diff options
Diffstat (limited to 'tools/plink/timing.c')
| -rw-r--r-- | tools/plink/timing.c | 243 |
1 files changed, 0 insertions, 243 deletions
diff --git a/tools/plink/timing.c b/tools/plink/timing.c deleted file mode 100644 index 2b7b70cb9..000000000 --- a/tools/plink/timing.c +++ /dev/null @@ -1,243 +0,0 @@ -/*
- * timing.c
- *
- * This module tracks any timers set up by schedule_timer(). It
- * keeps all the currently active timers in a list; it informs the
- * front end of when the next timer is due to go off if that
- * changes; and, very importantly, it tracks the context pointers
- * passed to schedule_timer(), so that if a context is freed all
- * the timers associated with it can be immediately annulled.
- */
-
-#include <assert.h>
-#include <stdio.h>
-
-#include "putty.h"
-#include "tree234.h"
-
-struct timer {
- timer_fn_t fn;
- void *ctx;
- long now;
-};
-
-static tree234 *timers = NULL;
-static tree234 *timer_contexts = NULL;
-static long now = 0L;
-
-static int compare_timers(void *av, void *bv)
-{
- struct timer *a = (struct timer *)av;
- struct timer *b = (struct timer *)bv;
- long at = a->now - now;
- long bt = b->now - now;
-
- if (at < bt)
- return -1;
- else if (at > bt)
- return +1;
-
- /*
- * Failing that, compare on the other two fields, just so that
- * we don't get unwanted equality.
- */
-#ifdef __LCC__
- /* lcc won't let us compare function pointers. Legal, but annoying. */
- {
- int c = memcmp(&a->fn, &b->fn, sizeof(a->fn));
- if (c < 0)
- return -1;
- else if (c > 0)
- return +1;
- }
-#else
- if (a->fn < b->fn)
- return -1;
- else if (a->fn > b->fn)
- return +1;
-#endif
-
- if (a->ctx < b->ctx)
- return -1;
- else if (a->ctx > b->ctx)
- return +1;
-
- /*
- * Failing _that_, the two entries genuinely are equal, and we
- * never have a need to store them separately in the tree.
- */
- return 0;
-}
-
-static int compare_timer_contexts(void *av, void *bv)
-{
- char *a = (char *)av;
- char *b = (char *)bv;
- if (a < b)
- return -1;
- else if (a > b)
- return +1;
- return 0;
-}
-
-static void init_timers(void)
-{
- if (!timers) {
- timers = newtree234(compare_timers);
- timer_contexts = newtree234(compare_timer_contexts);
- now = GETTICKCOUNT();
- }
-}
-
-long schedule_timer(int ticks, timer_fn_t fn, void *ctx)
-{
- long when;
- struct timer *t, *first;
-
- init_timers();
-
- when = ticks + GETTICKCOUNT();
-
- /*
- * Just in case our various defences against timing skew fail
- * us: if we try to schedule a timer that's already in the
- * past, we instead schedule it for the immediate future.
- */
- if (when - now <= 0)
- when = now + 1;
-
- t = snew(struct timer);
- t->fn = fn;
- t->ctx = ctx;
- t->now = when;
-
- if (t != add234(timers, t)) {
- sfree(t); /* identical timer already exists */
- } else {
- add234(timer_contexts, t->ctx);/* don't care if this fails */
- }
-
- first = (struct timer *)index234(timers, 0);
- if (first == t) {
- /*
- * This timer is the very first on the list, so we must
- * notify the front end.
- */
- timer_change_notify(first->now);
- }
-
- return when;
-}
-
-/*
- * Call to run any timers whose time has reached the present.
- * Returns the time (in ticks) expected until the next timer after
- * that triggers.
- */
-int run_timers(long anow, long *next)
-{
- struct timer *first;
-
- init_timers();
-
-#ifdef TIMING_SYNC
- /*
- * In this ifdef I put some code which deals with the
- * possibility that `anow' disagrees with GETTICKCOUNT by a
- * significant margin. Our strategy for dealing with it differs
- * depending on platform, because on some platforms
- * GETTICKCOUNT is more likely to be right whereas on others
- * `anow' is a better gold standard.
- */
- {
- long tnow = GETTICKCOUNT();
-
- if (tnow + TICKSPERSEC/50 - anow < 0 ||
- anow + TICKSPERSEC/50 - tnow < 0
- ) {
-#if defined TIMING_SYNC_ANOW
- /*
- * If anow is accurate and the tick count is wrong,
- * this is likely to be because the tick count is
- * derived from the system clock which has changed (as
- * can occur on Unix). Therefore, we resolve this by
- * inventing an offset which is used to adjust all
- * future output from GETTICKCOUNT.
- *
- * A platform which defines TIMING_SYNC_ANOW is
- * expected to have also defined this offset variable
- * in (its platform-specific adjunct to) putty.h.
- * Therefore we can simply reference it here and assume
- * that it will exist.
- */
- tickcount_offset += anow - tnow;
-#elif defined TIMING_SYNC_TICKCOUNT
- /*
- * If the tick count is more likely to be accurate, we
- * simply use that as our time value, which may mean we
- * run no timers in this call (because we got called
- * early), or alternatively it may mean we run lots of
- * timers in a hurry because we were called late.
- */
- anow = tnow;
-#else
-/*
- * Any platform which defines TIMING_SYNC must also define one of the two
- * auxiliary symbols TIMING_SYNC_ANOW and TIMING_SYNC_TICKCOUNT, to
- * indicate which measurement to trust when the two disagree.
- */
-#error TIMING_SYNC definition incomplete
-#endif
- }
- }
-#endif
-
- now = anow;
-
- while (1) {
- first = (struct timer *)index234(timers, 0);
-
- if (!first)
- return FALSE; /* no timers remaining */
-
- if (find234(timer_contexts, first->ctx, NULL) == NULL) {
- /*
- * This timer belongs to a context that has been
- * expired. Delete it without running.
- */
- delpos234(timers, 0);
- sfree(first);
- } else if (first->now - now <= 0) {
- /*
- * This timer is active and has reached its running
- * time. Run it.
- */
- delpos234(timers, 0);
- first->fn(first->ctx, first->now);
- sfree(first);
- } else {
- /*
- * This is the first still-active timer that is in the
- * future. Return how long it has yet to go.
- */
- *next = first->now;
- return TRUE;
- }
- }
-}
-
-/*
- * Call to expire all timers associated with a given context.
- */
-void expire_timer_context(void *ctx)
-{
- init_timers();
-
- /*
- * We don't bother to check the return value; if the context
- * already wasn't in the tree (presumably because no timers
- * ever actually got scheduled for it) then that's fine and we
- * simply don't need to do anything.
- */
- del234(timer_contexts, ctx);
-}
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