8150778: Reduce Throwable.getStackTrace() calls to the JVM
authorcoleenp
Thu, 10 Mar 2016 13:43:47 -0500
changeset 37064 5c82fa70d313
parent 37063 c9d5a3727011
child 37066 f4ebb8b35388
8150778: Reduce Throwable.getStackTrace() calls to the JVM Summary: replace JVM_GetStackTraceDepth and JVM_GetStackTraceElement, with JVM_GetStackTraceElements that gets all the elements in the StackTraceElement[] Reviewed-by: shade, mchung, dholmes, hseigel
hotspot/make/share/makefiles/mapfile-vers
hotspot/src/share/vm/classfile/javaClasses.cpp
hotspot/src/share/vm/classfile/javaClasses.hpp
hotspot/src/share/vm/classfile/vmSymbols.hpp
hotspot/src/share/vm/logging/logTag.hpp
hotspot/src/share/vm/prims/jvm.cpp
hotspot/src/share/vm/prims/jvm.h
hotspot/test/runtime/Throwable/StackTraceLogging.java
hotspot/test/runtime/Throwable/TestThrowable.java
--- a/hotspot/make/share/makefiles/mapfile-vers	Thu Mar 10 14:15:15 2016 +0100
+++ b/hotspot/make/share/makefiles/mapfile-vers	Thu Mar 10 13:43:47 2016 -0500
@@ -109,8 +109,7 @@
                 JVM_GetPrimitiveArrayElement;
                 JVM_GetProtectionDomain;
                 JVM_GetStackAccessControlContext;
-                JVM_GetStackTraceDepth;
-                JVM_GetStackTraceElement;
+                JVM_GetStackTraceElements;
                 JVM_GetSystemPackage;
                 JVM_GetSystemPackages;
                 JVM_GetTemporaryDirectory;
--- a/hotspot/src/share/vm/classfile/javaClasses.cpp	Thu Mar 10 14:15:15 2016 +0100
+++ b/hotspot/src/share/vm/classfile/javaClasses.cpp	Thu Mar 10 13:43:47 2016 -0500
@@ -1439,6 +1439,12 @@
   compute_offset(_ngroups_offset,     k, vmSymbols::ngroups_name(),     vmSymbols::int_signature());
 }
 
+
+void java_lang_Throwable::compute_offsets() {
+  Klass* k = SystemDictionary::Throwable_klass();
+  compute_offset(depth_offset, k, vmSymbols::depth_name(), vmSymbols::int_signature());
+}
+
 oop java_lang_Throwable::unassigned_stacktrace() {
   InstanceKlass* ik = SystemDictionary::Throwable_klass();
   address addr = ik->static_field_addr(static_unassigned_stacktrace_offset);
@@ -1458,11 +1464,13 @@
   throwable->release_obj_field_put(backtrace_offset, value);
 }
 
-
-oop java_lang_Throwable::message(oop throwable) {
-  return throwable->obj_field(detailMessage_offset);
-}
-
+int java_lang_Throwable::depth(oop throwable) {
+  return throwable->int_field(depth_offset);
+}
+
+void java_lang_Throwable::set_depth(oop throwable, int value) {
+  throwable->int_field_put(depth_offset, value);
+}
 
 oop java_lang_Throwable::message(Handle throwable) {
   return throwable->obj_field(detailMessage_offset);
@@ -1512,10 +1520,12 @@
   return method != NULL && (method->constants()->version() == version);
 }
 
+
 // This class provides a simple wrapper over the internal structure of
 // exception backtrace to insulate users of the backtrace from needing
 // to know what it looks like.
 class BacktraceBuilder: public StackObj {
+ friend class BacktraceIterator;
  private:
   Handle          _backtrace;
   objArrayOop     _head;
@@ -1526,8 +1536,6 @@
   int             _index;
   NoSafepointVerifier _nsv;
 
- public:
-
   enum {
     trace_methods_offset = java_lang_Throwable::trace_methods_offset,
     trace_bcis_offset    = java_lang_Throwable::trace_bcis_offset,
@@ -1560,6 +1568,8 @@
     return cprefs;
   }
 
