* Copyright 2007, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
* Distributed under the terms of the MIT License.
*
* Copyright 2002, Manuel J. Petit. All rights reserved.
* Distributed under the terms of the NewOS License.
*/
#include <image.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
int gForked = 0;
static void
usage(char const *app)
{
printf("usage: %s ###\n", app);
exit(-1);
}
int
main(int argc, char *argv[])
{
int result = 0;
if (argc != 2)
usage(argv[0]);
int num = atoi(argv[1]);
if (num < 2) {
result = num;
} else {
pid_t childA = fork();
if (childA == 0) {
char buffer[64];
char* args[]= { argv[0], buffer, NULL };
int argCount = 2;
gForked++;
snprintf(buffer, sizeof(buffer), "%d", num - 1);
return main(argCount, args);
} else if (childA < 0) {
fprintf(stderr, "fork() failed for child A: %s\n", strerror(errno));
return -1;
}
pid_t childB = fork();
if (childB == 0) {
char buffer[64];
char* args[]= { argv[0], buffer, NULL };
int argCount = 2;
gForked++;
snprintf(buffer, sizeof(buffer), "%d", num - 2);
return main(argCount, args);
} else if (childB < 0) {
fprintf(stderr, "fork() failed for child B: %s\n", strerror(errno));
return -1;
}
status_t status, returnValue = 0;
do {
status = wait_for_thread(childA, &returnValue);
} while (status == B_INTERRUPTED);
if (status == B_OK)
result = returnValue;
else
fprintf(stderr, "wait_for_thread(%ld) A failed: %s\n", childA, strerror(status));
do {
status = wait_for_thread(childB, &returnValue);
} while (status == B_INTERRUPTED);
if (status == B_OK)
result += returnValue;
else
fprintf(stderr, "wait_for_thread(%ld) B failed: %s\n", childB, strerror(status));
}
if (gForked) {
return result;
} else {
printf("%d\n", result);
return 0;
}
}
