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8176593: Throwable::getStackTrace performance regression

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Reviewed-by: jiangli, iklam, coleenp, sspitsyn
This commit is contained in:
Claes Redestad 2017-03-15 13:03:13 +01:00
parent 1cd78903a8
commit c40d2d5af7
2 changed files with 32 additions and 22 deletions
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37
hotspot/src/share/vm/classfile/stringTable.cpp
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@ -1,5 +1,5 @@
/*
* Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@ -96,10 +96,14 @@ CompactHashtable<oop, char> StringTable::_shared_table;
// Pick hashing algorithm
unsigned int StringTable::hash_string(const jchar* s, int len) {
return use_alternate_hashcode() ? AltHashing::murmur3_32(seed(), s, len) :
return use_alternate_hashcode() ? alt_hash_string(s, len) :
java_lang_String::hash_code(s, len);
}
unsigned int StringTable::alt_hash_string(const jchar* s, int len) {
return AltHashing::murmur3_32(seed(), s, len);
}
unsigned int StringTable::hash_string(oop string) {
EXCEPTION_MARK;
if (string == NULL) {
@ -117,11 +121,10 @@ unsigned int StringTable::hash_string(oop string) {
}
}
oop StringTable::lookup_shared(jchar* name, int len) {
// java_lang_String::hash_code() was used to compute hash values in the shared table. Don't
// use the hash value from StringTable::hash_string() as it might use alternate hashcode.
return _shared_table.lookup((const char*)name,
java_lang_String::hash_code(name, len), len);
oop StringTable::lookup_shared(jchar* name, int len, unsigned int hash) {
assert(hash == java_lang_String::hash_code(name, len),
"hash must be computed using java_lang_String::hash_code");
return _shared_table.lookup((const char*)name, hash, len);
}
oop StringTable::lookup_in_main_table(int index, jchar* name,
@ -156,7 +159,7 @@ oop StringTable::basic_add(int index_arg, Handle string, jchar* name,
unsigned int hashValue;
int index;
if (use_alternate_hashcode()) {
hashValue = hash_string(name, len);
hashValue = alt_hash_string(name, len);
index = hash_to_index(hashValue);
} else {
hashValue = hashValue_arg;
@ -199,12 +202,15 @@ static void ensure_string_alive(oop string) {
}
oop StringTable::lookup(jchar* name, int len) {
oop string = lookup_shared(name, len);
// shared table always uses java_lang_String::hash_code
unsigned int hash = java_lang_String::hash_code(name, len);
oop string = lookup_shared(name, len, hash);
if (string != NULL) {
return string;
}
unsigned int hash = hash_string(name, len);
if (use_alternate_hashcode()) {
hash = alt_hash_string(name, len);
}
int index = the_table()->hash_to_index(hash);
string = the_table()->lookup_in_main_table(index, name, len, hash);
@ -215,12 +221,15 @@ oop StringTable::lookup(jchar* name, int len) {
oop StringTable::intern(Handle string_or_null, jchar* name,
int len, TRAPS) {
oop found_string = lookup_shared(name, len);
// shared table always uses java_lang_String::hash_code
unsigned int hashValue = java_lang_String::hash_code(name, len);
oop found_string = lookup_shared(name, len, hashValue);
if (found_string != NULL) {
return found_string;
}
unsigned int hashValue = hash_string(name, len);
if (use_alternate_hashcode()) {
hashValue = alt_hash_string(name, len);
}
int index = the_table()->hash_to_index(hashValue);
found_string = the_table()->lookup_in_main_table(index, name, len, hashValue);