Avoid unnecessary copy of dex_gc_map.
Change-Id: I8a7209d92aeee853f6a4e9e9bb0e094c5acd5e05
diff --git a/runtime/verifier/method_verifier.cc b/runtime/verifier/method_verifier.cc
index 9cd8f73..c0e0370 100644
--- a/runtime/verifier/method_verifier.cc
+++ b/runtime/verifier/method_verifier.cc
@@ -1029,26 +1029,6 @@
return true;
}
-static const std::vector<uint8_t>* CreateLengthPrefixedDexGcMap(
- const std::vector<uint8_t>& gc_map) {
- std::vector<uint8_t>* length_prefixed_gc_map = new std::vector<uint8_t>;
- length_prefixed_gc_map->reserve(gc_map.size() + 4);
- length_prefixed_gc_map->push_back((gc_map.size() & 0xff000000) >> 24);
- length_prefixed_gc_map->push_back((gc_map.size() & 0x00ff0000) >> 16);
- length_prefixed_gc_map->push_back((gc_map.size() & 0x0000ff00) >> 8);
- length_prefixed_gc_map->push_back((gc_map.size() & 0x000000ff) >> 0);
- length_prefixed_gc_map->insert(length_prefixed_gc_map->end(),
- gc_map.begin(),
- gc_map.end());
- DCHECK_EQ(gc_map.size() + 4, length_prefixed_gc_map->size());
- DCHECK_EQ(gc_map.size(),
- static_cast<size_t>((length_prefixed_gc_map->at(0) << 24) |
- (length_prefixed_gc_map->at(1) << 16) |
- (length_prefixed_gc_map->at(2) << 8) |
- (length_prefixed_gc_map->at(3) << 0)));
- return length_prefixed_gc_map;
-}
-
bool MethodVerifier::VerifyCodeFlow() {
uint16_t registers_size = code_item_->registers_size_;
uint32_t insns_size = code_item_->insns_size_in_code_units_;
@@ -1088,16 +1068,15 @@
bool compile = IsCandidateForCompilation(ref, method_access_flags_);
if (compile) {
/* Generate a register map and add it to the method. */
- UniquePtr<const std::vector<uint8_t> > map(GenerateGcMap());
- if (map.get() == NULL) {
+ const std::vector<uint8_t>* dex_gc_map = GenerateLengthPrefixedGcMap();
+ if (dex_gc_map == NULL) {
DCHECK_NE(failures_.size(), 0U);
return false; // Not a real failure, but a failure to encode
}
if (kIsDebugBuild) {
- VerifyGcMap(*map);
+ VerifyLengthPrefixedGcMap(*dex_gc_map);
}
- const std::vector<uint8_t>* dex_gc_map = CreateLengthPrefixedDexGcMap(*(map.get()));
- verifier::MethodVerifier::SetDexGcMap(ref, *dex_gc_map);
+ verifier::MethodVerifier::SetDexGcMap(ref, dex_gc_map);
}
if (has_check_casts_) {
@@ -4077,7 +4056,7 @@
return pc_to_concrete_method_map.release();
}
-const std::vector<uint8_t>* MethodVerifier::GenerateGcMap() {
+const std::vector<uint8_t>* MethodVerifier::GenerateLengthPrefixedGcMap() {
size_t num_entries, ref_bitmap_bits, pc_bits;
ComputeGcMapSizes(&num_entries, &ref_bitmap_bits, &pc_bits);
// There's a single byte to encode the size of each bitmap
@@ -4115,7 +4094,12 @@
Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "Failed to encode GC map (size=" << table_size << ")";
return NULL;
}
- table->reserve(table_size);
+ table->reserve(table_size + 4); // table_size plus the length prefix
+ // Write table size
+ table->push_back((table_size & 0xff000000) >> 24);
+ table->push_back((table_size & 0x00ff0000) >> 16);
+ table->push_back((table_size & 0x0000ff00) >> 8);
+ table->push_back((table_size & 0x000000ff) >> 0);
// Write table header
table->push_back(format | ((ref_bitmap_bytes >> DexPcToReferenceMap::kRegMapFormatShift) &
~DexPcToReferenceMap::kRegMapFormatMask));
@@ -4133,14 +4117,18 @@
line->WriteReferenceBitMap(*table, ref_bitmap_bytes);
}
}
- DCHECK_EQ(table->size(), table_size);
+ DCHECK_EQ(table->size(), table_size + 4); // table_size plus the length prefix
return table;
}
-void MethodVerifier::VerifyGcMap(const std::vector<uint8_t>& data) {
+void MethodVerifier::VerifyLengthPrefixedGcMap(const std::vector<uint8_t>& data) {
// Check that for every GC point there is a map entry, there aren't entries for non-GC points,
// that the table data is well formed and all references are marked (or not) in the bitmap
- DexPcToReferenceMap map(&data[0], data.size());
+ DCHECK_GE(data.size(), 4u);
+ size_t table_size = data.size() - 4u;
+ DCHECK_EQ(table_size, static_cast<size_t>((data[0] << 24) | (data[1] << 16) |
+ (data[2] << 8) | (data[3] << 0)));
+ DexPcToReferenceMap map(&data[4], table_size);
size_t map_index = 0;
for (size_t i = 0; i < code_item_->insns_size_in_code_units_; i++) {
const uint8_t* reg_bitmap = map.FindBitMap(i, false);
@@ -4166,7 +4154,7 @@
}
}
-void MethodVerifier::SetDexGcMap(MethodReference ref, const std::vector<uint8_t>& gc_map) {
+void MethodVerifier::SetDexGcMap(MethodReference ref, const std::vector<uint8_t>* gc_map) {
DCHECK(Runtime::Current()->IsCompiler());
{
WriterMutexLock mu(Thread::Current(), *dex_gc_maps_lock_);
@@ -4175,7 +4163,7 @@
delete it->second;
dex_gc_maps_->erase(it);
}
- dex_gc_maps_->Put(ref, &gc_map);
+ dex_gc_maps_->Put(ref, gc_map);
}
DCHECK(GetDexGcMap(ref) != NULL);
}
diff --git a/runtime/verifier/method_verifier.h b/runtime/verifier/method_verifier.h
index 8a663f9..f72898e 100644
--- a/runtime/verifier/method_verifier.h
+++ b/runtime/verifier/method_verifier.h
@@ -614,10 +614,10 @@
* encode it in some clever fashion.
* Returns a pointer to a newly-allocated RegisterMap, or NULL on failure.
*/
- const std::vector<uint8_t>* GenerateGcMap();
+ const std::vector<uint8_t>* GenerateLengthPrefixedGcMap();
// Verify that the GC map associated with method_ is well formed
- void VerifyGcMap(const std::vector<uint8_t>& data);
+ void VerifyLengthPrefixedGcMap(const std::vector<uint8_t>& data);
// Compute sizes for GC map data
void ComputeGcMapSizes(size_t* gc_points, size_t* ref_bitmap_bits, size_t* log2_max_gc_pc);
@@ -629,7 +629,7 @@
MethodReferenceComparator> DexGcMapTable;
static ReaderWriterMutex* dex_gc_maps_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
static DexGcMapTable* dex_gc_maps_ GUARDED_BY(dex_gc_maps_lock_);
- static void SetDexGcMap(MethodReference ref, const std::vector<uint8_t>& dex_gc_map)
+ static void SetDexGcMap(MethodReference ref, const std::vector<uint8_t>* dex_gc_map)
LOCKS_EXCLUDED(dex_gc_maps_lock_);
