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/*
* Copyright (C) 2018 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ART_RUNTIME_INTERN_TABLE_INL_H_
#define ART_RUNTIME_INTERN_TABLE_INL_H_
#include "intern_table.h"
#include "dex/utf.h"
#include "gc/space/image_space.h"
#include "gc_root-inl.h"
#include "mirror/string-inl.h"
#include "oat/image.h"
#include "thread-current-inl.h"
namespace art HIDDEN {
ALWAYS_INLINE
inline uint32_t InternTable::Utf8String::Hash(uint32_t utf16_length, const char* utf8_data) {
DCHECK_EQ(utf16_length, CountModifiedUtf8Chars(utf8_data));
if (LIKELY(utf8_data[utf16_length] == 0)) {
int32_t hash = ComputeUtf16Hash(utf8_data, utf16_length);
DCHECK_EQ(hash, ComputeUtf16HashFromModifiedUtf8(utf8_data, utf16_length));
return hash;
} else {
return ComputeUtf16HashFromModifiedUtf8(utf8_data, utf16_length);
}
}
ALWAYS_INLINE
inline size_t InternTable::StringHash::operator()(const GcRoot<mirror::String>& root) const {
if (kIsDebugBuild) {
Locks::mutator_lock_->AssertSharedHeld(Thread::Current());
}
ObjPtr<mirror::String> s = root.Read<kWithoutReadBarrier>();
int32_t hash = s->GetStoredHashCode();
DCHECK_EQ(hash, s->ComputeHashCode());
// An additional cast to prevent undesired sign extension.
return static_cast<uint32_t>(hash);
}
ALWAYS_INLINE
inline bool InternTable::StringEquals::operator()(const GcRoot<mirror::String>& a,
const GcRoot<mirror::String>& b) const {
if (kIsDebugBuild) {
Locks::mutator_lock_->AssertSharedHeld(Thread::Current());
}
return a.Read<kWithoutReadBarrier>()->Equals(b.Read<kWithoutReadBarrier>());
}
ALWAYS_INLINE
inline bool InternTable::StringEquals::operator()(const GcRoot<mirror::String>& a,
const Utf8String& b) const {
if (kIsDebugBuild) {
Locks::mutator_lock_->AssertSharedHeld(Thread::Current());
}
ObjPtr<mirror::String> a_string = a.Read<kWithoutReadBarrier>();
uint32_t a_length = static_cast<uint32_t>(a_string->GetLength());
if (a_length != b.GetUtf16Length()) {
return false;
}
DCHECK_GE(strlen(b.GetUtf8Data()), a_length);
if (a_string->IsCompressed()) {
// Modified UTF-8 single byte character range is 0x01 .. 0x7f.
// The string compression occurs on regular ASCII with same exact range,
// not on extended ASCII which is up to 0xff.
return b.GetUtf8Data()[a_length] == 0 &&
memcmp(b.GetUtf8Data(), a_string->GetValueCompressed(), a_length * sizeof(uint8_t)) == 0;
} else if (mirror::kUseStringCompression && b.GetUtf8Data()[a_length] == 0) {
// ASCII string `b` cannot equal non-ASCII `a_string`.
return false;
} else {
const uint16_t* a_value = a_string->GetValue();
return CompareModifiedUtf8ToUtf16AsCodePointValues(b.GetUtf8Data(), a_value, a_length) == 0;
}
}
template <typename Visitor>
inline void InternTable::AddImageStringsToTable(gc::space::ImageSpace* image_space,
const Visitor& visitor) {
DCHECK(image_space != nullptr);
// Only add if we have the interned strings section.
const ImageHeader& header = image_space->GetImageHeader();
const ImageSection& section = header.GetInternedStringsSection();
if (section.Size() > 0) {
AddTableFromMemory(image_space->Begin() + section.Offset(), visitor, !header.IsAppImage());
}
}
template <typename Visitor>
inline size_t InternTable::AddTableFromMemory(const uint8_t* ptr,
const Visitor& visitor,
bool is_boot_image) {
size_t read_count = 0;
UnorderedSet set(ptr, /*make copy*/false, &read_count);
{
// Hold the lock while calling the visitor to prevent possible race
// conditions with another thread adding intern strings.
MutexLock mu(Thread::Current(), *Locks::intern_table_lock_);
// Visit the unordered set, may remove elements.
visitor(set);
if (!set.empty()) {
strong_interns_.AddInternStrings(std::move(set), is_boot_image);
}
}
return read_count;
}
inline void InternTable::Table::AddInternStrings(UnorderedSet&& intern_strings,
bool is_boot_image) {
if (kIsDebugBuild) {
// Avoid doing read barriers since the space might not yet be added to the heap.
// See b/117803941
for (GcRoot<mirror::String>& string : intern_strings) {
ObjPtr<mirror::String> s = string.Read<kWithoutReadBarrier>();
uint32_t hash = static_cast<uint32_t>(s->GetStoredHashCode());
CHECK_EQ(hash, static_cast<uint32_t>(s->ComputeHashCode()));
CHECK(Find(s, hash) == nullptr)
<< "Already found " << string.Read<kWithoutReadBarrier>()->ToModifiedUtf8()
<< " in the intern table";
}
}
// Insert before the last (unfrozen) table since we add new interns into the back.
// Keep the order of previous frozen tables unchanged, so that we can can remember
// the number of searched frozen tables and not search them again.
DCHECK(!tables_.empty());
tables_.insert(tables_.end() - 1, InternalTable(std::move(intern_strings), is_boot_image));
}
template <typename Visitor>
inline void InternTable::VisitInterns(const Visitor& visitor,
bool visit_boot_images,
bool visit_non_boot_images) {
auto visit_tables = [&](dchecked_vector<Table::InternalTable>& tables)
NO_THREAD_SAFETY_ANALYSIS {
for (Table::InternalTable& table : tables) {
// Determine if we want to visit the table based on the flags.
const bool visit = table.IsBootImage() ? visit_boot_images : visit_non_boot_images;
if (visit) {
for (auto& intern : table.set_) {
visitor(intern);
}
}
}
};
visit_tables(strong_interns_.tables_);
visit_tables(weak_interns_.tables_);
}
inline size_t InternTable::CountInterns(bool visit_boot_images, bool visit_non_boot_images) const {
size_t ret = 0u;
auto visit_tables = [&](const dchecked_vector<Table::InternalTable>& tables)
NO_THREAD_SAFETY_ANALYSIS {
for (const Table::InternalTable& table : tables) {
// Determine if we want to visit the table based on the flags.
const bool visit = table.IsBootImage() ? visit_boot_images : visit_non_boot_images;
if (visit) {
ret += table.set_.size();
}
}
};
visit_tables(strong_interns_.tables_);
visit_tables(weak_interns_.tables_);
return ret;
}
} // namespace art
#endif // ART_RUNTIME_INTERN_TABLE_INL_H_
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