use ftable like btable and itable

7f399cca · rsc · ce72cadb · 7f399cca
--- a/file.c
+++ b/file.c
@@ -6,31 +6,32 @@
 #include "dev.h"
 struct devsw devsw[NDEV];
-struct spinlock file_table_lock;
+struct {
-struct file file[NFILE];
+  struct spinlock lock;
+  struct file file[NFILE];
+} ftable;
 void
 fileinit(void)
 {
-  initlock(&file_table_lock, "file_table");
+  initlock(&ftable.lock, "file_table");
 }
 // Allocate a file structure.
 struct file*
 filealloc(void)
 {
-  int i;
+  struct file *f;
-  acquire(&file_table_lock);
+  acquire(&ftable.lock);
-  for(i = 0; i < NFILE; i++){
+  for(f = ftable.file; f < ftable.file + NFILE; f++){
-    if(file[i].type == FD_CLOSED){
+    if(f->ref == 0){
-      file[i].type = FD_NONE;
+      f->ref = 1;
-      file[i].ref = 1;
+      release(&ftable.lock);
-      release(&file_table_lock);
+      return f;
-      return file + i;
    }
  }
-  release(&file_table_lock);
+  release(&ftable.lock);
  return 0;
 }
@@ -38,11 +39,11 @@ filealloc(void)
 struct file*
 filedup(struct file *f)
 {
-  acquire(&file_table_lock);
+  acquire(&ftable.lock);
-  if(f->ref < 1 || f->type == FD_CLOSED)
+  if(f->ref < 1)
    panic("filedup");
  f->ref++;
-  release(&file_table_lock);
+  release(&ftable.lock);
  return f;
 }
@@ -52,24 +53,22 @@ fileclose(struct file *f)
 {
  struct file ff;
-  acquire(&file_table_lock);
+  acquire(&ftable.lock);
-  if(f->ref < 1 || f->type == FD_CLOSED)
+  if(f->ref < 1)
    panic("fileclose");
  if(--f->ref > 0){
-    release(&file_table_lock);
+    release(&ftable.lock);
    return;
  }
  ff = *f;
  f->ref = 0;
-  f->type = FD_CLOSED;
+  f->type = FD_NONE;
-  release(&file_table_lock);
+  release(&ftable.lock);
  if(ff.type == FD_PIPE)
    pipeclose(ff.pipe, ff.writable);
  else if(ff.type == FD_INODE)
    iput(ff.ip);
-  else
-    panic("fileclose");
 }
 // Get metadata about file f.