spinning cv example too

threads-cv/Makefile

@@ -2,6 +2,7 @@ CC     := gcc
 CFLAGS := -Wall -Werror -I../include 
 
 SRCS   := join.c \
+	join_spin.c \
 	join_modular.c
 
 OBJS   := ${SRCS:c=o}

threads-cv/join_spin.c

@@ -0,0 +1,24 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <pthread.h>
+#include "common.h"
+#include "common_threads.h"
+
+volatile int done = 0;
+
+void *child(void *arg) {
+    printf("child\n");
+    sleep(5);
+    done = 1;
+    return NULL;
+}
+
+int main(int argc, char *argv[]) {
+    pthread_t p;
+    printf("parent: begin\n");
+    Pthread_create(&p, NULL, child, NULL);
+    while (done == 0) 
+	; // spin
+    printf("parent: end\n");
+    return 0;
+}