newlib-cygwin/winsup/cygwin/timer.cc

607 lines
13 KiB
C++

/* timer.cc: posix timers
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#include "winsup.h"
#include "thread.h"
#include "cygtls.h"
#include "sigproc.h"
#include "path.h"
#include "fhandler.h"
#include "dtable.h"
#include "cygheap.h"
#include "timer.h"
#include <sys/param.h>
#define EVENT_DISARMED 0
#define EVENT_ARMED -1
#define EVENT_LOCK 1
timer_tracker NO_COPY ttstart (CLOCK_REALTIME, NULL);
class lock_timer_tracker
{
static muto protect;
public:
lock_timer_tracker ();
~lock_timer_tracker ();
};
muto NO_COPY lock_timer_tracker::protect;
lock_timer_tracker::lock_timer_tracker ()
{
protect.init ("timer_protect")->acquire ();
}
lock_timer_tracker::~lock_timer_tracker ()
{
protect.release ();
}
bool
timer_tracker::cancel ()
{
if (!hcancel)
return false;
SetEvent (hcancel);
DWORD res = WaitForSingleObject (syncthread, INFINITE);
if (res != WAIT_OBJECT_0)
system_printf ("WFSO returned unexpected value %u, %E", res);
return true;
}
timer_tracker::~timer_tracker ()
{
if (cancel ())
{
CloseHandle (hcancel);
#ifdef DEBUGGING
hcancel = NULL;
#endif
}
if (syncthread)
CloseHandle (syncthread);
magic = 0;
}
timer_tracker::timer_tracker (clockid_t c, const sigevent *e)
{
if (e != NULL)
evp = *e;
else
{
evp.sigev_notify = SIGEV_SIGNAL;
evp.sigev_signo = SIGALRM;
evp.sigev_value.sival_ptr = this;
}
clock_id = c;
magic = TT_MAGIC;
hcancel = NULL;
event_running = EVENT_DISARMED;
overrun_count_curr = 0;
overrun_count = 0;
if (this != &ttstart)
{
lock_timer_tracker here;
next = ttstart.next;
ttstart.next = this;
}
}
static inline int64_t
timespec_to_us (const timespec& ts)
{
int64_t res = ts.tv_sec;
res *= USPERSEC;
res += (ts.tv_nsec + (NSPERSEC/USPERSEC) - 1) / (NSPERSEC/USPERSEC);
return res;
}
/* Returns 0 if arming successful, -1 if a signal is already queued.
If so, it also increments overrun_count. */
LONG
timer_tracker::arm_event ()
{
LONG ret;
while ((ret = InterlockedCompareExchange (&event_running, EVENT_ARMED,
EVENT_DISARMED)) == EVENT_LOCK)
yield ();
if (ret == EVENT_ARMED)
InterlockedIncrement64 (&overrun_count);
return ret;
}
LONG
timer_tracker::disarm_event ()
{
LONG ret;
while ((ret = InterlockedCompareExchange (&event_running, EVENT_LOCK,
EVENT_ARMED)) == EVENT_LOCK)
yield ();
if (ret == EVENT_ARMED)
{
LONG64 ov_cnt;
InterlockedExchange64 (&ov_cnt, overrun_count);
if (ov_cnt > DELAYTIMER_MAX || ov_cnt < 0)
overrun_count_curr = DELAYTIMER_MAX;
else
overrun_count_curr = ov_cnt;
ret = overrun_count_curr;
InterlockedExchange64 (&overrun_count, 0);
InterlockedExchange (&event_running, EVENT_DISARMED);
}
return ret;
}
static void *
notify_thread_wrapper (void *arg)
{
timer_tracker *tt = (timer_tracker *) arg;
sigevent_t *evt = tt->sigevt ();
void * (*notify_func) (void *) = (void * (*) (void *))
evt->sigev_notify_function;
tt->disarm_event ();
return notify_func (evt->sigev_value.sival_ptr);
}
DWORD
timer_tracker::thread_func ()
{
int64_t now;
