| /* |
| * Copyright (c) 2005, 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 sun.java2d.pipe; |
| |
| import java.util.HashSet; |
| import java.util.Set; |
| import sun.awt.SunToolkit; |
| |
| /** |
| * The RenderQueue class encapsulates a RenderBuffer on which rendering |
| * operations are enqueued. Note that the RenderQueue lock must be acquired |
| * before performing any operations on the queue (e.g. enqueuing an operation |
| * or flushing the queue). A sample usage scenario follows: |
| * |
| * public void drawSomething(...) { |
| * rq.lock(); |
| * try { |
| * ctx.validate(...); |
| * rq.ensureCapacity(4); |
| * rq.getBuffer().putInt(DRAW_SOMETHING); |
| * ... |
| * } finally { |
| * rq.unlock(); |
| * } |
| * } |
| * |
| * If you are enqueuing an operation that involves 8-byte parameters (i.e. |
| * long or double values), it is imperative that you ensure proper |
| * alignment of the underlying RenderBuffer. This can be accomplished |
| * simply by providing an offset to the first 8-byte parameter in your |
| * operation to the ensureCapacityAndAlignment() method. For example: |
| * |
| * public void drawStuff(...) { |
| * rq.lock(); |
| * try { |
| * RenderBuffer buf = rq.getBuffer(); |
| * ctx.validate(...); |
| * // 28 total bytes in the operation, 12 bytes to the first long |
| * rq.ensureCapacityAndAlignment(28, 12); |
| * buf.putInt(DRAW_STUFF); |
| * buf.putInt(x).putInt(y); |
| * buf.putLong(addr1); |
| * buf.putLong(addr2); |
| * } finally { |
| * rq.unlock(); |
| * } |
| * } |
| */ |
| public abstract class RenderQueue { |
| |
| /** The size of the underlying buffer, in bytes. */ |
| private static final int BUFFER_SIZE = 32000; |
| |
| /** The underlying buffer for this queue. */ |
| protected RenderBuffer buf; |
| |
| /** |
| * A Set containing hard references to Objects that must stay alive until |
| * the queue has been completely flushed. |
| */ |
| protected Set refSet; |
| |
| protected RenderQueue() { |
| refSet = new HashSet(); |
| buf = RenderBuffer.allocate(BUFFER_SIZE); |
| } |
| |
| /** |
| * Locks the queue for read/write access. |
| */ |
| public final void lock() { |
| /* |
| * Implementation note: In theory we should have two separate locks: |
| * one lock to synchronize access to the RenderQueue, and then a |
| * separate lock (the AWT lock) that only needs to be acquired when |
| * we are about to flush the queue (using native windowing system |
| * operations). In practice it has been difficult to enforce the |
| * correct lock ordering; sometimes AWT will have already acquired |
| * the AWT lock before grabbing the RQ lock (see 6253009), while the |
| * expected order should be RQ lock and then AWT lock. Due to this |
| * issue, using two separate locks is prone to deadlocks. Therefore, |
| * to solve this issue we have decided to eliminate the separate RQ |
| * lock and instead just acquire the AWT lock here. (Someday it might |
| * be nice to go back to the old two-lock system, but that would |
| * require potentially risky changes to AWT to ensure that it never |
| * acquires the AWT lock before calling into 2D code that wants to |
| * acquire the RQ lock.) |
| */ |
| SunToolkit.awtLock(); |
| } |
| |
| /** |
| * Attempts to lock the queue. If successful, this method returns true, |
| * indicating that the caller is responsible for calling |
| * <code>unlock</code>; otherwise this method returns false. |
| */ |
| public final boolean tryLock() { |
| return SunToolkit.awtTryLock(); |
| } |
| |
| /** |
| * Unlocks the queue. |
| */ |
| public final void unlock() { |
| SunToolkit.awtUnlock(); |
| } |
| |
| /** |
| * Adds the given Object to the set of hard references, which will |
| * prevent that Object from being disposed until the queue has been |
| * flushed completely. This is useful in cases where some enqueued |
| * data could become invalid if the reference Object were garbage |
| * collected before the queue could be processed. (For example, keeping |
| * a hard reference to a FontStrike will prevent any enqueued glyph |
| * images associated with that strike from becoming invalid before the |
| * queue is flushed.) The reference set will be cleared immediately |
| * after the queue is flushed each time. |
| */ |
| public final void addReference(Object ref) { |
| refSet.add(ref); |
| } |
| |
| /** |
| * Returns the encapsulated RenderBuffer object. |
| */ |
| public final RenderBuffer getBuffer() { |
| return buf; |
| } |
| |
| /** |
| * Ensures that there will be enough room on the underlying buffer |
| * for the following operation. If the operation will not fit given |
| * the remaining space, the buffer will be flushed immediately, leaving |
| * an empty buffer for the impending operation. |
| * |
| * @param opsize size (in bytes) of the following operation |
| */ |
| public final void ensureCapacity(int opsize) { |
| if (buf.remaining() < opsize) { |
| flushNow(); |
| } |
| } |
| |
| /** |
| * Convenience method that is equivalent to calling ensureCapacity() |
| * followed by ensureAlignment(). The ensureCapacity() call allows for an |
| * extra 4 bytes of space in case the ensureAlignment() method needs to |
| * insert a NOOP token on the buffer. |
| * |
| * @param opsize size (in bytes) of the following operation |
| * @param first8ByteValueOffset offset (in bytes) from the current |
| * position to the first 8-byte value used in the following operation |
| */ |
| public final void ensureCapacityAndAlignment(int opsize, |
| int first8ByteValueOffset) |
| { |
| ensureCapacity(opsize + 4); |
| ensureAlignment(first8ByteValueOffset); |
| } |
| |
| /** |
| * Inserts a 4-byte NOOP token when necessary to ensure that all 8-byte |
| * parameters for the following operation are added to the underlying |
| * buffer with an 8-byte memory alignment. |
| * |
| * @param first8ByteValueOffset offset (in bytes) from the current |
| * position to the first 8-byte value used in the following operation |
| */ |
| public final void ensureAlignment(int first8ByteValueOffset) { |
| int first8ByteValuePosition = buf.position() + first8ByteValueOffset; |
| if ((first8ByteValuePosition & 7) != 0) { |
| buf.putInt(BufferedOpCodes.NOOP); |
| } |
| } |
| |
| /** |
| * Immediately processes each operation currently pending on the buffer. |
| * This method will block until the entire buffer has been flushed. The |
| * queue lock must be acquired before calling this method. |
| */ |
| public abstract void flushNow(); |
| |
| /** |
| * Immediately processes each operation currently pending on the buffer, |
| * and then invokes the provided task. This method will block until the |
| * entire buffer has been flushed and the provided task has been executed. |
| * The queue lock must be acquired before calling this method. |
| */ |
| public abstract void flushAndInvokeNow(Runnable task); |
| |
| /** |
| * Updates the current position of the underlying buffer, and then |
| * flushes the queue immediately. This method is useful when native code |
| * has added data to the queue and needs to flush immediately. |
| */ |
| public void flushNow(int position) { |
| buf.position(position); |
| flushNow(); |
| } |
| } |