forked from forks/qmk_firmware
74 lines
2.9 KiB
C
74 lines
2.9 KiB
C
/*
|
|
The MIT License (MIT)
|
|
|
|
Copyright (c) 2016 Fred Sundvik
|
|
|
|
Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
of this software and associated documentation files (the "Software"), to deal
|
|
in the Software without restriction, including without limitation the rights
|
|
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
copies of the Software, and to permit persons to whom the Software is
|
|
furnished to do so, subject to the following conditions:
|
|
|
|
The above copyright notice and this permission notice shall be included in all
|
|
copies or substantial portions of the Software.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
|
SOFTWARE.
|
|
*/
|
|
|
|
#include "protocol/triple_buffered_object.h"
|
|
|
|
#define GET_READ_INDEX() object->state & 3
|
|
#define GET_WRITE_INDEX() (object->state >> 2) & 3
|
|
#define GET_SHARED_INDEX() (object->state >> 4) & 3
|
|
#define GET_DATA_AVAILABLE() (object->state >> 6) & 1
|
|
|
|
#define SET_READ_INDEX(i) object->state = ((object->state & ~3) | i)
|
|
#define SET_WRITE_INDEX(i) object->state = ((object->state & ~(3 << 2)) | (i << 2))
|
|
#define SET_SHARED_INDEX(i) object->state = ((object->state & ~(3 << 4)) | (i << 4))
|
|
#define SET_DATA_AVAILABLE(i) object->state = ((object->state & ~(1 << 6)) | (i << 6))
|
|
|
|
void triple_buffer_init(triple_buffer_object_t* object) {
|
|
object->state = 0;
|
|
SET_WRITE_INDEX(0);
|
|
SET_READ_INDEX(1);
|
|
SET_SHARED_INDEX(2);
|
|
SET_DATA_AVAILABLE(0);
|
|
}
|
|
|
|
static void triple_buffer_begin_read(uint16_t object_size, triple_buffer_object_t* object) {
|
|
uint8_t shared_index = GET_SHARED_INDEX();
|
|
uint8_t read_index = GET_READ_INDEX();
|
|
SET_READ_INDEX(shared_index);
|
|
SET_SHARED_INDEX(read_index);
|
|
}
|
|
|
|
static void triple_buffer_actual_read(uint16_t object_size, triple_buffer_object_t* object, void* dst) {
|
|
uint8_t read_index = GET_READ_INDEX();
|
|
memcpy(dst, object->buffer + object_size*read_index, object_size);
|
|
}
|
|
|
|
static void triple_buffer_end_read(uint16_t object_size, triple_buffer_object_t* object) {
|
|
}
|
|
|
|
void triple_buffer_write(uint16_t object_size, triple_buffer_object_t* object, void* src) {
|
|
|
|
uint8_t write_index = GET_WRITE_INDEX();
|
|
memcpy(object->buffer + object_size * write_index, src, object_size);
|
|
uint8_t shared_index = GET_SHARED_INDEX();
|
|
SET_SHARED_INDEX(write_index);
|
|
SET_WRITE_INDEX(shared_index);
|
|
}
|
|
|
|
void triple_buffer_read(uint16_t object_size, triple_buffer_object_t* object, void* dst) {
|
|
triple_buffer_begin_read(object_size, object);
|
|
triple_buffer_actual_read(object_size, object, dst);
|
|
triple_buffer_end_read(object_size, object);
|
|
}
|