8336401: Remove the option onjcmd from the jdwp agent

Reviewed-by: cjplummer, mbaesken

Author: parttimenerd

src/hotspot/share/services/diagnosticCommand.cpp

@@ -52,7 +52,6 @@
 #include "runtime/fieldDescriptor.inline.hpp"
 #include "runtime/flags/jvmFlag.hpp"
 #include "runtime/handles.inline.hpp"
-#include "runtime/interfaceSupport.inline.hpp"
 #include "runtime/javaCalls.hpp"
 #include "runtime/jniHandles.hpp"
 #include "runtime/os.hpp"
@@ -160,11 +159,6 @@ void DCmd::register_dcmds(){
   DCmdFactory::register_DCmdFactory(new DCmdFactoryImpl<JMXStopRemoteDCmd>(jmx_agent_export_flags, true,false));
   DCmdFactory::register_DCmdFactory(new DCmdFactoryImpl<JMXStatusDCmd>(jmx_agent_export_flags, true,false));
 
-  // 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, true));
-#endif // INCLUDE_JVMTI
-
 #if INCLUDE_CDS
   DCmdFactory::register_DCmdFactory(new DCmdFactoryImpl<DumpSharedArchiveDCmd>(full_export, true, false));
 #endif // INCLUDE_CDS
@@ -1058,45 +1052,6 @@ void DumpSharedArchiveDCmd::execute(DCmdSource source, TRAPS) {
 }
 #endif // INCLUDE_CDS
 
-#if INCLUDE_JVMTI
-extern "C" typedef char const* (JNICALL *debugInit_startDebuggingViaCommandPtr)(JNIEnv* env, jthread thread, char const** transport_name,
-                                                                                char const** address, jboolean* first_start);
-static debugInit_startDebuggingViaCommandPtr dvc_start_ptr = nullptr;
-
-void DebugOnCmdStartDCmd::execute(DCmdSource source, TRAPS) {
-  char const* transport = nullptr;
-  char const* addr = nullptr;
-  jboolean is_first_start = JNI_FALSE;
-  JavaThread* thread = THREAD;
-  jthread jt = JNIHandles::make_local(thread->threadObj());
-  ThreadToNativeFromVM ttn(thread);
-  const char *error = "Could not find jdwp agent.";
-
-  if (!dvc_start_ptr) {
-    JvmtiAgentList::Iterator it = JvmtiAgentList::agents();
-    while (it.has_next()) {
-      JvmtiAgent* agent = it.next();
-      if ((strcmp("jdwp", agent->name()) == 0) && (dvc_start_ptr == nullptr)) {
-        char const* func = "debugInit_startDebuggingViaCommand";
-        dvc_start_ptr = (debugInit_startDebuggingViaCommandPtr) os::find_agent_function(agent, false, &func, 1);
-      }
-    }
-  }
-
-  if (dvc_start_ptr) {
-    error = dvc_start_ptr(thread->jni_environment(), jt, &transport, &addr, &is_first_start);
-  }
-
-  if (error != nullptr) {
-    output()->print_cr("Debugging has not been started: %s", error);
-  } else {
-    output()->print_cr(is_first_start ? "Debugging has been started." : "Debugging is already active.");
-    output()->print_cr("Transport : %s", transport ? transport : "#unknown");
-    output()->print_cr("Address : %s", addr ? addr : "#unknown");
-  }
-}
-#endif // INCLUDE_JVMTI
-
 ThreadDumpToFileDCmd::ThreadDumpToFileDCmd(outputStream* output, bool heap) :
                                            DCmdWithParser(output, heap),
   _overwrite("-overwrite", "May overwrite existing file", "BOOLEAN", false, "false"),

src/hotspot/share/services/diagnosticCommand.hpp

@@ -886,27 +886,6 @@ class ClassesDCmd : public DCmdWithParser {
   virtual void execute(DCmdSource source, TRAPS);
 };
 
-#if INCLUDE_JVMTI
-class DebugOnCmdStartDCmd : public DCmd {
-public:
-  DebugOnCmdStartDCmd(outputStream* output, bool heap) : DCmd(output, heap) {}
-  static const char* name() {
-    return "VM.start_java_debugging";
-  }
-  static const char* description() {
-    return "Starts up the Java debugging if the jdwp agentlib was enabled with the option onjcmd=y.";
-  }
-  static const char* impact() {
-    return "High: Switches the VM into Java debug mode.";
-  }
-  static const JavaPermission permission() {
-    JavaPermission p = { "java.lang.management.ManagementPermission", "control", nullptr };
-    return p;
-  }
-  virtual void execute(DCmdSource source, TRAPS);
-};
-#endif // INCLUDE_JVMTI
-
 class EventLogDCmd : public DCmdWithParser {
 protected:
   DCmdArgument<char*> _log;

src/jdk.jdwp.agent/share/native/libjdwp/debugInit.c

@@ -81,9 +81,6 @@ static unsigned logflags = 0;               /* Log flags */
 
 static char *names;                         /* strings derived from OnLoad options */
 