+ public:
+
   // constructor for new backtrace
   BacktraceBuilder(TRAPS): _methods(NULL), _bcis(NULL), _head(NULL), _mirrors(NULL), _cprefs(NULL) {
     expand(CHECK);
@@ -1645,9 +1655,68 @@
 
 };
 
+struct BacktraceElement : public StackObj {
+  int _method_id;
+  int _bci;
+  int _version;
+  int _cpref;
+  Handle _mirror;
+  BacktraceElement(Handle mirror, int mid, int version, int bci, int cpref) :
+                   _mirror(mirror), _method_id(mid), _version(version), _bci(bci), _cpref(cpref) {}
+};
+
+class BacktraceIterator : public StackObj {
+  int _index;
+  objArrayHandle  _result;
+  objArrayHandle  _mirrors;
+  typeArrayHandle _methods;
+  typeArrayHandle _bcis;
+  typeArrayHandle _cprefs;
+
+  void init(objArrayHandle result, Thread* thread) {
+    // Get method id, bci, version and mirror from chunk
+    _result = result;
+    if (_result.not_null()) {
+      _methods = typeArrayHandle(thread, BacktraceBuilder::get_methods(_result));
+      _bcis = typeArrayHandle(thread, BacktraceBuilder::get_bcis(_result));
+      _mirrors = objArrayHandle(thread, BacktraceBuilder::get_mirrors(_result));
+      _cprefs = typeArrayHandle(thread, BacktraceBuilder::get_cprefs(_result));
+      _index = 0;
+    }
+  }
+ public:
+  BacktraceIterator(objArrayHandle result, Thread* thread) {
+    init(result, thread);
+    assert(_methods->length() == java_lang_Throwable::trace_chunk_size, "lengths don't match");
+  }
+
+  BacktraceElement next(Thread* thread) {
+    BacktraceElement e (Handle(thread, _mirrors->obj_at(_index)),
+                        _methods->short_at(_index),
+                        Backtrace::version_at(_bcis->int_at(_index)),
+                        Backtrace::bci_at(_bcis->int_at(_index)),
+                        _cprefs->short_at(_index));
+    _index++;
+
+    if (_index >= java_lang_Throwable::trace_chunk_size) {
+      int next_offset = java_lang_Throwable::trace_next_offset;
+      // Get next chunk
+      objArrayHandle result (thread, objArrayOop(_result->obj_at(next_offset)));
+      init(result, thread);
+    }
+    return e;
+  }
+
+  bool repeat() {
+    return _result.not_null() && _mirrors->obj_at(_index) != NULL;
+  }
+};
+
+
 // Print stack trace element to resource allocated buffer
-char* java_lang_Throwable::print_stack_element_to_buffer(Handle mirror,
-                                  int method_id, int version, int bci, int cpref) {
+static void print_stack_element_to_stream(outputStream* st, Handle mirror, int method_id,
+                                          int version, int bci, int cpref) {
+  ResourceMark rm;
 
   // Get strings and string lengths
   InstanceKlass* holder = InstanceKlass::cast(java_lang_Class::as_Klass(mirror()));
@@ -1698,26 +1767,16 @@
     }
   }
 
-  return buf;
-}
-
-void java_lang_Throwable::print_stack_element(outputStream *st, Handle mirror,
-                                              int method_id, int version, int bci, int cpref) {
-  ResourceMark rm;
-  char* buf = print_stack_element_to_buffer(mirror, method_id, version, bci, cpref);
   st->print_cr("%s", buf);
 }
 
+
 void java_lang_Throwable::print_stack_element(outputStream *st, const methodHandle& method, int bci) {
   Handle mirror = method->method_holder()->java_mirror();
   int method_id = method->orig_method_idnum();
   int version = method->constants()->version();
   int cpref = method->name_index();
-  print_stack_element(st, mirror, method_id, version, bci, cpref);
-}
-
-const char* java_lang_Throwable::no_stack_trace_message() {
-  return "\t<<no stack trace available>>";
+  print_stack_element_to_stream(st, mirror, method_id, version, bci, cpref);
 }
 
