Scheduler: Restructure signal blocking/unblocking
[senf.git] / Scheduler / FIFORunner.cc
index 7fbd9df..545b4ae 100644 (file)
@@ -36,8 +36,9 @@
 #define prefix_
 ///////////////////////////////cc.p////////////////////////////////////////
 
-prefix_ senf::scheduler::FIFORunner::FIFORunner()
-    : tasks_ (), next_ (tasks_.end()), watchdogMs_ (1000), watchdogCount_(0), hangCount_ (0)
+prefix_ senf::scheduler::detail::FIFORunner::FIFORunner()
+    : tasks_ (), next_ (tasks_.end()), watchdogRunning_ (false), watchdogMs_ (1000), 
+      watchdogCount_(0), hangCount_ (0)
 {
     struct sigevent ev;
     ::memset(&ev, 0, sizeof(ev));
@@ -59,14 +60,44 @@ prefix_ senf::scheduler::FIFORunner::FIFORunner()
     sigaddset(&mask, SIGURG);
     if (sigprocmask(SIG_UNBLOCK, &mask, 0) < 0)
         SENF_THROW_SYSTEM_EXCEPTION("sigprocmask()");
+
+    tasks_.push_back(highPriorityEnd_);
+    tasks_.push_back(normalPriorityEnd_);
 }
 
-prefix_ senf::scheduler::FIFORunner::~FIFORunner()
+prefix_ senf::scheduler::detail::FIFORunner::~FIFORunner()
 {
     timer_delete(watchdogId_);
     signal(SIGURG, SIG_DFL);
 }
 
+prefix_ void senf::scheduler::detail::FIFORunner::startWatchdog()
+{
+    struct itimerspec timer;
+    ::memset(&timer, 0, sizeof(timer));
+
+    timer.it_interval.tv_sec = watchdogMs_ / 1000;
+    timer.it_interval.tv_nsec = (watchdogMs_ % 1000) * 1000000ul;
+    timer.it_value.tv_sec = timer.it_interval.tv_sec;
+    timer.it_value.tv_nsec = timer.it_interval.tv_nsec;
+
+    if (timer_settime(watchdogId_, 0, &timer, 0) < 0)
+        SENF_THROW_SYSTEM_EXCEPTION("timer_settime()");
+
+    watchdogRunning_ = true;
+}
+
+prefix_ void senf::scheduler::detail::FIFORunner::stopWatchdog()
+{
+    struct itimerspec timer;
+    ::memset(&timer, 0, sizeof(timer));
+
+    if (timer_settime(watchdogId_, 0, &timer, 0) < 0)
+        SENF_THROW_SYSTEM_EXCEPTION("timer_settime()");
+
+    watchdogRunning_ = false;
+}
+
 // At the moment, the FIFORunner is not very efficient with many non-runnable tasks since the
 // complete list of tasks is traversed on each run().
 //
@@ -89,7 +120,7 @@ prefix_ senf::scheduler::FIFORunner::~FIFORunner()
 // will mostly be localized to the end of the queue. only occasionally one of the dormant tasks will
 // be runnable. This additional traversal time will be amortized over a larger time.
 
-prefix_ void senf::scheduler::FIFORunner::dequeue(TaskInfo * task)
+prefix_ void senf::scheduler::detail::FIFORunner::dequeue(TaskInfo * task)
 {
     TaskList::iterator i (TaskList::current(*task));
     if (next_ == i)
@@ -97,48 +128,54 @@ prefix_ void senf::scheduler::FIFORunner::dequeue(TaskInfo * task)
     tasks_.erase(i);
 }
 
-namespace {
-    struct NullTask 
-        : public senf::scheduler::FIFORunner::TaskInfo
-    {
-        void run() {};
-    };
+prefix_ void senf::scheduler::detail::FIFORunner::run()
+{
+    TaskList::iterator f (tasks_.begin());
+    TaskList::iterator l (TaskList::current(highPriorityEnd_));
+    run(f, l);
+
+    f = l; ++f;
+    l = TaskList::current(normalPriorityEnd_);
+    run(f, l);
+        
+    f = l; ++f;
+    l = tasks_.end();
+    run(f, l);
 }
 
