public AllocationSampler(Map<String, Long> trackSources, Set<String> trackLengths) {
checkNotNull(trackSources, "trackSources");
checkNotNull(trackLengths, "trackLengths");
this.trackSources = trackSources;
for (Map.Entry<String, Long> track : trackSources.entrySet())
traces.put(track.getKey(), new ConcurrentLinkedQueue<StackTraceElement[]>());
for (String name : trackLengths) arrayLengths.put(name, AtomicLongMap.<Integer>create());
}
public class AllocationSampler implements Sampler {
private final Map<String, Long> trackSources;
private final AtomicLongMap<String> totalBytes = AtomicLongMap.create();
private final AtomicLongMap<String> lastSampledSize = AtomicLongMap.create();
private final Map<String, ConcurrentLinkedQueue<StackTraceElement[]>> traces =
new ConcurrentHashMap<String, ConcurrentLinkedQueue<StackTraceElement[]>>();
private final Map<String, AtomicLongMap<Integer>> arrayLengths =
new ConcurrentHashMap<String, AtomicLongMap<Integer>>();
public AllocationSampler(Map<String, Long> trackSources, Set<String> trackLengths) {
checkNotNull(trackSources, "trackSources");
checkNotNull(trackLengths, "trackLengths");
this.trackSources = trackSources;
for (Map.Entry<String, Long> track : trackSources.entrySet())
traces.put(track.getKey(), new ConcurrentLinkedQueue<StackTraceElement[]>());
for (String name : trackLengths) arrayLengths.put(name, AtomicLongMap.<Integer>create());
}
// not atomic, so some information may be lost
// and we may over- or under- sample
public void clear() {
totalBytes.clear();
lastSampledSize.clear();
for (Queue<?> el : traces.values()) el.clear();
for (AtomicLongMap<?> el : arrayLengths.values()) el.clear();
}
@Override
public void sampleAllocation(int count, String name, Object instance, long sizeBytes) {
if (count != -1) {
AtomicLongMap<Integer> lengths = arrayLengths.get(name);
if (lengths != null) lengths.getAndIncrement(count);
}
Long threshold = trackSources.get(name);
Long now = totalBytes.addAndGet(name, sizeBytes);
if (threshold != null) {
// if this whole lookup/check/put could be made atomic, that'd be awesome
if (now - threshold >= lastSampledSize.get(name)) {
lastSampledSize.put(name, now);
// eek, object creation getting the trace
StackTraceElement[] trace = AllocationEfficientStacktrace.stack(2, 50);
traces.get(name).offer(trace);
}
}
}
////////////////////////////////////////////////////////
// the following methods are not part of the sample path
////////////////////////////////////////////////////////
public Map<String, Long> snapshotTotalBytes() {
return snap(totalBytes);
}
public Map<String, List<StackTraceElement[]>> snapshotTraces() {
Map<String, List<StackTraceElement[]>> snapshot =
new HashMap<String, List<StackTraceElement[]>>();
for (Map.Entry<String, ConcurrentLinkedQueue<StackTraceElement[]>> entry : traces.entrySet()) {
if (entry.getValue().isEmpty()) continue;
List<StackTraceElement[]> samples = new ArrayList<StackTraceElement[]>(entry.getValue());
snapshot.put(entry.getKey(), samples);
}
return snapshot;
}
public Map<String, Map<Integer, Long>> snapshotArrayLengths() {
Map<String, Map<Integer, Long>> snapshot = new HashMap<String, Map<Integer, Long>>();
for (Map.Entry<String, AtomicLongMap<Integer>> entry : arrayLengths.entrySet()) {
if (entry.getValue().isEmpty()) continue;
Map<Integer, Long> lengths = snap(entry.getValue());
snapshot.put(entry.getKey(), lengths);
}
return snapshot;
}
private <T> Map<T, Long> snap(AtomicLongMap<T> atomic) {
Map<T, Long> builder = new HashMap<T, Long>();
for (Map.Entry<T, AtomicLong> e : atomic.underlying().entrySet()) {
builder.put(e.getKey(), e.getValue().get());
}
return builder;
}
}