New PollingScheduler class for calculating timeouts for select() and

moments when next polling pass should be started. Current
implementation does not change scheduling algorithm used in previous
versions, so this change is just a code refactoring to prepare for
ongoing improvements.

git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@493 3789f03b-4d11-0410-bbf8-ca57d06f2519

diff --git a/x0vncserver/Makefile.in b/x0vncserver/Makefile.in
index 4227a5187b33748530da573de7643393d7deae6a..f9a2ad76a0367904cead55eb62cb3251cc4f580b 100644 (file)
--- a/x0vncserver/Makefile.in
+++ b/x0vncserver/Makefile.in
@@ -1,6 +1,6 @@
 
 SRCS = Image.cxx CPUMonitor.cxx TimeMillis.cxx PollingManager.cxx \
-       x0vncserver.cxx
+       PollingScheduler.cxx x0vncserver.cxx
 
 OBJS = $(SRCS:.cxx=.o)
 

diff --git a/x0vncserver/PollingScheduler.cxx b/x0vncserver/PollingScheduler.cxx
new file mode 100644 (file)
index 0000000..2d28491
--- /dev/null
+++ b/x0vncserver/PollingScheduler.cxx
@@ -0,0 +1,60 @@
+/* Copyright (C) 2006 Constantin Kaplinsky.  All Rights Reserved.
+ *    
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this software; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+ * USA.
+ */
+
+//
+// PollingScheduler.cxx
+//
+
+#include <x0vncserver/PollingScheduler.h>
+
+PollingScheduler::PollingScheduler(int interval)
+{
+  setInterval(interval);
+  reset();
+}
+
+void PollingScheduler::setInterval(int interval)
+{
+  m_interval = interval;
+}
+
+void PollingScheduler::reset()
+{
+  initialState = true;
+}
+
+void PollingScheduler::newPass()
+{
+  m_passStarted.update();
+  initialState = false;
+}
+
+int PollingScheduler::millisRemaining() const
+{
+  if (initialState)
+    return 0;
+
+  TimeMillis timeNow;
+  int elapsed = timeNow.diffFrom(m_passStarted);
+
+  if (elapsed > m_interval)
+    return 0;
+
+  return (m_interval - elapsed);
+}
+

diff --git a/x0vncserver/PollingScheduler.h b/x0vncserver/PollingScheduler.h
new file mode 100644 (file)
index 0000000..777a665
--- /dev/null
+++ b/x0vncserver/PollingScheduler.h
@@ -0,0 +1,55 @@
+/* Copyright (C) 2006 Constantin Kaplinsky.  All Rights Reserved.
+ *    
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this software; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+ * USA.
+ */
+
+//
+// PollingScheduler.h
+//
+
+#ifndef __POLLINGSCHEDULER_H__
+#define __POLLINGSCHEDULER_H__
+
+#include <x0vncserver/TimeMillis.h>
+
+class PollingScheduler {
+
+public:
+
+  PollingScheduler(int interval);
+
+  // Set desired polling interval.
+  void setInterval(int interval);
+
+  // Reset the object into the initial state (no polling performed).
+  void reset();
+
+  // Tell the scheduler that new polling pass is just being started.
+  void newPass();
+
+  // This function estimates time remaining before new polling pass.
+  int millisRemaining() const;
+
+protected:
+
+  bool initialState;
+  int m_interval;
+  TimeMillis m_passStarted;
+
+};
+
+#endif // __POLLINGSCHEDULER_H__
+

diff --git a/x0vncserver/x0vncserver.cxx b/x0vncserver/x0vncserver.cxx
index af63ad00e0ab82a460489bccb8c7d6ad861f7ee9..27c130a42f3f5b331d6094e05e896d5a76b1f8f3 100644 (file)
--- a/x0vncserver/x0vncserver.cxx
+++ b/x0vncserver/x0vncserver.cxx
@@ -44,7 +44,7 @@
 #include <x0vncserver/Image.h>
 #include <x0vncserver/PollingManager.h>
 #include <x0vncserver/CPUMonitor.h>
-#include <x0vncserver/TimeMillis.h>
+#include <x0vncserver/PollingScheduler.h>
 
 using namespace rfb;
 using namespace network;
@@ -417,8 +417,8 @@ int main(int argc, char** argv)
 
     CPUMonitor cpumon((int)maxProcessorUsage, 1000);
     int dynPollingCycle = (int)pollingCycle;
+    PollingScheduler sched(dynPollingCycle);
 
-    TimeMillis timeSaved, timeNow;
     fd_set rfds;
     struct timeval tv;
 
@@ -437,14 +437,8 @@ int main(int argc, char** argv)
       }
 
       if (clients_connected) {
-        int poll_ms = 20;
-        if (timeNow.update()) {
-          poll_ms = timeNow.diffFrom(timeSaved);
-        }
-        int wait_ms = dynPollingCycle - poll_ms;
-        if (wait_ms < 0) {
-          wait_ms = 0;
-        } else if (wait_ms > 500) {
+        int wait_ms = sched.millisRemaining();
+        if (wait_ms > 500) {
           wait_ms = 500;
         }
         tv.tv_usec = wait_ms * 1000;
@@ -452,7 +446,8 @@ int main(int argc, char** argv)
         fprintf(stderr, "[%d]\t", wait_ms);
 #endif
       } else {
-        tv.tv_usec = 50000;
+        sched.reset();
+        tv.tv_usec = 100000;
       }
       tv.tv_sec = 0;
 
@@ -490,16 +485,10 @@ int main(int argc, char** argv)
 
       server.checkTimeouts();
 
-      if (timeNow.update()) {
-        int diff = timeNow.diffFrom(timeSaved);
-        if (diff >= dynPollingCycle) {
-          adjustPollingCycle(&dynPollingCycle, &cpumon);
-          timeSaved = timeNow;
-          desktop.poll();
-        }
-      } else {
-        // Something strange has happened -- TimeMillis::update() failed.
-        // Poll after each select(), as in the original VNC4 code.
+      if (sched.millisRemaining() <= 0) {
+        adjustPollingCycle(&dynPollingCycle, &cpumon);
+        sched.setInterval(dynPollingCycle);
+        sched.newPass();
         desktop.poll();
       }
     }