rewrite pipe.c

kernel/Makefile

@@ -8,7 +8,6 @@ KERNEL_SOURCES = \
   bio.c \
   fs.c \
   log.c \
-  pipe.c \
   exec.c \
   sysfile.c \
   kernelvec.c \

kernel/defs.h

@@ -2,13 +2,15 @@
 #include "types.h"
 #include "riscv.h"
 
+#define PIPESIZE 512
+
 struct buf;
 struct context;
 struct file;
 struct inode;
+struct spinlock;
 struct pipe;
 struct proc;
-struct spinlock;
 struct sleeplock;
 struct stat;
 struct superblock;

kernel/pipe.c

@@ -1,130 +0,0 @@
-#include "types.h"
-#include "riscv.h"
-#include "defs.h"
-#include "param.h"
-#include "spinlock.h"
-#include "proc.h"
-#include "fs.h"
-#include "sleeplock.h"
-#include "file.h"
-
-#define PIPESIZE 512
-
-struct pipe {
-  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
-};
-
-int
-pipealloc(struct file **f0, struct file **f1)
-{
-  struct pipe *pi;
-
-  pi = 0;
-  *f0 = *f1 = 0;
-  if((*f0 = filealloc()) == 0 || (*f1 = filealloc()) == 0)
-    goto bad;
-  if((pi = (struct pipe*)kalloc()) == 0)
-    goto bad;
-  pi->readopen = 1;
-  pi->writeopen = 1;
-  pi->nwrite = 0;
-  pi->nread = 0;
-  initlock(&pi->lock, "pipe");
-  (*f0)->type = FD_PIPE;
-  (*f0)->readable = 1;
-  (*f0)->writable = 0;
-  (*f0)->pipe = pi;
-  (*f1)->type = FD_PIPE;
-  (*f1)->readable = 0;
-  (*f1)->writable = 1;
-  (*f1)->pipe = pi;
-  return 0;
-
- bad:
-  if(pi)
-    kfree((char*)pi);
-  if(*f0)
-    fileclose(*f0);
-  if(*f1)
-    fileclose(*f1);
-  return -1;
-}
-
-void
-pipeclose(struct pipe *pi, int writable)
-{
-  acquire(&pi->lock);
-  if(writable){
-    pi->writeopen = 0;
-    wakeup(&pi->nread);
-  } else {
-    pi->readopen = 0;
-    wakeup(&pi->nwrite);
-  }
-  if(pi->readopen == 0 && pi->writeopen == 0){
-    release(&pi->lock);
-    kfree((char*)pi);
-  } else
-    release(&pi->lock);
-}
-
-int
-pipewrite(struct pipe *pi, uint64 addr, int n)
-{
-  int i = 0;
-  struct proc *pr = myproc();
-
-  acquire(&pi->lock);
-  while(i < n){
-    if(pi->readopen == 0 || killed(pr)){
-      release(&pi->lock);
-      return -1;
-    }
-    if(pi->nwrite == pi->nread + PIPESIZE){ //DOC: pipewrite-full
-      wakeup(&pi->nread);
-      sleep_lock(&pi->nwrite, &pi->lock);
-    } else {
-      char ch;
-      if(copyin(pr->pagetable, &ch, addr + i, 1) == -1)
-        break;
-      pi->data[pi->nwrite++ % PIPESIZE] = ch;
-      i++;
-    }
-  }
-  wakeup(&pi->nread);
-  release(&pi->lock);
-
-  return i;
-}
-
-int
-piperead(struct pipe *pi, uint64 addr, int n)
-{
-  int i;
-  struct proc *pr = myproc();
-  char ch;
-
-  acquire(&pi->lock);
-  while(pi->nread == pi->nwrite && pi->writeopen){  //DOC: pipe-empty
-    if(killed(pr)){
-      release(&pi->lock);
-      return -1;
-    }
-    sleep_lock(&pi->nread, &pi->lock); // DOC: piperead-sleep
-  }
-  for(i = 0; i < n; i++){  //DOC: piperead-copy
-    if(pi->nread == pi->nwrite)
-      break;
-    ch = pi->data[pi->nread++ % PIPESIZE];
-    if(copyout(pr->pagetable, addr + i, &ch, 1) == -1)
-      break;
-  }
-  wakeup(&pi->nwrite);  //DOC: piperead-wakeup
-  release(&pi->lock);
-  return i;
-}

kernel/rustkernel/src/console/uart.rs

@@ -1,12 +1,7 @@
 //! Low-level driver routines for 16550a UART.
 #![allow(non_upper_case_globals)]
 
