8340334: Update jcmd VM.events max parameter to be INT

Reviewed-by: cjplummer, kevinw

Author: lmesnik

src/hotspot/share/services/diagnosticCommand.cpp

@@ -884,21 +884,17 @@ void CodeHeapAnalyticsDCmd::execute(DCmdSource source, TRAPS) {
 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, nullptr),
-  _max("max", "Maximum number of events to be printed (newest first). If omitted, all events are printed.", "STRING", false, nullptr)
+  _max("max", "Maximum number of events to be printed (newest first). If omitted or zero, all events are printed.", "INT", false, "0")
 {
   _dcmdparser.add_dcmd_option(&_log);
   _dcmdparser.add_dcmd_option(&_max);
 }
 
 void EventLogDCmd::execute(DCmdSource source, TRAPS) {
-  const char* max_value = _max.value();
-  int max = -1;
-  if (max_value != nullptr) {
-    char* endptr = nullptr;
-    if (!parse_integer(max_value, &max)) {
-      output()->print_cr("Invalid max option: \"%s\".", max_value);
-      return;
-    }
+  int max = (int)_max.value();
+  if (max < 0) {
+    output()->print_cr("Invalid max option: \"%d\".", max);
+    return;
   }
   const char* log_name = _log.value();
   if (log_name != nullptr) {

src/hotspot/share/services/diagnosticCommand.hpp

@@ -889,7 +889,7 @@ class ClassesDCmd : public DCmdWithParser {
 class EventLogDCmd : public DCmdWithParser {
 protected:
   DCmdArgument<char*> _log;
-  DCmdArgument<char*> _max;
+  DCmdArgument<jlong> _max;
 public:
   static int num_arguments() { return 2; }
   EventLogDCmd(outputStream* output, bool heap);

src/jdk.jcmd/share/man/jcmd.md

@@ -836,7 +836,7 @@ The following commands are available:
     -   `log`: (Optional) Name of log to be printed.
         If omitted, all logs are printed. (STRING, no default value)
     -   `max`: (Optional) Maximum number of events to be printed (newest first).
-        If omitted, all events are printed. (STRING, no default value)
+        If omitted or zero, all events are printed. (INT, 0)
 
 `VM.flags` \[*options*\]
 :   Print the VM flag options and their current values.