Ticket #2782: dynamic_jobqueue-0.21.patch

libs/libmythtv/jobqueue.cpp

@@ -167 +167 @@
     int sleepTime;
 
     QMap<QString, int> jobStatus;
-    int maxJobs;
     QString message;
     QMap<int, JobQueueEntry> jobs;
     bool atMax = false;
@@ -180 +179 @@
 
         startedJobAlready = false;
         sleepTime = gContext->GetNumSetting("JobQueueCheckFrequency", 30);
-        maxJobs = gContext->GetNumSetting("JobQueueMaxSimultaneousJobs", 3);
-        VERBOSE(VB_JOBQUEUE, LOC +
-                QString("Currently set to run up to %1 job(s) max.")
-                        .arg(maxJobs));
 
         jobStatus.clear();
 
@@ -205 +200 @@
                 jobsRunning++;
             }
 
+            int totalTime, idleTime;
             message = QString("Currently Running %1 jobs.")
                               .arg(jobsRunning);
             if (!inTimeWindow)
@@ -214 +210 @@
                                    "started.");
                 VERBOSE(VB_JOBQUEUE, LOC + message);
             }
-            else if (jobsRunning >= maxJobs)
+            else if (jobsRunning > 0 && getCPUStats(totalTime, idleTime) && 
+                    (idleTime * 100 / totalTime) < 25)
             {
-                message += " (At Maximum, no new jobs can be started until "
-                           "a running job completes)";
-
-                if (!atMax)
-                    VERBOSE(VB_JOBQUEUE, LOC + message);
-
+                // don't permit more than one job if there's no free CPU
+                message += QString(" CPU near full capacity (%1% idle), "
+                                   "will not start more jobs")
+                                   .arg(idleTime * 100 / totalTime);
+                VERBOSE(VB_JOBQUEUE, LOC + message);
                 atMax = true;
             }
             else
@@ -232 +228 @@
 
 
             for (unsigned int x = 0;
-                 (x < jobs.size()) && (jobsRunning < maxJobs); x++)
+                 x < jobs.size(); x++)
             {
                 id = jobs[x].id;
                 chanid = jobs[x].chanid;
@@ -418 +414 @@
                 }
 
                 // never start or claim more than one job in a single run
-                if (startedJobAlready)
+                if (startedJobAlready || atMax)
                     continue;
 
                 if ((inTimeWindow) &&
@@ -457 +453 @@
             }
         }
 
-        if (startedJobAlready)
-            sleep(5);
-        else
-            sleep(sleepTime);
+        sleep(sleepTime);
     }
 }
 

libs/libmyth/util.cpp

@@ -955 +955 @@
     return approx_size;
 #endif
 }
+
+bool getCPUStats(int &totalTime, int &idleTime)
+{
+#ifdef __linux__
+        bool found = false;
+    char line[256];
+        FILE *stat = fopen("/proc/stat", "r");
+        if (stat)
+        {
+        while ( (found = fgets(line, sizeof line, stat)) && strncmp(line, "cpu ", 4) )
+                ;
+
+        fclose(stat);
+        }
+        
+    if (found)
+        {
+            char what[32];
+            unsigned long user_time, nice_time, system_time, idle_time, wait_time = 0;
+            sscanf(line, "%s %lu %lu %lu %lu %lu", what, &user_time, &nice_time,
+                &system_time, &idle_time, &wait_time);
+
+        unsigned long total_time = user_time + nice_time + system_time + idle_time + wait_time ;
+            static unsigned long last_total_time = 0, last_idle_time = 0;
+            totalTime = total_time - last_total_time;
+            last_total_time = total_time;
+            idleTime = idle_time - last_idle_time;
+            last_idle_time = idle_time;
+            return true;        
+        }
+        else
+        {
+                VERBOSE(VB_IMPORTANT, "cpuCPUAvail(): can't read /proc/stat");
+                return false;
+        }
+#else
+        VERBOSE(VB_IMPORTANT, "getCPUAvail(): Unknown platform. "
+                        "How do I get CPU stats?");
+        return false;
+#endif
+}

libs/libmyth/util.h

@@ -67 +67 @@
 MPUBLIC long long getDiskSpace(const QString&,long long&,long long&);
 MPUBLIC bool getUptime(time_t &uptime);
 MPUBLIC bool getMemStats(int &totalMB, int &freeMB, int &totalVM, int &freeVM);
+MPUBLIC bool getCPUStats(int &totalTime, int &idleTime);
 
 MPUBLIC void myth_eject(void);
 

programs/mythtv-setup/backendsettings.cpp

@@ -465 +465 @@
     return gc;
 };
 
-static HostSpinBox *JobQueueMaxSimultaneousJobs()
-{
-    HostSpinBox *gc = new HostSpinBox("JobQueueMaxSimultaneousJobs", 1, 10, 1);
-    gc->setLabel(QObject::tr("Maximum simultaneous jobs on this backend"));
-    gc->setHelpText(QObject::tr("The Job Queue will be limited to running "
-                    "this many simultaneous jobs on this backend."));
-    gc->setValue(1);
-    return gc;
-};
-
 static HostSpinBox *JobQueueCheckFrequency()
 {
     HostSpinBox *gc = new HostSpinBox("JobQueueCheckFrequency", 5, 300, 5);
@@ -727 +717 @@
 
     VerticalConfigurationGroup* group5 = new VerticalConfigurationGroup(false);
     group5->setLabel(QObject::tr("Job Queue (Backend-Specific)"));
-    group5->addChild(JobQueueMaxSimultaneousJobs());
     group5->addChild(JobQueueCheckFrequency());
 
     HorizontalConfigurationGroup* group5a =