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Diffstat (limited to 'package/openwrt/libshared/linux_timer.c')
-rw-r--r--package/openwrt/libshared/linux_timer.c707
1 files changed, 707 insertions, 0 deletions
diff --git a/package/openwrt/libshared/linux_timer.c b/package/openwrt/libshared/linux_timer.c
new file mode 100644
index 0000000000..eece9f84e8
--- /dev/null
+++ b/package/openwrt/libshared/linux_timer.c
@@ -0,0 +1,707 @@
+/*
+ * Copyright 2004, Broadcom Corporation
+ * All Rights Reserved.
+ *
+ * THIS SOFTWARE IS OFFERED "AS IS", AND BROADCOM GRANTS NO WARRANTIES OF ANY
+ * KIND, EXPRESS OR IMPLIED, BY STATUTE, COMMUNICATION OR OTHERWISE. BROADCOM
+ * SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A SPECIFIC PURPOSE OR NONINFRINGEMENT CONCERNING THIS SOFTWARE.
+ *
+ * Low resolution timer interface linux specific implementation.
+ *
+ * $Id$
+ */
+
+/*
+* debug facilities
+*/
+#define TIMER_DEBUG 0
+#if TIMER_DEBUG
+#define TIMERDBG(fmt, args...) printf("%s: " fmt "\n" , __FUNCTION__ , ## args)
+#else
+#define TIMERDBG(fmt, args...)
+#endif
+
+
+/*
+ * POSIX timer support for Linux. Taken from linux_timer.c in upnp
+ */
+
+#define __USE_GNU
+
+
+#include <stdlib.h> // for malloc, free, etc.
+#include <string.h> // for memset, strncasecmp, etc.
+#include <assert.h> // for assert, of course.
+#include <signal.h> // for sigemptyset, etc.
+#include <stdio.h> // for printf, etc.
+#include <sys/time.h>
+#include <time.h>
+
+/* define TIMER_PROFILE to enable code which guages how accurate the timer functions are.
+ For each expiring timer the code will print the expected time interval and the actual time interval.
+#define TIMER_PROFILE
+*/
+#undef TIMER_PROFILE
+
+/*
+timer_cancel( ) - cancel a timer
+timer_connect( ) - connect a user routine to the timer signal
+timer_create( ) - allocate a timer using the specified clock for a timing base (POSIX)
+timer_delete( ) - remove a previously created timer (POSIX)
+timer_gettime( ) - get the remaining time before expiration and the reload value (POSIX)
+timer_getoverrun( ) - return the timer expiration overrun (POSIX)
+timer_settime( ) - set the time until the next expiration and arm timer (POSIX)
+nanosleep( ) - suspend the current task until the time interval elapses (POSIX)
+*/
+
+#define MS_PER_SEC 1000
+#define US_PER_SEC 1000000
+#define US_PER_MS 1000
+#define UCLOCKS_PER_SEC 1000000
+
+typedef void (*event_callback_t)(timer_t, int);
+
+#ifndef TIMESPEC_TO_TIMEVAL
+# define TIMESPEC_TO_TIMEVAL(tv, ts) { \
+ (tv)->tv_sec = (ts)->tv_sec; \
+ (tv)->tv_usec = (ts)->tv_nsec / 1000; \
+}
+#endif
+
+#ifndef TIMEVAL_TO_TIMESPEC
+# define TIMEVAL_TO_TIMESPEC(tv, ts) { \
+ (ts)->tv_sec = (tv)->tv_sec; \
+ (ts)->tv_nsec = (tv)->tv_usec * 1000; \
+}
+#endif
+
+#define ROUNDUP(x,y) ((((x)+(y)-1)/(y))*(y))
+
+#define timerroundup(t,g) \
+ do { \
+ if (!timerisset(t)) (t)->tv_usec=1; \
+ if ((t)->tv_sec == 0) (t)->tv_usec=ROUNDUP((t)->tv_usec, g); \
+ } while (0)
+
+typedef long uclock_t;
+
+#define TFLAG_NONE 0
+#define TFLAG_CANCELLED (1<<0)
+#define TFLAG_DELETED (1<<1)
+
+struct event {
+ struct timeval it_interval;
+ struct timeval it_value;
