--- a/src/defs.h	Fri Feb 22 22:15:33 2019 +0900
+++ b/src/defs.h	Fri Feb 22 22:36:17 2019 +0900
@@ -121,6 +121,7 @@
 int             pipealloc(struct file**, struct file**);
 void            pipeclose(struct pipe*, int);
 int             piperead(struct pipe*, char*, int);
+__code          cbc_piperead(struct pipe*, char*, int, __code (*)(int));
 int             pipewrite(struct pipe*, char*, int);
 
 //PAGEBREAK: 16
@@ -138,6 +139,7 @@
 void            sleep(void*, struct spinlock*);
 void            userinit(void);
 int             wait(void);
+__code          cbc_wakeup(void*, __code(*next1)());
 void            wakeup(void*);
 void            yield(void);
 

--- a/src/pipe.c	Fri Feb 22 22:15:33 2019 +0900
+++ b/src/pipe.c	Fri Feb 22 22:36:17 2019 +0900
@@ -119,6 +119,7 @@
 __code cbc_piperead3(){
     struct pipe *p = proc->cbc_arg.cbc_console_arg.p;
     int i = proc->cbc_arg.cbc_console_arg.i;
+    __code(*next)(int ret) = proc->cbc_arg.cbc_console_arg.next;
     release(&p->lock);
 
     goto next(i);
@@ -129,10 +130,7 @@
     int n = proc->cbc_arg.cbc_console_arg.n;
     struct pipe *p = proc->cbc_arg.cbc_console_arg.p;
     char *addr = proc->cbc_arg.cbc_console_arg.addr;
-    if (i < n) {
-        if(p->nread == p->nwrite) {
-            break;
-        }
+    if (i < n && !(p->nread == p->nwrite)) {
         addr[i] = p->data[p->nread++ % PIPESIZE];
         i ++;
         proc->cbc_arg.cbc_console_arg.i = i;
@@ -146,6 +144,7 @@
 
 __code cbc_piperead1(){
     struct pipe *p = proc->cbc_arg.cbc_console_arg.p;
+    __code(*next)(int ret) = proc->cbc_arg.cbc_console_arg.next;
     if (p->nread == p->nwrite && p->writeopen){
         if(proc->killed){
             release(&p->lock);
@@ -166,6 +165,7 @@
     proc->cbc_arg.cbc_console_arg.n = n;
     proc->cbc_arg.cbc_console_arg.p = p;
     proc->cbc_arg.cbc_console_arg.addr = addr;
+    proc->cbc_arg.cbc_console_arg.next = next;
     goto cbc_piperead1();
 }
 

--- a/src/proc.c	Fri Feb 22 22:15:33 2019 +0900
+++ b/src/proc.c	Fri Feb 22 22:36:17 2019 +0900
@@ -539,12 +539,13 @@
     }
 
     release(&ptable.lock);
-    goto next();
+    goto proc->cbc_next();
 }
 
-__code cbc_wakeup(void *chan) 
+__code cbc_wakeup(void *chan, __code(*next1)()) 
 {
     acquire(&ptable.lock);
+    proc->cbc_next = next1;
     cbc_wakeup1(chan);
 }
 

--- a/src/proc.h	Fri Feb 22 22:15:33 2019 +0900
+++ b/src/proc.h	Fri Feb 22 22:36:17 2019 +0900
@@ -70,12 +70,15 @@
     char            name[16];       // Process name (debugging)
     union cbc_arg {
         struct cbc_console_arg {
-	    int n;
+            int n;
             int target;
             char* dst;
             struct inode *ip;
             struct file *f;
             int num;
+            struct pipe *p;
+            char *addr;
+            int i;
             __code (*next)(int ret);
         } cbc_console_arg;
     } cbc_arg;

--- a/src/spinlock.c	Fri Feb 22 22:15:33 2019 +0900
+++ b/src/spinlock.c	Fri Feb 22 22:36:17 2019 +0900
@@ -46,6 +46,7 @@
 #endif
 }
 
+/*
 void cbc_acquire(struct spinlock *lk, __code (*next)(int ret))
 {
     pushcli();		// disable interrupts to avoid deadlock.
@@ -68,7 +69,9 @@
 #endif
     goto next();
 }
+*/
 
+/*
 // Release the lock.
 void cbc_release(struct spinlock *lk, __code (*next)(int ret))
 {
@@ -95,6 +98,7 @@
     popcli();
     goto next();
 }
+*/
 
 void release(struct spinlock *lk)
 {