hotspot/src/share/vm/services/attachListener.cpp
changeset 1 489c9b5090e2
child 2141 e9a644aaff87
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/services/attachListener.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,451 @@
+/*
+ * Copyright 2005-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+# include "incls/_precompiled.incl"
+# include "incls/_attachListener.cpp.incl"
+
+volatile bool AttachListener::_initialized;
+
+// Implementation of "properties" command.
+//
+// Invokes sun.misc.VMSupport.serializePropertiesToByteArray to serialize
+// the system properties into a byte array.
+
+static klassOop load_and_initialize_klass(symbolHandle sh, TRAPS) {
+  klassOop k = SystemDictionary::resolve_or_fail(sh, true, CHECK_NULL);
+  instanceKlassHandle ik (THREAD, k);
+  if (ik->should_be_initialized()) {
+    ik->initialize(CHECK_NULL);
+  }
+  return ik();
+}
+
+static jint get_properties(AttachOperation* op, outputStream* out, symbolHandle serializePropertiesMethod) {
+  Thread* THREAD = Thread::current();
+  HandleMark hm;
+
+  // load sun.misc.VMSupport
+  symbolHandle klass = vmSymbolHandles::sun_misc_VMSupport();
+  klassOop k = load_and_initialize_klass(klass, THREAD);
+  if (HAS_PENDING_EXCEPTION) {
+    java_lang_Throwable::print(PENDING_EXCEPTION, out);
+    CLEAR_PENDING_EXCEPTION;
+    return JNI_ERR;
+  }
+  instanceKlassHandle ik(THREAD, k);
+
+  // invoke the serializePropertiesToByteArray method
+  JavaValue result(T_OBJECT);
+  JavaCallArguments args;
+
+
+  symbolHandle signature = vmSymbolHandles::serializePropertiesToByteArray_signature();
+  JavaCalls::call_static(&result,
+                           ik,
+                           serializePropertiesMethod,
+                           signature,
+                           &args,
+                           THREAD);
+  if (HAS_PENDING_EXCEPTION) {
+    java_lang_Throwable::print(PENDING_EXCEPTION, out);
+    CLEAR_PENDING_EXCEPTION;
+    return JNI_ERR;
+  }
+
+  // The result should be a [B
+  oop res = (oop)result.get_jobject();
+  assert(res->is_typeArray(), "just checking");
+  assert(typeArrayKlass::cast(res->klass())->element_type() == T_BYTE, "just checking");
+
+  // copy the bytes to the output stream
+  typeArrayOop ba = typeArrayOop(res);
+  jbyte* addr = typeArrayOop(res)->byte_at_addr(0);
+  out->print_raw((const char*)addr, ba->length());
+
+  return JNI_OK;
+}
+
+// Implementation of "properties" command.
+static jint get_system_properties(AttachOperation* op, outputStream* out) {
+  return get_properties(op, out, vmSymbolHandles::serializePropertiesToByteArray_name());
+}
+
+// Implementation of "agent_properties" command.
+static jint get_agent_properties(AttachOperation* op, outputStream* out) {
+  return get_properties(op, out, vmSymbolHandles::serializeAgentPropertiesToByteArray_name());
+}
+
+// Implementation of "datadump" command.
+//
+// Raises a SIGBREAK signal so that VM dump threads, does deadlock detection,
+// etc. In theory this command should only post a DataDumpRequest to any
+// JVMTI environment that has enabled this event. However it's useful to
+// trigger the SIGBREAK handler.
