--- a/src/hotspot/share/services/diagnosticCommand.cpp	Thu Oct 17 20:27:44 2019 +0100
+++ b/src/hotspot/share/services/diagnosticCommand.cpp	Thu Oct 17 20:53:35 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 2019, 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
@@ -48,6 +48,7 @@
 #include "services/management.hpp"
 #include "services/writeableFlags.hpp"
 #include "utilities/debug.hpp"
+#include "utilities/events.hpp"
 #include "utilities/formatBuffer.hpp"
 #include "utilities/macros.hpp"
 
@@ -95,6 +96,7 @@
   DCmdFactory::register_DCmdFactory(new DCmdFactoryImpl<SymboltableDCmd>(full_export, true, false));
   DCmdFactory::register_DCmdFactory(new DCmdFactoryImpl<StringtableDCmd>(full_export, true, false));
   DCmdFactory::register_DCmdFactory(new DCmdFactoryImpl<metaspace::MetaspaceDCmd>(full_export, true, false));
+  DCmdFactory::register_DCmdFactory(new DCmdFactoryImpl<EventLogDCmd>(full_export, true, false));
 #if INCLUDE_JVMTI // Both JVMTI and SERVICES have to be enabled to have this dcmd
   DCmdFactory::register_DCmdFactory(new DCmdFactoryImpl<JVMTIAgentLoadDCmd>(full_export, true, false));
 #endif // INCLUDE_JVMTI
@@ -127,7 +129,7 @@
 
   // Debug on cmd (only makes sense with JVMTI since the agentlib needs it).
 #if INCLUDE_JVMTI
-  DCmdFactory::register_DCmdFactory(new DCmdFactoryImpl<DebugOnCmdStartDCmd>(full_export, true, false));
+  DCmdFactory::register_DCmdFactory(new DCmdFactoryImpl<DebugOnCmdStartDCmd>(full_export, true, true));
 #endif // INCLUDE_JVMTI
 
 }
@@ -944,13 +946,20 @@
 CodeHeapAnalyticsDCmd::CodeHeapAnalyticsDCmd(outputStream* output, bool heap) :
                                              DCmdWithParser(output, heap),
   _function("function", "Function to be performed (aggregate, UsedSpace, FreeSpace, MethodCount, MethodSpace, MethodAge, MethodNames, discard", "STRING", false, "all"),
-  _granularity("granularity", "Detail level - smaller value -> more detail", "STRING", false, "4096") {
+  _granularity("granularity", "Detail level - smaller value -> more detail", "INT", false, "4096") {
   _dcmdparser.add_dcmd_argument(&_function);
   _dcmdparser.add_dcmd_argument(&_granularity);
 }
 
 void CodeHeapAnalyticsDCmd::execute(DCmdSource source, TRAPS) {
-  CompileBroker::print_heapinfo(output(), _function.value(), _granularity.value());
+  jlong granularity = _granularity.value();
+  if (granularity < 1) {
+    Exceptions::fthrow(THREAD_AND_LOCATION, vmSymbols::java_lang_IllegalArgumentException(),
+                       "Invalid granularity value " JLONG_FORMAT  ". Should be positive.\n", granularity);
+    return;
+  }
+
+  CompileBroker::print_heapinfo(output(), _function.value(), granularity);
 }
 
 int CodeHeapAnalyticsDCmd::num_arguments() {
@@ -965,6 +974,45 @@
 }
 //---<  END  >--- CodeHeap State Analytics.
 
+EventLogDCmd::EventLogDCmd(outputStream* output, bool heap) :
+  DCmdWithParser(output, heap),
+  _log("log", "Name of log to be printed. If omitted, all logs are printed.", "STRING", false, NULL),
+  _max("max", "Maximum number of events to be printed (newest first). If omitted, all events are printed.", "STRING", false, NULL)
+{
+  _dcmdparser.add_dcmd_option(&_log);
+  _dcmdparser.add_dcmd_option(&_max);
+}
+
+void EventLogDCmd::execute(DCmdSource source, TRAPS) {
+  const char* max_value = _max.value();
+  long max = -1;
+  if (max_value != NULL) {
+    char* endptr = NULL;
+    max = ::strtol(max_value, &endptr, 10);
+    if (max == 0 && max_value == endptr) {
+      output()->print_cr("Invalid max option: \"%s\".", max_value);
+      return;
+    }
+  }
+  const char* log_name = _log.value();
+  if (log_name != NULL) {
+    Events::print_one(output(), log_name, max);
+  } else {
+    Events::print_all(output(), max);
+  }
+}
+
+int EventLogDCmd::num_arguments() {
+  ResourceMark rm;
+  EventLogDCmd* dcmd = new EventLogDCmd(NULL, false);
+  if (dcmd != NULL) {
+    DCmdMark mark(dcmd);
+    return dcmd->_dcmdparser.num_arguments();
+  } else {
+    return 0;
+  }
+}
+
 void CompilerDirectivesPrintDCmd::execute(DCmdSource source, TRAPS) {
   DirectivesStack::print(output());
 }