 /**
@@ -1734,32 +1793,17 @@
   while (throwable.not_null()) {
     objArrayHandle result (THREAD, objArrayOop(backtrace(throwable())));
     if (result.is_null()) {
-      st->print_raw_cr(no_stack_trace_message());
+      st->print_raw_cr("\t<<no stack trace available>>");
       return;
     }
-
-    while (result.not_null()) {
-      // Get method id, bci, version and mirror from chunk
-      typeArrayHandle methods (THREAD, BacktraceBuilder::get_methods(result));
-      typeArrayHandle bcis (THREAD, BacktraceBuilder::get_bcis(result));
-      objArrayHandle mirrors (THREAD, BacktraceBuilder::get_mirrors(result));
-      typeArrayHandle cprefs (THREAD, BacktraceBuilder::get_cprefs(result));
-
-      int length = methods()->length();
-      for (int index = 0; index < length; index++) {
-        Handle mirror(THREAD, mirrors->obj_at(index));
-        // NULL mirror means end of stack trace
-        if (mirror.is_null()) goto handle_cause;
-        int method = methods->short_at(index);
-        int version = Backtrace::version_at(bcis->int_at(index));
-        int bci = Backtrace::bci_at(bcis->int_at(index));
-        int cpref = cprefs->short_at(index);
-        print_stack_element(st, mirror, method, version, bci, cpref);
-      }
-      result = objArrayHandle(THREAD, objArrayOop(result->obj_at(trace_next_offset)));
+    BacktraceIterator iter(result, THREAD);
+
+    while (iter.repeat()) {
+      BacktraceElement bte = iter.next(THREAD);
+      print_stack_element_to_stream(st, bte._mirror, bte._method_id, bte._version, bte._bci, bte._cpref);
     }
-  handle_cause:
     {
+      // Call getCause() which doesn't necessarily return the _cause field.
       EXCEPTION_MARK;
       JavaValue cause(T_OBJECT);
       JavaCalls::call_virtual(&cause,
@@ -1811,6 +1855,7 @@
 
   int max_depth = MaxJavaStackTraceDepth;
   JavaThread* thread = (JavaThread*)THREAD;
+
   BacktraceBuilder bt(CHECK);
 
   // If there is no Java frame just return the method that was being called
@@ -1818,6 +1863,8 @@
   if (!thread->has_last_Java_frame()) {
     if (max_depth >= 1 && method() != NULL) {
       bt.push(method(), 0, CHECK);
+      log_info(stacktrace)("%s, %d", throwable->klass()->external_name(), 1);
+      set_depth(throwable(), 1);
       set_backtrace(throwable(), bt.backtrace());
     }
     return;
@@ -1925,8 +1972,11 @@
     total_count++;
   }
 
+  log_info(stacktrace)("%s, %d", throwable->klass()->external_name(), total_count);
+
   // Put completed stack trace into throwable object
   set_backtrace(throwable(), bt.backtrace());
+  set_depth(throwable(), total_count);
 }
 
 void java_lang_Throwable::fill_in_stack_trace(Handle throwable, const methodHandle& method) {
@@ -1980,94 +2030,60 @@
   // methods as preallocated errors aren't created by "java" code.
 
   // fill in as much stack trace as possible
-  typeArrayOop methods = BacktraceBuilder::get_methods(backtrace);
-  int max_chunks = MIN2(methods->length(), (int)MaxJavaStackTraceDepth);
   int chunk_count = 0;
-
   for (;!st.at_end(); st.next()) {
     bt.push(st.method(), st.bci(), CHECK);
     chunk_count++;
 
     // Bail-out for deep stacks
-    if (chunk_count >= max_chunks) break;
+    if (chunk_count >= trace_chunk_size) break;
   }
+  set_depth(throwable(), chunk_count);
+  log_info(stacktrace)("%s, %d", throwable->klass()->external_name(), chunk_count);
 
   // We support the Throwable immutability protocol defined for Java 7.
   java_lang_Throwable::set_stacktrace(throwable(), java_lang_Throwable::unassigned_stacktrace());
   assert(java_lang_Throwable::unassigned_stacktrace() != NULL, "not initialized");
 }
 