+
+static jint data_dump(AttachOperation* op, outputStream* out) {
+  if (!ReduceSignalUsage) {
+    AttachListener::pd_data_dump();
+  } else {
+    if (JvmtiExport::should_post_data_dump()) {
+      JvmtiExport::post_data_dump();
+    }
+  }
+  return JNI_OK;
+}
+
+// Implementation of "threaddump" command - essentially a remote ctrl-break
+//
+static jint thread_dump(AttachOperation* op, outputStream* out) {
+  bool print_concurrent_locks = false;
+  if (op->arg(0) != NULL && strcmp(op->arg(0), "-l") == 0) {
+    print_concurrent_locks = true;
+  }
+
+  // thread stacks
+  VM_PrintThreads op1(out, print_concurrent_locks);
+  VMThread::execute(&op1);
+
+  // JNI global handles
+  VM_PrintJNI op2(out);
+  VMThread::execute(&op2);
+
+  // Deadlock detection
+  VM_FindDeadlocks op3(out);
+  VMThread::execute(&op3);
+
+  return JNI_OK;
+}
+
+#ifndef SERVICES_KERNEL   // Heap dumping not supported
+// Implementation of "dumpheap" command.
+//
+// Input arguments :-
+//   arg0: Name of the dump file
+//   arg1: "-live" or "-all"
+jint dump_heap(AttachOperation* op, outputStream* out) {
+  const char* path = op->arg(0);
+  if (path == NULL || path[0] == '\0') {
+    out->print_cr("No dump file specified");
+  } else {
+    bool live_objects_only = true;   // default is true to retain the behavior before this change is made
+    const char* arg1 = op->arg(1);
+    if (arg1 != NULL && (strlen(arg1) > 0)) {
+      if (strcmp(arg1, "-all") != 0 && strcmp(arg1, "-live") != 0) {
+        out->print_cr("Invalid argument to dumpheap operation: %s", arg1);
+        return JNI_ERR;
+      }
+      live_objects_only = strcmp(arg1, "-live") == 0;
+    }
+
+    // Request a full GC before heap dump if live_objects_only = true
+    // This helps reduces the amount of unreachable objects in the dump
+    // and makes it easier to browse.
+    HeapDumper dumper(live_objects_only /* request GC */);
+    int res = dumper.dump(op->arg(0));
+    if (res == 0) {
+      out->print_cr("Heap dump file created");
+    } else {
+      // heap dump failed
+      ResourceMark rm;
+      char* error = dumper.error_as_C_string();
+      if (error == NULL) {
+        out->print_cr("Dump failed - reason unknown");
+      } else {
+        out->print_cr("%s", error);
+      }
+    }
+  }
+  return JNI_OK;
+}
+#endif // SERVICES_KERNEL
+
+// Implementation of "inspectheap" command
+//
+// Input arguments :-
+//   arg0: "-live" or "-all"
+static jint heap_inspection(AttachOperation* op, outputStream* out) {
+  bool live_objects_only = true;   // default is true to retain the behavior before this change is made
+  const char* arg0 = op->arg(0);
+  if (arg0 != NULL && (strlen(arg0) > 0)) {
+    if (strcmp(arg0, "-all") != 0 && strcmp(arg0, "-live") != 0) {
+      out->print_cr("Invalid argument to inspectheap operation: %s", arg0);
+      return JNI_ERR;
+    }
+    live_objects_only = strcmp(arg0, "-live") == 0;
+  }
+  VM_GC_HeapInspection heapop(out, live_objects_only /* request gc */);
+  VMThread::execute(&heapop);
+  return JNI_OK;
+}
+
+// set a boolean global flag using value from AttachOperation
+static jint set_bool_flag(const char* name, AttachOperation* op, outputStream* out) {
+  bool value = true;
+  const char* arg1;
+  if ((arg1 = op->arg(1)) != NULL) {
+    int tmp;
+    int n = sscanf(arg1, "%d", &tmp);
+    if (n != 1) {
+      out->print_cr("flag value has to be boolean (1 or 0)");
+      return JNI_ERR;
+    }
+    value = (tmp != 0);
+  }
+  bool res = CommandLineFlags::boolAtPut((char*)name, &value, ATTACH_ON_DEMAND);
+  if (! res) {
+    out->print_cr("setting flag %s failed", name);
+  }
+  return res? JNI_OK : JNI_ERR;
+}
+
+// set a intx global flag using value from AttachOperation
