OVMS3-idf/components/xtensa/stdatomic.c
2019-06-20 12:06:52 +08:00

47 lines
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1.5 KiB
C

// Copyright 2015-2019 Espressif Systems (Shanghai) PTE LTD
//
// 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.
//replacement for gcc built-in functions
#include "sdkconfig.h"
#include "freertos/FreeRTOS.h"
#include "freertos/portmacro.h"
#include "xtensa/config/core-isa.h"
#define CMP_EXCHANGE(n, type) bool __atomic_compare_exchange_ ## n (type* mem, type* expect, type desired, int success, int failure) \
{ \
bool ret = false; \
unsigned state = portENTER_CRITICAL_NESTED(); \
if (*mem == *expect) { \
ret = true; \
*mem = desired; \
} else { \
*expect = *mem; \
} \
portEXIT_CRITICAL_NESTED(state); \
return ret; \
}
//this piece of code should only be compiled if the cpu doesn't support atomic compare and swap (s32c1i)
#if XCHAL_HAVE_S32C1I == 0
#pragma GCC diagnostic ignored "-Wbuiltin-declaration-mismatch"
CMP_EXCHANGE(1, uint8_t)
CMP_EXCHANGE(2, uint16_t)
CMP_EXCHANGE(4, uint32_t)
CMP_EXCHANGE(8, uint64_t)
#endif