Add hash map, reduce excessive hashing
Changed the class def index to use a HashMap instead of unordered_map
so that we can use FindWithHash to reduce how often we need to compute
hashes.
Fixed a bug in ClassLinker::UpdateClass where we didn't properly
handle classes with the same descriptor but different class loaders.
Introduced by previous CL.
Before (fb launch):
1.74% art::ComputeModifiedUtf8Hash(char const*)
After:
0.95% art::ComputeModifiedUtf8Hash(char const*)
Bug: 18054905
Bug: 16828525
Change-Id: Iba2ee37c9837289e0ea187800ba4af322225a994
(cherry picked from commit 564ff985184737977aa26c485d0c1a413e530705)
diff --git a/runtime/native/java_lang_VMClassLoader.cc b/runtime/native/java_lang_VMClassLoader.cc
index 45563d2..35932e0 100644
--- a/runtime/native/java_lang_VMClassLoader.cc
+++ b/runtime/native/java_lang_VMClassLoader.cc
@@ -36,14 +36,16 @@
}
ClassLinker* cl = Runtime::Current()->GetClassLinker();
std::string descriptor(DotToDescriptor(name.c_str()));
- mirror::Class* c = cl->LookupClass(soa.Self(), descriptor.c_str(), loader);
+ const size_t descriptor_hash = ComputeModifiedUtf8Hash(descriptor.c_str());
+ mirror::Class* c = cl->LookupClass(soa.Self(), descriptor.c_str(), descriptor_hash, loader);
if (c != nullptr && c->IsResolved()) {
return soa.AddLocalReference<jclass>(c);
}
if (loader != nullptr) {
// Try the common case.
StackHandleScope<1> hs(soa.Self());
- c = cl->FindClassInPathClassLoader(soa, soa.Self(), descriptor.c_str(), hs.NewHandle(loader));
+ c = cl->FindClassInPathClassLoader(soa, soa.Self(), descriptor.c_str(), descriptor_hash,
+ hs.NewHandle(loader));
if (c != nullptr) {
return soa.AddLocalReference<jclass>(c);
}