Calculate Performance Statistics

code/scheduler.c

@@ -17,6 +17,8 @@
 int msgQID;
 process_t *currentProcess = NULL;
 
+perfStats stats;
+
 /**
  * main - The main function of the scheduler.
  *
@@ -48,6 +50,8 @@ int main(int argc, char *argv[]) {
   schedule(schedulerType, quantem, gen_msgQID);
   printf(ANSI_BLUE "==>SCH: Scheduler Finished\n" ANSI_RESET);
 
+  // writePerfFile(); // moved it to the end of schedule() function
+
   // TODO Initialize Scheduler
   //  Create Wait queue ??
   //  Create log file
@@ -148,6 +152,9 @@ void schedule(scheduler_type schType, int quantem, int gen_msgQID) {
   }
   printf(ANSI_BLUE "==>SCH: " ANSI_RED ANSI_BOLD
                    "All processes are done\n" ANSI_RESET);
+
+  writePerfFile();
+
   // FIXME: If I exit here it's all sunshines and rainbows
   //  if I got back to main it gets angry
   //  something about the stack needs to be fixed
@@ -518,6 +525,12 @@ void createLogFile() {
     exit(-1);
   }
 
+  // to initiate performance statistics counters [maybe not the best place to do it]
+  stats.numFinished = 0;
+  stats.totalWaitingTime = 0;
+  stats.totalWorkingTime = 0;
+  stats.totalWTA = 0;
+
   printf("Started Logging\n");
   fclose(logFileptr);
 }
@@ -540,9 +553,42 @@ void logger(char *msg, process_t *p) {
 
   if (strcmp(msg, "finished") == 0) {
     fprintf(logFileptr, " TA %i WTA %.2f", p->TA, WTA);
+    stats.WTAs[stats.numFinished] = WTA;
+    stats.numFinished += 1;
+    stats.totalWorkingTime += p->BT;
+    stats.totalWaitingTime += p->WT;
+    stats.totalWTA += WTA;
   }
 
   fprintf(logFileptr, "\n");
 
   fclose(logFileptr);
 }
+
+void writePerfFile() {
+  FILE * perfFile = fopen("scheduler.perf", "w");
+
+  if (perfFile == NULL) {
+    perror("Can't open perf file");
+    exit(-1);
+  }
+
+  int finalTime = getClk();
+
+  stats.CPU_utilization = 100.0 * stats.totalWorkingTime / finalTime;
+  stats.avgWTA = (double) stats.totalWTA / stats.numFinished;
+  stats.avgWaitingTime = (double) stats.totalWaitingTime / stats.numFinished;
+
+  // calculate STD Deviation of Weighted Turn around time
+  double sumSquaresErr = 0;
+  for (int i = 0; i < stats.numFinished; i++) {
+    sumSquaresErr += (stats.WTAs[i] - stats.avgWTA) * (stats.WTAs[i] - stats.avgWTA);
+  }
+
+  stats.stdWTA = sumSquaresErr / stats.numFinished;
+
+  fprintf(perfFile, "CPU utilization = %.2f%%\n", stats.CPU_utilization);
+  fprintf(perfFile, "Avg WTA = %.2f\n", stats.avgWTA);
+  fprintf(perfFile, "Avg Waiting = %.2f\n", stats.avgWaitingTime);
+  fprintf(perfFile, "Std WTA = %.2f\n", stats.stdWTA);
+}

code/scheduler.h

@@ -48,4 +48,5 @@ void sigUsr1Handler(int signum);
 //==============================
 
 void createLogFile();
-void logger(char * action, process_t* process_pcb);
+void logger(char * action, process_t* process_pcb);
+void writePerfFile();

