Bug 497166: Support the user using the 'run' command in the gdb console

This commit introduces a PersistentPTY.  By using it, we now allow the
user to restart the process from the GDB console (by pressing 'run').
In this case, the I/O will continue using the PersistentPTY.

Previously, the PTY would have been closed, and GDB would fail to
restart the process because it would fail to use the closed PTY.

Change-Id: I395b402e297a2043af8fce33df163eddef9e6c7a

3 files changed, 106 insertions, 2 deletions

diff --git a/core/org.eclipse.cdt.core.native/META-INF/MANIFEST.MF b/core/org.eclipse.cdt.core.native/META-INF/MANIFEST.MF
index d5dc688af3e..94f7b0d29f4 100644
--- a/core/org.eclipse.cdt.core.native/META-INF/MANIFEST.MF
+++ b/core/org.eclipse.cdt.core.native/META-INF/MANIFEST.MF
@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %pluginName
 Bundle-SymbolicName: org.eclipse.cdt.core.native;singleton:=true
-Bundle-Version: 5.9.0.qualifier
+Bundle-Version: 5.10.0.qualifier
 Bundle-Activator: org.eclipse.cdt.internal.core.natives.CNativePlugin
 Bundle-Vendor: %providerName
 Bundle-Localization: plugin
diff --git a/core/org.eclipse.cdt.core.native/pom.xml b/core/org.eclipse.cdt.core.native/pom.xml
index 249c4e3223d..46091e422e6 100644
--- a/core/org.eclipse.cdt.core.native/pom.xml
+++ b/core/org.eclipse.cdt.core.native/pom.xml
@@ -11,7 +11,7 @@
     <relativePath>../../pom.xml</relativePath>
   </parent>
 
-  <version>5.9.0-SNAPSHOT</version>
+  <version>5.10.0-SNAPSHOT</version>
   <artifactId>org.eclipse.cdt.core.native</artifactId>
   <packaging>eclipse-plugin</packaging>
 </project>
diff --git a/core/org.eclipse.cdt.core.native/src/org/eclipse/cdt/utils/pty/PersistentPTY.java b/core/org.eclipse.cdt.core.native/src/org/eclipse/cdt/utils/pty/PersistentPTY.java
new file mode 100644
index 00000000000..9780d405853
--- /dev/null
+++ b/core/org.eclipse.cdt.core.native/src/org/eclipse/cdt/utils/pty/PersistentPTY.java
@@ -0,0 +1,104 @@
+/*******************************************************************************
+ * Copyright (c) 2016 Ericsson and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *******************************************************************************/
+package org.eclipse.cdt.utils.pty;
+
+import java.io.IOException;
+
+import org.eclipse.core.runtime.Platform;
+
+/**
+ * A type of PTY that is persistent.  This means that closing
+ * its streams (e.g., once the connection to the process is lost)
+ * will not close the PTY or the streams; instead, they will 
+ * remain open to be used again by reconnecting to the streams.
+ * {@link PersistentPTY#closeStreams()} must be called to properly
+ * cleanup the streams once the PersistentPTY is known not be needed
+ * anymore.
+ * 
+ * @since 5.10
+ */
+public class PersistentPTY extends PTY {
+
+	private class PersistentPTYInputStream extends PTYInputStream {
+		public PersistentPTYInputStream(MasterFD fd) {
+			super(fd);
+		}
+
+		@Override
+		public void close() throws IOException {
+			// This is the change to bring persistence.
+			// Don't actually close the stream.
+		}
+		
+		public void realClose() throws IOException {
+			// This method should be called to actually close
+			// the stream once we know it won't be needed anymore
+			super.close();
+		}
+		
+		@Override
+		protected void finalize() throws IOException {
+			realClose();
+		}
+	}
+	
+	private class PersistentPTYOutputStream extends PTYOutputStream {
+		public PersistentPTYOutputStream(MasterFD fd, boolean sendEotBeforeClose) {
+			super(fd, sendEotBeforeClose);
+		}
+
+		@Override
+		public void close() throws IOException {
+			// This is the change to bring persistence.
+			// Don't actually close the stream.
+		}
+		
+		public void realClose() throws IOException {
+			// This method should be called to actually close
+			// the stream once we know it won't be needed anymore
+			super.close();
+		}
+
+		@Override
+		protected void finalize() throws IOException {
+			realClose();
+		}
+	}
+
+	final PersistentPTYInputStream in2;
+	final PersistentPTYOutputStream out2;
+	
+	public PersistentPTY() throws IOException {
+		this(Mode.CONSOLE);
+	}
+
+	public PersistentPTY(Mode mode) throws IOException {
+		super(mode);
+		in2 = new PersistentPTYInputStream(new MasterFD());
+		out2 = new PersistentPTYOutputStream(new MasterFD(), !Platform.OS_WIN32.equals(Platform.getOS()));
+	}
+	
+	@Override
+	public PTYInputStream getInputStream() {
+		return in2;
+	}
+	
+	@Override
+	public PTYOutputStream getOutputStream() {
+		return out2;
+	}
+	
+	/**
+	 * This method must be called once the PersistentPTY is
+	 * no longer needed, so that its streams can be closed. 
+	 */
+	public void closeStreams() throws IOException {
+		in2.realClose();
+		out2.realClose();
+	}
+}