diff options
Diffstat (limited to 'java/src')
| -rw-r--r-- | java/src/Ice/src/main/java/IceUtil/Cache.java | 298 | ||||
| -rw-r--r-- | java/src/Ice/src/main/java/IceUtil/FileLockException.java | 71 | ||||
| -rw-r--r-- | java/src/Ice/src/main/java/IceUtil/Store.java | 25 | ||||
| -rw-r--r-- | java/src/Ice/src/main/java/IceUtilInternal/FileLock.java | 169 |
4 files changed, 0 insertions, 563 deletions
diff --git a/java/src/Ice/src/main/java/IceUtil/Cache.java b/java/src/Ice/src/main/java/IceUtil/Cache.java deleted file mode 100644 index 8c60c7bef15..00000000000 --- a/java/src/Ice/src/main/java/IceUtil/Cache.java +++ /dev/null @@ -1,298 +0,0 @@ -// ********************************************************************** -// -// Copyright (c) 2003-2015 ZeroC, Inc. All rights reserved. -// -// This copy of Ice is licensed to you under the terms described in the -// ICE_LICENSE file included in this distribution. -// -// ********************************************************************** - -package IceUtil; - -/** - * An abstraction to efficiently maintain a cache, without holding - * a lock on the entire cache while objects are being loaded from - * their backing store. This class is useful mainly to implement - * evictors, such as used by Freeze. - * - * @see Store - * @see Freeze.Evictor - **/ - -public class Cache -{ - /** - * Initialize a cache using the specified backing store. - **/ - public Cache(Store store) - { - _store = store; - } - - /** - * Return the value stored for the given key from the cache. - * - * @param key The key for the object to look up in the cache. - * - * @return If the cache contains an entry for the key, the return value - * is the object corresponding to the key; otherwise, the return value - * is null. <code>getIfPinned</code> does not call {@link Store#load}. - * - * @see Store#load - **/ - public Object - getIfPinned(Object key) - { - synchronized(_map) - { - CacheValue val = _map.get(key); - return val == null ? null : val.obj; - } - } - - /** - * Removes the entry for the given key from the cache. - * - * @param key The key for the entry to remove. - * - * @return If the cache contains an entry for the key, the - * return value is the corresponding object; otherwise, the - * return value is <code>null</code>. - **/ - public Object - unpin(Object key) - { - synchronized(_map) - { - CacheValue val = _map.remove(key); - return val == null ? null : val.obj; - } - } - - /** - * Removes all entries from the cache. - **/ - public void - clear() - { - synchronized(_map) - { - _map.clear(); - } - } - - /** - * Returns the number of entries in the cache. - * - * @return The number of entries. - **/ - public int - size() - { - synchronized(_map) - { - return _map.size(); - } - } - - /** - * Adds a key-value pair to the cache. - * This version of <code>pin</code> does not call {@link Store#load} to retrieve - * an entry from backing store if an entry for the given key is not yet in the cache. This - * is useful to add a newly-created object to the cache. - * - * @param key The key for the entry. - * @param o The value for the entry. - * @return If the cache already contains an entry with the given key, the entry is - * unchanged and <code>pin(Object, Object)</code> returns the original value for the entry; otherwise, - * the entry is added and <code>pin(Object, Object)</code> returns <code>null</code>. - **/ - public Object - pin(Object key, Object o) - { - synchronized(_map) - { - CacheValue existingVal = _map.put(key, new CacheValue(o)); - if(existingVal != null) - { - _map.put(key, existingVal); - return existingVal.obj; - } - else - { - return null; - } - } - } - - /** - * Returns an object from the cache. - * If no entry with the given key is in the cache, <code>pin</code> calls - * {@link Store#load} to retrieve the corresponding value (if any) from the - * backing store. - * - * @param key The key for the entry to retrieve. - * @return Returns the value for the corresponding key if the cache - * contains an entry for the key. Otherwise, <code>pin(Object)</code> calls - * {@link Store#load} and the return value is whatever is returned by - * <code>load</code>; if <code>load</code> throws an exception, that exception - * is thrown by <code>pin(Object)</code>. - **/ - public Object - pin(Object key) - { - return pinImpl(key, null); - } - - /** - * Adds a key-value pair to the cache. - * @param key The key for the entry. - * @param newObj The value for the entry. - * @return If the cache already contains an entry for the given key, - * <code>putIfAbsent</code> returns the original value for that key. - * If no entry is for the given key is in the cache, <code>putIfAbsent</code> - * calls {@link Store#load} to retrieve the corresponding entry (if any) from - * the backings store and returns the value returned by <code>load</code>. - * If the cache does not contain an entry for the given key and <code>load</code> - * does not return a value for the key, <code>putIfAbsent</code> adds the new entry - * and returns <code>null</code>. - **/ - public Object - putIfAbsent(Object key, Object newObj) - { - return pinImpl(key, newObj); - } - - static private class CacheValue - { - CacheValue() - { - } - - CacheValue(Object obj) - { - this.obj = obj; - } - - Object obj = null; - java.util.concurrent.CountDownLatch latch = null; - } - - private Object - pinImpl(Object key, Object newObj) - { - for(;;) - { - CacheValue val = null; - java.util.concurrent.CountDownLatch latch = null; - - synchronized(_map) - { - val = _map.get(key); - if(val == null) - { - val = new CacheValue(); - _map.put(key, val); - } - else - { - if(val.obj != null) - { - return val.obj; - } - if(val.latch == null) - { - // - // The first queued thread creates the latch - // - val.latch = new java.util.concurrent.CountDownLatch(1); - } - latch = val.latch; - } - } - - if(latch != null) - { - try - { - latch.await(); - } - catch(InterruptedException e) - { - // Ignored - } - - // - // val could be stale now, e.g. some other thread pinned and unpinned the - // object while we were waiting. - // So start over. - // - continue; - } - else - { - Object obj; - try - { - obj = _store.load(key); - } - catch(RuntimeException e) - { - synchronized(_map) - { - _map.remove(key); - latch = val.latch; - val.latch = null; - } - if(latch != null) - { - latch.countDown(); - assert latch.getCount() == 0; - } - throw e; - } - - synchronized(_map) - { - if(obj != null) - { - val.obj = obj; - } - else - { - if(newObj == null) - { - // - // pin() did not find the object - // - - // - // The waiting threads will have to call load() to see by themselves. - // - _map.remove(key); - } - else - { - // - // putIfAbsent() inserts key/newObj - // - val.obj = newObj; - } - } - - latch = val.latch; - val.latch = null; - } - if(latch != null) - { - latch.countDown(); - assert latch.getCount() == 0; - } - return obj; - } - } - } - - private final java.util.Map<Object, CacheValue> _map = new java.util.HashMap<Object, CacheValue>(); - private final Store _store; -} diff --git a/java/src/Ice/src/main/java/IceUtil/FileLockException.java b/java/src/Ice/src/main/java/IceUtil/FileLockException.java deleted file mode 100644 index 74d2568596f..00000000000 --- a/java/src/Ice/src/main/java/IceUtil/FileLockException.java +++ /dev/null @@ -1,71 +0,0 @@ -// ********************************************************************** -// -// Copyright (c) 2003-2015 ZeroC, Inc. All rights reserved. -// -// This copy of Ice is licensed to you under the terms described in the -// ICE_LICENSE file included in this distribution. -// -// ********************************************************************** - -package IceUtil; - -public class FileLockException extends RuntimeException implements Cloneable -{ - public FileLockException() - { - } - - public FileLockException(String path) - { - this.path = path; - } - - public FileLockException(Throwable cause) - { - super(cause); - } - - public FileLockException(String path, Throwable cause) - { - super(cause); - this.path = path; - } - - @Override - public FileLockException clone() - { - FileLockException c = null; - try - { - c = (FileLockException)super.clone(); - } - catch(CloneNotSupportedException ex) - { - assert false; - } - return c; - } - - public String - ice_name() - { - return "IceUtil::FileLockException"; - } - - @Override - public String - toString() - { - java.io.StringWriter sw = new java.io.StringWriter(); - java.io.PrintWriter pw = new java.io.PrintWriter(sw); - IceUtilInternal.OutputBase out = new IceUtilInternal.OutputBase(pw); - out.setUseTab(false); - out.print(getClass().getName()); - out.inc(); - IceInternal.ValueWriter.write(this, out); - pw.flush(); - return sw.toString(); - } - - public String path; -} diff --git a/java/src/Ice/src/main/java/IceUtil/Store.java b/java/src/Ice/src/main/java/IceUtil/Store.java deleted file mode 100644 index 63f45783660..00000000000 --- a/java/src/Ice/src/main/java/IceUtil/Store.java +++ /dev/null @@ -1,25 +0,0 @@ -// ********************************************************************** -// -// Copyright (c) 2003-2015 ZeroC, Inc. All rights reserved. -// -// This copy of Ice is licensed to you under the terms described in the -// ICE_LICENSE file included in this distribution. -// -// ********************************************************************** - -package