[kaffe] Pipes kept open after executing subprocesses

[Ito Kazumitsu]

In message "[kaffe] Pipes kept open after executing subprocesses"
    on 04/06/07, Ito Kazumitsu <ito.kazumitsu at mail.hidec.co.jp> writes:

> The attached program shows that some pipes used for executing subprocesses
> are not closed when they are no longer needed.  This will cause a
> "too many open files" error in a long run.

> I am afraid that FileDescriptor sync_fd in
> libraries/javalib/kaffe/lang/UNIXProcess.java has something to do
> with this problem.

I do not know how the FileDescriptor sync_fd is used, but I think
it should be closed when the subprocess is finished.

Not only sync_fd but also stdin, stdout and stderr should be
closed because the application that called the subprocess
may not have closed them.

So here is my suggested patch.

--- kaffe/lang/UNIXProcess.java.orig	Tue Apr 13 00:18:30 2004
+++ kaffe/lang/UNIXProcess.java	Tue Jun  8 08:57:30 2004
@@ -34,6 +34,7 @@
 	OutputStream stdin_stream;
 	InputStream raw_stdout;
 	InputStream raw_stderr;
+	FileOutputStream sync;
 	Throwable throwable;		// saved to rethrow in correct thread
 
 public UNIXProcess(final String argv[], final String arge[], File dir)
@@ -75,6 +76,10 @@
 				this.notifyAll();
 			}
 			synchronized(UNIXProcess.this) {
+				try_close(raw_stdout);
+				try_close(raw_stderr);
+				try_close(stdin_stream);
+				try_close(sync);
 				UNIXProcess.this.notifyAll();
 			}
 		}
@@ -116,7 +121,7 @@
 		raw_stderr = new FileInputStream(stderr_fd);
 
 		// now signal child to proceed
-		FileOutputStream sync = new FileOutputStream(sync_fd);
+		sync = new FileOutputStream(sync_fd);
 		byte[] sbuf = new byte[1];
 		try {
 			sync.write(sbuf);
@@ -164,6 +169,7 @@
 		raw_stdout.close();
 		raw_stderr.close();
 		stdin_stream.close();
+		sync.close();
 	}
 	catch (IOException e) {
 		e.printStackTrace();
@@ -185,5 +191,23 @@
 private native static void sendSignal0(int pid, int signum);
 private native static int getKillSignal();
 
+private static void try_close(InputStream stream) {
+	if (stream != null) {
+		try {
+			stream.close();
+		}
+		catch (IOException e) {}
+	}
+}
+
+private static void try_close(OutputStream stream) {
+	if (stream != null) {
+		try {
+			stream.close();
+		}
+		catch (IOException e) {}
+	}
+}
+
 }