| /* |
| * Copyright (c) 2016, 2019, 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. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * 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 jdk.jfr.internal; |
| |
| import jdk.internal.misc.Unsafe; |
| import jdk.jfr.internal.consumer.StringParser; |
| |
| /** |
| * Class must reside in a package with package restriction. |
| * |
| * Users should not have direct access to underlying memory. |
| * |
| */ |
| public final class EventWriter { |
| private static final Unsafe unsafe = Unsafe.getUnsafe(); |
| private final static JVM jvm = JVM.getJVM(); |
| |
| private long startPosition; |
| private long startPositionAddress; |
| private long currentPosition; |
| private long maxPosition; |
| private final long threadID; |
| private PlatformEventType eventType; |
| private int maxEventSize; |
| private boolean started; |
| private boolean valid; |
| private boolean flushOnEnd; |
| // set by the JVM, not private to avoid being optimized out |
| boolean notified; |
| |
| public static EventWriter getEventWriter() { |
| EventWriter ew = (EventWriter)JVM.getEventWriter(); |
| return ew != null ? ew : JVM.newEventWriter(); |
| } |
| |
| public void putBoolean(boolean i) { |
| if (isValidForSize(Byte.BYTES)) { |
| currentPosition += Bits.putBoolean(currentPosition, i); |
| } |
| } |
| |
| public void putByte(byte i) { |
| if (isValidForSize(Byte.BYTES)) { |
| unsafe.putByte(currentPosition, i); |
| ++currentPosition; |
| } |
| } |
| |
| public void putChar(char v) { |
| if (isValidForSize(Character.BYTES + 1)) { |
| putUncheckedLong(v); |
| } |
| } |
| |
| private void putUncheckedChar(char v) { |
| putUncheckedLong(v); |
| } |
| |
| public void putShort(short v) { |
| if (isValidForSize(Short.BYTES + 1)) { |
| putUncheckedLong(v & 0xFFFF); |
| } |
| } |
| |
| public void putInt(int v) { |
| if (isValidForSize(Integer.BYTES + 1)) { |
| putUncheckedLong(v & 0x00000000ffffffffL); |
| } |
| } |
| |
| private void putUncheckedInt(int v) { |
| putUncheckedLong(v & 0x00000000ffffffffL); |
| } |
| |
| public void putFloat(float i) { |
| if (isValidForSize(Float.BYTES)) { |
| currentPosition += Bits.putFloat(currentPosition, i); |
| } |
| } |
| |
| public void putLong(long v) { |
| if (isValidForSize(Long.BYTES + 1)) { |
| putUncheckedLong(v); |
| } |
| } |
| |
| public void putDouble(double i) { |
| if (isValidForSize(Double.BYTES)) { |
| currentPosition += Bits.putDouble(currentPosition, i); |
| } |
| } |
| |
| public void putString(String s, StringPool pool) { |
| if (s == null) { |
| putByte(StringParser.Encoding.NULL.byteValue()); |
| return; |
| } |
| int length = s.length(); |
| if (length == 0) { |
| putByte(StringParser.Encoding.EMPTY_STRING.byteValue()); |
| return; |
| } |
| if (length > StringPool.MIN_LIMIT && length < StringPool.MAX_LIMIT) { |
| long l = StringPool.addString(s); |
| if (l > 0) { |
| putByte(StringParser.Encoding.CONSTANT_POOL.byteValue()); |
| putLong(l); |
| return; |
| } |
| } |
| putStringValue(s); |
| return; |
| } |
| |
| private void putStringValue(String s) { |
| int length = s.length(); |
| if (isValidForSize(1 + 5 + 3 * length)) { |
| putUncheckedByte(StringParser.Encoding.CHAR_ARRAY.byteValue()); // 1 byte |
| putUncheckedInt(length); // max 5 bytes |
| for (int i = 0; i < length; i++) { |
| putUncheckedChar(s.charAt(i)); // max 3 bytes |
| } |
| } |
| } |
| |
| public void putEventThread() { |
| putLong(threadID); |
| } |
| |
| public void putThread(Thread athread) { |
| if (athread == null) { |
| putLong(0L); |
| } else { |
| putLong(jvm.getThreadId(athread)); |
| } |
| } |
| |
| public void putClass(Class<?> aClass) { |
| if (aClass == null) { |
| putLong(0L); |
| } else { |
| putLong(JVM.getClassIdNonIntrinsic(aClass)); |
| } |
| } |
| |
| public void putStackTrace() { |
| if (eventType.getStackTraceEnabled()) { |
| putLong(jvm.getStackTraceId(eventType.getStackTraceOffset())); |
| } else { |
| putLong(0L); |
| } |
| } |
| |
| private void reserveEventSizeField() { |
| // move currentPosition Integer.Bytes offset from start position |
| if (isValidForSize(Integer.BYTES)) { |
| currentPosition += Integer.BYTES; |
