src/hotspot/share/gc/shared/vmGCOperations.hpp
changeset 47216 71c04702a3d5
parent 40892 330a02d935ad
child 49377 ecd91135d645
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/shared/vmGCOperations.hpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,241 @@
+/*
+ * Copyright (c) 2005, 2016, 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.
+ *
+ * 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_GC_SHARED_VMGCOPERATIONS_HPP
+#define SHARE_VM_GC_SHARED_VMGCOPERATIONS_HPP
+
+#include "gc/shared/collectedHeap.hpp"
+#include "gc/shared/genCollectedHeap.hpp"
+#include "memory/heapInspection.hpp"
+#include "prims/jvmtiExport.hpp"
+#include "runtime/handles.hpp"
+#include "runtime/jniHandles.hpp"
+#include "runtime/synchronizer.hpp"
+#include "runtime/vm_operations.hpp"
+
+// The following class hierarchy represents
+// a set of operations (VM_Operation) related to GC.
+//
+//  VM_Operation
+//      VM_GC_Operation
+//          VM_GC_HeapInspection
+//          VM_GenCollectFull
+//          VM_GenCollectFullConcurrent
+//          VM_ParallelGCSystemGC
+//          VM_CollectForAllocation
+//              VM_GenCollectForAllocation
+//              VM_ParallelGCFailedAllocation
+//  VM_GC_Operation
+//   - implements methods common to all classes in the hierarchy:
+//     prevents multiple gc requests and manages lock on heap;
+//
+//  VM_GC_HeapInspection
+//   - prints class histogram on SIGBREAK if PrintClassHistogram
+//     is specified; and also the attach "inspectheap" operation
+//
+//  VM_CollectForAllocation
+//  VM_GenCollectForAllocation
+//  VM_ParallelGCFailedAllocation
+//   - this operation is invoked when allocation is failed;
+//     operation performs garbage collection and tries to
+//     allocate afterwards;
+//
+//  VM_GenCollectFull
+//  VM_GenCollectFullConcurrent
+//  VM_ParallelGCSystemGC
+//   - these operations preform full collection of heaps of
+//     different kind
+//
+
+class VM_GC_Operation: public VM_Operation {
+ protected:
+  uint           _gc_count_before;         // gc count before acquiring PLL
+  uint           _full_gc_count_before;    // full gc count before acquiring PLL
+  bool           _full;                    // whether a "full" collection
+  bool           _prologue_succeeded;      // whether doit_prologue succeeded
+  GCCause::Cause _gc_cause;                // the putative cause for this gc op
+  bool           _gc_locked;               // will be set if gc was locked
+
+  virtual bool skip_operation() const;
+
+ public:
+  VM_GC_Operation(uint gc_count_before,
+                  GCCause::Cause _cause,
+                  uint full_gc_count_before = 0,
+                  bool full = false) {
+    _full = full;
+    _prologue_succeeded = false;
+    _gc_count_before    = gc_count_before;
+
+    // A subclass constructor will likely overwrite the following
+    _gc_cause           = _cause;
+
+    _gc_locked = false;
+
+    _full_gc_count_before = full_gc_count_before;
+    // In ParallelScavengeHeap::mem_allocate() collections can be
+    // executed within a loop and _all_soft_refs_clear can be set
+    // true after they have been cleared by a collection and another
+    // collection started so that _all_soft_refs_clear can be true
+    // when this collection is started.  Don't assert that
+    // _all_soft_refs_clear have to be false here even though
+    // mutators have run.  Soft refs will be cleared again in this
+    // collection.
+  }
+  ~VM_GC_Operation();
+
+  // Acquire the reference synchronization lock
+  virtual bool doit_prologue();
+  // Do notifyAll (if needed) and release held lock
+  virtual void doit_epilogue();
+
+  virtual bool allow_nested_vm_operations() const  { return true; }
+  bool prologue_succeeded() const { return _prologue_succeeded; }
+
+  void set_gc_locked() { _gc_locked = true; }
+  bool gc_locked() const  { return _gc_locked; }
+
+  static void notify_gc_begin(bool full = false);
+  static void notify_gc_end();
+};
+
+
+class VM_GC_HeapInspection: public VM_GC_Operation {
+ private:
+  outputStream* _out;
+  bool _full_gc;
+  bool _csv_format; // "comma separated values" format for spreadsheet.
