#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <stdio.h>
#include "ntp_machine.h"
#include "ntp_fp.h"
#include "ntp_stdlib.h"
#include "ntp_syslog.h"
#include <isc/list.h>
#include "transmitbuff.h"
#define TRANSMIT_INIT 10
#define TRANSMIT_LOWAT 3
#define TRANSMIT_INC 5
#define TRANSMIT_TOOMANY 40
static volatile u_long full_transmitbufs = 0;
static volatile u_long free_transmitbufs = 0;
ISC_LIST(transmitbuf_t) free_transmit_list;
ISC_LIST(transmitbuf_t) full_transmit_list;
static u_long total_transmitbufs = 0;
static u_long lowater_additions = 0;
static CRITICAL_SECTION TransmitLock;
# define LOCK(lock) EnterCriticalSection(lock)
# define UNLOCK(lock) LeaveCriticalSection(lock)
static void
initialise_buffer(transmitbuf *buff)
{
memset((char *) buff, 0, sizeof(transmitbuf));
buff->wsabuf.len = 0;
buff->wsabuf.buf = (char *) &buff->pkt;
}
static void
add_buffer_to_freelist(transmitbuf *tb)
{
ISC_LIST_APPEND(free_transmit_list, tb, link);
free_transmitbufs++;
}
static void
create_buffers(int nbufs)
{
transmitbuf_t *buf;
int i;
buf = (transmitbuf_t *) emalloc(nbufs*sizeof(transmitbuf_t));
for (i = 0; i < nbufs; i++)
{
initialise_buffer(buf);
add_buffer_to_freelist(buf);
total_transmitbufs++;
buf++;
}
lowater_additions++;
}
extern void
init_transmitbuff(void)
{
ISC_LIST_INIT(full_transmit_list);
ISC_LIST_INIT(free_transmit_list);
free_transmitbufs = total_transmitbufs = 0;
full_transmitbufs = lowater_additions = 0;
create_buffers(TRANSMIT_INIT);
InitializeCriticalSection(&TransmitLock);
}
static void
delete_buffer_from_full_list(transmitbuf_t *tb) {
transmitbuf_t *next = NULL;
transmitbuf_t *lbuf = ISC_LIST_HEAD(full_transmit_list);
while (lbuf != NULL) {
next = ISC_LIST_NEXT(lbuf, link);
if (lbuf == tb) {
ISC_LIST_DEQUEUE(full_transmit_list, lbuf, link);
break;
}
else
lbuf = next;
}
full_transmitbufs--;
}
extern void
free_transmit_buffer(transmitbuf_t *rb)
{
LOCK(&TransmitLock);
delete_buffer_from_full_list(rb);
add_buffer_to_freelist(rb);
UNLOCK(&TransmitLock);
}
extern transmitbuf *
get_free_transmit_buffer(void)
{
transmitbuf_t * buffer = NULL;
LOCK(&TransmitLock);
if (free_transmitbufs <= 0) {
create_buffers(TRANSMIT_INC);
}
buffer = ISC_LIST_HEAD(free_transmit_list);
if (buffer != NULL)
{
ISC_LIST_DEQUEUE(free_transmit_list, buffer, link);
free_transmitbufs--;
ISC_LIST_APPEND(full_transmit_list, buffer, link);
full_transmitbufs++;
}
UNLOCK(&TransmitLock);
return (buffer);
}