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view graal/com.oracle.max.base/src/com/sun/max/program/Trace.java @ 4186:71a2cd79c375
Made stdout for mx unbuffered.
author | Doug Simon <doug.simon@oracle.com> |
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date | Tue, 03 Jan 2012 13:53:38 +0100 |
parents | bc8527f3071c |
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/* * Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package com.sun.max.program; import java.io.*; import com.sun.max.annotate.*; import com.sun.max.io.*; import com.sun.max.program.option.*; /** * Tracing output for debugging purposes. No performance impact when disabled. Some performance impact when active, even * without output. Possibly significant performance impact when producing a lot of output. */ public final class Trace { private Trace() { // do nothing. } private static PrintStream stream; public static PrintStream stream() { return stream; } public static void setStream(PrintStream stream) { Trace.stream = stream; } private static final boolean showThread; static { showThread = System.getProperty("max.trace.showThread") != null; final String traceFileName = System.getProperty("max.trace.file"); stream = System.out; if (traceFileName != null) { final File traceFile = new File(traceFileName); try { final OutputStream fileStream = new BufferedOutputStream(new FileOutputStream(traceFile)); if (System.getProperty("max.trace.noconsole") != null) { stream = new PrintStream(fileStream); } else { stream = new PrintStream(new MultiOutputStream(fileStream, System.out)); } } catch (IOException ioException) { System.err.println("Could not open file for trace output: " + traceFile.getAbsolutePath()); } } } /** * Static master switch. Set by source code editing only (for now). * * Set '_enabled' to 'true' to enable tracing output, according to your other trace-related settings. * * Set '_enabled' to 'false' to prevent any tracing. All tracing routines will thus become dead code. The optimizing * compiler should then be able to eliminate the runtime overhead. */ private static final boolean ENABLED = true; public static void addTo(OptionSet options) { options.addOption(new Option<Integer>("trace", 0, OptionTypes.INT_TYPE, "Sets tracing level.") { @Override public void setValue(Integer value) { super.setValue(value); level = value; } }); } /** * Dynamically sets tracing level, causing trace commands at this or lower levels to produce output. */ public static void on(int newLevel) { assert newLevel >= 0; level = newLevel; } /** * Dynamically turns tracing on for all levels. */ public static void on() { on(Integer.MAX_VALUE); } @RESET private static long count; /** * The threshold of trace calls before traces are actually sent to the trace stream. * * This field can be updated by the inspector. */ @RESET @INSPECTED private static long threshold; /** * The current trace level. * * This field can be updated by the inspector. */ @RESET @INSPECTED private static int level; /** * Dynamically sets the current tracing level to the greater of the current level or the specified new level. */ public static void atLeast(int l) { if (l > level) { level = l; } } /** * Dynamically turns tracing off by setting current level to zero. */ public static void off() { level = 0; } /** * @return current tracing level, which must equal or exceed the level specified by trace commands for output to be produced. */ public static int level() { return level; } /** * Does the current tracing level equal or exceed the specified level. */ public static boolean hasLevel(int requiredLevel) { count++; return level >= requiredLevel && count >= threshold; } @RESET private static int indentation; private static void printInt(int n) { if (n < 10) { stream.write(((char) n) + '0'); } else { final int m = n / 10; printInt(m); printInt(n - (m * 10)); } } /** * This should not cause allocation/GC. */ private static void printPrefix(int requiredLevel) { if (showThread) { stream.print(Thread.currentThread().getName() + " <Trace"); } else { stream.print("<Trace "); } printInt(requiredLevel); stream.print("> "); for (int i = 0; i < indentation; i++) { stream.print(" "); } } /** * Prints a newline on trace output if tracing is globally enabled and current tracing level is at least the level required. */ public static void line(int requiredLevel) { if (ENABLED) { if (hasLevel(requiredLevel)) { stream.println(); stream.flush(); } } } /** * Prints a line of trace output if tracing is globally enabled and if current tracing level is at least the level required. */ public static void line(int requiredLevel, Object message) { if (ENABLED) { if (hasLevel(requiredLevel)) { printPrefix(requiredLevel); stream.println(message); stream.flush(); } } } /** * Prints a "BEGIN" line of trace output if tracing is globally enabled and if current tracing level is at least the level required; increases indentation. */ public static void begin(int requiredLevel, Object message) { if (ENABLED) { if (hasLevel(requiredLevel)) { printPrefix(requiredLevel); stream.print("BEGIN: "); stream.println(message); stream.flush(); indentation++; } } } /** * Prints an "END" line of trace output if tracing is globally enabled and if current tracing level is at least the level required; decreases indentation. */ public static void end(int requiredLevel, Object message) { end(requiredLevel, message, 0); } /** * Prints an "END" line of trace output if tracing is globally enabled and if current tracing level is at least the level required; decreases indentation; * appends a timing message, expressed in milliseconds, if a non-zero starting time is supplied. * @param requiredLevel * @param message * @param startTimeMillis a starting time, output from {@link System#currentTimeMillis()}; no timing message appears if zero. */ public static void end(int requiredLevel, Object message, long startTimeMillis) { if (ENABLED) { if (hasLevel(requiredLevel)) { final long endTimeMillis = System.currentTimeMillis(); indentation--; // It's quite possible for indentation to go negative in a multithreaded environment //assert _indentation >= 0; printPrefix(requiredLevel); stream.print("END: "); if (startTimeMillis > 0) { stream.print(message); stream.print(" ("); stream.print(endTimeMillis - startTimeMillis); stream.println("ms)"); } else { stream.println(message); stream.flush(); } } } } }