-
-int java_lang_Throwable::get_stack_trace_depth(oop throwable, TRAPS) {
-  if (throwable == NULL) {
-    THROW_0(vmSymbols::java_lang_NullPointerException());
+void java_lang_Throwable::get_stack_trace_elements(Handle throwable,
+                                                   objArrayHandle stack_trace_array_h, TRAPS) {
+
+  if (throwable.is_null() || stack_trace_array_h.is_null()) {
+    THROW(vmSymbols::java_lang_NullPointerException());
   }
-  objArrayOop chunk = objArrayOop(backtrace(throwable));
-  int depth = 0;
-  if (chunk != NULL) {
-    // Iterate over chunks and count full ones
-    while (true) {
-      objArrayOop next = objArrayOop(chunk->obj_at(trace_next_offset));
-      if (next == NULL) break;
-      depth += trace_chunk_size;
-      chunk = next;
-    }
-    assert(chunk != NULL && chunk->obj_at(trace_next_offset) == NULL, "sanity check");
-    // Count element in remaining partial chunk.  NULL value for mirror
-    // marks the end of the stack trace elements that are saved.
-    objArrayOop mirrors = BacktraceBuilder::get_mirrors(chunk);
-    assert(mirrors != NULL, "sanity check");
-    for (int i = 0; i < mirrors->length(); i++) {
-      if (mirrors->obj_at(i) == NULL) break;
-      depth++;
-    }
-  }
-  return depth;
-}
-
-
-oop java_lang_Throwable::get_stack_trace_element(oop throwable, int index, TRAPS) {
-  if (throwable == NULL) {
-    THROW_0(vmSymbols::java_lang_NullPointerException());
-  }
-  if (index < 0) {
-    THROW_(vmSymbols::java_lang_IndexOutOfBoundsException(), NULL);
+
+  assert(stack_trace_array_h->is_objArray(), "Stack trace array should be an array of StackTraceElenent");
+
+  if (stack_trace_array_h->length() != depth(throwable())) {
+    THROW(vmSymbols::java_lang_IndexOutOfBoundsException());
   }
-  // Compute how many chunks to skip and index into actual chunk
-  objArrayOop chunk = objArrayOop(backtrace(throwable));
-  int skip_chunks = index / trace_chunk_size;
-  int chunk_index = index % trace_chunk_size;
-  while (chunk != NULL && skip_chunks > 0) {
-    chunk = objArrayOop(chunk->obj_at(trace_next_offset));
-        skip_chunks--;
-  }
-  if (chunk == NULL) {
-    THROW_(vmSymbols::java_lang_IndexOutOfBoundsException(), NULL);
+
+  objArrayHandle result(THREAD, objArrayOop(backtrace(throwable())));
+  BacktraceIterator iter(result, THREAD);
+
+  int index = 0;
+  while (iter.repeat()) {
+    BacktraceElement bte = iter.next(THREAD);
+
+    Handle stack_trace_element(THREAD, stack_trace_array_h->obj_at(index++));
+
+    if (stack_trace_element.is_null()) {
+      THROW(vmSymbols::java_lang_NullPointerException());
+    }
+
+    InstanceKlass* holder = InstanceKlass::cast(java_lang_Class::as_Klass(bte._mirror()));
+    methodHandle method (THREAD, holder->method_with_orig_idnum(bte._method_id, bte._version));
+
+    java_lang_StackTraceElement::fill_in(stack_trace_element, holder,
+                                         method,
+                                         bte._version,
+                                         bte._bci,
+                                         bte._cpref, CHECK);
   }
-  // Get method id, bci, version, mirror and cpref from chunk
-  typeArrayOop methods = BacktraceBuilder::get_methods(chunk);
-  typeArrayOop bcis = BacktraceBuilder::get_bcis(chunk);
-  objArrayOop mirrors = BacktraceBuilder::get_mirrors(chunk);
-  typeArrayOop cprefs = BacktraceBuilder::get_cprefs(chunk);
-
-  assert(methods != NULL && bcis != NULL && mirrors != NULL, "sanity check");
-
-  int method = methods->short_at(chunk_index);
-  int version = Backtrace::version_at(bcis->int_at(chunk_index));
-  int bci = Backtrace::bci_at(bcis->int_at(chunk_index));
-  int cpref = cprefs->short_at(chunk_index);
-  Handle mirror(THREAD, mirrors->obj_at(chunk_index));
-
-  // Chunk can be partial full
-  if (mirror.is_null()) {
-    THROW_(vmSymbols::java_lang_IndexOutOfBoundsException(), NULL);
-  }
-  oop element = java_lang_StackTraceElement::create(mirror, method, version, bci, cpref, CHECK_0);
-  return element;
-}
-
-oop java_lang_StackTraceElement::create(Handle mirror, int method_id,
-                                        int version, int bci, int cpref, TRAPS) {
+}
+
+oop java_lang_StackTraceElement::create(const methodHandle& method, int bci, TRAPS) {
   // Allocate java.lang.StackTraceElement instance
   Klass* k = SystemDictionary::StackTraceElement_klass();
   assert(k != NULL, "must be loaded in 1.4+");
@@ -2078,23 +2094,31 @@
 