IceUtil; - -/** - * A base interface for retrieving persistent objects from a backing store. - **/ - -public interface Store -{ - /** - * Instantiate an object, initializing its state from a backing store. - * - * @param key The database key for the object to instantiate. - * - **/ - Object load(Object key); -} diff --git a/java/src/Ice/src/main/java/IceUtilInternal/FileLock.java b/java/src/Ice/src/main/java/IceUtilInternal/FileLock.java deleted file mode 100644 index e2049fb1457..00000000000 --- a/java/src/Ice/src/main/java/IceUtilInternal/FileLock.java +++ /dev/null @@ -1,169 +0,0 @@ -// ********************************************************************** -// -// Copyright (c) 2003-2015 ZeroC, Inc. All rights reserved. -// -// This copy of Ice is licensed to you under the terms described in the -// ICE_LICENSE file included in this distribution. -// -// ********************************************************************** - -package IceUtilInternal; - -import java.io.File; -import java.io.RandomAccessFile; -import java.nio.channels.FileChannel; -import java.lang.reflect.Method; - -public final class FileLock -{ - // - // The constructor opens the given file (eventually creating it) - // and acquires a lock on the file or throws FileLockException if - // the file couldn't be locked. - // - // If the lock can be acquired, the Java VM name is written to the - // file. - // - public FileLock(String path) - { - _file = new File(path); - - FileChannel channel; - try - { - _randFile = new RandomAccessFile(_file, "rw"); - channel = _randFile.getChannel(); - } - catch(java.io.FileNotFoundException e) - { - throw new IceUtil.FileLockException(path); - } - - java.nio.channels.FileLock lock; - try - { - lock = channel.tryLock(); - } - catch(Exception ex) - { - throw new IceUtil.FileLockException(path, ex); - } - - if(lock == null) - { - throw new IceUtil.FileLockException(path); - } - - // - // In Windows we don't write the process pid to the file, as is not posible - // to read the file from other process while it is locked here. - // - if(!System.getProperty("os.name").startsWith("Windows")) - { - try - { - // - // Java doesn't provide get pid operation. This code - // writes the Java VM name instead of the pid. - // - // The output is JVM dependent. With the Sun - // implementation it's `pid@hostname' - // - try - { - // - // We access java.lang.management classes using reflection - // because these classes are not available with Android - // Dalvik JVM. - // - if(!System.getProperty("java.vm.name").startsWith("Dalvik")) - { - Class<?> fC = IceInternal.Util.findClass("java.lang.management.ManagementFactory", null); - Class<?> mC = IceInternal.Util.findClass("java.lang.management.RuntimeMXBean", null); - - Method getRuntimeMXBean = fC.getDeclaredMethod("getRuntimeMXBean", (Class<?>[])null); - - Method getName = mC.getDeclaredMethod("getName", (Class<?>[])null); - - Object mxBean = getRuntimeMXBean.invoke(null); - _randFile.writeUTF((String)getName.invoke(mxBean)); - } - else - { - // - // In Android with Dalvik we can use android.os.Process to get the - // process pid. That is done using reflection because it is specific - // for Android Dalvik VM. - // - Class<?> pC = IceInternal.Util.findClass("android.os.Process", null); - Method myPid = pC.getDeclaredMethod("myPid", (Class<?>[])null); - _randFile.writeUTF(((Integer)myPid.invoke(null)).toString()); - } - } - catch(NoSuchMethodException ex) - { - } - catch(IllegalAccessException ex) - { - } - catch(java.lang.reflect.InvocationTargetException ex) - { - } - // - // Don't close _randFile here or the lock will be released. It is called - // during release see comments there. - // - } - catch(java.io.IOException ex) - { - release(); - throw new IceUtil.FileLockException(path, ex); - } - } - } - - // - // Remove the lock if it is owned by the class instance. - // - public void release() - { - if(System.getProperty("os.name").startsWith("Windows")) - { - if(_randFile != null) - { - // - // In Windows we need to close the file handler before - // we try to delete the file. Note that the call to close - // also release the file lock. - // - try - { - _randFile.close(); - } - catch(java.io.IOException ex) - { - } - _randFile = null; - } - } - // - // on UNIX the call to delete remove the file and that - // release the lock. - // - // In Windows the call to delete will success if at that point - // the file has not been opened by any process. - // - if(_file != null) - { - _file.delete(); - _file = null; - } - } - - // - // We need to keep these refrences to delete the lock file during release - // - private File _file; - private RandomAccessFile _randFile; - -} |