USDT event for JVMTI object allocation sample

Author: jbachorik

src/hotspot/os/posix/dtrace/hotspot_jvmti.d

@@ -0,0 +1,9 @@
+provider hotspot_jvmti {
+  probe AllocObject__sample(char*, size_t, size_t);
+};
+
+#pragma D attributes Standard/Standard/Common provider hotspot_jvmti provider
+#pragma D attributes Private/Private/Unknown provider hotspot_jvmti module
+#pragma D attributes Private/Private/Unknown provider hotspot_jvmti function
+#pragma D attributes Standard/Standard/Common provider hotspot_jvmti name
+#pragma D attributes Evolving/Evolving/Common provider hotspot_jvmti args

src/hotspot/share/runtime/threadHeapSampler.cpp

@@ -32,6 +32,9 @@
 #include "runtime/threadHeapSampler.hpp"
 #include "utilities/checkedCast.hpp"
 
+#include "oops/oop.inline.hpp"
+#include "utilities/dtrace.hpp"
+
 // Cheap random number generator.
 uint64_t ThreadHeapSampler::_rnd;
 // Default is 512kb.
@@ -424,6 +427,8 @@ void ThreadHeapSampler::check_for_sampling(oop obj, size_t allocation_size, size
     return;
   }
 
+  HOTSPOT_JVMTI_ALLOCOBJECT_SAMPLE(obj->klass()->name()->as_C_string(), allocation_size, bytes_since_allocation);
+
   JvmtiExport::sampled_object_alloc_event_collector(obj);
 
   size_t overflow_bytes = total_allocated_bytes - _bytes_until_sample;

src/hotspot/share/utilities/dtrace.hpp

@@ -36,6 +36,7 @@
 
 #include "dtracefiles/hotspot.h"
 #include "dtracefiles/hotspot_jni.h"
+#include "dtracefiles/hotspot_jvmti.h"
 #include "dtracefiles/hs_private.h"
 
 #else /* defined(DTRACE_ENABLED) */

src/hotspot/share/utilities/dtrace_disabled.hpp

@@ -1080,6 +1080,9 @@
 #define HOTSPOT_JNI_UNREGISTERNATIVES_RETURN(arg0)
 #define HOTSPOT_JNI_UNREGISTERNATIVES_RETURN_ENABLED()  0
 
+/* JVMTI */
+#define HOTSPOT_JVMTI_ALLOCOBJECT_SAMPLE(arg0, arg1, arg2)
+
 /* Modules */
 #define HOTSPOT_JNI_GETMODULE_ENTRY(arg0, arg1)
 #define HOTSPOT_JNI_GETMODULE_ENTRY_ENABLED()  0