+  bool _print_help;
+  bool _print_class_stats;
+  const char* _columns;
+ public:
+  VM_GC_HeapInspection(outputStream* out, bool request_full_gc) :
+    VM_GC_Operation(0 /* total collections,      dummy, ignored */,
+                    GCCause::_heap_inspection /* GC Cause */,
+                    0 /* total full collections, dummy, ignored */,
+                    request_full_gc) {
+    _out = out;
+    _full_gc = request_full_gc;
+    _csv_format = false;
+    _print_help = false;
+    _print_class_stats = false;
+    _columns = NULL;
+  }
+
+  ~VM_GC_HeapInspection() {}
+  virtual VMOp_Type type() const { return VMOp_GC_HeapInspection; }
+  virtual bool skip_operation() const;
+  virtual void doit();
+  void set_csv_format(bool value) {_csv_format = value;}
+  void set_print_help(bool value) {_print_help = value;}
+  void set_print_class_stats(bool value) {_print_class_stats = value;}
+  void set_columns(const char* value) {_columns = value;}
+ protected:
+  bool collect();
+};
+
+class VM_CollectForAllocation : public VM_GC_Operation {
+ protected:
+  size_t    _word_size; // Size of object to be allocated (in number of words)
+  HeapWord* _result;    // Allocation result (NULL if allocation failed)
+
+ public:
+  VM_CollectForAllocation(size_t word_size, uint gc_count_before, GCCause::Cause cause);
+
+  HeapWord* result() const {
+    return _result;
+  }
+};
+
+class VM_GenCollectForAllocation : public VM_CollectForAllocation {
+ private:
+  bool        _tlab;                       // alloc is of a tlab.
+ public:
+  VM_GenCollectForAllocation(size_t word_size,
+                             bool tlab,
+                             uint gc_count_before)
+    : VM_CollectForAllocation(word_size, gc_count_before, GCCause::_allocation_failure),
+      _tlab(tlab) {
+    assert(word_size != 0, "An allocation should always be requested with this operation.");
+  }
+  ~VM_GenCollectForAllocation()  {}
+  virtual VMOp_Type type() const { return VMOp_GenCollectForAllocation; }
+  virtual void doit();
+};
+
+// VM operation to invoke a collection of the heap as a
+// GenCollectedHeap heap.
+class VM_GenCollectFull: public VM_GC_Operation {
+ private:
+  GenCollectedHeap::GenerationType _max_generation;
+ public:
+  VM_GenCollectFull(uint gc_count_before,
+                    uint full_gc_count_before,
+                    GCCause::Cause gc_cause,
+                    GenCollectedHeap::GenerationType max_generation)
+    : VM_GC_Operation(gc_count_before, gc_cause, full_gc_count_before, true /* full */),
+      _max_generation(max_generation) { }
+  ~VM_GenCollectFull() {}
+  virtual VMOp_Type type() const { return VMOp_GenCollectFull; }
+  virtual void doit();
+};
+
+class VM_CollectForMetadataAllocation: public VM_GC_Operation {
+ private:
+  MetaWord*                _result;
+  size_t                   _size;     // size of object to be allocated
+  Metaspace::MetadataType  _mdtype;
+  ClassLoaderData*         _loader_data;
+
+ public:
+  VM_CollectForMetadataAllocation(ClassLoaderData* loader_data,
+                                  size_t size,
+                                  Metaspace::MetadataType mdtype,
+                                  uint gc_count_before,
+                                  uint full_gc_count_before,
+                                  GCCause::Cause gc_cause);
+
+  virtual VMOp_Type type() const { return VMOp_CollectForMetadataAllocation; }
+  virtual void doit();
+  MetaWord* result() const       { return _result; }
+
+  bool initiate_concurrent_GC();
+};
+
+class SvcGCMarker : public StackObj {
+ private:
+  JvmtiGCMarker _jgcm;
+ public:
+  typedef enum { MINOR, FULL, OTHER } reason_type;
+
+  SvcGCMarker(reason_type reason ) {
+    VM_GC_Operation::notify_gc_begin(reason == FULL);
+  }
+
+  ~SvcGCMarker() {
+    VM_GC_Operation::notify_gc_end();
+  }
+};
+
+#endif // SHARE_VM_GC_SHARED_VMGCOPERATIONS_HPP