+ event_callback_t func;
+ int arg;
+ unsigned short flags;
+ struct event *next;
+#ifdef TIMER_PROFILE
+ uint expected_ms;
+ uclock_t start;
+#endif
+};
+
+void timer_cancel(timer_t timerid);
+
+static void alarm_handler(int i);
+static void check_event_queue();
+static void print_event_queue();
+static void check_timer();
+#if THIS_FINDS_USE
+static int count_queue(struct event *);
+#endif
+
+void block_timer();
+void unblock_timer();
+
+static struct event *event_queue = NULL;
+static struct event *event_freelist;
+static uint g_granularity;
+static int g_maxevents = 0;
+
+uclock_t uclock()
+{
+ struct timeval tv;
+
+ gettimeofday(&tv, NULL);
+ return ((tv.tv_sec * US_PER_SEC) + tv.tv_usec);
+}
+
+
+void init_event_queue(int n)
+{
+ int i;
+ struct itimerval tv;
+
+ g_maxevents = n;
+ event_freelist = (struct event *) malloc(n * sizeof(struct event));
+ memset(event_freelist, 0, n * sizeof(struct event));
+
+ for (i = 0; i < (n-1); i++)
+ event_freelist[i].next = &event_freelist[i+1];
+
+ event_freelist[i].next = NULL;
+
+ tv.it_interval.tv_sec = 0;
+ tv.it_interval.tv_usec = 1;
+ tv.it_value.tv_sec = 0;
+ tv.it_value.tv_usec = 0;
+ setitimer (ITIMER_REAL, &tv, 0);
+ setitimer (ITIMER_REAL, 0, &tv);
+ g_granularity = tv.it_interval.tv_usec;
+
+ signal(SIGALRM, alarm_handler);
+}
+
+
+int clock_gettime(
+ clockid_t clock_id, /* clock ID (always CLOCK_REALTIME) */
+ struct timespec * tp /* where to store current time */
+)
+{
+ struct timeval tv;
+ int n;
+
+
+ n = gettimeofday(&tv, NULL);
+ TIMEVAL_TO_TIMESPEC(&tv, tp);
+
+ return n;
+}
+
+
+int timer_create(
+ clockid_t clock_id, /* clock ID (always CLOCK_REALTIME) */
+ struct sigevent * evp, /* user event handler */
+ timer_t * pTimer /* ptr to return value */
+)
+{
+ struct event *event;
+
+ if (clock_id != CLOCK_REALTIME) {
+ TIMERDBG("timer_create can only support clock id CLOCK_REALTIME");
+ exit(1);
+ }
+
+ if (evp != NULL) {
+ if (evp->sigev_notify != SIGEV_SIGNAL || evp->sigev_signo != SIGALRM) {
+ TIMERDBG("timer_create can only support signalled alarms using SIGALRM");
+ exit(1);
+ }
+ }
+
+ event = event_freelist;
+ if (event == NULL) {
+ print_event_queue();
+ }
+ assert(event != NULL);
+
+ event->flags = TFLAG_NONE;
+
+ event_freelist = event->next;
+ event->next = NULL;
+
+ check_event_queue();
+
+ *pTimer = (timer_t) event;
+
+ return 0;
+}
+
+int timer_delete(
+ timer_t timerid /* timer ID */
+)
+{
+ struct event *event = (struct event *) timerid;
+
+ if (event->flags & TFLAG_DELETED) {
+ TIMERDBG("Cannot delete a deleted event");
+ return 1;
+ }
+
+ timer_cancel(timerid);
+
+ event->flags |= TFLAG_DELETED;
+
+ event->next = event_freelist;
+ event_freelist = event;
+
+ return 0;
+}
+
+int timer_connect
+(
+ timer_t timerid, /* timer ID */
+ void (*routine)(timer_t, int), /* user routine */
+ int arg /* user argument */
+)
+{
+ struct event *event = (struct event *) timerid;
+
+ assert(routine != NULL);
+ event->func = routine;
+ event->arg = arg;
+
+ return 0;
+}
+
+
+int timer_settime
+(
+ timer_t timerid, /* timer ID */
+ int flags, /* absolute or relative */
+ const struct itimerspec * value, /* time to be set */
