os_ring.c

来自「arm_bootloader _flash writter &USB」· C语言 代码 · 共 80 行

#include <ucos_ii.h>
#include "os_ring.h"

// return value < 0:    putring fail
// return value == 0:   putring success
int putring(ring_buf_t *ring, unsigned char src[], unsigned int len)
{
    unsigned int i;
#if OS_CRITICAL_METHOD == 3
    OS_CPU_SR  cpu_sr = 0;                                  /* Storage for CPU status register         */
#endif

    OS_ENTER_CRITICAL();

    // Check whether space is enough
    if((ring->buffersize + len) >= sizeof(ring->buffer))
    {
        OS_EXIT_CRITICAL();
        return RING_FAIL;
    }
    
    ring->buffersize+=len;
    for(i=0; i<len; i++)
    {
        ring->buffer[ring->putindex] = src[i];
        ring->putindex = (ring->putindex + 1) & RING_BUFFER_INDEX_MASK;
    }
    
    OS_EXIT_CRITICAL();
    
    return RING_SUCCESS;
}

int putring_char(ring_buf_t *ring, unsigned char c)
{
    return putring(ring, &c, 1);
}

int getring(ring_buf_t *ring, unsigned char buf[], unsigned int len)
{
    unsigned int i;
    unsigned int get_byte = 0;
#if OS_CRITICAL_METHOD == 3
    OS_CPU_SR  cpu_sr = 0;                                  /* Storage for CPU status register         */
#endif

    OS_ENTER_CRITICAL();
    if((ring->buffersize) == 0)
    {
        OS_EXIT_CRITICAL();
        return RING_FAIL;
    }
    
    for(i=0; i<len; i++)
    {
        buf[i] = ring->buffer[ring->getindex];
        get_byte++;
        
        ring->buffersize--;
        ring->getindex = (ring->getindex + 1) & RING_BUFFER_INDEX_MASK;
        
        if(ring->buffersize == 0)
            break;
    }
    OS_EXIT_CRITICAL();
    
    return get_byte;
}

int getring_char(ring_buf_t *ring, unsigned char *c)
{
    return getring(ring, c, 1);
}

void ring_flush(ring_buf_t *ring)
{
    ring->buffersize = 0;
    ring->getindex = ring->putindex;
}