From 33795e7046ed40244cabce8b04c01ea1eb60c2d7 Mon Sep 17 00:00:00 2001
From: akwizgran <akwizgran@users.sourceforge.net>
Date: Fri, 16 Sep 2016 10:49:41 +0100
Subject: [PATCH] Use compareAndSet() instead of locking.
---
.../android/forum/ForumControllerImpl.java | 50 ++++++++-----------
1 file changed, 22 insertions(+), 28 deletions(-)
diff --git a/briar-android/src/org/briarproject/android/forum/ForumControllerImpl.java b/briar-android/src/org/briarproject/android/forum/ForumControllerImpl.java
index 51e23cfc4a..ef66d18bc5 100644
--- a/briar-android/src/org/briarproject/android/forum/ForumControllerImpl.java
+++ b/briar-android/src/org/briarproject/android/forum/ForumControllerImpl.java
@@ -67,7 +67,8 @@ public class ForumControllerImpl extends DbControllerImpl
protected volatile IdentityManager identityManager;
private final Map<MessageId, byte[]> bodyCache = new ConcurrentHashMap<>();
- private volatile AtomicLong newestTimeStamp = new AtomicLong();
+ private final AtomicLong newestTimeStamp = new AtomicLong();
+
private volatile LocalAuthor localAuthor = null;
private volatile Forum forum = null;
@@ -109,15 +110,12 @@ public class ForumControllerImpl extends DbControllerImpl
if (e instanceof ForumPostReceivedEvent) {
final ForumPostReceivedEvent pe = (ForumPostReceivedEvent) e;
if (pe.getGroupId().equals(forum.getId())) {
- LOG.info("Forum Post received, adding...");
+ LOG.info("Forum post received, adding...");
final ForumPostHeader fph = pe.getForumPostHeader();
+ updateNewestTimestamp(fph.getTimestamp());
activity.runOnUiThread(new Runnable() {
@Override
public void run() {
- synchronized (this) {
- if (fph.getTimestamp() > newestTimeStamp.get())
- newestTimeStamp.set(fph.getTimestamp());
- }
listener.onExternalEntryAdded(fph);
}
});
@@ -147,8 +145,7 @@ public class ForumControllerImpl extends DbControllerImpl
forum = forumManager.getForum(groupId);
long duration = System.currentTimeMillis() - now;
if (LOG.isLoggable(INFO))
- LOG.info("Loading forum took " + duration +
- " ms");
+ LOG.info("Loading forum took " + duration + " ms");
// Get First Identity
now = System.currentTimeMillis();
@@ -157,8 +154,7 @@ public class ForumControllerImpl extends DbControllerImpl
.next();
duration = System.currentTimeMillis() - now;
if (LOG.isLoggable(INFO))
- LOG.info("Loading author took " + duration +
- " ms");
+ LOG.info("Loading author took " + duration + " ms");
}
/**
@@ -210,11 +206,9 @@ public class ForumControllerImpl extends DbControllerImpl
return entries;
}
- private synchronized void checkNewestTimeStamp(
- Collection<ForumPostHeader> headers) {
+ private void updateNewestTimeStamp(Collection<ForumPostHeader> headers) {
for (ForumPostHeader h : headers) {
- if (h.getTimestamp() > newestTimeStamp.get())
- newestTimeStamp.set(h.getTimestamp());
+ updateNewestTimestamp(h.getTimestamp());
}
}
@@ -224,15 +218,14 @@ public class ForumControllerImpl extends DbControllerImpl
runOnDbThread(new Runnable() {
@Override
public void run() {
- if (LOG.isLoggable(INFO))
- LOG.info("Loading forum...");
+ LOG.info("Loading forum...");
try {
if (forum == null) {
loadForum(groupId);
}
// Get Forum Posts and Bodies
Collection<ForumPostHeader> headers = loadHeaders();
- checkNewestTimeStamp(headers);
+ updateNewestTimeStamp(headers);
loadBodies(headers);
resultHandler.onResult(buildForumEntries(headers));
} catch (DbException e) {
@@ -328,14 +321,9 @@ public class ForumControllerImpl extends DbControllerImpl
cryptoExecutor.execute(new Runnable() {
@Override
public void run() {
- if (LOG.isLoggable(INFO))
- LOG.info("create post..");
+ LOG.info("Create post...");
long timestamp = System.currentTimeMillis();
- // FIXME next two lines Synchronized ?
- // Only reading the atomic value, and even if it is changed
- // between the first and second get, the condition will hold
- if (timestamp < newestTimeStamp.get())
- timestamp = newestTimeStamp.get();
+ timestamp = Math.max(timestamp, newestTimeStamp.get());
ForumPost p;
try {
KeyParser keyParser = crypto.getSignatureKeyParser();
@@ -353,20 +341,19 @@ public class ForumControllerImpl extends DbControllerImpl
});
}
+ @Override
public void storePost(final ForumPost p,
final ResultHandler<ForumEntry> resultHandler) {
runOnDbThread(new Runnable() {
@Override
public void run() {
try {
- if (LOG.isLoggable(INFO))
- LOG.info("Store post...");
+ LOG.info("Store post...");
long now = System.currentTimeMillis();
forumManager.addLocalPost(p);
long duration = System.currentTimeMillis() - now;
if (LOG.isLoggable(INFO))
- LOG.info(
- "Storing message took " + duration + " ms");
+ LOG.info("Storing message took " + duration + " ms");
ForumPostHeader h =
new ForumPostHeader(p.getMessage().getId(),
@@ -386,4 +373,11 @@ public class ForumControllerImpl extends DbControllerImpl
});
}
+ private void updateNewestTimestamp(long update) {
+ long newest = newestTimeStamp.get();
+ while (newest < update) {
+ if (newestTimeStamp.compareAndSet(newest, update)) return;
+ newest = newestTimeStamp.get();
+ }
+ }
}
--
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