int64_t cur_sleepto_us = sleepto_us;
while (1)
{
int64_t sleep_us;
LONG sleep_ms;
/* Account for delays in starting thread
and sending the signal */
now = get_clock (clock_id)->usecs ();
sleep_us = cur_sleepto_us - now;
if (sleep_us > 0)
{
sleepto_us = cur_sleepto_us;
sleep_ms = (sleep_us + (USPERSEC / MSPERSEC) - 1)
/ (USPERSEC / MSPERSEC);
}
else
{
int64_t num_intervals = (now - cur_sleepto_us) / interval_us;
InterlockedAdd64 (&overrun_count, num_intervals);
cur_sleepto_us += num_intervals * interval_us;
sleepto_us = cur_sleepto_us;
sleep_ms = 0;
}
debug_printf ("%p waiting for %u ms", this, sleep_ms);
switch (WaitForSingleObject (hcancel, sleep_ms))
{
case WAIT_TIMEOUT:
debug_printf ("timed out");
break;
case WAIT_OBJECT_0:
debug_printf ("%p cancelled", this);
goto out;
default:
debug_printf ("%p wait failed, %E", this);
goto out;
}
switch (evp.sigev_notify)
{
case SIGEV_SIGNAL:
{
if (arm_event ())
{
debug_printf ("%p timer signal already queued", this);
break;
}
siginfo_t si = {0};
si.si_signo = evp.sigev_signo;
si.si_code = SI_TIMER;
si.si_tid = (timer_t) this;
si.si_sigval.sival_ptr = evp.sigev_value.sival_ptr;
debug_printf ("%p sending signal %d", this, evp.sigev_signo);
sig_send (myself_nowait, si);
break;
}
case SIGEV_THREAD:
{
if (arm_event ())
{
debug_printf ("%p timer thread already queued", this);
break;
}
pthread_t notify_thread;
debug_printf ("%p starting thread", this);
pthread_attr_t *attr;
pthread_attr_t default_attr;
if (evp.sigev_notify_attributes)
attr = evp.sigev_notify_attributes;
else
{
pthread_attr_init(attr = &default_attr);
pthread_attr_setdetachstate (attr, PTHREAD_CREATE_DETACHED);
}
int rc = pthread_create (&notify_thread, attr,
notify_thread_wrapper, this);
if (rc)
{
debug_printf ("thread creation failed, %E");
return 0;
}
break;
}
}
if (!interval_us)
break;
cur_sleepto_us = sleepto_us + interval_us;
debug_printf ("looping");
}
out:
_my_tls._ctinfo->auto_release (); /* automatically return the cygthread to the cygthread pool */
return 0;
}
static DWORD WINAPI
timer_thread (VOID *x)
{
timer_tracker *tt = ((timer_tracker *) x);
return tt->thread_func ();
}
static inline bool
timespec_bad (const timespec& t)
{
if (t.tv_nsec < 0 || t.tv_nsec >= NSPERSEC || t.tv_sec < 0)
{
set_errno (EINVAL);
return true;
}
return false;
}
int
timer_tracker::settime (int in_flags, const itimerspec *value, itimerspec *ovalue)
{
int ret = -1;
__try
{
if (!value)
{
set_errno (EINVAL);
__leave;
}
if (timespec_bad (value->it_value) || timespec_bad (value->it_interval))
__leave;
lock_timer_tracker here;
cancel ();
if (ovalue)
gettime (ovalue);
if (!value->it_value.tv_sec && !value->it_value.tv_nsec)
interval_us = sleepto_us = 0;
else
{
interval_us = timespec_to_us (value->it_interval);
if (in_flags & TIMER_ABSTIME)
{
int64_t now = get_clock (clock_id)->usecs ();
sleepto_us = timespec_to_us (value->it_value);
if (sleepto_us <= now)
{
int64_t ov_cnt = (now - sleepto_us + (interval_us + 1))