+static jint set_intx_flag(const char* name, AttachOperation* op, outputStream* out) {
+  intx value;
+  const char* arg1;
+  if ((arg1 = op->arg(1)) != NULL) {
+    int n = sscanf(arg1, INTX_FORMAT, &value);
+    if (n != 1) {
+      out->print_cr("flag value has to be integer");
+      return JNI_ERR;
+    }
+  }
+  bool res = CommandLineFlags::intxAtPut((char*)name,  &value, ATTACH_ON_DEMAND);
+  if (! res) {
+    out->print_cr("setting flag %s failed", name);
+  }
+
+  return res? JNI_OK : JNI_ERR;
+}
+
+// set a uintx global flag using value from AttachOperation
+static jint set_uintx_flag(const char* name, AttachOperation* op, outputStream* out) {
+  uintx value;
+  const char* arg1;
+  if ((arg1 = op->arg(1)) != NULL) {
+    int n = sscanf(arg1, UINTX_FORMAT, &value);
+    if (n != 1) {
+      out->print_cr("flag value has to be integer");
+      return JNI_ERR;
+    }
+  }
+  bool res = CommandLineFlags::uintxAtPut((char*)name,  &value, ATTACH_ON_DEMAND);
+  if (! res) {
+    out->print_cr("setting flag %s failed", name);
+  }
+
+  return res? JNI_OK : JNI_ERR;
+}
+
+// set a string global flag using value from AttachOperation
+static jint set_ccstr_flag(const char* name, AttachOperation* op, outputStream* out) {
+  const char* value;
+  if ((value = op->arg(1)) == NULL) {
+    out->print_cr("flag value has to be a string");
+    return JNI_ERR;
+  }
+  bool res = CommandLineFlags::ccstrAtPut((char*)name,  &value, ATTACH_ON_DEMAND);
+  if (res) {
+    FREE_C_HEAP_ARRAY(char, value);
+  } else {
+    out->print_cr("setting flag %s failed", name);
+  }
+
+  return res? JNI_OK : JNI_ERR;
+}
+
+// Implementation of "setflag" command
+static jint set_flag(AttachOperation* op, outputStream* out) {
+
+  const char* name = NULL;
+  if ((name = op->arg(0)) == NULL) {
+    out->print_cr("flag name is missing");
+    return JNI_ERR;
+  }
+
+  Flag* f = Flag::find_flag((char*)name, strlen(name));
+  if (f && f->is_external() && f->is_writeable()) {
+    if (f->is_bool()) {
+      return set_bool_flag(name, op, out);
+    } else if (f->is_intx()) {
+      return set_intx_flag(name, op, out);
+    } else if (f->is_uintx()) {
+      return set_uintx_flag(name, op, out);
+    } else if (f->is_ccstr()) {
+      return set_ccstr_flag(name, op, out);
+    } else {
+      ShouldNotReachHere();
+      return JNI_ERR;
+    }
+  } else {
+    return AttachListener::pd_set_flag(op, out);
+  }
+}
+
+// Implementation of "printflag" command
+static jint print_flag(AttachOperation* op, outputStream* out) {
+  const char* name = NULL;
+  if ((name = op->arg(0)) == NULL) {
+    out->print_cr("flag name is missing");
+    return JNI_ERR;
+  }
+  Flag* f = Flag::find_flag((char*)name, strlen(name));
+  if (f) {
+    f->print_as_flag(out);
+    out->print_cr("");
+  } else {
+    out->print_cr("no such flag '%s'", name);
+  }
+  return JNI_OK;
+}
+
+// Table to map operation names to functions.
+
+// names must be of length <= AttachOperation::name_length_max
+static AttachOperationFunctionInfo funcs[] = {
+  { "agentProperties",  get_agent_properties },
+  { "datadump",         data_dump },
+#ifndef SERVICES_KERNEL
+  { "dumpheap",         dump_heap },
+#endif  // SERVICES_KERNEL
+  { "load",             JvmtiExport::load_agent_library },
+  { "properties",       get_system_properties },
+  { "threaddump",       thread_dump },
+  { "inspectheap",      heap_inspection },
+  { "setflag",          set_flag },
+  { "printflag",        print_flag },
+  { NULL,               NULL }
+};
+
+
+
+// The Attach Listener threads services a queue. It dequeues an operation
+// from the queue, examines the operation name (command), and dispatches
+// to the corresponding function to perform the operation.
