1 /* 2 * Copyright (C) 2016 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_IMTABLE_H_ 18 #define ART_RUNTIME_IMTABLE_H_ 19 20 #ifndef IMT_SIZE 21 #error IMT_SIZE not defined 22 #endif 23 24 namespace art { 25 26 class ArtMethod; 27 28 class ImTable { 29 public: 30 // Interface method table size. Increasing this value reduces the chance of two interface methods 31 // colliding in the interface method table but increases the size of classes that implement 32 // (non-marker) interfaces. 33 static constexpr size_t kSize = IMT_SIZE; 34 35 ArtMethod* Get(size_t index, size_t pointer_size) { 36 DCHECK_LT(index, kSize); 37 uint8_t* ptr = reinterpret_cast<uint8_t*>(this) + OffsetOfElement(index, pointer_size); 38 if (pointer_size == 4) { 39 uint32_t value = *reinterpret_cast<uint32_t*>(ptr); 40 return reinterpret_cast<ArtMethod*>(value); 41 } else { 42 uint64_t value = *reinterpret_cast<uint64_t*>(ptr); 43 return reinterpret_cast<ArtMethod*>(value); 44 } 45 } 46 47 void Set(size_t index, ArtMethod* method, size_t pointer_size) { 48 DCHECK_LT(index, kSize); 49 uint8_t* ptr = reinterpret_cast<uint8_t*>(this) + OffsetOfElement(index, pointer_size); 50 if (pointer_size == 4) { 51 uintptr_t value = reinterpret_cast<uintptr_t>(method); 52 DCHECK_EQ(static_cast<uint32_t>(value), value); // Check that we dont lose any non 0 bits. 53 *reinterpret_cast<uint32_t*>(ptr) = static_cast<uint32_t>(value); 54 } else { 55 *reinterpret_cast<uint64_t*>(ptr) = reinterpret_cast<uint64_t>(method); 56 } 57 } 58 59 static size_t OffsetOfElement(size_t index, size_t pointer_size) { 60 return index * pointer_size; 61 } 62 63 void Populate(ArtMethod** data, size_t pointer_size) { 64 for (size_t i = 0; i < kSize; ++i) { 65 Set(i, data[i], pointer_size); 66 } 67 } 68 69 constexpr static size_t SizeInBytes(size_t pointer_size) { 70 return kSize * pointer_size; 71 } 72 }; 73 74 } // namespace art 75 76 #endif // ART_RUNTIME_IMTABLE_H_ 77 78
