1 /* 2 * Copyright (c) 2019, Red Hat, Inc. All rights reserved. 3 * 4 * This code is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 only, as 6 * published by the Free Software Foundation. 7 * 8 * This code is distributed in the hope that it will be useful, but WITHOUT 9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 11 * version 2 for more details (a copy is included in the LICENSE file that 12 * accompanied this code). 13 * 14 * You should have received a copy of the GNU General Public License version 15 * 2 along with this work; if not, write to the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 17 * 18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 19 * or visit www.oracle.com if you need additional information or have any 20 * questions. 21 * 22 */ 23 24 #ifndef SHARE_SERVICES_THREADSTACKTRACKER_HPP 25 #define SHARE_SERVICES_THREADSTACKTRACKER_HPP 26 27 #if INCLUDE_NMT 28 29 #include "services/allocationSite.hpp" 30 #include "services/mallocSiteTable.hpp" 31 #include "services/nmtCommon.hpp" 32 #include "utilities/nativeCallStack.hpp" 33 #include "utilities/linkedlist.hpp" 34 35 class SimpleThreadStackSite; 36 37 class SimpleThreadStack { 38 friend class SimpleThreadStackSite; 39 private: 40 address _base; 41 size_t _size; 42 public: SimpleThreadStack()43 SimpleThreadStack() : _base(NULL), _size(0) { } equals(const SimpleThreadStack & s) const44 bool equals(const SimpleThreadStack& s) const { 45 return base() == s.base(); 46 } 47 size() const48 size_t size() const { return _size; } base() const49 address base() const { return _base; } 50 private: set_size(size_t size)51 void set_size(size_t size) { _size = size; } set_base(address base)52 void set_base(address base) { _base = base; } 53 }; 54 55 class SimpleThreadStackSite : public AllocationSite<SimpleThreadStack> { 56 public: SimpleThreadStackSite(address base,size_t size,const NativeCallStack & stack)57 SimpleThreadStackSite(address base, size_t size, const NativeCallStack& stack) : 58 AllocationSite<SimpleThreadStack>(stack, mtThreadStack) { 59 data()->set_size(size); 60 data()->set_base(base); 61 } 62 SimpleThreadStackSite(address base,size_t size)63 SimpleThreadStackSite(address base, size_t size) : 64 AllocationSite<SimpleThreadStack>(NativeCallStack::empty_stack(), mtThreadStack) { 65 data()->set_base(base); 66 data()->set_size(size); 67 } 68 equals(const SimpleThreadStackSite & mts) const69 bool equals(const SimpleThreadStackSite& mts) const { 70 bool eq = base() == mts.base(); 71 assert(!eq || size() == mts.size(), "Must match"); 72 return eq; 73 } 74 size() const75 size_t size() const { return peek()->size(); } base() const76 address base() const { return peek()->base(); } 77 }; 78 79 /* 80 * Most of platforms, that hotspot support, have their thread stacks backed by 81 * virtual memory by default. For these cases, thread stack tracker simply 82 * delegates tracking to virtual memory tracker. 83 * However, there are exceptions, (e.g. AIX), that platforms can provide stacks 84 * that are not page aligned. A hypothetical VM implementation, it can provide 85 * it own stacks. In these case, track_as_vm() should return false and manage 86 * stack tracking by this tracker internally. 87 * During memory snapshot, tracked thread stacks memory data is walked and stored 88 * along with malloc'd data inside baseline. The regions are not scanned and assumed 89 * all committed for now. Can add scanning phase when there is a need. 90 */ 91 class ThreadStackTracker : AllStatic { 92 private: 93 static volatile size_t _thread_count; 94 95 static int compare_thread_stack_base(const SimpleThreadStackSite& s1, const SimpleThreadStackSite& s2); 96 static SortedLinkedList<SimpleThreadStackSite, compare_thread_stack_base>* _simple_thread_stacks; 97 public: 98 // Late phase initialization 99 static bool late_initialize(NMT_TrackingLevel level); 100 static bool transition(NMT_TrackingLevel from, NMT_TrackingLevel to); 101 102 static void new_thread_stack(void* base, size_t size, const NativeCallStack& stack); 103 static void delete_thread_stack(void* base, size_t size); 104 track_as_vm()105 static bool track_as_vm() { return AIX_ONLY(false) NOT_AIX(true); } thread_count()106 static size_t thread_count() { return _thread_count; } 107 108 // Snapshot support. Piggyback thread stack data in malloc slot, NMT always handles 109 // thread stack slot specially since beginning. 110 static bool walk_simple_thread_stack_site(MallocSiteWalker* walker); 111 }; 112 113 #endif // INCLUDE_NMT 114 #endif // SHARE_SERVICES_THREADSTACKTRACKER_HPP 115