FYI: Writer subclasses -vs- IOException

[Tom Tromey]

I'm checking this in.  This makes PipedWriter and BufferedWriter
correctly conform to the Writer semantics regarding close().

I didn't check the other Writer subclasses in Classpath.  I did for
libgcj, though, so if somebody (maybe me, someday) merges the classes
then presumably this will be fixed then.

2001-02-20  Tom Tromey  <address@hidden>

        * java/io/PipedWriter.java (flush): Throw exception if stream
        closed.
        * java/io/BufferedWriter.java (close): Clear `buffer'.
        (flush): Throw IOException if stream is closed.
        (write): Likewise.

Tom

Index: java/io/BufferedWriter.java
===================================================================
RCS file: /cvs/classpath/java/io/BufferedWriter.java,v
retrieving revision 1.5
diff -u -r1.5 BufferedWriter.java
--- java/io/BufferedWriter.java 2000/05/20 20:32:56     1.5
+++ java/io/BufferedWriter.java 2001/02/20 18:58:31
@@ -84,8 +84,14 @@
    */
   public void close () throws IOException
   {
-    localFlush ();
-    out.close();
+    synchronized (lock)
+      {
+       // It is safe to call localFlush even if the stream is already
+       // closed.
+       localFlush ();
+       out.close();
+       buffer = null;
+      }
   }
 
   /**
@@ -96,8 +102,13 @@
    */
   public void flush () throws IOException
   {
-    localFlush ();
-    out.flush();
+    synchronized (lock)
+      {
+       if (buffer == null)
+         throw new IOException ("Stream closed");
+       localFlush ();
+       out.flush();
+      }
   }
 
   /**
@@ -126,6 +137,8 @@
   {
     synchronized (lock)
       {
+       if (buffer == null)
+         throw new IOException ("Stream closed");
        buffer[count++] = (char) oneChar;
        if (count == buffer.length)
          localFlush ();
@@ -152,6 +165,9 @@
 
     synchronized (lock)
       {
+       if (buffer == null)
+         throw new IOException ("Stream closed");
+
        // Bypass buffering if there is too much incoming data.
        if (count + len > buffer.length)
          {
@@ -188,6 +204,9 @@
 
     synchronized (lock)
       {
+       if (buffer == null)
+         throw new IOException ("Stream closed");
+
        if (count + len > buffer.length)
          {
            localFlush ();
Index: java/io/PipedWriter.java
===================================================================
RCS file: /cvs/classpath/java/io/PipedWriter.java,v
retrieving revision 1.4
diff -u -r1.4 PipedWriter.java
--- java/io/PipedWriter.java    2001/01/05 08:22:42     1.4
+++ java/io/PipedWriter.java    2001/02/20 18:58:31
@@ -142,8 +142,10 @@
     *           had read all available data. Thats not the case - this method
     *           appears to be a no-op?
     */
-  public void flush()
+  public void flush() throws IOException
   {
+    if (closed)
+      throw new IOException ("Pipe closed");
   }
   
   /**