finished MPI Histogram

Histogram/main.cpp

@@ -0,0 +1,98 @@
+/*
+ ============================================================================
+ Name        : Program2B.c
+ Author      : Joshua Chong
+ Version     : Part B
+ Description : Calculate histogram program parallelized with pthreads.
+ ============================================================================
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <float.h>
+#include <time.h>
+#include <pthread.h>
+
+#define NUMBINS 1000
+#define NUM_THREADS 4
+
+pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+
+int *histogramVals;    /*global histogram array for all threads*/
+float binSize;		   /*bin size calculated from min and max of array values*/
+int numDataPoints;
+float rawData[1000000];
+int cnt = 1000000;
+int resultCode;
+float maxVal;
+float minVal;
+
+void* calcHistogram (void* arg);
+
+int main(void) {
+	clock_t begin = clock();
+	histogramVals = static_cast<int *>(malloc(NUMBINS * sizeof(int)));
+
+	FILE *fileIn = fopen("numbers.bin", "rb");
+	resultCode = fread(rawData, sizeof(rawData[0]), sizeof(rawData)/sizeof(rawData[0]), fileIn);
+	maxVal = FLT_MIN;
+	minVal = FLT_MAX;
+	for(int cnt1 = 0; cnt1 < cnt; cnt1++ ) {
+		if ( rawData[cnt1] > maxVal )
+			maxVal = rawData[cnt1];
+		if ( rawData[cnt1] < minVal )
+			minVal = rawData[cnt1];
+		}
+	binSize = (maxVal-minVal)/(float)NUMBINS;
+
+	if (fileIn == NULL){
+		printf("File not opened\n");
+		return 0;
+	}
+	printf("minVal: %f  maxVal: %f  binSize: %f\n", minVal, maxVal, binSize);
+	fclose(fileIn);
+
+	pthread_t thread[NUM_THREADS];
+	int index;
+	for (index = 0; index < NUM_THREADS; index++) {
+		//creating threads
+		pthread_create(&thread[index], NULL, calcHistogram, &rawData[index * (cnt/NUM_THREADS)]);
+	}
+	for (index = 0; index < NUM_THREADS; index++) {
+		// block until thread 'index' completes
+		pthread_join(thread[index], NULL);
+	}
+	for (int cnt1 = 0; cnt1 < NUMBINS; cnt1++){
+		 //printf("bin: %d  binStart: %f   binEnd:  %f  Histogram Value: %d\n", cnt1, binSize*(float)cnt1, binSize*(float)(cnt1+1), histogramVals[cnt1]);
+	}
+
+	/* Calculating the time the program takes to run */
+	clock_t end = clock();
+	double time_spent = (double)(end - begin) / CLOCKS_PER_SEC;
+	printf("Time in seconds: %f", time_spent);
+	return EXIT_SUCCESS;
+}
+
+
+
+/*-------------------------------------------------------------------
+ * Function:    calcHistogram
+ * Purpose:     Calculate Histogram result is in a global variable histogramVals.
+ * In args:     arg: changed to one parameter in order to fit pthread_create
+ * 				arg is the starting points of each thread. Example: 0, 250000, 500000,
+ * 				1000000.
+ * Outputs:     Histogram of values stored in global histogramVals
+				binSize in global variable.
+ *
+ */
+
+void* calcHistogram (void* arg) {
+	float* data = (float*)arg;
+	for (int i = 0; i < cnt/NUM_THREADS ; i++){
+		int binNum = (int)((data[i] - minVal) / binSize);
+		pthread_mutex_lock(&mutex);
+		histogramVals[binNum]++;
+		pthread_mutex_unlock(&mutex);
+	}
+	pthread_exit(NULL);
+}
+