lib/classes/isabelle/IsabelleProcess.java

+/*
+ * $Id$
+ *
+ * Posix process wrapper for Isabelle (see also src/Pure/Tools/isabelle_process.ML).
+ *
+ * The process model:
+ *
+ *  (1) input
+ *    - stdin stream
+ *    - signals (interrupt, kill)
+ *
+ *  (2) output/results
+ *    - stdout stream, interspersed with marked Isabelle messages
+ *    - stderr stream
+ *    - process exit (return code)
+ *
+ * I/O is fully asynchronous, with unrestricted buffers.  Text is encoded as UTF-8.
+ */
+
+package isabelle;
+
+import java.io.*;
+import java.util.Locale;
+import java.util.concurrent.LinkedBlockingQueue;
+
+public class IsabelleProcess {
+    private volatile Process proc = null;
+    private volatile String pid = null;
+    private volatile boolean closing = false;
+    private LinkedBlockingQueue<String> output = null;
+
+
+    /* exceptions */
+
+    public static class IsabelleProcessException extends Exception {
+        public IsabelleProcessException() {
+            super();
+        }
+        public IsabelleProcessException(String msg) {
+            super(msg);
+        }
+    };
+
+
+    /* results from the process */
+
+    public static class Result {
+        public enum Kind {
+            STDIN, STDOUT, STDERR, SIGNAL, EXIT,                // Posix channels/events
+            WRITELN, PRIORITY, TRACING, WARNING, ERROR, DEBUG,  // Isabelle messages
+            SYSTEM                                              // internal system notification
+        };
+        public Kind kind;
+        public String result;
+
+        public Result(Kind kind, String result) {
+            this.kind = kind;
+            this.result = result;
+        }
+
+        public String toString() {
+            return this.kind.toString() + " [[" + this.result + "]]";
+        }
+    }
+
+    public LinkedBlockingQueue<Result> results;
+
+    private synchronized void putResult(Result.Kind kind, String result) {
+        try {
+            results.put(new Result(kind, result));
+        } catch (InterruptedException exn) {  }
+    }
+
+
+    /* interrupt process */
+
+    public synchronized void interrupt() throws IsabelleProcessException
+    {
+        if (proc != null && pid != null) {
+            try {
+                putResult(Result.Kind.SIGNAL, "INT");
+                int rc = Runtime.getRuntime().exec("kill -INT " + pid).waitFor();
+                if (rc != 0) {
+                    throw new IsabelleProcessException("Cannot interrupt: kill command failed");
+                }
+            } catch (IOException exn) {
+                throw new IsabelleProcessException(exn.getMessage());
+            } catch (InterruptedException exn) {
+                throw new IsabelleProcessException("Cannot interrupt: aborted");
+            }
+        } else {
+            throw new IsabelleProcessException("Cannot interrupt: no process");
+        }
+    }
+
+
+    /* kill process */
+
+    public synchronized void kill() throws IsabelleProcessException
+    {
+        if (proc != null) {
+            tryClose();
+            try {
+                Thread.sleep(300);
+            } catch (InterruptedException exn) { }
+            putResult(Result.Kind.SIGNAL, "KILL");
+            proc.destroy();
+            proc = null;
+        } else {
+            throw new IsabelleProcessException("Cannot kill: no process");
+        }
+    }
+
+
+    /* encode text as string token */
+
+    public static String encodeString(String str) {
+        Locale locale = null;
+        StringBuffer buf = new StringBuffer(100);
+        int i;
+        char c;
+
+        buf.append("\"");
+        for (i = 0; i < str.length(); i++) {
+            c = str.charAt(i);
+            if (c < 32 || c == '\\' || c == '\"') {
+                buf.append(String.format(locale, "\\%03d", (int) c));
+            } else {
+                buf.append(c);
+            }
+        }
+        buf.append("\"");
+        return buf.toString();
+    }
+
+
+    /* output being piped into the process (stdin) */
+
+    private volatile BufferedWriter outputWriter;
+    private class OutputThread extends Thread
+    {
+        public void run()
+        {
+            while (outputWriter != null) {
+                try {
+                    String s = output.take();
+                    if (s.equals("\u0000")) {
+                        outputWriter.close();
+                        outputWriter = null;
+                    } else {
+                        putResult(Result.Kind.STDIN, s);
+                        outputWriter.write(s);
+                        outputWriter.flush();
+                    }
+                } catch (InterruptedException exn) {
+                    putResult(Result.Kind.SYSTEM, "Output thread interrupted");
+                } catch (IOException exn) {
+                    putResult(Result.Kind.SYSTEM, exn.getMessage());
+                }
+            }
+            putResult(Result.Kind.SYSTEM, "Output thread terminated");
+        }
+    }
+    private OutputThread outputThread;
+
+
+    // public operations
+
+    public synchronized void output(String text) throws IsabelleProcessException
+    {
+        if (proc != null && !closing) {
+            try {
+                output.put(text);
+            } catch (InterruptedException ex) {
+               throw new IsabelleProcessException("Cannot output: aborted");
+            }
+        } else if (proc == null) {
+            throw new IsabelleProcessException("Cannot output: no process");
+        } else {
+            throw new IsabelleProcessException("Cannot output: already closing");
+        }
+    }
+
+    public synchronized void close() throws IsabelleProcessException
+    {
+        output("\u0000");
+        closing = true;
+        // FIXME watchdog/timeout
+    }
+
+    public synchronized void tryClose()
+    {
+        if (proc != null && !closing) {
+            try {
+                close();
+            } catch (IsabelleProcessException ex) {  }
+        }
+    }
+
+    private synchronized void outputSync(String text) throws IsabelleProcessException
+    {
+        output(" \\<^sync>\n; " + text + " \\<^sync>;\n");
+    }
+
+    public synchronized void command(String text) throws IsabelleProcessException
+    {
+        outputSync("Isabelle.command " + encodeString(text));
+    }
+
+    public synchronized void ML(String text) throws IsabelleProcessException
+    {
+        outputSync("ML " + encodeString(text));
+    }
+
+
+    /* input from the process (stdout/stderr) */