   Handle element = ik->allocate_instance_handle(CHECK_0);
 
+  int cpref = method->name_index();
+  int version = method->constants()->version();
+  fill_in(element, method->method_holder(), method, version, bci, cpref, CHECK_0);
+  return element();
+}
+
+void java_lang_StackTraceElement::fill_in(Handle element,
+                                          InstanceKlass* holder, const methodHandle& method,
+                                          int version, int bci, int cpref, TRAPS) {
+  assert(element->is_a(SystemDictionary::StackTraceElement_klass()), "sanity check");
+
   // Fill in class name
   ResourceMark rm(THREAD);
-  InstanceKlass* holder = InstanceKlass::cast(java_lang_Class::as_Klass(mirror()));
   const char* str = holder->external_name();
-  oop classname = StringTable::intern((char*) str, CHECK_0);
+  oop classname = StringTable::intern((char*) str, CHECK);
   java_lang_StackTraceElement::set_declaringClass(element(), classname);
 
-  Method* method = holder->method_with_orig_idnum(method_id, version);
-
   // The method can be NULL if the requested class version is gone
-  Symbol* sym = (method != NULL) ? method->name() : holder->constants()->symbol_at(cpref);
+  Symbol* sym = !method.is_null() ? method->name() : holder->constants()->symbol_at(cpref);
 
   // Fill in method name
-  oop methodname = StringTable::intern(sym, CHECK_0);
+  oop methodname = StringTable::intern(sym, CHECK);
   java_lang_StackTraceElement::set_methodName(element(), methodname);
 
-  if (!version_matches(method, version)) {
+  if (!version_matches(method(), version)) {
     // The method was redefined, accurate line number information isn't available
     java_lang_StackTraceElement::set_fileName(element(), NULL);
     java_lang_StackTraceElement::set_lineNumber(element(), -1);
@@ -2103,20 +2127,12 @@
     Symbol* source = Backtrace::get_source_file_name(holder, version);
     if (ShowHiddenFrames && source == NULL)
       source = vmSymbols::unknown_class_name();
-    oop filename = StringTable::intern(source, CHECK_0);
+    oop filename = StringTable::intern(source, CHECK);
     java_lang_StackTraceElement::set_fileName(element(), filename);
 
     int line_number = Backtrace::get_line_number(method, bci);
     java_lang_StackTraceElement::set_lineNumber(element(), line_number);
   }
-  return element();
-}
-
-oop java_lang_StackTraceElement::create(const methodHandle& method, int bci, TRAPS) {
-  Handle mirror (THREAD, method->method_holder()->java_mirror());
-  int method_id = method->orig_method_idnum();
-  int cpref = method->name_index();
-  return create(mirror, method_id, method->constants()->version(), bci, cpref, THREAD);
 }
 
 Method* java_lang_StackFrameInfo::get_method(Handle stackFrame, InstanceKlass* holder, TRAPS) {
@@ -3477,8 +3493,8 @@
 GrowableArray<Klass*>* java_lang_Class::_fixup_mirror_list = NULL;
 int java_lang_Throwable::backtrace_offset;
 int java_lang_Throwable::detailMessage_offset;
-int java_lang_Throwable::cause_offset;
 int java_lang_Throwable::stackTrace_offset;
+int java_lang_Throwable::depth_offset;
 int java_lang_Throwable::static_unassigned_stacktrace_offset;
 int java_lang_reflect_AccessibleObject::override_offset;
 int java_lang_reflect_Method::clazz_offset;
@@ -3679,7 +3695,6 @@
   // Throwable Class
   java_lang_Throwable::backtrace_offset  = java_lang_Throwable::hc_backtrace_offset  * x + header;
   java_lang_Throwable::detailMessage_offset = java_lang_Throwable::hc_detailMessage_offset * x + header;
-  java_lang_Throwable::cause_offset      = java_lang_Throwable::hc_cause_offset      * x + header;
   java_lang_Throwable::stackTrace_offset = java_lang_Throwable::hc_stackTrace_offset * x + header;
   java_lang_Throwable::static_unassigned_stacktrace_offset = java_lang_Throwable::hc_static_unassigned_stacktrace_offset *  x;
 