+ struct itimerspec * ovalue /* previous time set (NULL=no result) */
+)
+{
+ struct itimerval itimer;
+ struct event *event = (struct event *) timerid;
+ struct event **ppevent;
+
+ TIMESPEC_TO_TIMEVAL(&event->it_interval, &value->it_interval);
+ TIMESPEC_TO_TIMEVAL(&event->it_value, &value->it_value);
+
+ /* if .it_value is zero, the timer is disarmed */
+ if (!timerisset(&event->it_value)) {
+ timer_cancel(timerid);
+ return 0;
+ }
+
+ block_timer();
+
+#ifdef TIMER_PROFILE
+ event->expected_ms = (event->it_value.tv_sec * MS_PER_SEC) + (event->it_value.tv_usec / US_PER_MS);
+ event->start = uclock();
+#endif
+ if (event->next) {
+ TIMERDBG("calling timer_settime with a timer that is already on the queue.");
+ }
+
+
+ /* We always want to make sure that the event at the head of the
+ queue has a timeout greater than the itimer granularity.
+ Otherwise we end up with the situation that the time remaining
+ on an itimer is greater than the time at the head of the queue
+ in the first place. */
+ timerroundup(&event->it_value, g_granularity);
+
+ timerclear(&itimer.it_value);
+ getitimer(ITIMER_REAL, &itimer);
+ if (timerisset(&itimer.it_value)) {
+ // reset the top timer to have an interval equal to the remaining interval
+ // when the timer was cancelled.
+ if (event_queue) {
+ if (timercmp(&(itimer.it_value), &(event_queue->it_value), >)) {
+ // it is an error if the amount of time remaining is more than the amount of time
+ // requested by the top event.
+ //
+ TIMERDBG("timer_settime: TIMER ERROR!");
+
+ } else {
+ // some portion of the top event has already expired.
+ // Reset the interval of the top event to remaining
+ // time left in that interval.
+ //
+ event_queue->it_value = itimer.it_value;
+
+ // if we were the earliest timer before now, we are still the earliest timer now.
+ // we do not need to reorder the list.
+ }
+ }
+ }
+
+ // Now, march down the list, decrementing the new timer by the
+ // current it_value of each event on the queue.
+ ppevent = &event_queue;
+ while (*ppevent) {
+ if ( timercmp(&(event->it_value), &((*ppevent)->it_value), <) ) {
+ // if the proposed event will trigger sooner than the next event
+ // in the queue, we will insert the new event just before the next one.
+ //
+ // we also need to adjust the delta value to the next event.
+ timersub(&((*ppevent)->it_value), &(event->it_value), &((*ppevent)->it_value));
+ break;
+ }
+ // subtract the interval of the next event from the proposed interval.
+ timersub(&(event->it_value), &((*ppevent)->it_value), &(event->it_value));
+
+ ppevent = &((*ppevent)->next);
+ }
+
+ // we have found our proper place in the queue,
+ // link our new event into the pending event queue.
+ event->next = *ppevent;
+ *ppevent = event;
+
+ check_event_queue();
+
+ // if our new event ended up at the front of the queue, reissue the timer.
+ if (event == event_queue) {
+ timerroundup(&event_queue->it_value, g_granularity);
+ timerclear(&itimer.it_interval);
+ itimer.it_value = event_queue->it_value;
+
+ // we want to be sure to never turn off the timer completely,
+ // so if the next interval is zero, set it to some small value.
