Files
simtrace2/firmware/libcommon/source/ringbuffer.c
Harald Welte 05cc7f6531 ringbuffer: Don't print/TRAC from ringbuffer
In commit eac1bec428 we start to use the
ringbuffer inside the console printing code.  As a result, we must not
use TRACE_*() or printf() from within ringbuffer.c code to avoid
infinite recursion.

Instead, let rbuf_write() return a negative return value in case the
ring buffer overflows.  This way, the callers (outside the
console/stdout code) can print an error message themselves.

Change-Id: Ib009f013be119dbad22fa2b7d60ec8dee59baee5
2018-07-04 04:42:22 +02:00

76 lines
1.3 KiB
C

#include "ringbuffer.h"
#include "trace.h"
#include "utils.h"
/* WARNINGI: Since console output is internally using this ringbuffer to implement
* buffered writes, we cannot use any TRACE_*() or printf() style functions here,
* as it would create infinite recursion! */
void rbuf_reset(volatile ringbuf * rb)
{
unsigned long state;
local_irq_save(state);
rb->ird = 0;
rb->iwr = 0;
local_irq_restore(state);
}
uint8_t rbuf_read(volatile ringbuf * rb)
{
unsigned long state;
uint8_t val;
local_irq_save(state);
val = rb->buf[rb->ird];
rb->ird = (rb->ird + 1) % RING_BUFLEN;
local_irq_restore(state);
return val;
}
uint8_t rbuf_peek(volatile ringbuf * rb)
{
return rb->buf[rb->ird];
}
bool rbuf_is_empty(volatile ringbuf * rb)
{
return rb->ird == rb->iwr;
}
static bool __rbuf_is_full(volatile ringbuf * rb)
{
return rb->ird == (rb->iwr + 1) % RING_BUFLEN;
}
bool rbuf_is_full(volatile ringbuf * rb)
{
unsigned long state;
bool rc;
local_irq_save(state);
rc = rb->ird == (rb->iwr + 1) % RING_BUFLEN;
local_irq_restore(state);
return rc;
}
int rbuf_write(volatile ringbuf * rb, uint8_t item)
{
unsigned long state;
local_irq_save(state);
if (!__rbuf_is_full(rb)) {
rb->buf[rb->iwr] = item;
rb->iwr = (rb->iwr + 1) % RING_BUFLEN;
local_irq_restore(state);
return 0;
} else {
local_irq_restore(state);
return -1;
}
}