delta The amount being decremented.
- * @return The new decremented value.
- */
-uint32_t core_util_atomic_decr_u32(volatile uint32_t *valuePtr, uint32_t delta);
-
-/**
- * Atomic decrement.
- * @param valuePtr Target memory location being decremented.
- * @param delta The amount being decremented in bytes.
- * @return The new decremented value.
- *
- * @note The type of the pointer argument is not taken into account
- * and the pointer is decremented by bytes
- */
-void *core_util_atomic_decr_ptr(void *volatile *valuePtr, ptrdiff_t delta);
-
-#ifdef __cplusplus
-} // extern "C"
-#endif
-/**@}*/
-
-/**@}*/
-
-#endif // __MBED_UTIL_CRITICAL_H__
-
-
-