Initial commit.

programming-assignment.c

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+#include "pch.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include <Windows.h>
+#include <string.h>
+
+/**************************************************************************
+ * Authors: Gary Fleming, Amber McCloughan
+ * Class: CIS452 - Operating Systems Concepts
+ * Professor: Dr. Greg Wolffe
+ * Date: 4/11/2019
+ * 
+ * A mini programming assignment where we do some memory operations in
+ * Windows. We get the page size of the system, allocate memory,
+ * check the state of that memory, deallocate the memory, and then check 
+ * the state of the memory again.
+ ***************************************************************************/
+
+// See function implementation for details.
+const char *checkMemState(DWORD);
+
+/**
+ * Main function for driving the program.
+ */
+int main()
+{
+    // Buffer for holding system info.
+    SYSTEM_INFO sysInf;
+
+    // Grabbing system info.
+    GetSystemInfo(&sysInf);
+
+    // Figuring out the size of a page and printing it.
+    printf("The size of a page is: %lu\n", sysInf.dwPageSize);
+
+    // Allocating a large sum of memory (1M).
+    printf("Allocating memory...\n");
+    int *bigboy = (int *)malloc(1048576);
+
+    // Buffer for holding memory information.
+    MEMORY_BASIC_INFORMATION buf;
+
+    // Querying memory information about the memory we allocated.
+    VirtualQuery(bigboy, &buf, sizeof(MEMORY_BASIC_INFORMATION));
+
+    // Printing out the memory's state.
+    printf("The state of the memory is: %s\n", checkMemState(buf.State));
+
+    // Freeing the allocated memory.
+    printf("Freeing memory...\n");
+    free(bigboy);
+
+    // Querying memory information about the memory location again.
+    VirtualQuery(bigboy, &buf, sizeof(MEMORY_BASIC_INFORMATION));
+
+    // Printing out the memory's state again.
+    printf("The state of the memory is: %s\n", checkMemState(buf.State));
+
+    // Goodbye.
+    return 0;
+}
+
+/**
+ * Function that takes the memory state and
+ * turns it into a user-readable string.
+ *
+ * @param DWORD state, the raw value for the
+ * memory state.
+ */
+const char *checkMemState(DWORD state)
+{
+    // Committed state (0x1000)
+    if (state == 4096)
+    {
+        return "COMMITTED";
+    }
+    // Free state (0x10000)
+    else if (state == 65536)
+    {
+        return "FREE";
+    }
+    // Reserved state (0x2000)
+    else if (state == 8192)
+    {
+        return "RESERVED";
+    }
+    // Catch-all for any issues.
+    else
+    {
+        return "UNKNOWN";
+    }
+}