+ if (!timerisset(&(itimer.it_value)))
+ itimer.it_value = (struct timeval) { 0, 1 };
+
+ assert(!timerisset(&itimer.it_interval));
+ assert(itimer.it_value.tv_sec > 0 || itimer.it_value.tv_usec >= g_granularity);
+ assert(event_queue->it_value.tv_sec > 0 || event_queue->it_value.tv_usec >= g_granularity);
+ setitimer(ITIMER_REAL, &itimer, NULL);
+ check_timer();
+ }
+
+ event->flags &= ~TFLAG_CANCELLED;
+
+ unblock_timer();
+
+ return 0;
+}
+
+static void check_timer()
+{
+ struct itimerval itimer;
+
+ getitimer(ITIMER_REAL, &itimer);
+ if (timerisset(&itimer.it_interval)) {
+ TIMERDBG("ERROR timer interval is set.");
+ }
+ if (timercmp(&(itimer.it_value), &(event_queue->it_value), >)) {
+ TIMERDBG("ERROR timer expires later than top event.");
+ }
+}
+
+
+static void check_event_queue()
+{
+ struct timeval sum;
+ struct event *event;
+ int i = 0;
+
+#ifdef notdef
+ int nfree = 0;
+ struct event *p;
+ for (p = event_freelist; p; p = p->next)
+ nfree++;
+ printf("%d free events\n", nfree);
+#endif
+
+ timerclear(&sum);
+ for (event = event_queue; event; event = event->next) {
+ if (i > g_maxevents) {
+ TIMERDBG("timer queue looks like it loops back on itself!");
+ print_event_queue();
+ exit(1);
+ }
+ i++;
+ }
+}
+
+#if THIS_FINDS_USE
+/* The original upnp version has this unused function, so I left it in
+ to maintain the resemblance. */
+static int count_queue(struct event *event_queue)
+{
+ struct event *event;
+ int i = 0;
+ for (event = event_queue; event; event = event->next)
+ i++;
+ return i;
+}
+#endif
+
+static void print_event_queue()
+{
+ struct event *event;
+ int i = 0;
+
+ for (event = event_queue; event; event = event->next) {
+ printf("#%d (0x%x)->0x%x: \t%d sec %d usec\t%p\n",
+ i++, (unsigned int) event, (unsigned int) event->next, (int) event->it_value.tv_sec, (int) event->it_value.tv_usec, event->func);
+ if (i > g_maxevents) {
+ printf("...(giving up)\n");
+ break;
+ }
+ }
+}
+
+// The top element of the event queue must have expired.
+// Remove that element, run its function, and reset the timer.
+// if there is no interval, recycle the event structure.
+static void alarm_handler(int i)
+{
+ struct event *event, **ppevent;
+ struct itimerval itimer;
+ struct timeval small_interval = { 0, g_granularity/2 };
+#ifdef TIMER_PROFILE
+ uint junk;
+ uclock_t end;
+ uint actual;
+#endif
+
+ block_timer();
+
+ // Loop through the event queue and remove the first event plus any
+ // subsequent events that will expire very soon thereafter (within 'small_interval'}.
+ //
+ do {
+ // remove the top event.
+ event = event_queue;
+ event_queue = event_queue->next;
+ event->next = NULL;
+
+#ifdef TIMER_PROFILE
+ end = uclock();
+ actual = ((end-event->start)/((uclock_t)UCLOCKS_PER_SEC/1000));
+ if (actual < 0)
+ junk = end;
+ TIMERDBG("expected %d ms actual %d ms", event->expected_ms, ((end-event->start)/((uclock_t)UCLOCKS_PER_SEC/1000)));
+#endif
+
+ // call the event callback function
+ (*(event->func))((timer_t) event, (int)event->arg);
+
+ /* If the event has been cancelled, do NOT put it back on the queue. */
+ if ( !(event->flags & TFLAG_CANCELLED) ) {
+
+ // if the event is a recurring event, reset the timer and
+ // find its correct place in the sorted list of events.