/ interval_us;
InterlockedAdd64 (&overrun_count, ov_cnt);
sleepto_us += ov_cnt * interval_us;
}
}
else
sleepto_us = get_clock (clock_id)->usecs ()
+ timespec_to_us (value->it_value);
it_interval = value->it_interval;
if (!hcancel)
hcancel = CreateEvent (&sec_none_nih, TRUE, FALSE, NULL);
else
ResetEvent (hcancel);
if (!syncthread)
syncthread = CreateEvent (&sec_none_nih, TRUE, FALSE, NULL);
else
ResetEvent (syncthread);
new cygthread (timer_thread, this, "itimer", syncthread);
}
ret = 0;
}
__except (EFAULT) {}
__endtry
return ret;
}
void
timer_tracker::gettime (itimerspec *ovalue)
{
if (!hcancel)
memset (ovalue, 0, sizeof (*ovalue));
else
{
ovalue->it_interval = it_interval;
int64_t now = get_clock (clock_id)->usecs ();
int64_t left_us = sleepto_us - now;
if (left_us < 0)
left_us = 0;
ovalue->it_value.tv_sec = left_us / USPERSEC;
ovalue->it_value.tv_nsec = (left_us % USPERSEC) * (NSPERSEC/USPERSEC);
}
}
int
timer_tracker::clean_and_unhook ()
{
for (timer_tracker *tt = &ttstart; tt->next != NULL; tt = tt->next)
if (tt->next == this)
{
tt->next = this->next;
return 0;
}
return -1;
}
void
timer_tracker::fixup_after_fork ()
{
ttstart.hcancel = ttstart.syncthread = NULL;
ttstart.event_running = EVENT_DISARMED;
ttstart.overrun_count_curr = 0;
ttstart.overrun_count = 0;
for (timer_tracker *tt = &ttstart; tt->next != NULL; /* nothing */)
{
timer_tracker *deleteme = tt->next;
tt->next = deleteme->next;
deleteme->hcancel = deleteme->syncthread = NULL;
delete deleteme;
}
}
void
fixup_timers_after_fork ()
{
timer_tracker::fixup_after_fork ();
}
extern "C" int
timer_gettime (timer_t timerid, struct itimerspec *ovalue)
{
int ret = -1;
__try
{
timer_tracker *tt = (timer_tracker *) timerid;
if (!tt->is_timer_tracker ())
{
set_errno (EINVAL);
return -1;
}
tt->gettime (ovalue);
ret = 0;
}
__except (EFAULT) {}
__endtry
return ret;
}
extern "C" int
timer_create (clockid_t clock_id, struct sigevent *__restrict evp,
timer_t *__restrict timerid)
{
int ret = -1;
__try
{
if (CLOCKID_IS_PROCESS (clock_id) || CLOCKID_IS_THREAD (clock_id))
{
set_errno (ENOTSUP);
return -1;
}
if (clock_id >= MAX_CLOCKS)
{
set_errno (EINVAL);
return -1;
}
*timerid = (timer_t) new timer_tracker (clock_id, evp);
ret = 0;
}
__except (EFAULT) {}
__endtry
return ret;
}
extern "C" int
timer_settime (timer_t timerid, int flags,
const struct itimerspec *__restrict value,
struct itimerspec *__restrict ovalue)
{
int ret = -1;
__try
{
timer_tracker *tt = (timer_tracker *) timerid;
if (!tt->is_timer_tracker ())
{
set_errno (EINVAL);
__leave;
}
ret = tt->settime (flags, value, ovalue);
}
__except (EFAULT) {}
__endtry
return ret;
}
extern "C" int
timer_getoverrun (timer_t timerid)
{
int ret = -1;
__try
{
timer_tracker *tt = (timer_tracker *) timerid;
if (!tt->is_timer_tracker ())
{
set_errno (EINVAL);
__leave;
}
ret = tt->getoverrun ();
}
__except (EFAULT) {}
__endtry
return ret;
}
extern "C" int
timer_delete (timer_t timerid)
{
int ret = -1;
__try
{
