#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/wait.h>
#include <unistd.h>

#include <OS.h>


static const int kAreaPagesCount = 4 * 1024;    // 16 MB


int
main()
{
        while (true) {
                uint8* address;
                area_id area = create_area("test area", (void**)&address, B_ANY_ADDRESS,
                        kAreaPagesCount * B_PAGE_SIZE, B_NO_LOCK,
                        B_READ_AREA | B_WRITE_AREA);
                if (area < 0) {
                        fprintf(stderr, "Creating the area failed: %s", strerror(area));
                        exit(1);
                }

                // touch half of the pages
                for (int i = 0; i < kAreaPagesCount / 2; i++)
                        address[i * B_PAGE_SIZE] = 42;

                // fork
                pid_t child = fork();
                if (child < 0) {
                        perror("fork() failed");
                        exit(1);
                }

                if (child == 0) {
                        // child

                        // delete the copied area
                        delete_area(area_for(address));

                        exit(0);
                }

                // parent

                // touch the other half of the pages
                for (int i = kAreaPagesCount / 2; i < kAreaPagesCount; i++)
                        address[i * B_PAGE_SIZE] = 42;

                int status;
                while (wait(&status) != child);

                delete_area(area);
        }

        return 0;
}