+ //
+ if (timerisset(&event->it_interval)) {
+ // event is recurring...
+ //
+ event->it_value = event->it_interval;
+#ifdef TIMER_PROFILE
+ event->expected_ms = (event->it_value.tv_sec * MS_PER_SEC) + (event->it_value.tv_usec / US_PER_MS);
+ event->start = uclock();
+#endif
+ timerroundup(&event->it_value, g_granularity);
+
+ // Now, march down the list, decrementing the new timer by the
+ // current delta of each event on the queue.
+ ppevent = &event_queue;
+ while (*ppevent) {
+ if ( timercmp(&(event->it_value), &((*ppevent)->it_value), <) ) {
+ // if the proposed event will trigger sooner than the next event
+ // in the queue, we will insert the new event just before the next one.
+ //
+ // we also need to adjust the delta value to the next event.
+ timersub(&((*ppevent)->it_value), &(event->it_value), &((*ppevent)->it_value));
+ break;
+ }
+ timersub(&(event->it_value), &((*ppevent)->it_value), &(event->it_value));
+ ppevent = &((*ppevent)->next);
+ }
+
+ // we have found our proper place in the queue,
+ // link our new event into the pending event queue.
+ event->next = *ppevent;
+ *ppevent = event;
+ } else {
+ // there is no interval, so recycle the event structure.
+ //timer_delete((timer_t) event);
+ }
+ }
+
+ check_event_queue();
+
+ } while (event_queue && timercmp(&event_queue->it_value, &small_interval, <));
+
+ // re-issue the timer...
+ if (event_queue) {
+ timerroundup(&event_queue->it_value, g_granularity);
+
+ timerclear(&itimer.it_interval);
+ itimer.it_value = event_queue->it_value;
+ // we want to be sure to never turn off the timer completely,
+ // so if the next interval is zero, set it to some small value.
+ if (!timerisset(&(itimer.it_value)))
+ itimer.it_value = (struct timeval) { 0, 1 };
+
+ setitimer(ITIMER_REAL, &itimer, NULL);
+ check_timer();
+ } else {
+ TIMERDBG("There are no events in the queue - timer not reset.");
+ }
+
+ unblock_timer();
+}
+
+static int block_count = 0;
+
+void block_timer()
+{
+ sigset_t set;
+
+ if (block_count++ == 0) {
+ sigemptyset(&set);
+ sigaddset(&set, SIGALRM);
+ sigprocmask(SIG_BLOCK, &set, NULL);
+ }
+}
+
+void unblock_timer()
+{
+ sigset_t set;
+
+ if (--block_count == 0) {
+ sigemptyset(&set);
+ sigaddset(&set, SIGALRM);
+ sigprocmask(SIG_UNBLOCK, &set, NULL);
+ }
+}
+
+void timer_cancel_all()
+{
+ struct itimerval timeroff = { { 0, 0 }, { 0, 0} };
+ struct event *event;
+ struct event **ppevent;
+
+ setitimer(ITIMER_REAL, &timeroff, NULL);
+
+ ppevent = &event_queue;
+ while (*ppevent) {
+ event = *ppevent;
+ *ppevent = event->next;
+ event->next = NULL;
+ }
+}
+
+
+
+void timer_cancel(timer_t timerid)
+{
+ struct itimerval itimer;
+ struct itimerval timeroff = { { 0, 0 }, { 0, 0} };
+ struct event *event = (struct event *) timerid;
+ struct event **ppevent;
+
+ if (event->flags & TFLAG_CANCELLED) {
+ TIMERDBG("Cannot cancel a cancelled event");
+ return;
+ }
+
+ block_timer();
+
+ ppevent = &event_queue;
+ while (*ppevent) {
+ if ( *ppevent == event ) {
+
+ /* RACE CONDITION - if the alarm goes off while we are in
+ this loop, and if the timer we want to cancel is the
