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Fix NPE in FileObserver when multiple events pile in for a defunct

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observer.  Also, fix up some bogus whitespace (hard tabs, etc).
This commit is contained in:
Dan Egnor
2010-02-05 13:52:35 -08:00
parent 53bd2522ca
commit d95244faef
1 changed files with 61 additions and 59 deletions
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120
core/java/android/os/FileObserver.java
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@@ -52,73 +52,75 @@ public abstract class FileObserver {
public static final int ALL_EVENTS = ACCESS | MODIFY | ATTRIB | CLOSE_WRITE
| CLOSE_NOWRITE | OPEN | MOVED_FROM | MOVED_TO | DELETE | CREATE
| DELETE_SELF | MOVE_SELF;
| DELETE_SELF | MOVE_SELF;
private static final String LOG_TAG = "FileObserver";
private static class ObserverThread extends Thread {
private HashMap<Integer, WeakReference> m_observers = new HashMap<Integer, WeakReference>();
private int m_fd;
private HashMap<Integer, WeakReference> m_observers = new HashMap<Integer, WeakReference>();
private int m_fd;
public ObserverThread() {
super("FileObserver");
m_fd = init();
}
public ObserverThread() {
super("FileObserver");
m_fd = init();
}
public void run() {
observe(m_fd);
}
public void run() {
observe(m_fd);
}
public int startWatching(String path, int mask, FileObserver observer) {
int wfd = startWatching(m_fd, path, mask);
public int startWatching(String path, int mask, FileObserver observer) {
int wfd = startWatching(m_fd, path, mask);
Integer i = new Integer(wfd);
if (wfd >= 0) {
synchronized (m_observers) {
m_observers.put(i, new WeakReference(observer));
}
}
Integer i = new Integer(wfd);
if (wfd >= 0) {
synchronized (m_observers) {
m_observers.put(i, new WeakReference(observer));
}
}
return i;
}
return i;
}
public void stopWatching(int descriptor) {
stopWatching(m_fd, descriptor);
}
public void stopWatching(int descriptor) {
stopWatching(m_fd, descriptor);
}
public void onEvent(int wfd, int mask, String path) {
// look up our observer, fixing up the map if necessary...
FileObserver observer;
public void onEvent(int wfd, int mask, String path) {
// look up our observer, fixing up the map if necessary...
FileObserver observer = null;
synchronized (m_observers) {
WeakReference weak = m_observers.get(wfd);
observer = (FileObserver) weak.get();
if (observer == null) {
m_observers.remove(wfd);
synchronized (m_observers) {
WeakReference weak = m_observers.get(wfd);
if (weak != null) { // can happen with lots of events from a dead wfd
observer = (FileObserver) weak.get();
if (observer == null) {
m_observers.remove(wfd);
}
}
}
// ...then call out to the observer without the sync lock held
if (observer != null) {
try {
observer.onEvent(mask, path);
} catch (Throwable throwable) {
Log.wtf(LOG_TAG, "Unhandled exception in FileObserver " + observer, throwable);
}
}
}
// ...then call out to the observer without the sync lock held
if (observer != null) {
try {
observer.onEvent(mask, path);
} catch (Throwable throwable) {
Log.wtf(LOG_TAG, "Unhandled exception in FileObserver " + observer, throwable);
}
}
}
private native int init();
private native void observe(int fd);
private native int startWatching(int fd, String path, int mask);
private native void stopWatching(int fd, int wfd);
private native int init();
private native void observe(int fd);
private native int startWatching(int fd, String path, int mask);
private native void stopWatching(int fd, int wfd);
}
private static ObserverThread s_observerThread;
static {
s_observerThread = new ObserverThread();
s_observerThread.start();
s_observerThread = new ObserverThread();
s_observerThread.start();
}
// instance
@@ -127,30 +129,30 @@ public abstract class FileObserver {
private int m_mask;
public FileObserver(String path) {
this(path, ALL_EVENTS);
this(path, ALL_EVENTS);
}
public FileObserver(String path, int mask) {
m_path = path;
m_mask = mask;
m_descriptor = -1;
m_path = path;
m_mask = mask;
m_descriptor = -1;
}
protected void finalize() {
stopWatching();
stopWatching();
}
public void startWatching() {
if (m_descriptor < 0) {
m_descriptor = s_observerThread.startWatching(m_path, m_mask, this);
}
if (m_descriptor < 0) {
m_descriptor = s_observerThread.startWatching(m_path, m_mask, this);
}
}
public void stopWatching() {
if (m_descriptor >= 0) {
s_observerThread.stopWatching(m_descriptor);
m_descriptor = -1;
}
if (m_descriptor >= 0) {
s_observerThread.stopWatching(m_descriptor);
m_descriptor = -1;
}
}
public abstract void onEvent(int event, String path);