A file class

229f28b7 · Silas Boyd-Wickizer · aaada9c3 · 229f28b7 · 229f28b7 · 229f28b7
--- a/include/file.hh
+++ b/include/file.hh
+#pragma once
 #include "cpputil.hh"
 #include "ns.hh"
 #include "gc.hh"
@@ -6,8 +8,14 @@
 u64 namehash(const strbuf<DIRSIZ>&);
 struct file {
-  enum { FD_NONE, FD_PIPE, FD_INODE, FD_SOCKET } type;
+  file() : type(file::FD_NONE), readable(0), writable(0), 
-  std::atomic<int> ref; // reference count
+           socket(0), pipe(nullptr), ip(nullptr), off(0), 
+           ref_(1) {}
+  file *dup();
+  void close();
+  enum { FD_NONE, FD_PIPE, FD_INODE, FD_SOCKET } type;  
  char readable;
  char writable;
@@ -15,8 +23,11 @@ struct file {
  struct pipe *pipe;
  struct inode *ip;
  u32 off;
-};
+  NEW_DELETE_OPS(file);
+private:
+  std::atomic<int> ref_;
+};
 // in-core file system types

--- a/include/filetable.hh
+++ b/include/filetable.hh
@@ -10,7 +10,7 @@ public:
  filetable(const filetable &f) : ref_(1) {
    for(int fd = 0; fd < NOFILE; fd++) {
      if (f.ofile_[fd])
-        ofile_[fd] = filedup(f.ofile_[fd]);
+        ofile_[fd] = f.ofile_[fd]->dup();
      else
        ofile_[fd] = nullptr;
    }
@@ -19,7 +19,7 @@ public:
  ~filetable() {
    for(int fd = 0; fd < NOFILE; fd++){
      if (ofile_[fd]){
-        fileclose(ofile_[fd]);
+        ofile_[fd]->close();
        ofile_[fd] = 0;
      }
    }
@@ -46,7 +46,7 @@ public:
  void close(int fd) {
    struct file *f = ofile_[fd];
    ofile_[fd] = nullptr;
-    fileclose(f);
+    f->close();
  }
  void decref() {

--- a/include/fs.h
+++ b/include/fs.h
+#pragma once
 // On-disk file system format. 
 // Both the kernel and user programs use this header file.

--- a/include/proc.hh
+++ b/include/proc.hh
@@ -3,6 +3,8 @@
 #include "spinlock.h"
 #include "atomic.hh"
 #include "cpputil.hh"
+#include "fs.h"
+#include "file.hh"
 #include "filetable.hh"
 // Saved registers for kernel context switches.

--- a/kernel/file.cc
+++ b/kernel/file.cc
@@ -9,41 +9,29 @@
 struct devsw __mpalign__ devsw[NDEV];
-// Allocate a file structure.
+void
-struct file*
+file::close(void)
-filealloc(void)
 {
-  struct file *f = (file*) kmalloc(sizeof(struct file));
+  if (--ref_ > 0)
-  f->ref = 1;
+    return;
-  f->type = file::FD_NONE;
-  return f;
-}
-// Increment ref count for file f.
+  if(type == file::FD_PIPE)
-struct file*
+    pipeclose(pipe, writable);
-filedup(struct file *f)
+  else if(type == file::FD_INODE)
-{
+    iput(ip);
-  if (f->ref++ < 1)
+  else if(type == file::FD_SOCKET)
-    panic("filedup");
+    netclose(socket);
-  return f;
+  else if(type != file::FD_NONE)
+    panic("file::close bad type");
+  delete this;
 }
-// Close file f.  (Decrement ref count, close when reaches 0.)
+file*
-void
+file::dup(void)
-fileclose(struct file *f)
 {
-  if (--f->ref > 0)
+  if (ref_++ < 1)
-    return;
+    panic("file::dup");
+  return this;
-  if(f->type == file::FD_PIPE)
-    pipeclose(f->pipe, f->writable);
-  else if(f->type == file::FD_INODE)
-    iput(f->ip);
-  else if(f->type == file::FD_SOCKET)
-    netclose(f->socket);
-  else if(f->type != file::FD_NONE)
-    panic("fileclose bad type");
-  kmfree(f, sizeof(struct file));
 }
 // Get metadata about file f.

--- a/kernel/pipe.cc
+++ b/kernel/pipe.cc
@@ -28,7 +28,7 @@ pipealloc(struct file **f0, struct file **f1)
  p = 0;
  *f0 = *f1 = 0;
-  if((*f0 = filealloc()) == 0 || (*f1 = filealloc()) == 0)
+  if((*f0 = new file()) == 0 || (*f1 = new file()) == 0)
    goto bad;
  if((p = (pipe*)kmalloc(sizeof(*p))) == 0)
    goto bad;
@@ -55,9 +55,9 @@ pipealloc(struct file **f0, struct file **f1)
    kmfree((char*)p, sizeof(*p));
  }
  if(*f0)
-    fileclose(*f0);
+    (*f0)->close();
  if(*f1)
-    fileclose(*f1);
+    (*f1)->close();
  return -1;
 }

--- a/kernel/sysfile.cc
+++ b/kernel/sysfile.cc
@@ -44,7 +44,7 @@ sys_dup(int ofd)
    return -1;
  if((fd=fdalloc(f)) < 0)
    return -1;
-  filedup(f);
+  f->dup();
  return fd;
 }
@@ -317,9 +317,9 @@ sys_openat(int dirfd, const char *path, int omode)
    }
  }
-  if((f = filealloc()) == 0 || (fd = fdalloc(f)) < 0){
+  if((f = new file()) == 0 || (fd = fdalloc(f)) < 0){
    if(f)
-      fileclose(f);
+      f->close();
    iunlockput(ip);
    return -1;
  }
@@ -416,7 +416,7 @@ sys_pipe(int *fd)
  if((fd0 = fdalloc(rf)) < 0 || (fd1 = fdalloc(wf)) < 0){
    if(fd0 >= 0)
      myproc()->ftable->close(fd0);
-    fileclose(wf);
+    wf->close();
    return -1;
  }
  fd[0] = fd0;
@@ -449,13 +449,13 @@ allocsocket(struct file **rf, int *rfd)
  struct file *f;
  int fd;
-  f = filealloc();
+  f = new file();
  if (f == nullptr)
    return -1;
  fd = fdalloc(f);
  if (fd < 0) {
-    fileclose(f);
+    f->close();
    return fd;
  }