Github user poornachandra commented on a diff in the pull request:
https://github.com/apache/incubator-tephra/pull/53#discussion_r138723289
--- Diff:
tephra-core/src/main/java/org/apache/tephra/persist/AbstractTransactionLog.java
---
@@ -85,44 +99,20 @@ public long getTimestamp() {
@Override
public void append(TransactionEdit edit) throws IOException {
- long startTime = System.nanoTime();
- synchronized (this) {
- ensureAvailable();
-
- Entry entry = new Entry(new
LongWritable(logSequence.getAndIncrement()), edit);
-
- // add to pending edits
- append(entry);
- }
-
- // wait for sync to complete
- sync();
- long durationMillis = (System.nanoTime() - startTime) / 1000000L;
- if (durationMillis > SLOW_APPEND_THRESHOLD) {
- LOG.info("Slow append to log " + getName() + ", took " +
durationMillis + " msec.");
- }
+ append(Collections.singletonList(edit));
}
@Override
public void append(List<TransactionEdit> edits) throws IOException {
- long startTime = System.nanoTime();
- synchronized (this) {
+ // synchronizing here ensures that elements in the queue are ordered
by seq number
+ synchronized (logSequence) {
ensureAvailable();
--- End diff --
`ensureAvailable()` can move out of the synchronized block since it uses a
couple of volatile variables and calls a synchronized method `init()`
---
