X-Git-Url: http://git.osdn.net/view?p=ffftp%2Fffftp.git;a=blobdiff_plain;f=putty%2FTIMING.C;fp=putty%2FTIMING.C;h=0000000000000000000000000000000000000000;hp=2b7b70cb954e1937fb6c5da1532b244fccb0627d;hb=2cca99db509753b45b80b6c79adaf6354e36a78d;hpb=c5f759cca631e9411e4705668c8cc90134fb9cd0 diff --git a/putty/TIMING.C b/putty/TIMING.C deleted file mode 100644 index 2b7b70c..0000000 --- a/putty/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 -#include - -#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); -}