code/scheduler.log

@@ -3,54 +3,22 @@ At time 7 process 1 finished arr 6 total 1 remain 0 wait 0 TA 1 WTA 1.00
 At time 16 process 2 started arr 16 total 2 remain 2 wait 0
 At time 18 process 2 finished arr 16 total 2 remain 0 wait 0 TA 2 WTA 1.00
 At time 18 process 3 started arr 17 total 11 remain 11 wait 1
-At time 21 process 3 stopped arr 17 total 11 remain 8 wait 1
-At time 21 process 3 resumed arr 17 total 11 remain 8 wait 4
-At time 26 process 3 stopped arr 17 total 11 remain 3 wait 4
-At time 26 process 3 resumed arr 17 total 11 remain 3 wait 9
-At time 29 process 3 finished arr 17 total 11 remain 0 wait 9 TA 12 WTA 1.09
+At time 29 process 3 finished arr 17 total 11 remain 0 wait 1 TA 12 WTA 1.09
 At time 29 process 4 started arr 28 total 1 remain 1 wait 1
 At time 30 process 4 finished arr 28 total 1 remain 0 wait 1 TA 2 WTA 2.00
 At time 30 process 5 started arr 29 total 23 remain 23 wait 1
-At time 31 process 5 stopped arr 29 total 23 remain 22 wait 1
-At time 31 process 5 resumed arr 29 total 23 remain 22 wait 2
-At time 36 process 5 stopped arr 29 total 23 remain 17 wait 2
-At time 36 process 6 started arr 34 total 4 remain 4 wait 2
-At time 40 process 6 finished arr 34 total 4 remain 0 wait 2 TA 6 WTA 1.50
-At time 40 process 5 resumed arr 29 total 23 remain 17 wait 11
-At time 41 process 5 stopped arr 29 total 23 remain 15 wait 11
-At time 41 process 5 resumed arr 29 total 23 remain 15 wait 12
-At time 46 process 5 stopped arr 29 total 23 remain 10 wait 12
-At time 46 process 7 started arr 44 total 24 remain 24 wait 2
-At time 51 process 7 stopped arr 44 total 24 remain 19 wait 2
-At time 51 process 5 resumed arr 29 total 23 remain 10 wait 22
-At time 56 process 5 stopped arr 29 total 23 remain 4 wait 22
-At time 56 process 7 resumed arr 44 total 24 remain 19 wait 12
-At time 61 process 7 stopped arr 44 total 24 remain 13 wait 12
-At time 61 process 8 started arr 51 total 4 remain 4 wait 10
-At time 65 process 8 finished arr 51 total 4 remain 0 wait 10 TA 14 WTA 3.50
-At time 65 process 9 started arr 52 total 21 remain 21 wait 13
-At time 66 process 9 stopped arr 52 total 21 remain 20 wait 13
-At time 66 process 10 started arr 56 total 17 remain 17 wait 10
-At time 71 process 10 stopped arr 56 total 17 remain 12 wait 10
-At time 71 process 5 resumed arr 29 total 23 remain 4 wait 42
-At time 74 process 5 finished arr 29 total 23 remain 0 wait 42 TA 45 WTA 1.96
-At time 74 process 7 resumed arr 44 total 24 remain 13 wait 30
-At time 76 process 7 stopped arr 44 total 24 remain 10 wait 30
-At time 76 process 9 resumed arr 52 total 21 remain 20 wait 24
-At time 81 process 9 stopped arr 52 total 21 remain 14 wait 24
-At time 81 process 10 resumed arr 56 total 17 remain 12 wait 25
-At time 86 process 10 stopped arr 56 total 17 remain 6 wait 25
-At time 86 process 7 resumed arr 44 total 24 remain 10 wait 42
-At time 91 process 7 stopped arr 44 total 24 remain 4 wait 42
-At time 91 process 9 resumed arr 52 total 21 remain 14 wait 39
-At time 96 process 9 stopped arr 52 total 21 remain 8 wait 39
-At time 96 process 10 resumed arr 56 total 17 remain 6 wait 40
-At time 101 process 10 finished arr 56 total 17 remain 0 wait 40 TA 45 WTA 2.65
-At time 101 process 7 resumed arr 44 total 24 remain 4 wait 57
-At time 101 process 7 stopped arr 44 total 24 remain 4 wait 57
-At time 101 process 9 resumed arr 52 total 21 remain 8 wait 49
-At time 106 process 9 stopped arr 52 total 21 remain 2 wait 49
-At time 106 process 7 resumed arr 44 total 24 remain 4 wait 62
-At time 109 process 7 finished arr 44 total 24 remain 0 wait 62 TA 65 WTA 2.71
-At time 109 process 9 resumed arr 52 total 21 remain 2 wait 57
-At time 110 process 9 finished arr 52 total 21 remain 0 wait 57 TA 58 WTA 2.76
+At time 34 process 5 stopped arr 29 total 23 remain 19 wait 1
+At time 34 process 6 started arr 34 total 4 remain 4 wait 0
+At time 38 process 6 finished arr 34 total 4 remain 0 wait 0 TA 4 WTA 1.00
+At time 38 process 5 resumed arr 29 total 23 remain 19 wait 9
+At time 51 process 5 stopped arr 29 total 23 remain 5 wait 9
+At time 51 process 8 started arr 51 total 4 remain 4 wait 0
+At time 55 process 8 finished arr 51 total 4 remain 0 wait 0 TA 4 WTA 1.00
+At time 55 process 5 resumed arr 29 total 23 remain 5 wait 26
+At time 59 process 5 finished arr 29 total 23 remain 0 wait 26 TA 30 WTA 1.30
+At time 59 process 10 started arr 56 total 17 remain 17 wait 3
+At time 76 process 10 finished arr 56 total 17 remain 0 wait 3 TA 20 WTA 1.18
+At time 76 process 9 started arr 52 total 21 remain 21 wait 24
+At time 97 process 9 finished arr 52 total 21 remain 0 wait 24 TA 45 WTA 2.14
+At time 97 process 7 started arr 44 total 24 remain 24 wait 53
+At time 121 process 7 finished arr 44 total 24 remain 0 wait 53 TA 77 WTA 3.21

code/scheduler.perf

@@ -0,0 +1,4 @@
+CPU utilization = 89.26%
+Avg WTA = 1.49
+Avg Waiting = 10.80
+Std WTA = 0.49

code/structs.h

@@ -29,3 +29,22 @@ union SemUn {
   unsigned short *array; /* Array for GETALL, SETALL */
   struct seminfo *__buf; /* Buffer for IPC_INFO (Linux-specific) */
 };
+
+// To create scheduler.perf.
+// The scheduler will create only one instant from this struct
+typedef struct perfStats {
+
+  // these are incrementally updated each time a process finishes
+  int totalWorkingTime;   // sum of burst times
+  int totalWaitingTime;   // sum of waiting times
+  double totalWTA;        // sum of weighted turnaround times
+  int numFinished;        // number of finished processes
+  double WTAs[1000];      // to calculate standard deviation (not best solution)
+
+  // and these are calculated when the last process finishes
+  double CPU_utilization; // = totalWorkingTime / totalTime
+  double avgWaitingTime;  // totalWaitingTime / N
+  double avgWTA;          // totalWTA / N
+  double stdWTA;          // Standard deviation of weighted turnaround time
+                          //= SUM( (WTA[i] - avgWTA)^2 ) / N
+} perfStats;