--- a/src/hotspot/share/gc/shared/collectedHeap.cpp Mon Jun 11 15:28:24 2018 +0200
+++ b/src/hotspot/share/gc/shared/collectedHeap.cpp Fri Jun 15 00:49:54 2018 -0700
@@ -378,6 +378,27 @@
}
HeapWord* CollectedHeap::allocate_from_tlab_slow(Klass* klass, size_t size, TRAPS) {
+ HeapWord* obj = NULL;
+
+ // In assertion mode, check that there was a sampling collector present
+ // in the stack. This enforces checking that no path is without a sampling
+ // collector.
+ // Only check if the sampler could actually sample something in this call path.
+ assert(!JvmtiExport::should_post_sampled_object_alloc()
+ || !JvmtiSampledObjectAllocEventCollector::object_alloc_is_safe_to_sample()
+ || THREAD->heap_sampler().sampling_collector_present(),
+ "Sampling collector not present.");
+
+ if (ThreadHeapSampler::enabled()) {
+ // Try to allocate the sampled object from TLAB, it is possible a sample
+ // point was put and the TLAB still has space.
+ obj = THREAD->tlab().allocate_sampled_object(size);
+
+ if (obj != NULL) {
+ return obj;
+ }
+ }
+
ThreadLocalAllocBuffer& tlab = THREAD->tlab();
// Retain tlab and allocate object in shared space if
@@ -401,7 +422,7 @@
// between minimal and new_tlab_size is accepted.
size_t actual_tlab_size = 0;
size_t min_tlab_size = ThreadLocalAllocBuffer::compute_min_size(size);
- HeapWord* obj = Universe::heap()->allocate_new_tlab(min_tlab_size, new_tlab_size, &actual_tlab_size);
+ obj = Universe::heap()->allocate_new_tlab(min_tlab_size, new_tlab_size, &actual_tlab_size);
if (obj == NULL) {
assert(actual_tlab_size == 0, "Allocation failed, but actual size was updated. min: " SIZE_FORMAT ", desired: " SIZE_FORMAT ", actual: " SIZE_FORMAT,
min_tlab_size, new_tlab_size, actual_tlab_size);
@@ -425,6 +446,14 @@
Copy::fill_to_words(obj + hdr_size, actual_tlab_size - hdr_size, badHeapWordVal);
#endif // ASSERT
}
+
+ // Send the thread information about this allocation in case a sample is
+ // requested.
+ if (ThreadHeapSampler::enabled()) {
+ size_t tlab_bytes_since_last_sample = THREAD->tlab().bytes_since_last_sample_point();
+ THREAD->heap_sampler().check_for_sampling(obj, size, tlab_bytes_since_last_sample);
+ }
+
tlab.fill(obj, obj + size, actual_tlab_size);
return obj;
}