Modify PID Manager with threads

threads/ex417.c

@@ -0,0 +1,31 @@
+#include <pthread.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+int value = 0;
+void *runner(void *param);
+
+int main(int argc, char *argv[]) {
+  pid_t pid;
+  pthread_t tid;
+  pthread_attr_t attr;
+
+  pid = fork();
+
+  if (pid == 0) {
+    pthread_attr_init(&attr);
+    pthread_create(&tid, &attr, runner, NULL);
+    pthread_join(tid, NULL);
+    printf("CHILD: value = %d\n", value);
+  } else if (pid > 0) {
+    wait(NULL);
+    printf("PARENT: value = %d\n", value);
+  }
+}
+
+void *runner(void *param) {
+  value = 5;
+  pthread_exit(0);
+}