Sequential buffer reads and writes.

CMakeLists.txt

+cmake_minimum_required(VERSION 3.20)
+project(Pmem_tests C)
+
+set(CMAKE_C_STANDARD 99)
+
+add_executable(Pmem_tests main.c)

Makefile

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+#=============================================================================
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+
+# Help Target
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+	@echo "... depend"
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+	@echo "... main.s"
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+
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+

main.c

+#include <stdio.h>
+#include <time.h>
+#include <stdlib.h>
+
+static const long buffer_size = 100000000;
+
+struct array{
+    char *buffer;
+};
+//Sequential read
+void iterate_read(const char *buffer){
+    for(int i = 0; i < buffer_size; i++ ){
+        buffer[i];
+    }
+}
+
+//Sequential read
+void iterate_read_rand(const char *buffer){
+    for(int i = 0; i < buffer_size; i++ ){
+        buffer[rand() % buffer_size];
+    }
+}
+
+//Sequential write VS Random
+void iterate_write(char *buffer){
+    for(int i = 0; i < buffer_size; i++ ){
+        buffer[i] = 'a';
+    }
+}
+//Random writes
+void iterate_write_rand(char *buffer){
+    for(int i = 0; i < buffer_size; i++ ){
+        buffer[rand() % buffer_size] = 'a';
+    }
+}
+
+void execute(struct array *ap, void *r(), void *w()){
+    clock_t begin = clock();
+    srand(time(NULL));
+    w(ap->buffer);
+    clock_t write_finished = clock();
+    r(ap->buffer);
+    clock_t read_finished = clock();
+
+    double time_spent_writing = (double)(write_finished - begin) / CLOCKS_PER_SEC;
+    double time_spent_reading = (double)(read_finished - write_finished) / CLOCKS_PER_SEC;
+
+    printf("Writing: %f, Reading: %f \n", time_spent_writing, time_spent_reading);
+}
+
+int main() {
+    /**
+     * Case 1: DRAM only.
+     */
+     //Initialise array on the heap:
+    struct array *ap = malloc(sizeof (struct array));
+    ap->buffer = malloc(sizeof (char)*buffer_size);
+    printf("Sequential time: ");
+    execute(ap, iterate_write, iterate_read);
+    printf("Random time: ");
+    execute(ap, iterate_write_rand, iterate_read_rand);
+
+
+    return 0;
+}