-prefix_ void senf::scheduler::FIFORunner::run()
+
+prefix_ void senf::scheduler::detail::FIFORunner::run(TaskList::iterator f, TaskList::iterator l)
 {
+    if (f == l)
+        // We'll have problems inserting NullTask between f and l below, so just explicitly bail out
+        return;
+
     // This algorithm is carefully adjusted to make it work even when arbitrary tasks are removed
     // from the queue
     // - Before we begin, we add a NullTask to the queue. The only purpose of this node is, to mark
     //   the current end of the queue. The iterator to this node becomes the end iterator of the
     //   range to process
-    // - We update the TaskInfo and move it to the end of the queue before calling the callback so
+    // - We update the TaskInfo and move it to the next queue Element before calling the callback so
     //   we don't access the TaskInfo if it is removed while the callback is running
     // - We keep the next to-be-processed node in a class variable which is checked and updated
     //   whenever a node is removed.
+
     NullTask null;
-    struct itimerspec timer;
-    timer.it_interval.tv_sec = watchdogMs_ / 1000;
-    timer.it_interval.tv_nsec = (watchdogMs_ % 1000) * 1000000ul;
-    timer.it_value.tv_sec = timer.it_interval.tv_sec;
-    timer.it_value.tv_nsec = timer.it_interval.tv_nsec;
-    tasks_.push_back(null);
+    tasks_.insert(l, null);
     TaskList::iterator end (TaskList::current(null));
-    next_ = tasks_.begin();
+    next_ = f;
     try {
-        if (timer_settime(watchdogId_, 0, &timer, 0) < 0)
-            SENF_THROW_SYSTEM_EXCEPTION("timer_settime()");
         while (next_ != end) {
             TaskInfo & task (*next_);
-            if (task.runnable) {
-                task.runnable = false;
-                runningName_ = task.name;
+            if (task.runnable_) {
+                task.runnable_ = false;
+                runningName_ = task.name();
 #           ifdef SENF_DEBUG
-                runningBacktrace_ = task.backtrace;
+                runningBacktrace_ = task.backtrace_;
 #           endif
                 TaskList::iterator i (next_);
                 ++ next_;
-                tasks_.splice(tasks_.end(), tasks_, i);
+                tasks_.splice(l, tasks_, i);
                 watchdogCount_ = 1;
                 task.run();
             }
@@ -148,27 +185,28 @@ prefix_ void senf::scheduler::FIFORunner::run()
     }
     catch (...) {
         watchdogCount_ = 0;
-        timer.it_interval.tv_sec = 0;
-        timer.it_interval.tv_nsec = 0;
-        timer.it_value.tv_sec = 0;
-        timer.it_value.tv_nsec = 0;
-        timer_settime(watchdogId_, 0, &timer, 0);
-        tasks_.erase(end);
-        next_ = tasks_.end();
+        next_ = l;
         throw;
     }
     watchdogCount_ = 0;
-    timer.it_interval.tv_sec = 0;
-    timer.it_interval.tv_nsec = 0;
-    timer.it_value.tv_sec = 0;
-    timer.it_value.tv_nsec = 0;
-    if (timer_settime(watchdogId_, 0, &timer, 0) < 0)
-        SENF_THROW_SYSTEM_EXCEPTION("timer_settime()");
-    tasks_.erase(end);
-    next_ = tasks_.end();
+    next_ = l;
+}
+
+prefix_ senf::scheduler::detail::FIFORunner::TaskList::iterator
+senf::scheduler::detail::FIFORunner::priorityEnd(TaskInfo::Priority p)
+{
+    switch (p) {
+    case senf::scheduler::detail::FIFORunner::TaskInfo::PRIORITY_LOW : 
+        return tasks_.end();
+    case senf::scheduler::detail::FIFORunner::TaskInfo::PRIORITY_NORMAL : 
+        return TaskList::current(normalPriorityEnd_);
+    case senf::scheduler::detail::FIFORunner::TaskInfo::PRIORITY_HIGH : 
+        return TaskList::current(highPriorityEnd_);
+    }
+    return tasks_.begin();
 }
 
-prefix_ void senf::scheduler::FIFORunner::watchdog(int, siginfo_t * si, void *)
+prefix_ void senf::scheduler::detail::FIFORunner::watchdog(int, siginfo_t * si, void *)
 {
     FIFORunner & runner (*static_cast<FIFORunner *>(si->si_value.sival_ptr));
     if (runner.watchdogCount_ > 0) {