+
+    private volatile BufferedReader inputReader;
+    private class InputThread extends Thread
+    {
+        public void run()
+        {
+            Result.Kind kind = Result.Kind.STDOUT;
+            StringBuffer buf = new StringBuffer(100);
+
+            try {
+                while (inputReader != null) {
+                    if (kind == Result.Kind.STDOUT && pid != null) {
+                        // char mode
+                        int c = -1;
+                        while ((buf.length() == 0 || inputReader.ready()) &&
+                                  (c = inputReader.read()) > 0 && c != 2) {
+                            buf.append((char) c);
+                        }
+                        if (buf.length() > 0) {
+                            putResult(kind, buf.toString());
+                            buf = new StringBuffer(100);
+                        }
+                        if (c == 2) {
+                            c = inputReader.read();
+                            switch (c) {
+                                case 'A': kind = Result.Kind.WRITELN; break;
+                                case 'B': kind = Result.Kind.PRIORITY; break;
+                                case 'C': kind = Result.Kind.TRACING; break;
+                                case 'D': kind = Result.Kind.WARNING; break;
+                                case 'E': kind = Result.Kind.ERROR; break;
+                                case 'F': kind = Result.Kind.DEBUG; break;
+                                default: kind = Result.Kind.STDOUT; break;
+                            }
+                        }
+                        if (c == -1) {
+                            inputReader.close();
+                            inputReader = null;
+                            tryClose();
+                        }
+                    } else {
+                        // line mode
+                        String line = null;
+                        if ((line = inputReader.readLine()) != null) {
+                            if (pid == null && kind == Result.Kind.STDOUT && line.startsWith("PID=")) {
+                                pid = line.substring("PID=".length());
+                            } else if (kind == Result.Kind.STDOUT) {
+                                buf.append(line);
+                                buf.append("\n");
+                                putResult(kind, buf.toString());
+                                buf = new StringBuffer(100);
+                            } else {
+                                int len = line.length();
+                                if (len >= 2 && line.charAt(len - 2) == 2 && line.charAt(len - 1) == '.') {
+                                    buf.append(line.substring(0, len - 2));
+                                    putResult(kind, buf.toString());
+                                    buf = new StringBuffer(100);
+                                    kind = Result.Kind.STDOUT;
+                                } else {
+                                    buf.append(line);
+                                    buf.append("\n");
+                                }
+                            }
+                        } else {
+                            inputReader.close();
+                            inputReader = null;
+                            tryClose();
+                        }
+                    }
+                }
+            } catch (IOException exn) {
+                putResult(Result.Kind.SYSTEM, exn.getMessage());
+            }
+            putResult(Result.Kind.SYSTEM, "Input thread terminated");
+        }
+    }
+    private InputThread inputThread;
+
+    private volatile BufferedReader errorReader;
+    private class ErrorThread extends Thread
+    {
+        public void run()
+        {
+            try {
+                while (errorReader != null) {
+                    StringBuffer buf = new StringBuffer(100);
+                    int c;
+                    while ((buf.length() == 0 || errorReader.ready()) && (c = errorReader.read()) > 0) {
+                        buf.append((char) c);
+                    }
+                    if (buf.length() > 0) {
+                        putResult(Result.Kind.STDERR, buf.toString());
+                    } else {
+                        errorReader.close();
+                        errorReader = null;
+                        tryClose();
+                    }
+                }
+            } catch (IOException exn) {
+                putResult(Result.Kind.SYSTEM, exn.getMessage());
+            }
+            putResult(Result.Kind.SYSTEM, "Error thread terminated");
+        }
+    }
+    private ErrorThread errorThread;
+
+
+    /* exit thread */
+
+    private class ExitThread extends Thread
+    {
+        public void run()
+        {
+            try {
+                int rc = proc.waitFor();
+                putResult(Result.Kind.EXIT, Integer.toString(rc));
+                proc = null;
+            } catch (InterruptedException exn) {
+                putResult(Result.Kind.SYSTEM, "Exit thread interrupted");
+            }
+            putResult(Result.Kind.SYSTEM, "Exit thread terminated");
+        }
+    }
+    private ExitThread exitThread;
+
+
+    /* create process */
+
+    public IsabelleProcess(String logic) throws IsabelleProcessException
+    {
+        String [] cmdline = {"bash", "isabelle-process", "-W", logic};
+        String charset = "UTF-8";
+        try {
+            proc = Runtime.getRuntime().exec(cmdline);
+        } catch (IOException exn) {
+            throw new IsabelleProcessException(exn.getMessage());
+        }
+
+        try {
+            outputWriter = new BufferedWriter(new OutputStreamWriter(proc.getOutputStream(), charset));
+            inputReader = new BufferedReader(new InputStreamReader(proc.getInputStream(), charset));
+            errorReader = new BufferedReader(new InputStreamReader(proc.getErrorStream(), charset));
+        } catch (UnsupportedEncodingException exn) {
+            proc.destroy();
+            throw new Error(exn.getMessage());
+        }
+
+        output = new LinkedBlockingQueue<String>();
+        outputThread = new OutputThread();
+
+        results = new LinkedBlockingQueue<Result>();
+        inputThread = new InputThread();
+        errorThread = new ErrorThread();
+        exitThread = new ExitThread();
+
+        outputThread.start();
+        inputThread.start();
+        errorThread.start();
+        exitThread.start();
+    }
+}