+
+static void attach_listener_thread_entry(JavaThread* thread, TRAPS) {
+  os::set_priority(thread, NearMaxPriority);
+
+  if (AttachListener::pd_init() != 0) {
+    return;
+  }
+  AttachListener::set_initialized();
+
+  for (;;) {
+    AttachOperation* op = AttachListener::dequeue();
+    if (op == NULL) {
+      return;   // dequeue failed or shutdown
+    }
+
+    ResourceMark rm;
+    bufferedStream st;
+    jint res = JNI_OK;
+
+    // handle special detachall operation
+    if (strcmp(op->name(), AttachOperation::detachall_operation_name()) == 0) {
+      AttachListener::detachall();
+    } else {
+      // find the function to dispatch too
+      AttachOperationFunctionInfo* info = NULL;
+      for (int i=0; funcs[i].name != NULL; i++) {
+        const char* name = funcs[i].name;
+        assert(strlen(name) <= AttachOperation::name_length_max, "operation <= name_length_max");
+        if (strcmp(op->name(), name) == 0) {
+          info = &(funcs[i]);
+          break;
+        }
+      }
+
+      // check for platform dependent attach operation
+      if (info == NULL) {
+        info = AttachListener::pd_find_operation(op->name());
+      }
+
+      if (info != NULL) {
+        // dispatch to the function that implements this operation
+        res = (info->func)(op, &st);
+      } else {
+        st.print("Operation %s not recognized!", op->name());
+        res = JNI_ERR;
+      }
+    }
+
+    // operation complete - send result and output to client
+    op->complete(res, &st);
+  }
+}
+
+// Starts the Attach Listener thread
+void AttachListener::init() {
+  EXCEPTION_MARK;
+  klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK);
+  instanceKlassHandle klass (THREAD, k);
+  instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
+
+  const char thread_name[] = "Attach Listener";
+  Handle string = java_lang_String::create_from_str(thread_name, CHECK);
+
+  // Initialize thread_oop to put it into the system threadGroup
+  Handle thread_group (THREAD, Universe::system_thread_group());
+  JavaValue result(T_VOID);
+  JavaCalls::call_special(&result, thread_oop,
+                       klass,
+                       vmSymbolHandles::object_initializer_name(),
+                       vmSymbolHandles::threadgroup_string_void_signature(),
+                       thread_group,
+                       string,
+                       CHECK);
+
+  KlassHandle group(THREAD, SystemDictionary::threadGroup_klass());
+  JavaCalls::call_special(&result,
+                        thread_group,
+                        group,
+                        vmSymbolHandles::add_method_name(),
+                        vmSymbolHandles::thread_void_signature(),
+                        thread_oop,             // ARG 1
+                        CHECK);
+
+  { MutexLocker mu(Threads_lock);
+    JavaThread* listener_thread = new JavaThread(&attach_listener_thread_entry);
+
+    // Check that thread and osthread were created
+    if (listener_thread == NULL || listener_thread->osthread() == NULL) {
+      vm_exit_during_initialization("java.lang.OutOfMemoryError",
+                                    "unable to create new native thread");
+    }
+
+    java_lang_Thread::set_thread(thread_oop(), listener_thread);
+    java_lang_Thread::set_daemon(thread_oop());
+
+    listener_thread->set_threadObj(thread_oop());
+    Threads::add(listener_thread);
+    Thread::start(listener_thread);
+  }
+}
+
+// Performs clean-up tasks on platforms where we can detect that the last
+// client has detached
+void AttachListener::detachall() {
+  // call the platform dependent clean-up
+  pd_detachall();
+}