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#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <stdio.h>
#include "ntp_machine.h"
#include "ntp_fp.h"
#include "ntp_syslog.h"
#include "ntp_stdlib.h"
#include "ntp_io.h"
#include "recvbuff.h"
#include "iosignal.h"
#include <isc/list.h>
/*
* Memory allocation
*/
static u_long volatile full_recvbufs; /* number of recvbufs on fulllist */
static u_long volatile free_recvbufs; /* number of recvbufs on freelist */
static u_long volatile total_recvbufs; /* total recvbufs currently in use */
static u_long volatile lowater_adds; /* number of times we have added memory */
static u_long volatile buffer_shortfall;/* number of missed free receive buffers
between replenishments */
static ISC_LIST(recvbuf_t) full_recv_list; /* Currently used recv buffers */
static ISC_LIST(recvbuf_t) free_recv_list; /* Currently unused buffers */
#if defined(SYS_WINNT)
/*
* For Windows we need to set up a lock to manipulate the
* recv buffers to prevent corruption. We keep it lock for as
* short a time as possible
*/
static CRITICAL_SECTION RecvLock;
# define LOCK() EnterCriticalSection(&RecvLock)
# define UNLOCK() LeaveCriticalSection(&RecvLock)
#else
# define LOCK()
# define UNLOCK()
#endif
u_long
free_recvbuffs (void)
{
return free_recvbufs;
}
u_long
full_recvbuffs (void)
{
return full_recvbufs;
}
u_long
total_recvbuffs (void)
{
return total_recvbufs;
}
u_long
lowater_additions(void)
{
return lowater_adds;
}
static void
initialise_buffer(recvbuf_t *buff)
{
memset((char *) buff, 0, sizeof(recvbuf_t));
#if defined SYS_WINNT
buff->wsabuff.len = RX_BUFF_SIZE;
buff->wsabuff.buf = (char *) buff->recv_buffer;
#endif
}
static void
create_buffers(int nbufs)
{
register recvbuf_t *bufp;
int i, abuf;
abuf = nbufs + buffer_shortfall;
buffer_shortfall = 0;
bufp = (recvbuf_t *) emalloc(abuf*sizeof(recvbuf_t));
for (i = 0; i < abuf; i++)
{
memset((char *) bufp, 0, sizeof(recvbuf_t));
ISC_LIST_APPEND(free_recv_list, bufp, link);
bufp++;
free_recvbufs++;
total_recvbufs++;
}
lowater_adds++;
}
void
init_recvbuff(int nbufs)
{
/*
* Init buffer free list and stat counters
*/
ISC_LIST_INIT(full_recv_list);
ISC_LIST_INIT(free_recv_list);
free_recvbufs = total_recvbufs = 0;
full_recvbufs = lowater_adds = 0;
create_buffers(nbufs);
#if defined(SYS_WINNT)
InitializeCriticalSection(&RecvLock);
#endif
}
/*
* freerecvbuf - make a single recvbuf available for reuse
*/
void
freerecvbuf(recvbuf_t *rb)
{
if (rb == NULL) {
msyslog(LOG_ERR, "freerecvbuff received NULL buffer");
return;
}
LOCK();
(rb->used)--;
if (rb->used != 0)
msyslog(LOG_ERR, "******** freerecvbuff non-zero usage: %d *******", rb->used);
ISC_LIST_APPEND(free_recv_list, rb, link);
#if defined SYS_WINNT
rb->wsabuff.len = RX_BUFF_SIZE;
rb->wsabuff.buf = (char *) rb->recv_buffer;
#endif
free_recvbufs++;
UNLOCK();
}
void
add_full_recv_buffer(recvbuf_t *rb)
{
if (rb == NULL) {
msyslog(LOG_ERR, "add_full_recv_buffer received NULL buffer");
return;
}
LOCK();
ISC_LIST_APPEND(full_recv_list, rb, link);
full_recvbufs++;
UNLOCK();
}
recvbuf_t *
get_free_recv_buffer(void)
{
recvbuf_t * buffer = NULL;
LOCK();
buffer = ISC_LIST_HEAD(free_recv_list);
if (buffer != NULL)
{
ISC_LIST_DEQUEUE(free_recv_list, buffer, link);
free_recvbufs--;
initialise_buffer(buffer);
(buffer->used)++;
}
else
{
buffer_shortfall++;
}
UNLOCK();
return (buffer);
}
#ifdef HAVE_IO_COMPLETION_PORT
recvbuf_t *
get_free_recv_buffer_alloc(void)
{
recvbuf_t * buffer = get_free_recv_buffer();
if (buffer == NULL)
{
create_buffers(RECV_INC);
buffer = get_free_recv_buffer();
}
return (buffer);
}
#endif
recvbuf_t *
get_full_recv_buffer(void)
{
recvbuf_t *rbuf;
LOCK();
#ifdef HAVE_SIGNALED_IO
/*
* make sure there are free buffers when we
* wander off to do lengthy paket processing with
* any buffer we grab from the full list.
*
* fixes malloc() interrupted by SIGIO risk
* (Bug 889)
*/
rbuf = ISC_LIST_HEAD(free_recv_list);
if (rbuf == NULL || buffer_shortfall > 0) {
/*
* try to get us some more buffers
*/
create_buffers(RECV_INC);
}
#endif
/*
* try to grab a full buffer
*/
rbuf = ISC_LIST_HEAD(full_recv_list);
if (rbuf != NULL)
{
ISC_LIST_DEQUEUE(full_recv_list, rbuf, link);
--full_recvbufs;
}
else
{
/*
* Make sure we reset the full count to 0
*/
full_recvbufs = 0;
}
UNLOCK();
return (rbuf);
}
/*
* Checks to see if there are buffers to process
*/
isc_boolean_t has_full_recv_buffer(void)
{
if (ISC_LIST_HEAD(full_recv_list) != NULL)
return (ISC_TRUE);
else
return (ISC_FALSE);
}
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