From e7e9a66629ada359ad6a35cdb12e0e35b49e889c Mon Sep 17 00:00:00 2001 From: marha Date: Fri, 7 Aug 2009 12:33:59 +0000 Subject: Added plink tool (version without console, except if output is generated) Added possibility to build console application or windows application in makefile.after --- tools/plink/timing.c | 243 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 243 insertions(+) create mode 100644 tools/plink/timing.c (limited to 'tools/plink/timing.c') diff --git a/tools/plink/timing.c b/tools/plink/timing.c new file mode 100644 index 000000000..2b7b70cb9 --- /dev/null +++ b/tools/plink/timing.c @@ -0,0 +1,243 @@ +/* + * 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); +} -- cgit v1.2.3