src/share/vm/jfr/leakprofiler/leakProfiler.cpp

rev 9055 : 8214542: JFR: Old Object Sample event slow on a deep heap in debug builds
Reviewed-by: egahlin, rwestberg

*** 1,7 ****
  /*
!  * Copyright (c) 2014, 2018, 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
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
--- 1,7 ----
  /*
!  * Copyright (c) 2014, 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
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
*** 21,132 ****
   * questions.
   *
   */
  
  #include "precompiled.hpp"
- #include "jfr/leakprofiler/emitEventOperation.hpp"
  #include "jfr/leakprofiler/leakProfiler.hpp"
  #include "jfr/leakprofiler/startOperation.hpp"
  #include "jfr/leakprofiler/stopOperation.hpp"
  #include "jfr/leakprofiler/sampling/objectSampler.hpp"
  #include "jfr/recorder/service/jfrOptionSet.hpp"
  #include "memory/iterator.hpp"
- #include "oops/oop.hpp"
- #include "runtime/atomic.hpp"
- #include "runtime/orderAccess.hpp"
  #include "runtime/thread.inline.hpp"
  #include "runtime/vmThread.hpp"
- #include "utilities/ostream.hpp"
  
! // Only to be updated during safepoint
! ObjectSampler* LeakProfiler::_object_sampler = NULL;
  
! static volatile jbyte suspended = 0;
! bool LeakProfiler::start(jint sample_count) {
!   if (_object_sampler != NULL) {
!     // already started
      return true;
    }
    // Allows user to disable leak profiler on command line by setting queue size to zero.
!   if (sample_count > 0) {
      StartOperation op(sample_count);
      VMThread::execute(&op);
!     return _object_sampler != NULL;
!   }
    return false;
  }
  
  bool LeakProfiler::stop() {
!   if (_object_sampler == NULL) {
!     // already stopped/not started
!     return true;
    }
    StopOperation op;
    VMThread::execute(&op);
!   return _object_sampler == NULL;
  }
  
! void LeakProfiler::emit_events(jlong cutoff_ticks, bool emit_all) {
    if (!is_running()) {
      return;
    }
!   EmitEventOperation op(cutoff_ticks, emit_all);
!   VMThread::execute(&op);
  }
  
  void LeakProfiler::oops_do(BoolObjectClosure* is_alive, OopClosure* f) {
    assert(SafepointSynchronize::is_at_safepoint(),
      "Leak Profiler::oops_do(...) may only be called during safepoint");
! 
!   if (_object_sampler != NULL) {
!     _object_sampler->oops_do(is_alive, f);
    }
  }
  
! void LeakProfiler::sample(HeapWord* object,
!                           size_t size,
!                           JavaThread* thread) {
    assert(is_running(), "invariant");
    assert(thread != NULL, "invariant");
    assert(thread->thread_state() == _thread_in_vm, "invariant");
  
    // exclude compiler threads and code sweeper thread
    if (thread->is_hidden_from_external_view()) {
      return;
    }
  
!   _object_sampler->add(object, size, thread);
! }
! 
! ObjectSampler* LeakProfiler::object_sampler() {
!   assert(is_suspended() || SafepointSynchronize::is_at_safepoint(),
!     "Leak Profiler::object_sampler() may only be called during safepoint");
!   return _object_sampler;
! }
! 
! void LeakProfiler::set_object_sampler(ObjectSampler* object_sampler) {
!   assert(SafepointSynchronize::is_at_safepoint(),
!     "Leak Profiler::set_object_sampler() may only be called during safepoint");
!   _object_sampler = object_sampler;
! }
! 
! bool LeakProfiler::is_running() {
!   return _object_sampler != NULL && !suspended;
! }
! 
! bool LeakProfiler::is_suspended() {
!   return _object_sampler != NULL && suspended;
! }
! 
! void LeakProfiler::resume() {
!   assert(is_suspended(), "invariant");
!   OrderAccess::storestore();
!   Atomic::store((jbyte)0, &suspended);
!   assert(is_running(), "invariant");
! }
! 
! void LeakProfiler::suspend() {
!   assert(SafepointSynchronize::is_at_safepoint(), "invariant");
!   assert(_object_sampler != NULL, "invariant");
!   assert(!is_suspended(), "invariant");
!   suspended = (jbyte)1; // safepoint visible
  }
--- 21,110 ----
   * questions.
   *
   */
  
  #include "precompiled.hpp"
  #include "jfr/leakprofiler/leakProfiler.hpp"
  #include "jfr/leakprofiler/startOperation.hpp"
  #include "jfr/leakprofiler/stopOperation.hpp"
+ #include "jfr/leakprofiler/checkpoint/eventEmitter.hpp"
  #include "jfr/leakprofiler/sampling/objectSampler.hpp"
  #include "jfr/recorder/service/jfrOptionSet.hpp"
  #include "memory/iterator.hpp"
  #include "runtime/thread.inline.hpp"
  #include "runtime/vmThread.hpp"
  
! bool LeakProfiler::is_running() {
!   return ObjectSampler::is_created();
! }
  
! bool LeakProfiler::start(int sample_count) {
!   if (is_running()) {
      return true;
    }
+ 
    // Allows user to disable leak profiler on command line by setting queue size to zero.
!   if (sample_count == 0) {
!     return false;
!   }
! 
!   assert(!is_running(), "invariant");
!   assert(sample_count > 0, "invariant");
! 
!   // schedule the safepoint operation for installing the object sampler
    StartOperation op(sample_count);
    VMThread::execute(&op);
! 
!   if (!is_running()) {
!     if (LogJFR && Verbose) tty->print_cr("Object sampling could not be started because the sampler could not be allocated");
      return false;
+   }
+   assert(is_running(), "invariant");
+   if (LogJFR && Verbose) tty->print_cr("Object sampling started");
+   return true;
  }
  
  bool LeakProfiler::stop() {
!   if (!is_running()) {
!     return false;
    }
+ 
+   // schedule the safepoint operation for uninstalling and destroying the object sampler
    StopOperation op;
    VMThread::execute(&op);
! 
!   assert(!is_running(), "invariant");
!   if (LogJFR && Verbose) tty->print_cr("Object sampling stopped");
!   return true;
  }
  
! void LeakProfiler::emit_events(int64_t cutoff_ticks, bool emit_all) {
    if (!is_running()) {
      return;
    }
!   // exclusive access to object sampler instance
!   ObjectSampler* const sampler = ObjectSampler::acquire();
!   assert(sampler != NULL, "invariant");
!   EventEmitter::emit(sampler, cutoff_ticks, emit_all);
!   ObjectSampler::release();
  }
  
  void LeakProfiler::oops_do(BoolObjectClosure* is_alive, OopClosure* f) {
    assert(SafepointSynchronize::is_at_safepoint(),
      "Leak Profiler::oops_do(...) may only be called during safepoint");
!   if (is_running()) {
!     ObjectSampler::oops_do(is_alive, f);
    }
  }
  
! void LeakProfiler::sample(HeapWord* object, size_t size, JavaThread* thread) {
    assert(is_running(), "invariant");
    assert(thread != NULL, "invariant");
    assert(thread->thread_state() == _thread_in_vm, "invariant");
  
    // exclude compiler threads and code sweeper thread
    if (thread->is_hidden_from_external_view()) {
      return;
    }
  
!   ObjectSampler::sample(object, size, thread);
  }