forked from forks/qmk_firmware
Simplify the triple buffer implementation
This commit is contained in:
parent
4bb5733cdc
commit
8e2d70d11f
|
@ -25,28 +25,28 @@ SOFTWARE.
|
|||
#include "protocol/triple_buffered_object.h"
|
||||
|
||||
#define GET_READ_INDEX() object->state & 3
|
||||
#define GET_WRITE1_INDEX() (object->state >> 2) & 3
|
||||
#define GET_WRITE2_INDEX() (object->state >> 4) & 3
|
||||
#define GET_FREE_INDEX() (object->state >> 6) & 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_WRITE1_INDEX(i) object->state = ((object->state & ~(3 << 2)) | (i << 2))
|
||||
#define SET_WRITE2_INDEX(i) object->state = ((object->state & ~(3 << 4)) | (i << 4))
|
||||
#define SET_FREE_INDEX(i) object->state = ((object->state & ~(3 << 6)) | (i << 6))
|
||||
#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_WRITE1_INDEX(0);
|
||||
SET_WRITE2_INDEX(0);
|
||||
SET_WRITE_INDEX(0);
|
||||
SET_READ_INDEX(1);
|
||||
SET_FREE_INDEX(2);
|
||||
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 newest = GET_WRITE2_INDEX();
|
||||
uint8_t free_index = GET_READ_INDEX();
|
||||
SET_READ_INDEX(newest);
|
||||
SET_FREE_INDEX(free_index);
|
||||
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) {
|
||||
|
@ -58,22 +58,12 @@ static void triple_buffer_end_read(uint16_t object_size, triple_buffer_object_t*
|
|||
}
|
||||
|
||||
void triple_buffer_write(uint16_t object_size, triple_buffer_object_t* object, void* src) {
|
||||
uint8_t write1_index = GET_WRITE1_INDEX();
|
||||
uint8_t write2_index = GET_WRITE2_INDEX();
|
||||
uint8_t read_index = GET_READ_INDEX();
|
||||
uint8_t free_index = GET_FREE_INDEX();
|
||||
|
||||
if (write2_index == read_index) {
|
||||
// We are reading from the other write index
|
||||
SET_WRITE1_INDEX(free_index);
|
||||
memcpy(object->buffer + object_size * free_index, src, object_size);
|
||||
SET_WRITE2_INDEX(free_index);
|
||||
}
|
||||
else {
|
||||
SET_WRITE1_INDEX(write2_index);
|
||||
memcpy(object->buffer + object_size * write2_index, src, object_size);
|
||||
SET_WRITE2_INDEX(write2_index);
|
||||
}
|
||||
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) {
|
||||
|
|
|
@ -77,4 +77,22 @@ Ensure(TripleBufferedObject, performs_another_write_in_the_middle_of_read) {
|
|||
triple_buffer_actual_read(4, (triple_buffer_object_t*)&test_object, &dst);
|
||||
triple_buffer_end_read(4, (triple_buffer_object_t*)&test_object);
|
||||
assert_that(dst, is_equal_to(1));
|
||||
triple_buffer_read(4, (triple_buffer_object_t*)&test_object, &dst);
|
||||
assert_that(dst, is_equal_to(2));
|
||||
}
|
||||
|
||||
Ensure(TripleBufferedObject, performs_two_writes_in_the_middle_of_read) {
|
||||
uint32_t src = 1;
|
||||
uint32_t dst;
|
||||
triple_buffer_write(4, (triple_buffer_object_t*)&test_object, &src);
|
||||
triple_buffer_begin_read(4, (triple_buffer_object_t*)&test_object);
|
||||
src = 2;
|
||||
triple_buffer_write(4, (triple_buffer_object_t*)&test_object, &src);
|
||||
src = 3;
|
||||
triple_buffer_write(4, (triple_buffer_object_t*)&test_object, &src);
|
||||
triple_buffer_actual_read(4, (triple_buffer_object_t*)&test_object, &dst);
|
||||
triple_buffer_end_read(4, (triple_buffer_object_t*)&test_object);
|
||||
assert_that(dst, is_equal_to(1));
|
||||
triple_buffer_read(4, (triple_buffer_object_t*)&test_object, &dst);
|
||||
assert_that(dst, is_equal_to(3));
|
||||
}
|
||||
|
|
Loading…
Reference in a new issue