@@ -3730,6 +3745,7 @@
 void JavaClasses::compute_offsets() {
   // java_lang_Class::compute_offsets was called earlier in bootstrap
   java_lang_ClassLoader::compute_offsets();
+  java_lang_Throwable::compute_offsets();
   java_lang_Thread::compute_offsets();
   java_lang_ThreadGroup::compute_offsets();
   java_lang_invoke_MethodHandle::compute_offsets();
@@ -3883,8 +3899,8 @@
 
   CHECK_OFFSET("java/lang/Throwable", java_lang_Throwable, backtrace, "Ljava/lang/Object;");
   CHECK_OFFSET("java/lang/Throwable", java_lang_Throwable, detailMessage, "Ljava/lang/String;");
-  CHECK_OFFSET("java/lang/Throwable", java_lang_Throwable, cause, "Ljava/lang/Throwable;");
   CHECK_OFFSET("java/lang/Throwable", java_lang_Throwable, stackTrace, "[Ljava/lang/StackTraceElement;");
+  CHECK_OFFSET("java/lang/Throwable", java_lang_Throwable, depth, "I");
 
   // Boxed primitive objects (java_lang_boxing_object)
 
--- a/hotspot/src/share/vm/classfile/javaClasses.hpp	Thu Mar 10 14:15:15 2016 +0100
+++ b/hotspot/src/share/vm/classfile/javaClasses.hpp	Thu Mar 10 13:43:47 2016 -0500
@@ -440,6 +440,7 @@
 
 class java_lang_Throwable: AllStatic {
   friend class BacktraceBuilder;
+  friend class BacktraceIterator;
 
  private:
   // Offsets
@@ -465,16 +466,12 @@
 
   static int backtrace_offset;
   static int detailMessage_offset;
-  static int cause_offset;
   static int stackTrace_offset;
+  static int depth_offset;
   static int static_unassigned_stacktrace_offset;
 
-  // Printing
-  static char* print_stack_element_to_buffer(Handle mirror, int method, int version, int bci, int cpref);
   // StackTrace (programmatic access, new since 1.4)
   static void clear_stacktrace(oop throwable);
-  // No stack trace available
-  static const char* no_stack_trace_message();
   // Stacktrace (post JDK 1.7.0 to allow immutability protocol to be followed)
   static void set_stacktrace(oop throwable, oop st_element_array);
   static oop unassigned_stacktrace();
@@ -483,19 +480,20 @@
   // Backtrace
   static oop backtrace(oop throwable);
   static void set_backtrace(oop throwable, oop value);
+  static int depth(oop throwable);
+  static void set_depth(oop throwable, int value);
   // Needed by JVMTI to filter out this internal field.
   static int get_backtrace_offset() { return backtrace_offset;}
   static int get_detailMessage_offset() { return detailMessage_offset;}
   // Message
-  static oop message(oop throwable);
   static oop message(Handle throwable);
   static void set_message(oop throwable, oop value);
   static Symbol* detail_message(oop throwable);
-  static void print_stack_element(outputStream *st, Handle mirror, int method,
-                                  int version, int bci, int cpref);
   static void print_stack_element(outputStream *st, const methodHandle& method, int bci);
   static void print_stack_usage(Handle stream);
 
