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8074345: Enable RewriteBytecodes when VM runs with CDS

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Enable bytecode rewriting when CDS turned on.

Co-authored-by: Ioi Lam <ioi.lam@oracle.com>
Reviewed-by: coleenp, iklam
This commit is contained in:
Yumin Qi 2015-03-25 15:18:37 -07:00
parent c08ffb03e4
commit 3e6cf09c39
13 changed files with 202 additions and 97 deletions
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33
hotspot/src/share/vm/memory/metaspaceShared.cpp
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@ -30,6 +30,8 @@
#include "classfile/symbolTable.hpp"
#include "classfile/systemDictionary.hpp"
#include "code/codeCache.hpp"
#include "interpreter/bytecodes.hpp"
#include "interpreter/bytecodeStream.hpp"
#include "memory/filemap.hpp"
#include "memory/gcLocker.hpp"
#include "memory/metaspace.hpp"
@ -104,15 +106,33 @@ static void remove_unshareable_in_classes() {
}
}
// Walk all methods in the class list and assign a fingerprint.
// so that this part of the ConstMethod* is read only.
static void calculate_fingerprints() {
static void rewrite_nofast_bytecode(Method* method) {
RawBytecodeStream bcs(method);
while (!bcs.is_last_bytecode()) {
Bytecodes::Code opcode = bcs.raw_next();
switch (opcode) {
case Bytecodes::_getfield: *bcs.bcp() = Bytecodes::_nofast_getfield; break;
case Bytecodes::_putfield: *bcs.bcp() = Bytecodes::_nofast_putfield; break;
case Bytecodes::_aload_0: *bcs.bcp() = Bytecodes::_nofast_aload_0; break;
case Bytecodes::_iload: *bcs.bcp() = Bytecodes::_nofast_iload; break;
default: break;
}
}
}
// Walk all methods in the class list to ensure that they won't be modified at
// run time. This includes:
// [1] Rewrite all bytecodes as needed, so that the ConstMethod* will not be modified
// at run time by RewriteBytecodes/RewriteFrequentPairs
// [2] Assign a fingerprint, so one doesn't need to be assigned at run-time.
static void rewrite_nofast_bytecodes_and_calculate_fingerprints() {
for (int i = 0; i < _global_klass_objects->length(); i++) {
Klass* k = _global_klass_objects->at(i);
if (k->oop_is_instance()) {
InstanceKlass* ik = InstanceKlass::cast(k);
for (int i = 0; i < ik->methods()->length(); i++) {
Method* m = ik->methods()->at(i);
rewrite_nofast_bytecode(m);
Fingerprinter fp(m);
// The side effect of this call sets method's fingerprint field.
fp.fingerprint();
@ -476,9 +496,10 @@ void VM_PopulateDumpSharedSpace::doit() {
tty->print_cr(" type array classes = %5d", num_type_array);
}
// Update all the fingerprints in the shared methods.
tty->print("Calculating fingerprints ... ");
calculate_fingerprints();
// Ensure the ConstMethods won't be modified at run-time
tty->print("Updating ConstMethods ... ");
rewrite_nofast_bytecodes_and_calculate_fingerprints();
tty->print_cr("done. ");
// Remove all references outside the metadata