Utils/Logger: Implement TimeSource facility
[senf.git] / Scheduler / Scheduler.cc
index f692402..adbb6a6 100644 (file)
 // Custom includes
 #include <errno.h>
 #include <sys/epoll.h>
-#include "Utils/Exception.hh"
-#include "Utils/MicroTime.hh"
+#include "../Utils/Exception.hh"
 
 static const int EPollInitialSize = 16;
 
 #define prefix_
 ///////////////////////////////cc.p////////////////////////////////////////
 
-prefix_ senf::Scheduler::Scheduler & senf::Scheduler::instance()
-{
-    static Scheduler instance;
-    return instance;
-}
-
-prefix_ void senf::Scheduler::timeout(unsigned long timeout, TimerCallback const & cb)
-{
-    timerQueue_.push(TimerSpec(now()+1000*timeout,cb));
-}
-
 prefix_ senf::Scheduler::Scheduler()
-    : epollFd_(epoll_create(EPollInitialSize))
+    : timerIdCounter_(0), epollFd_ (epoll_create(EPollInitialSize)), terminate_(false),
+      eventTime_(0)
 {
     if (epollFd_<0)
         throw SystemException(errno);
@@ -116,8 +105,6 @@ prefix_ void senf::Scheduler::do_add(int fd, SimpleCallback const & cb, int even
     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));
@@ -137,8 +124,6 @@ prefix_ void senf::Scheduler::do_remove(int fd, int eventMask)
     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));
@@ -163,75 +148,110 @@ prefix_ int senf::Scheduler::EventSpec::epollMask()
     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 senf::Scheduler::process()
 {
     terminate_ = false;
+    eventTime_ = ClockService::now();
     while (! terminate_) {
 
-        MicroTime timeNow = now();
-        while ( ! timerQueue_.empty() && timerQueue_.top().timeout <= timeNow ) {
-            timerQueue_.top().cb();
+        // 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();
         }
-        if (terminate_)
-            return;
-        int timeout = timerQueue_.empty() ? -1 : int((timerQueue_.top().timeout - timeNow)/1000);
 
+        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, timeout);
         if (events<0)
-            // Hmm ... man epoll says, it will NOT return with EINTR ??
-            throw SystemException(errno);
-        if (events==0)
-            // Timeout .. it will be run when reachiung the top of the loop
+            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_READ);
+            spec.cb_read(EventId(EV_READ | extraFlags));
         }
         else if (ev.events & EPOLLPRI) {
             BOOST_ASSERT(spec.cb_prio);
-            spec.cb_prio(EV_PRIO);
+            spec.cb_prio(EventId(EV_PRIO | extraFlags));
         }
         else if (ev.events & EPOLLOUT) {
             BOOST_ASSERT(spec.cb_write);
-            spec.cb_write(EV_WRITE);
-        }
-
-        else if (ev.events & EPOLLHUP) {
-            if (spec.cb_hup)
-                spec.cb_hup(EV_HUP);
-            else if (ev.events & EPOLLERR) {
-                /** \fixme This is stupid, if cb_write and cb_read are
-                    the same. The same below. We really have to
-                    exactly define sane semantics of what to do on
-                    EPOLLHUP and EPOLLERR. */
-                if (spec.cb_write) spec.cb_write(EV_HUP);
-                if (spec.cb_read) spec.cb_read(EV_HUP);
-            }
+            spec.cb_write(EventId(EV_WRITE | extraFlags));
         }
-        else if (ev.events & EPOLLERR && ! ev.events & EPOLLHUP) {
-            if (spec.cb_err)
-                spec.cb_err(EV_ERR);
-            else {
-                if (spec.cb_write) spec.cb_write(EV_ERR);
-                if (spec.cb_read) spec.cb_read(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));
         }
-
     }
 }
 
+///////////////////////////////////////////////////////////////////////////
+// senf::SchedulerLogTimeSource
+
+prefix_ boost::posix_time::ptime senf::SchedulerLogTimeSource::operator()()
+    const
+{
+    return ClockService::abstime(Scheduler::instance().eventTime());
+}
+
 ///////////////////////////////cc.e////////////////////////////////////////
 #undef prefix_
 
@@ -242,4 +262,6 @@ prefix_ void senf::Scheduler::process()
 // c-file-style: "senf"
 // indent-tabs-mode: nil
 // ispell-local-dictionary: "american"
+// compile-command: "scons -u test"
+// comment-column: 40
 // End: