hotspot/src/share/vm/runtime/statSampler.cpp
changeset 1 489c9b5090e2
child 987 843415f667e6
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/runtime/statSampler.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,359 @@
+/*
+ * Copyright 2001-2006 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/_statSampler.cpp.incl"
+
+// --------------------------------------------------------
+// StatSamplerTask
+
+class StatSamplerTask : public PeriodicTask {
+  public:
+    StatSamplerTask(int interval_time) : PeriodicTask(interval_time) {}
+    void task() { StatSampler::collect_sample(); }
+};
+
+
+//----------------------------------------------------------
+// Implementation of StatSampler
+
+StatSamplerTask*              StatSampler::_task   = NULL;
+PerfDataList*                 StatSampler::_sampled = NULL;
+
+/*
+ * the initialize method is called from the engage() method
+ * and is responsible for initializing various global variables.
+ */
+void StatSampler::initialize() {
+
+  if (!UsePerfData) return;
+
+  // create performance data that could not be created prior
+  // to vm_init_globals() or otherwise have no logical home.
+
+  create_misc_perfdata();
+
+  // get copy of the sampled list
+  _sampled = PerfDataManager::sampled();
+
+}
+
+/*
+ * The engage() method is called at initialization time via
+ * Thread::create_vm() to initialize the StatSampler and
+ * register it with the WatcherThread as a periodic task.
+ */
+void StatSampler::engage() {
+
+  if (!UsePerfData) return;
+
+  if (!is_active()) {
+
+    initialize();
+
+    // start up the periodic task
+    _task = new StatSamplerTask(PerfDataSamplingInterval);
+    _task->enroll();
+  }
+}
+
+
+/*
+ * the disengage() method is responsible for deactivating the periodic
+ * task and, if logging was enabled, for logging the final sample. This
+ * method is called from before_exit() in java.cpp and is only called
+ * after the WatcherThread has been stopped.
+ */
+void StatSampler::disengage() {
+
+  if (!UsePerfData) return;
+
+  if (!is_active())
+    return;
+
+  // remove StatSamplerTask
+  _task->disenroll();
+  delete _task;
+  _task = NULL;
+
+  // force a final sample
+  sample_data(_sampled);
+}
+
+/*
+ * the destroy method is responsible for releasing any resources used by
+ * the StatSampler prior to shutdown of the VM. this method is called from
+ * before_exit() in java.cpp and is only called after the WatcherThread
+ * has stopped.
+ */
+void StatSampler::destroy() {
+
+  if (!UsePerfData) return;
+
+  if (_sampled != NULL) {
+    delete(_sampled);
+    _sampled = NULL;
+  }
+}
+
+/*
+ * The sample_data() method is responsible for sampling the
+ * the data value for each PerfData instance in the given list.
+ */
+void StatSampler::sample_data(PerfDataList* list) {
+
+  assert(list != NULL, "null list unexpected");
+
+  for (int index = 0; index < list->length(); index++) {
+    PerfData* item = list->at(index);
+    item->sample();
+  }
+}
+
+/*
+ * the collect_sample() method is the method invoked by the
+ * WatcherThread via the PeriodicTask::task() method. This method
+ * is responsible for collecting data samples from sampled
+ * PerfData instances every PerfDataSamplingInterval milliseconds.
+ * It is also responsible for logging the requested set of
+ * PerfData instances every _sample_count milliseconds. While
+ * logging data, it will output a column header after every _print_header
+ * rows of data have been logged.
+ */
+void StatSampler::collect_sample() {
+
+  // future - check for new PerfData objects. PerfData objects might
+  // get added to the PerfDataManager lists after we have already
+  // built our local copies.
+  //
+  // if (PerfDataManager::count() > previous) {
+  //   // get a new copy of the sampled list
+  //   if (_sampled != NULL) {
+  //     delete(_sampled);
+  //     _sampled = NULL;
+  //   }
+  //   _sampled = PerfDataManager::sampled();
+  // }
+
+  assert(_sampled != NULL, "list not initialized");
+
+  sample_data(_sampled);
+}
+
+/*
+ * method to upcall into Java to return the value of the specified
+ * property as a utf8 string, or NULL if does not exist. The caller
+ * is responsible for setting a ResourceMark for proper cleanup of
+ * the utf8 strings.
+ */
+const char* StatSampler::get_system_property(const char* name, TRAPS) {
+
+  // setup the arguments to getProperty
+  Handle key_str   = java_lang_String::create_from_str(name, CHECK_NULL);
+
+  // return value
+  JavaValue result(T_OBJECT);
+
+  // public static String getProperty(String key, String def);
+  JavaCalls::call_static(&result,
+                         KlassHandle(THREAD, SystemDictionary::system_klass()),
+                         vmSymbolHandles::getProperty_name(),
+                         vmSymbolHandles::string_string_signature(),
+                         key_str,
+                         CHECK_NULL);
+
+  oop value_oop = (oop)result.get_jobject();
+  if (value_oop == NULL) {
+    return NULL;
+  }
+
+  // convert Java String to utf8 string
+  char* value = java_lang_String::as_utf8_string(value_oop);
+
+  return value;
+}
+
+/*
+ * The list of System Properties that have corresponding PerfData
+ * string instrumentation created by retrieving the named property's
+ * value from System.getProperty() and unconditionally creating a
+ * PerfStringConstant object initialized to the retreived value. This
+ * is not an exhustive list of Java properties with corresponding string
+ * instrumentation as the create_system_property_instrumentation() method
+ * creates other property based instrumentation conditionally.
+ */
+
+// stable interface, supported counters
+static const char* property_counters_ss[] = {
+  "java.vm.specification.version",
+  "java.vm.specification.name",
+  "java.vm.specification.vendor",
+  "java.vm.version",
+  "java.vm.name",
+  "java.vm.vendor",
+  "java.vm.info",
+  "java.library.path",
+  "java.class.path",
+  "java.endorsed.dirs",
+  "java.ext.dirs",
+  "java.home",
+  NULL
+};
+
+// unstable interface, supported counters
+static const char* property_counters_us[] = {
+  NULL
+};
+
+// unstable interface, unsupported counters
+static const char* property_counters_uu[] = {
+  "sun.boot.class.path",
+  "sun.boot.library.path",
+  NULL
+};
+
+typedef struct {
+  const char** property_list;
+  CounterNS name_space;
+} PropertyCounters;
+
+static PropertyCounters property_counters[] = {
+  { property_counters_ss, JAVA_PROPERTY },
+  { property_counters_us, COM_PROPERTY },
+  { property_counters_uu, SUN_PROPERTY },
+  { NULL, SUN_PROPERTY }
+};
+
+
+/*
+ * Method to create PerfData string instruments that contain the values
+ * of various system properties. String instruments are created for each
+ * property specified in the property lists provided in property_counters[].
+ * Property counters have a counter name space prefix prepended to the
+ * property name as indicated in property_counters[].
+ */
+void StatSampler::create_system_property_instrumentation(TRAPS) {
+
+  ResourceMark rm;
+
+  for (int i = 0; property_counters[i].property_list != NULL; i++) {
+
+    for (int j = 0; property_counters[i].property_list[j] != NULL; j++) {
+
+      const char* property_name = property_counters[i].property_list[j];
+      assert(property_name != NULL, "property name should not be NULL");
+
+      const char* value = get_system_property(property_name, CHECK);
+
+      // the property must exist
+      assert(value != NULL, "property name should be valid");
+
+      if (value != NULL) {
+        // create the property counter
+        PerfDataManager::create_string_constant(property_counters[i].name_space,
+                                                property_name, value, CHECK);
+      }
+    }
+  }
+}
+
+/*
+ * The create_misc_perfdata() method provides a place to create
+ * PerfData instances that would otherwise have no better place
+ * to exist.
+ */
+void StatSampler::create_misc_perfdata() {
+
+  ResourceMark rm;
+  EXCEPTION_MARK;
+
+  // numeric constants
+
+  // frequency of the native high resolution timer
+  PerfDataManager::create_constant(SUN_OS, "hrt.frequency",
+                                   PerfData::U_Hertz, os::elapsed_frequency(),
+                                   CHECK);
+
+  // string constants
+
+  // create string instrumentation for various Java properties.
+  create_system_property_instrumentation(CHECK);
+
+  // hotspot flags (from .hotspotrc) and args (from command line)
+  //
+  PerfDataManager::create_string_constant(JAVA_RT, "vmFlags",
+                                          Arguments::jvm_flags(), CHECK);
+  PerfDataManager::create_string_constant(JAVA_RT, "vmArgs",
+                                          Arguments::jvm_args(), CHECK);
+
+  // java class name/jar file and arguments to main class
+  // note: name is cooridnated with launcher and Arguments.cpp
+  PerfDataManager::create_string_constant(SUN_RT, "javaCommand",
+                                          Arguments::java_command(), CHECK);
+
+  // the Java VM Internal version string
+  PerfDataManager::create_string_constant(SUN_RT, "internalVersion",
+                                         VM_Version::internal_vm_info_string(),
+                                         CHECK);
+
+  // create sampled instrumentation objects
+  create_sampled_perfdata();
+}
+
+/*
+ * helper class to provide for sampling of the elapsed_counter value
+ * maintained in the OS class.
+ */
+class HighResTimeSampler : public PerfSampleHelper {
+  public:
+    jlong take_sample() { return os::elapsed_counter(); }
+};
+
+/*
+ * the create_sampled_perdata() method provides a place to instantiate
+ * sampled PerfData instances that would otherwise have no better place
+ * to exist.
+ */
+void StatSampler::create_sampled_perfdata() {
+
+  EXCEPTION_MARK;
+
+  // setup sampling of the elapsed time counter maintained in the
+  // the os class. This counter can be used as either a time stamp
+  // for each logged entry or as a liveness indicator for the VM.
+  PerfSampleHelper* psh = new HighResTimeSampler();
+  PerfDataManager::create_counter(SUN_OS, "hrt.ticks",
+                                  PerfData::U_Ticks, psh, CHECK);
+}
+
+/*
+ * the statSampler_exit() function is called from os_init.cpp on
+ * exit of the vm.
+ */
+void statSampler_exit() {
+
+  if (!UsePerfData) return;
+
+  StatSampler::destroy();
+}