#include "../context.h"
#interface "file.h"

// ----
// typedef struct pipe<Impl, Isa> impl file {
//     #define PIPESIZE 512
//     struct spinlock lock;
//     char data[PIPESIZE];
//     uint nread;     // number of bytes read
//     uint nwrite;    // number of bytes written
//     int readopen;   // read fd is still open
//     int writeopen;  // write fd is still open
// } pipe;
// ----

file* createpipe(struct Context* cbc_context) {
    struct file* file  = new file();
    struct pipe* pipe = new pipe();
    file->file = (union Data*)pipe;
    pipe->lock = 0;
    pipe->spinlock  = 0;
    pipe->data  = 0;
    pipe->nread  = 0;
    pipe->nwrite  = 0;
    pipe->readopen  = 0;
    pipe->writeopen  = 0;
    file->off = 0;
    file->st = NULL;
    file->addr = NULL;
    file->n  = 0;
    file->stat = C_statpipe;
    file->read = C_readpipe;
    file->write = C_writepipe;
    file->close = C_closepipe;
    return file;
}
__code statpipe(struct pipe* file, struct stat* st, __code next(...)) {

  goto next(...);
}

__code readpipe(struct pipe* file, char* addr, int n, __code next(...)) {
    acquire(&p->lock);
    goto cbc_piperead1(file,addr,n,next);
}

__code piperead1(struct pipe* p, char* addr, int n, __code next(...)) {
    if (p->nread == p->nwrite && p->writeopen){
        if(proc->killed){
            release(&p->lock);
            goto cbc_context->error();
        }
        goto cbc_sleep(p,&p->nread, &p->lock, cbc_piperead1);
    }
    n = 0;
    goto cbc_piperead2(p,n);
}

__code writepipe(struct pipe* file, char* addr, int n, __code next(...)) {

  goto next(...);
}

__code closepipe(struct pipe* file,__code next(...)) {

  goto next(...);
}