// $Id$
//
-// Copyright (C) 2006
+// Copyright (C) 2006
// Fraunhofer Institut fuer offene Kommunikationssysteme (FOKUS)
// Kompetenzzentrum fuer Satelitenkommunikation (SatCom)
// Stefan Bund <stefan.bund@fokus.fraunhofer.de>
// Free Software Foundation, Inc.,
// 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
-// TODO: Implement signal handling
+/** \file
+ \brief Scheduler non-inline non-template implementation
+
+ \idea Implement signal handling (See source for more discussion
+ about this)
+
+ \idea Multithreading support: To support multithreading, the
+ static member Scheduler::instance() must return a thread-local
+ value (that is Scheduler::instance() must allocate one Scheduler
+ instance per thread). Another possibility would be to distribute
+ the async load unto several threads (one scheduler for multiple
+ threads)
+ */
+
// Here a basic concept of how to add signal support to the scheduler:
//
// Every signal to be reported by the scheduler will be asigned a
// // call epoll
// // block all relevant signals again
// }
-//
+//
// // now handle the event
//
// The signal handler is then simply defined as
// You should use sigaction to register the signal handlers and define
// a sa_mask so all Scheduler-registered signals are automatically
// *blocked* whenever one of the signals is called (including the
-// called signal!). This ensures, that no two signals can be delivered
-// on top of each other. And of course any signal registered with the
-// scheduler must be blocked as soon as it is registered with the
-// scheduler.
-
-// TODO: Multithreading support
-// To support multithreading, the static member Scheduler::instance()
-// must return a thread-local value (that is Scheduler::instance()
-// must allocate one Scheduler instance per thread)
-
-// Definition of non-inline non-template functions
+// called signal!) (This also means, we will have to re-register all
+// signals if we change the registration of some signal since the
+// sa_mask changes). This ensures, that no two signals can be
+// delivered on top of each other. And of course any signal registered
+// with the scheduler must be blocked as soon as it is registered with
+// the scheduler.
#include "Scheduler.hh"
//#include "Scheduler.ih"
// Custom includes
#include <errno.h>
#include <sys/epoll.h>
-#include "Utils/Exception.hh"
+#include "../Utils/Exception.hh"
static const int EPollInitialSize = 16;
#define prefix_
///////////////////////////////cc.p////////////////////////////////////////
-prefix_ satcom::lib::Scheduler::Scheduler & satcom::lib::Scheduler::instance()
-{
- static Scheduler instance;
- return instance;
-}
-
-prefix_ satcom::lib::Scheduler::Scheduler()
- : epollFd_(epoll_create(EPollInitialSize))
+prefix_ senf::Scheduler::Scheduler()
+ : timerIdCounter_(0), epollFd_ (epoll_create(EPollInitialSize)), terminate_(false),
+ eventTime_(0)
{
if (epollFd_<0)
throw SystemException(errno);
}
-prefix_ void satcom::lib::Scheduler::add(int fd, Callback const & cb, EventId eventMask)
+prefix_ void senf::Scheduler::do_add(int fd, SimpleCallback const & cb, int eventMask)
{
FdTable::iterator i (fdTable_.find(fd));
int action (EPOLL_CTL_MOD);
if (eventMask & EV_READ) i->second.cb_read = cb;
if (eventMask & EV_PRIO) i->second.cb_prio = cb;
if (eventMask & EV_WRITE) i->second.cb_write = cb;
- if (eventMask & EV_HUP) i->second.cb_hup = cb;
- if (eventMask & EV_ERR) i->second.cb_err = cb;
epoll_event ev;
memset(&ev,0,sizeof(ev));
ev.events = i->second.epollMask();
ev.data.fd = fd;
-
+
if (epoll_ctl(epollFd_, action, fd, &ev)<0)
throw SystemException(errno);
}
-prefix_ void satcom::lib::Scheduler::remove(int fd, EventId eventMask)
+prefix_ void senf::Scheduler::do_remove(int fd, int eventMask)
{
FdTable::iterator i (fdTable_.find(fd));
- if (i == fdTable_.end())
+ if (i == fdTable_.end())
return;
if (eventMask & EV_READ) i->second.cb_read = 0;
if (eventMask & EV_PRIO) i->second.cb_prio = 0;
if (eventMask & EV_WRITE) i->second.cb_write = 0;
- if (eventMask & EV_HUP) i->second.cb_hup = 0;
- if (eventMask & EV_ERR) i->second.cb_err = 0;
epoll_event ev;
memset(&ev,0,sizeof(ev));
throw SystemException(errno);
}
-prefix_ int satcom::lib::Scheduler::EventSpec::epollMask()
+
+prefix_ int senf::Scheduler::EventSpec::epollMask()
const
{
int mask (0);
if (cb_read) mask |= EPOLLIN;
if (cb_prio) mask |= EPOLLPRI;
if (cb_write) mask |= EPOLLOUT;
- if (cb_hup) mask |= EPOLLHUP;
- if (cb_err) mask |= EPOLLERR;
return mask;
}
-prefix_ void satcom::lib::Scheduler::process()
+prefix_ void senf::Scheduler::process()
{
terminate_ = false;
+ eventTime_ = ClockService::now();
while (! terminate_) {
+
+ // Since a callback may have disabled further timers, we need to check for canceled timeouts
+ // again.
