--- a/src/impl/file_impl_pipe.cbc	Wed Jan 15 19:56:28 2020 +0900
+++ b/src/impl/file_impl_pipe.cbc	Thu Jan 16 15:52:47 2020 +0900
@@ -50,12 +50,35 @@
             release(&p->lock);
             goto cbc_context->error();
         }
-        goto cbc_sleep(p,&p->nread, &p->lock, cbc_piperead1);
+        goto cbc_sleep(p,&p->nread, &p->lock, next,cbc_piperead1);
     }
     n = 0;
     goto cbc_piperead2(p,n);
 }
 
+__code cbc_sleep(struct pipe* p, unit* nread, struct spinlock* lock, __code next(...), __code pread(...)){
+    if(proc == 0) {
+        goto cbc_context->panic("sleep");
+    }
+
+    if(lk == 0) {
+        goto cbc_context->panic("sleep without lk");
+    }
+
+    if(lk != &ptable.lock){  //DOC: sleeplock0
+        acquire(&ptable.lock);  //DOC: sleeplock1
+        release(lk);
+    }
+    goto cbc_sched(cbc_sleep1);
+}
+
+__code cbc_sched_stub(struct pipe* p, unit* nread, struct spinlock* lock, __code next(...), __code pread(...)){
+    proc->chan = chan;
+    proc->state = SLEEPING;
+    proc->lk = lk;
+    proc->cbc_next = next1;
+}
+
 __code writepipe(struct pipe* file, char* addr, int n, __code next(...)) {
 
   goto next(...);