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/*
* Copyright (C) 2008 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.
*/
#include "reference_table.h"
#include "indirect_reference_table.h"
#include "object.h"
namespace art {
ReferenceTable::ReferenceTable(const char* name, size_t initial_size, size_t max_size)
: name_(name), max_size_(max_size) {
CHECK_LE(initial_size, max_size);
entries_.reserve(initial_size);
}
ReferenceTable::~ReferenceTable() {
}
void ReferenceTable::Add(const Object* obj) {
DCHECK(obj != NULL);
if (entries_.size() == max_size_) {
LOG(FATAL) << "ReferenceTable '" << name_ << "' "
<< "overflowed (" << max_size_ << " entries)";
}
entries_.push_back(obj);
}
void ReferenceTable::Remove(const Object* obj) {
// We iterate backwards on the assumption that references are LIFO.
for (int i = entries_.size() - 1; i >= 0; --i) {
if (entries_[i] == obj) {
entries_.erase(entries_.begin() + i);
return;
}
}
}
// If "obj" is an array, return the number of elements in the array.
// Otherwise, return zero.
size_t GetElementCount(const Object* obj) {
if (obj == NULL || obj == kClearedJniWeakGlobal || !obj->IsArrayInstance()) {
return 0;
}
return obj->AsArray()->GetLength();
}
struct ObjectComparator {
bool operator()(const Object* obj1, const Object* obj2){
// Ensure null references and cleared jweaks appear at the end.
if (obj1 == NULL) {
return true;
} else if (obj2 == NULL) {
return false;
}
if (obj1 == kClearedJniWeakGlobal) {
return true;
} else if (obj2 == kClearedJniWeakGlobal) {
return false;
}
// Sort by class...
if (obj1->GetClass() != obj2->GetClass()) {
return reinterpret_cast<uintptr_t>(obj1->GetClass()) <
reinterpret_cast<uintptr_t>(obj2->GetClass());
} else {
// ...then by size...
size_t count1 = obj1->SizeOf();
size_t count2 = obj2->SizeOf();
if (count1 != count2) {
return count1 < count2;
} else {
// ...and finally by address.
return reinterpret_cast<uintptr_t>(obj1) <
reinterpret_cast<uintptr_t>(obj2);
}
}
}
};
// Log an object with some additional info.
//
// Pass in the number of elements in the array (or 0 if this is not an
// array object), and the number of additional objects that are identical
// or equivalent to the original.
void LogSummaryLine(const Object* obj, size_t elems, int identical, int equiv) {
if (obj == NULL) {
LOG(WARNING) << " NULL reference (count=" << equiv << ")";
return;
}
if (obj == kClearedJniWeakGlobal) {
LOG(WARNING) << " cleared jweak (count=" << equiv << ")";
return;
}
std::string className(PrettyTypeOf(obj));
if (obj->IsClass()) {
// We're summarizing multiple instances, so using the exemplar
// Class' type parameter here would be misleading.
className = "java.lang.Class";
}
if (elems != 0) {
StringAppendF(&className, " (%zd elements)", elems);
}
size_t total = identical + equiv + 1;
std::string msg(StringPrintf("%5d of %s", total, className.c_str()));
if (identical + equiv != 0) {
StringAppendF(&msg, " (%d unique instances)", equiv + 1);
}
LOG(WARNING) << " " << msg;
}
size_t ReferenceTable::Size() const {
return entries_.size();
}
void ReferenceTable::Dump() const {
LOG(WARNING) << name_ << " reference table dump:";
Dump(entries_);
}
void ReferenceTable::Dump(const Table& entries) {
if (entries.empty()) {
LOG(WARNING) << " (empty)";
return;
}
// Dump the most recent N entries.
const size_t kLast = 10;
size_t count = entries.size();
int first = count - kLast;
if (first < 0) {
first = 0;
}
LOG(WARNING) << " Last " << (count - first) << " entries (of " << count << "):";
for (int idx = count - 1; idx >= first; --idx) {
const Object* ref = entries[idx];
if (ref == NULL) {
continue;
}
if (ref == kClearedJniWeakGlobal) {
LOG(WARNING) << StringPrintf(" %5d: cleared jweak", idx);
continue;
}
if (ref->GetClass() == NULL) {
// should only be possible right after a plain dvmMalloc().
size_t size = ref->SizeOf();
LOG(WARNING) << StringPrintf(" %5d: %p (raw) (%zd bytes)", idx, ref, size);
continue;
}
std::string className(PrettyTypeOf(ref));
std::string extras;
size_t elems = GetElementCount(ref);
if (elems != 0) {
StringAppendF(&extras, " (%zd elements)", elems);
}
#if 0
// TODO: support dumping string data.
else if (ref->GetClass() == gDvm.classJavaLangString) {
const StringObject* str = reinterpret_cast<const StringObject*>(ref);
extras += " \"";
size_t count = 0;
char* s = dvmCreateCstrFromString(str);
char* p = s;
for (; *p && count < 16; ++p, ++count) {
extras += *p;
}
if (*p == 0) {
extras += "\"";
} else {
StringAppendF(&extras, "... (%d chars)", str->length());
}
free(s);
}
#endif
LOG(WARNING) << StringPrintf(" %5d: ", idx) << ref << " " << className << extras;
}
// Make a copy of the table and sort it.
Table sorted_entries(entries.begin(), entries.end());
std::sort(sorted_entries.begin(), sorted_entries.end(), ObjectComparator());
// Remove any uninteresting stuff from the list. The sort moved them all to the end.
while (!sorted_entries.empty() && sorted_entries.back() == NULL) {
sorted_entries.pop_back();
}
while (!sorted_entries.empty() && sorted_entries.back() == kClearedJniWeakGlobal) {
sorted_entries.pop_back();
}
if (sorted_entries.empty()) {
return;
}
// Dump a summary of the whole table.
LOG(WARNING) << " Summary:";
size_t equiv = 0;
size_t identical = 0;
for (size_t idx = 1; idx < count; idx++) {
const Object* prev = sorted_entries[idx-1];
const Object* current = sorted_entries[idx];
size_t elems = GetElementCount(prev);
if (current == prev) {
// Same reference, added more than once.
identical++;
} else if (current->GetClass() == prev->GetClass() && GetElementCount(current) == elems) {
// Same class / element count, different object.
equiv++;
} else {
// Different class.
LogSummaryLine(prev, elems, identical, equiv);
equiv = identical = 0;
}
}
// Handle the last entry.
LogSummaryLine(sorted_entries.back(), GetElementCount(sorted_entries.back()), identical, equiv);
}
void ReferenceTable::VisitRoots(Heap::RootVisitor* visitor, void* arg) {
typedef Table::const_iterator It; // TODO: C++0x auto
for (It it = entries_.begin(), end = entries_.end(); it != end; ++it) {
visitor(*it, arg);
}
}
} // namespace art