-static jboolean allowStartViaJcmd = JNI_FALSE;  /* if true we allow the debugging to be started via a jcmd */
-static jboolean startedViaJcmd = JNI_FALSE;     /* if false, we have not yet started debugging via a jcmd */
-
 /*
  * Elements of the transports bag
  */
@@ -983,7 +980,6 @@ parseOptions(char *options)
     int length;
     char *str;
     char *errmsg;
-    jboolean onJcmd = JNI_FALSE;
 
     /* Set defaults */
     gdata->assertOn     = DEFAULT_ASSERT_ON;
@@ -1231,10 +1227,6 @@ parseOptions(char *options)
             if ( !get_boolean(&str, &useStandardAlloc) ) {
                 goto syntax_error;
             }
-        } else if (strcmp(buf, "onjcmd") == 0) {
-            if (!get_boolean(&str, &onJcmd)) {
-                goto syntax_error;
-            }
         } else {
             goto syntax_error;
         }
@@ -1285,20 +1277,6 @@ parseOptions(char *options)
         }
     }
 
-    if (onJcmd) {
-        if (launchOnInit != NULL) {
-            errmsg = "Cannot combine onjcmd and launch suboptions";
-            goto bad_option_with_errmsg;
-        }
-        if (!isServer) {
-            errmsg = "Can only use onjcmd with server=y";
-            goto bad_option_with_errmsg;
-        }
-        suspendOnInit = JNI_FALSE;
-        initOnStartup = JNI_FALSE;
-        allowStartViaJcmd = JNI_TRUE;
-    }
-
     return JNI_TRUE;
 
 syntax_error:
@@ -1367,45 +1345,3 @@ debugInit_exit(jvmtiError error, const char *msg)
     // Last chance to die, this kills the entire process.
     forceExit(EXIT_JVMTI_ERROR);
 }
-
-static jboolean getFirstTransport(void *item, void *arg)
-{
-    TransportSpec** store = arg;
-    *store = item;
-
-    return JNI_FALSE; /* Want the first */
-}
-
-/* Call to start up debugging. */
-JNIEXPORT char const* JNICALL debugInit_startDebuggingViaCommand(JNIEnv* env, jthread thread, char const** transport_name,
-                                                                char const** address, jboolean* first_start) {
-    jboolean is_first_start = JNI_FALSE;
-    TransportSpec* spec = NULL;
-
-    if (!vmInitialized) {
-        return "Not yet initialized. Try again later.";
-    }
-
-    if (!allowStartViaJcmd) {
-        return "Starting debugging via jcmd was not enabled via the onjcmd option of the jdwp agent.";
-    }
-
-    if (!startedViaJcmd) {
-        startedViaJcmd = JNI_TRUE;
-        is_first_start = JNI_TRUE;
-        initialize(env, thread, EI_VM_INIT, NULL);
-    }
-
-    bagEnumerateOver(transports, getFirstTransport, &spec);
-
-    if ((spec != NULL) && (transport_name != NULL) && (address != NULL)) {
-        *transport_name = spec->name;
-        *address = spec->address;
-    }
-
-    if (first_start != NULL) {
-        *first_start = is_first_start;
-    }
-
-    return NULL;
-}

test/jdk/com/sun/jdi/OnJcmdTest.java

@@ -65,7 +65,7 @@
  *      jdk.jfr.event.runtime.TestAgentEvent
  *      testJavaDynamic
  *
- * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:-UseFastUnorderedTimeStamps -agentlib:jdwp=transport=dt_socket,server=y,address=any,onjcmd=y
+ * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:-UseFastUnorderedTimeStamps -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=0
  *      jdk.jfr.event.runtime.TestAgentEvent
  *      testNativeStatic
  */
@@ -122,7 +122,7 @@ private static void testNativeStatic() throws Throwable {
             RecordedEvent e = events.get(1);
             System.out.println(e);
             Events.assertField(e, "name").equal("jdwp");
-            Events.assertField(e, "options").equal("transport=dt_socket,server=y,address=any,onjcmd=y");
+            Events.assertField(e, "options").equal("transport=dt_socket,server=y,suspend=n,address=0");
             Events.assertField(e, "dynamic").equal(false);
             Instant initializationTime = e.getInstant("initializationTime");
             if (initializationTime.isAfter(interval.getStartTime())) {