+ next to expire, the alarm will end up firing
+ after this routine is complete, causing it to go off early. */
+
+ /* If the cancelled timer is the next to expire,
+ we need to do something special to clean up correctly. */
+ if (event == event_queue && event->next != NULL) {
+ timerclear(&itimer.it_value);
+ getitimer(ITIMER_REAL, &itimer);
+
+ /* subtract the time that has already passed while waiting for this timer... */
+ timersub(&(event->it_value), &(itimer.it_value), &(event->it_value));
+
+ /* and add any remainder to the next timer in the list */
+ timeradd(&(event->next->it_value), &(event->it_value), &(event->next->it_value));
+ }
+
+ *ppevent = event->next;
+ event->next = NULL;
+
+ if (event_queue) {
+ timerroundup(&event_queue->it_value, g_granularity);
+ timerclear(&itimer.it_interval);
+ itimer.it_value = event_queue->it_value;
+
+ /* We want to be sure to never turn off the timer
+ completely if there are more events on the queue,
+ so if the next interval is zero, set it to some
+ small value. */
+
+ if (!timerisset(&(itimer.it_value)))
+ itimer.it_value = (struct timeval) { 0, 1 };
+
+ assert(itimer.it_value.tv_sec > 0 || itimer.it_value.tv_usec >= g_granularity);
+ assert(event_queue->it_value.tv_sec > 0 || event_queue->it_value.tv_usec >= g_granularity);
+ setitimer(ITIMER_REAL, &itimer, NULL);
+ check_timer();
+ } else {
+ setitimer(ITIMER_REAL, &timeroff, NULL);
+ }
+ break;
+ }
+ ppevent = &((*ppevent)->next);
+ }
+
+ event->flags |= TFLAG_CANCELLED;
+
+ unblock_timer();
+}
+
+/*
+* timer related headers
+*/
+#include "bcmtimer.h"
+
+/*
+* locally used global variables and constants
+*/
+
+/*
+* Initialize internal resources used in the timer module. It must be called
+* before any other timer function calls. The param 'timer_entries' is used
+* to pre-allocate fixed number of timer entries.
+*/
+int bcm_timer_module_init(int timer_entries, bcm_timer_module_id *module_id)
+{
+ init_event_queue(timer_entries);
+ *module_id = (bcm_timer_module_id)event_freelist;
+ return 0;
+}
+
+/*
+* Cleanup internal resources used by this timer module. It deletes all
+* pending timer entries from the backend timer system as well.
+*/
+int bcm_timer_module_cleanup(bcm_timer_module_id module_id)
+{
+ module_id = 0;
+ return 0;
+}
+
+int bcm_timer_create(bcm_timer_module_id module_id, bcm_timer_id *timer_id)
+{
+ module_id = 0;
+ return timer_create(CLOCK_REALTIME, NULL, (timer_t *)timer_id);
+}
+
+int bcm_timer_delete(bcm_timer_id timer_id)
+{
+ return timer_delete((timer_t)timer_id);
+}
+
+int bcm_timer_gettime(bcm_timer_id timer_id, struct itimerspec *timer_spec)
+{
+ return -1;
+}
+
+int bcm_timer_settime(bcm_timer_id timer_id, const struct itimerspec *timer_spec)
+{
+ return timer_settime((timer_t)timer_id, 0, timer_spec, NULL);
+}
+
+int bcm_timer_connect(bcm_timer_id timer_id, bcm_timer_cb func, int data)
+{
+ return timer_connect((timer_t)timer_id, (void *)func, data);
+}
+
+int bcm_timer_cancel(bcm_timer_id timer_id)
+{
+ timer_cancel((timer_t)timer_id);
+ return 0;
+}
+
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