| } |
| } |
| |
| private void reset() { |
| currentPosition = startPosition; |
| if (flushOnEnd) { |
| flushOnEnd = flush(); |
| } |
| valid = true; |
| started = false; |
| } |
| |
| private boolean isValidForSize(int requestedSize) { |
| if (!valid) { |
| return false; |
| } |
| if (currentPosition + requestedSize > maxPosition) { |
| flushOnEnd = flush(usedSize(), requestedSize); |
| // retry |
| if (!valid) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| private boolean isNotified() { |
| return notified; |
| } |
| |
| private void resetNotified() { |
| notified = false; |
| } |
| |
| private int usedSize() { |
| return (int) (currentPosition - startPosition); |
| } |
| |
| private boolean flush() { |
| return flush(usedSize(), 0); |
| } |
| |
| private boolean flush(int usedSize, int requestedSize) { |
| return JVM.flush(this, usedSize, requestedSize); |
| } |
| |
| public boolean beginEvent(PlatformEventType eventType) { |
| if (started) { |
| // recursive write attempt |
| return false; |
| } |
| started = true; |
| this.eventType = eventType; |
| reserveEventSizeField(); |
| putLong(eventType.getId()); |
| return true; |
| } |
| |
| public boolean endEvent() { |
| if (!valid) { |
| reset(); |
| return true; |
| } |
| final int eventSize = usedSize(); |
| if (eventSize > maxEventSize) { |
| reset(); |
| return true; |
| } |
| Bits.putInt(startPosition, makePaddedInt(eventSize)); |
| if (isNotified()) { |
| resetNotified(); |
| reset(); |
| // returning false will trigger restart of the event write attempt |
| return false; |
| } |
| startPosition = currentPosition; |
| unsafe.putAddress(startPositionAddress, startPosition); |
| // the event is now committed |
| if (flushOnEnd) { |
| flushOnEnd = flush(); |
| } |
| started = false; |
| return true; |
| } |
| |
| private EventWriter(long startPos, long maxPos, long startPosAddress, long threadID, boolean valid) { |
| startPosition = currentPosition = startPos; |
| maxPosition = maxPos; |
| startPositionAddress = startPosAddress; |
| this.threadID = threadID; |
| started = false; |
| flushOnEnd = false; |
| this.valid = valid; |
| notified = false; |
| // event may not exceed size for a padded integer |
| maxEventSize = (1 << 28) -1; |
| } |
| |
| private static int makePaddedInt(int v) { |
| // bit 0-6 + pad => bit 24 - 31 |
| long b1 = (((v >>> 0) & 0x7F) | 0x80) << 24; |
| |
| // bit 7-13 + pad => bit 16 - 23 |
| long b2 = (((v >>> 7) & 0x7F) | 0x80) << 16; |
| |
| // bit 14-20 + pad => bit 8 - 15 |
| long b3 = (((v >>> 14) & 0x7F) | 0x80) << 8; |
| |
| // bit 21-28 => bit 0 - 7 |
| long b4 = (((v >>> 21) & 0x7F)) << 0; |
| |
| return (int) (b1 + b2 + b3 + b4); |
| } |
| |
| private void putUncheckedLong(long v) { |
| if ((v & ~0x7FL) == 0L) { |
| putUncheckedByte((byte) v); // 0-6 |
| return; |
| } |
| putUncheckedByte((byte) (v | 0x80L)); // 0-6 |
| v >>>= 7; |
| if ((v & ~0x7FL) == 0L) { |
| putUncheckedByte((byte) v); // 7-13 |
| return; |
| } |
| putUncheckedByte((byte) (v | 0x80L)); // 7-13 |
| v >>>= 7; |
| if ((v & ~0x7FL) == 0L) { |
| putUncheckedByte((byte) v); // 14-20 |
| return; |
| } |
| putUncheckedByte((byte) (v | 0x80L)); // 14-20 |
| v >>>= 7; |
| if ((v & ~0x7FL) == 0L) { |
| putUncheckedByte((byte) v); // 21-27 |
| return; |
| } |
| putUncheckedByte((byte) (v | 0x80L)); // 21-27 |
| v >>>= 7; |
| if ((v & ~0x7FL) == 0L) { |
| putUncheckedByte((byte) v); // 28-34 |
| return; |
| } |
| putUncheckedByte((byte) (v | 0x80L)); // 28-34 |
| v >>>= 7; |
| if ((v & ~0x7FL) == 0L) { |
| putUncheckedByte((byte) v); // 35-41 |
| return; |
| } |
| putUncheckedByte((byte) (v | 0x80L)); // 35-41 |
| v >>>= 7; |
| if ((v & ~0x7FL) == 0L) { |
| putUncheckedByte((byte) v); // 42-48 |
| return; |
| } |
| putUncheckedByte((byte) (v | 0x80L)); // 42-48 |
| v >>>= 7; |
| |
| if ((v & ~0x7FL) == 0L) { |
| putUncheckedByte((byte) v); // 49-55 |
| return; |
| } |
| putUncheckedByte((byte) (v | 0x80L)); // 49-55 |
| putUncheckedByte((byte) (v >>> 7)); // 56-63, last byte as is. |
| } |
| |
| private void putUncheckedByte(byte i) { |
| unsafe.putByte(currentPosition, i); |
| ++currentPosition; |
| } |
| } |