-use crate::{
-    console::consoleintr,
-    proc::wakeup,
-    sync::spinlock::Spinlock,
-    trap::InterruptBlocker,
-};
+use crate::{console::consoleintr, proc::wakeup, sync::spinlock::Spinlock, trap::InterruptBlocker};
 use core::ptr::addr_of;
 
 // The UART control registers.
@@ -209,4 +204,3 @@ impl Uart {
         }
     }
 }
-

kernel/rustkernel/src/fs/file.rs

@@ -22,19 +22,19 @@ pub enum FileType {
 #[repr(C)]
 #[derive(Copy, Clone)]
 pub struct File {
-    kind: FileType,
+    pub kind: FileType,
     /// Reference count.
-    references: i32,
-    readable: u8,
-    writable: u8,
+    pub references: i32,
+    pub readable: u8,
+    pub writable: u8,
     /// FileType::Pipe
-    pipe: *mut Pipe,
+    pub pipe: *mut Pipe,
     /// FileType::Inode and FileType::Device
-    ip: *mut Inode,
+    pub ip: *mut Inode,
     /// FileType::Inode
-    off: u32,
+    pub off: u32,
     /// FileType::Device
-    major: i16,
+    pub major: i16,
 }
 impl File {
     pub const unsafe fn uninitialized() -> File {

kernel/rustkernel/src/io/pipe.rs

@@ -1,25 +1,154 @@
-use crate::{fs::file::File, sync::spinlock::Spinlock};
-use core::ffi::c_char;
+use crate::{
+    fs::file::{filealloc, fileclose, File, FileType},
+    mem::{
+        kalloc::{kalloc, kfree},
+        virtual_memory::{copyin, copyout},
+    },
+    proc::{killed, myproc, wakeup},
+    sync::spinlock::Spinlock,
+};
+use core::ptr::{addr_of, addr_of_mut};
 
-pub const PIPESIZE: usize = 512usize;
+pub const PIPESIZE: usize = 512;
 
 #[repr(C)]
 pub struct Pipe {
-    lock: Spinlock,
-    data: [c_char; PIPESIZE],
+    pub lock: Spinlock,
+    pub data: [u8; PIPESIZE],
     /// Number of bytes read.
-    nread: u32,
+    pub bytes_read: u32,
     /// Number of bytes written.
-    nwrite: u32,
+    pub bytes_written: u32,
     /// Read fd is still open.
-    readopen: i32,
+    pub is_read_open: i32,
     /// Write fd is still open.
-    writeopen: i32,
+    pub is_write_open: i32,
+}
+impl Pipe {
+    pub fn new() -> Pipe {
+        Pipe {
+            lock: Spinlock::new(),
+            data: [0u8; PIPESIZE],
+            bytes_read: 0,
+            bytes_written: 0,
+            is_read_open: 1,
+            is_write_open: 1,
+        }
+    }
 }
 