+  static void compute_offsets();
+
   // Allocate space for backtrace (created but stack trace not filled in)
   static void allocate_backtrace(Handle throwable, TRAPS);
   // Fill in current stack trace for throwable with preallocated backtrace (no GC)
@@ -504,8 +502,7 @@
   static void fill_in_stack_trace(Handle throwable, const methodHandle& method, TRAPS);
   static void fill_in_stack_trace(Handle throwable, const methodHandle& method = methodHandle());
   // Programmatic access to stack trace
-  static oop  get_stack_trace_element(oop throwable, int index, TRAPS);
-  static int  get_stack_trace_depth(oop throwable, TRAPS);
+  static void get_stack_trace_elements(Handle throwable, objArrayHandle stack_trace, TRAPS);
   // Printing
   static void print(Handle throwable, outputStream* st);
   static void print_stack_trace(Handle throwable, outputStream* st);
@@ -1277,17 +1274,19 @@
   static int fileName_offset;
   static int lineNumber_offset;
 
- public:
   // Setters
   static void set_declaringClass(oop element, oop value);
   static void set_methodName(oop element, oop value);
   static void set_fileName(oop element, oop value);
   static void set_lineNumber(oop element, int value);
 
+ public:
   // Create an instance of StackTraceElement
-  static oop create(Handle mirror, int method, int version, int bci, int cpref, TRAPS);
   static oop create(const methodHandle& method, int bci, TRAPS);
 
+  static void fill_in(Handle element, InstanceKlass* holder, const methodHandle& method,
+                      int version, int bci, int cpref, TRAPS);
+
   // Debugging
   friend class JavaClasses;
 };
--- a/hotspot/src/share/vm/classfile/vmSymbols.hpp	Thu Mar 10 14:15:15 2016 +0100
+++ b/hotspot/src/share/vm/classfile/vmSymbols.hpp	Thu Mar 10 13:43:47 2016 -0500
@@ -376,6 +376,7 @@
   template(fillInStackTrace_name,                     "fillInStackTrace")                         \
   template(getCause_name,                             "getCause")                                 \
   template(initCause_name,                            "initCause")                                \
+  template(depth_name,                                "depth")                                    \
   template(setProperty_name,                          "setProperty")                              \
   template(getProperty_name,                          "getProperty")                              \
   template(context_name,                              "context")                                  \
--- a/hotspot/src/share/vm/logging/logTag.hpp	Thu Mar 10 14:15:15 2016 +0100
+++ b/hotspot/src/share/vm/logging/logTag.hpp	Thu Mar 10 13:43:47 2016 -0500
@@ -76,6 +76,7 @@
   LOG_TAG(safepointcleanup) \
   LOG_TAG(scavenge) \
   LOG_TAG(scrub) \
+  LOG_TAG(stacktrace) \
   LOG_TAG(start) \
   LOG_TAG(startuptime) \
   LOG_TAG(state) \
--- a/hotspot/src/share/vm/prims/jvm.cpp	Thu Mar 10 14:15:15 2016 +0100
+++ b/hotspot/src/share/vm/prims/jvm.cpp	Thu Mar 10 13:43:47 2016 -0500
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -514,19 +514,13 @@
 JVM_END
 
 
-JVM_ENTRY(jint, JVM_GetStackTraceDepth(JNIEnv *env, jobject throwable))
-  JVMWrapper("JVM_GetStackTraceDepth");
-  oop exception = JNIHandles::resolve(throwable);
-  return java_lang_Throwable::get_stack_trace_depth(exception, THREAD);
-JVM_END
-
-
-JVM_ENTRY(jobject, JVM_GetStackTraceElement(JNIEnv *env, jobject throwable, jint index))
-  JVMWrapper("JVM_GetStackTraceElement");
-  JvmtiVMObjectAllocEventCollector oam; // This ctor (throughout this module) may trigger a safepoint/GC
-  oop exception = JNIHandles::resolve(throwable);
-  oop element = java_lang_Throwable::get_stack_trace_element(exception, index, CHECK_NULL);
-  return JNIHandles::make_local(env, element);
+JVM_ENTRY(void, JVM_GetStackTraceElements(JNIEnv *env, jobject throwable, jobjectArray stackTrace))
+  JVMWrapper("JVM_GetStackTraceElements");
+  Handle exception(THREAD, JNIHandles::resolve(throwable));
+  objArrayOop st = objArrayOop(JNIHandles::resolve(stackTrace));
+  objArrayHandle stack_trace(THREAD, st);
+  // Fill in the allocated stack trace
+  java_lang_Throwable::get_stack_trace_elements(exception, stack_trace, CHECK);
 JVM_END
 
