1 /* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ART_RUNTIME_NTH_CALLER_VISITOR_H_ 18 #define ART_RUNTIME_NTH_CALLER_VISITOR_H_ 19 20 #include "mirror/art_method.h" 21 #include "locks.h" 22 #include "stack.h" 23 24 namespace art { 25 class Thread; 26 27 // Walks up the stack 'n' callers, when used with Thread::WalkStack. 28 struct NthCallerVisitor : public StackVisitor { 29 NthCallerVisitor(Thread* thread, size_t n, bool include_runtime_and_upcalls = false) 30 : StackVisitor(thread, NULL), n(n), include_runtime_and_upcalls_(include_runtime_and_upcalls), 31 count(0), caller(NULL) {} 32 33 bool VisitFrame() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 34 mirror::ArtMethod* m = GetMethod(); 35 bool do_count = false; 36 if (m == NULL || m->IsRuntimeMethod()) { 37 // Upcall. 38 do_count = include_runtime_and_upcalls_; 39 } else { 40 do_count = true; 41 } 42 if (do_count) { 43 DCHECK(caller == NULL); 44 if (count == n) { 45 caller = m; 46 return false; 47 } 48 count++; 49 } 50 return true; 51 } 52 53 const size_t n; 54 const bool include_runtime_and_upcalls_; 55 size_t count; 56 mirror::ArtMethod* caller; 57 }; 58 59 } // namespace art 60 61 #endif // ART_RUNTIME_NTH_CALLER_VISITOR_H_ 62