 extern "C" {
-    pub fn pipealloc(a: *mut *mut File, b: *mut *mut File) -> i32;
-    pub fn pipeclose(pipe: *mut Pipe, writable: i32);
-    pub fn pipewrite(pipe: *mut Pipe, addr: u64, n: i32) -> i32;
-    pub fn piperead(pipe: *mut Pipe, addr: u64, n: i32) -> i32;
+    // pub fn pipealloc(a: *mut *mut File, b: *mut *mut File) -> i32;
+    // pub fn pipeclose(pipe: *mut Pipe, writable: i32);
+    // pub fn pipewrite(pipe: *mut Pipe, addr: u64, n: i32) -> i32;
+    // pub fn piperead(pipe: *mut Pipe, addr: u64, n: i32) -> i32;
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn pipealloc(a: *mut *mut File, b: *mut *mut File) -> i32 {
+    *a = filealloc();
+    *b = filealloc();
+    let pipe = kalloc() as *mut Pipe;
+
+    // If any of them fail, close and return -1.
+    if a.is_null() || b.is_null() || pipe.is_null() {
+        if !pipe.is_null() {
+            kfree(pipe as *mut u8);
+        }
+        if !a.is_null() {
+            fileclose(*a);
+        }
+        if !b.is_null() {
+            fileclose(*b);
+        }
+        -1
+    } else {
+        *pipe = Pipe::new();
+        (**a).kind = FileType::Pipe;
+        (**a).readable = 1;
+        (**a).writable = 0;
+        (**a).pipe = pipe;
+        (**b).kind = FileType::Pipe;
+        (**b).readable = 0;
+        (**b).writable = 1;
+        (**b).pipe = pipe;
+        0
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn pipeclose(pipe: *mut Pipe, writable: i32) {
+    let _guard = (*pipe).lock.lock();
+
+    if writable > 0 {
+        (*pipe).is_write_open = 0;
+        wakeup(addr_of!((*pipe).bytes_read).cast_mut().cast());
+    } else {
+        (*pipe).is_read_open = 0;
+        wakeup(addr_of!((*pipe).bytes_written).cast_mut().cast());
+    }
+
+    if (*pipe).is_read_open == 0 && (*pipe).is_write_open == 0 {
+        kfree(pipe.cast());
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn pipewrite(pipe: *mut Pipe, addr: u64, n: i32) -> i32 {
+    let mut i = 0;
+    let p = myproc();
+    let lock = (*pipe).lock.lock();
+
+    while i < n {
+        if (*pipe).is_read_open == 0 || killed(p) > 0 {
+            return -1;
+        }
+        if (*pipe).bytes_written == (*pipe).bytes_read + PIPESIZE as u32 {
+            // DOC: pipewrite-full
+            wakeup(addr_of!((*pipe).bytes_read).cast_mut().cast());
+            lock.sleep(addr_of!((*pipe).bytes_written).cast_mut().cast());
+        } else {
+            let mut b = 0u8;
+            if copyin((*p).pagetable, addr_of_mut!(b), addr + i as u64, 1) == -1 {
+                break;
+            }
+            (*pipe).data[(*pipe).bytes_written as usize % PIPESIZE] = b;
+            (*pipe).bytes_written += 1;
+            i += 1;
+        }
+    }
+    wakeup(addr_of!((*pipe).bytes_read).cast_mut().cast());
+    i
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn piperead(pipe: *mut Pipe, addr: u64, n: i32) -> i32 {
+    let mut i = 0;
+    let p = myproc();
+    let lock = (*pipe).lock.lock();
+
+    // DOC: pipe-empty
+    while (*pipe).bytes_read == (*pipe).bytes_written && (*pipe).is_write_open > 0 {
+        if killed(p) > 0 {
+            return -1;
+        } else {
+            // DOC: piperead-sleep
+            lock.sleep(addr_of!((*pipe).bytes_read).cast_mut().cast());
+        }
+    }
+
+    // DOC: piperead-copy
+    while i < n {
+        if (*pipe).bytes_read == (*pipe).bytes_written {
+            break;
+        }
+        let b = (*pipe).data[(*pipe).bytes_read as usize % PIPESIZE];
+        (*pipe).bytes_read += 1;
+        if copyout((*p).pagetable, addr + i as u64, addr_of!(b).cast_mut(), 1) == -1 {
+            break;
+        }
+        i += 1;
+    }
+    wakeup(addr_of!((*pipe).bytes_written).cast_mut().cast());
+    i
 }