putty/pinger.c

72 строки
1.5 KiB
C

/*
* pinger.c: centralised module that deals with sending TS_PING
* keepalives, to avoid replicating this code in multiple backends.
*/
#include "putty.h"
struct pinger_tag {
int interval;
int pending;
long next;
Backend *back;
void *backhandle;
};
static void pinger_schedule(Pinger pinger);
static void pinger_timer(void *ctx, long now)
{
Pinger pinger = (Pinger)ctx;
if (pinger->pending && now - pinger->next >= 0) {
pinger->back->special(pinger->backhandle, TS_PING);
pinger->pending = FALSE;
pinger_schedule(pinger);
}
}
static void pinger_schedule(Pinger pinger)
{
int next;
if (!pinger->interval) {
pinger->pending = FALSE; /* cancel any pending ping */
return;
}
next = schedule_timer(pinger->interval * TICKSPERSEC,
pinger_timer, pinger);
if (!pinger->pending || next < pinger->next) {
pinger->next = next;
pinger->pending = TRUE;
}
}
Pinger pinger_new(Config *cfg, Backend *back, void *backhandle)
{
Pinger pinger = snew(struct pinger_tag);
pinger->interval = cfg->ping_interval;
pinger->pending = FALSE;
pinger->back = back;
pinger->backhandle = backhandle;
pinger_schedule(pinger);
return pinger;
}
void pinger_reconfig(Pinger pinger, Config *oldcfg, Config *newcfg)
{
if (oldcfg->ping_interval != newcfg->ping_interval) {
pinger->interval = newcfg->ping_interval;
pinger_schedule(pinger);
}
}
void pinger_free(Pinger pinger)
{
expire_timer_context(pinger);
sfree(pinger);
}