 
--- a/hotspot/src/share/vm/prims/jvm.h	Thu Mar 10 14:15:15 2016 +0100
+++ b/hotspot/src/share/vm/prims/jvm.h	Thu Mar 10 13:43:47 2016 -0500
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -201,11 +201,8 @@
 JNIEXPORT void JNICALL
 JVM_FillInStackTrace(JNIEnv *env, jobject throwable);
 
-JNIEXPORT jint JNICALL
-JVM_GetStackTraceDepth(JNIEnv *env, jobject throwable);
-
-JNIEXPORT jobject JNICALL
-JVM_GetStackTraceElement(JNIEnv *env, jobject throwable, jint index);
+JNIEXPORT void JNICALL
+JVM_GetStackTraceElements(JNIEnv *env, jobject throwable, jobjectArray elements);
 
 /*
  * java.lang.StackWalker
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/Throwable/StackTraceLogging.java	Thu Mar 10 13:43:47 2016 -0500
@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.    See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8150778
+ * @summary check stacktrace logging
+ * @library /testlibrary
+ * @modules java.base/sun.misc
+ *          java.management
+ * @build jdk.test.lib.OutputAnalyzer jdk.test.lib.ProcessTools
+ * @compile TestThrowable.java
+ * @run driver StackTraceLogging
+ */
+
+import java.io.File;
+import java.util.Map;
+import jdk.test.lib.OutputAnalyzer;
+import jdk.test.lib.ProcessTools;
+
+public class StackTraceLogging {
+    static void updateEnvironment(ProcessBuilder pb, String environmentVariable, String value) {
+        Map<String, String> env = pb.environment();
+        env.put(environmentVariable, value);
+    }
+
+    static void analyzeOutputOn(ProcessBuilder pb) throws Exception {
+        OutputAnalyzer output = new OutputAnalyzer(pb.start());
+        // These depths match the ones in TestThrowable.java
+        int[] depths = {10, 34, 100, 1024};
+        for (int d : depths) {
+            output.shouldContain("java.lang.RuntimeException, " + d);
+        }
+        output.shouldHaveExitValue(0);
+    }
+
+
+    public static void main(String[] args) throws Exception {
+        ProcessBuilder pb = ProcessTools.createJavaProcessBuilder("-Xlog:stacktrace=info",
+                                                                  "-XX:MaxJavaStackTraceDepth=1024",
+                                                                  "TestThrowable");
+        analyzeOutputOn(pb);
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/Throwable/TestThrowable.java	Thu Mar 10 13:43:47 2016 -0500
@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8150778
+ * @summary Test exception depths, and code to get stack traces
+ * @library /testlibrary
+ * @run main/othervm -XX:MaxJavaStackTraceDepth=1024 TestThrowable
+ */
+
+import java.lang.reflect.Field;
+import jdk.test.lib.Asserts;
+
+public class TestThrowable {
+
+  // Inner class that throws a lot of exceptions
+  static class Thrower {
+    static int MaxJavaStackTraceDepth = 1024; // as above
+    int[] depths = {10, 34, 100, 1024, 2042};
+    int count = 0;
+
+    int getDepth(Throwable t) throws Exception {
+      Field f = Throwable.class.getDeclaredField("depth");
+      f.setAccessible(true); // it's private
+      return f.getInt(t);
+    }
+
+    void callThrow(int depth) {
+      if (++count < depth) {
+        callThrow(depth);
+      } else {
+        throw new RuntimeException("depth tested " + depth);
+      }
+    }
+    void testThrow() throws Exception {
+      for (int d : depths) {
+        try {
+          count = getDepth(new Throwable());
+          callThrow(d);
+        } catch(Exception e) {
+          e.getStackTrace();
+          System.out.println(e.getMessage());
+          int throwableDepth = getDepth(e);
+          Asserts.assertTrue(throwableDepth == d ||
+                     (d > MaxJavaStackTraceDepth && throwableDepth == MaxJavaStackTraceDepth),
+                     "depth should return the correct value: depth tested=" +
+                     d + " throwableDepth=" + throwableDepth);
+        }
+      }
+    }
+  }
+
+  public static void main(String... unused) throws Exception {
+    Thrower t = new Thrower();
+    t.testThrow();
+  }
+}