timer_tracker *in_tt = (timer_tracker *) timerid;
if (!in_tt->is_timer_tracker ())
{
set_errno (EINVAL);
__leave;
}
lock_timer_tracker here;
if (in_tt->clean_and_unhook () == 0)
{
delete in_tt;
ret = 0;
}
else
set_errno (EINVAL);
}
__except (EFAULT) {}
__endtry
return ret;
}
extern "C" int
setitimer (int which, const struct itimerval *__restrict value,
struct itimerval *__restrict ovalue)
{
int ret;
if (which != ITIMER_REAL)
{
set_errno (EINVAL);
ret = -1;
}
else
{
struct itimerspec spec_value, spec_ovalue;
spec_value.it_interval.tv_sec = value->it_interval.tv_sec;
spec_value.it_interval.tv_nsec = value->it_interval.tv_usec * 1000;
spec_value.it_value.tv_sec = value->it_value.tv_sec;
spec_value.it_value.tv_nsec = value->it_value.tv_usec * 1000;
ret = timer_settime ((timer_t) &ttstart, 0, &spec_value, &spec_ovalue);
if (ret)
ret = -1;
else if (ovalue)
{
ovalue->it_interval.tv_sec = spec_ovalue.it_interval.tv_sec;
ovalue->it_interval.tv_usec = spec_ovalue.it_interval.tv_nsec / 1000;
ovalue->it_value.tv_sec = spec_ovalue.it_value.tv_sec;
ovalue->it_value.tv_usec = spec_ovalue.it_value.tv_nsec / 1000;
}
}
syscall_printf ("%R = setitimer()", ret);
return ret;
}
extern "C" int
getitimer (int which, struct itimerval *ovalue)
{
int ret = -1;
if (which != ITIMER_REAL)
set_errno (EINVAL);
else
{
__try
{
struct itimerspec spec_ovalue;
ret = timer_gettime ((timer_t) &ttstart, &spec_ovalue);
if (!ret)
{
ovalue->it_interval.tv_sec = spec_ovalue.it_interval.tv_sec;
ovalue->it_interval.tv_usec = spec_ovalue.it_interval.tv_nsec / 1000;
ovalue->it_value.tv_sec = spec_ovalue.it_value.tv_sec;
ovalue->it_value.tv_usec = spec_ovalue.it_value.tv_nsec / 1000;
}
}
__except (EFAULT) {}
__endtry
}
syscall_printf ("%R = getitimer()", ret);
return ret;
}
/* FIXME: POSIX - alarm survives exec */
extern "C" unsigned int
alarm (unsigned int seconds)
{
struct itimerspec newt = {}, oldt;
/* alarm cannot fail, but only needs not be
correct for arguments < 64k. Truncate */
if (seconds > (CLOCK_DELAY_MAX / 1000 - 1))
seconds = (CLOCK_DELAY_MAX / 1000 - 1);
newt.it_value.tv_sec = seconds;
timer_settime ((timer_t) &ttstart, 0, &newt, &oldt);
int ret = oldt.it_value.tv_sec + (oldt.it_value.tv_nsec > 0);
syscall_printf ("%d = alarm(%u)", ret, seconds);
return ret;
}
extern "C" useconds_t
ualarm (useconds_t value, useconds_t interval)
{
struct itimerspec timer = {}, otimer;
/* ualarm cannot fail.
Interpret negative arguments as zero */
if (value > 0)
{
timer.it_value.tv_sec = value / USPERSEC;
timer.it_value.tv_nsec = (value % USPERSEC) * (NSPERSEC/USPERSEC);
}
if (interval > 0)
{
timer.it_interval.tv_sec = interval / USPERSEC;
timer.it_interval.tv_nsec = (interval % USPERSEC) * (NSPERSEC/USPERSEC);
}
timer_settime ((timer_t) &ttstart, 0, &timer, &otimer);
useconds_t ret = otimer.it_value.tv_sec * USPERSEC
+ (otimer.it_value.tv_nsec + (NSPERSEC/USPERSEC) - 1)
/ (NSPERSEC/USPERSEC);
syscall_printf ("%d = ualarm(%ld , %ld)", ret, value, interval);
return ret;
}