+
+ while (! timerQueue_.empty()) {
+ TimerMap::iterator i (timerQueue_.top());
+ if (! i->second.canceled)
+ break;
+ timerMap_.erase(i);
+ timerQueue_.pop();
+ }
+
+ int timeout (-1);
+ if (timerQueue_.empty()) {
+ if (fdTable_.empty())
+ break;
+ }
+ else {
+ ClockService::clock_type delta (
+ (timerQueue_.top()->second.timeout - eventTime_)/1000000UL);
+ timeout = delta < 0 ? 0 : delta;
+ }
+
+ ///\todo Handle more than one epoll_event per call
struct epoll_event ev;
- int events = epoll_wait(epollFd_, &ev, 1, 1000);
+ int events = epoll_wait(epollFd_, &ev, 1, timeout);
if (events<0)
- // Hmm ... man epoll says, it will NOT return with EINTR ??
- throw SystemException(errno);
- if (events==0)
+ if (errno != EINTR)
+ throw SystemException(errno);
+
+ eventTime_ = ClockService::now();
+
+ // We always run event handlers. This is important, even if a file-descriptor is signaled
+ // since some descriptors (e.g. real files) will *always* be ready and we still may want to
+ // handle timers.
+ // Time handlers are run before file events to not delay them unnecessarily.
+
+ while (! timerQueue_.empty()) {
+ TimerMap::iterator i (timerQueue_.top());
+ if (i->second.canceled)
+ ;
+ else if (i->second.timeout <= eventTime_)
+ i->second.cb();
+ else
+ break;
+ timerQueue_.pop();
+ timerMap_.erase(i);
+ }
+
+ if (events <= 0)
continue;
-
+
FdTable::iterator i = fdTable_.find(ev.data.fd);
BOOST_ASSERT (i != fdTable_.end() );
- EventSpec const & spec (i->second);
+ EventSpec spec (i->second);
+
+ unsigned extraFlags (0);
+ if (ev.events & EPOLLHUP) extraFlags |= EV_HUP;
+ if (ev.events & EPOLLERR) extraFlags |= EV_ERR;
if (ev.events & EPOLLIN) {
- BOOST_ASSERT(spec.cb_read);
- spec.cb_read(ev.data.fd, EV_READ);
+ BOOST_ASSERT(spec.cb_read);
+ spec.cb_read(EventId(EV_READ | extraFlags));
}
else if (ev.events & EPOLLPRI) {
BOOST_ASSERT(spec.cb_prio);
- spec.cb_prio (ev.data.fd, EV_PRIO);
+ spec.cb_prio(EventId(EV_PRIO | extraFlags));
}
else if (ev.events & EPOLLOUT) {
BOOST_ASSERT(spec.cb_write);
- spec.cb_write(ev.data.fd, EV_WRITE);
- }
-
- else if (ev.events & EPOLLHUP) {
- BOOST_ASSERT(spec.cb_hup);
- spec.cb_hup(ev.data.fd, EV_HUP);
+ spec.cb_write(EventId(EV_WRITE | extraFlags));
}
- else if (ev.events & EPOLLERR) {
- BOOST_ASSERT(spec.cb_err);
- spec.cb_err(ev.data.fd, EV_ERR);
+ else {
+ // This branch is only taken, if HUP or ERR is signaled but none of IN/OUT/PRI.
+ // In this case we will signal all registered callbacks. The callbacks must be
+ // prepared to be called multiple times if they are registered to more than
+ // one event.
+ if (spec.cb_write)
+ spec.cb_write(EventId(extraFlags));
+ if (spec.cb_prio)
+ spec.cb_prio(EventId(extraFlags));
+ if (spec.cb_read)
+ spec.cb_read(EventId(extraFlags));
}
}
}
\f
// Local Variables:
// mode: c++
-// c-file-style: "satcom"
+// fill-column: 100
+// c-file-style: "senf"
+// indent-tabs-mode: nil
+// ispell-local-dictionary: "american"
+// compile-command: "scons -u test"
+// comment-column: 40
// End: