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8176100: [REDO][REDO] G1 Needs pre barrier on dereference of weak JNI handles

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Reviewed-by: kbarrett, coleenp, tschatzl
This commit is contained in:
Mikael Gerdin 2017-03-22 15:25:21 +01:00
parent 6b15d9a82b
commit cc1aaab7e9
42 changed files with 1221 additions and 434 deletions
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39
hotspot/src/cpu/x86/vm/macroAssembler_x86.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
@ -5129,6 +5129,43 @@ void MacroAssembler::vxorps(XMMRegister dst, XMMRegister nds, AddressLiteral src
}
void MacroAssembler::resolve_jobject(Register value,
Register thread,
Register tmp) {
assert_different_registers(value, thread, tmp);
Label done, not_weak;
testptr(value, value);
jcc(Assembler::zero, done); // Use NULL as-is.
testptr(value, JNIHandles::weak_tag_mask); // Test for jweak tag.
jcc(Assembler::zero, not_weak);
// Resolve jweak.
movptr(value, Address(value, -JNIHandles::weak_tag_value));
verify_oop(value);
#if INCLUDE_ALL_GCS
if (UseG1GC) {
g1_write_barrier_pre(noreg /* obj */,
value /* pre_val */,
thread /* thread */,
tmp /* tmp */,
true /* tosca_live */,
true /* expand_call */);
}
#endif // INCLUDE_ALL_GCS
jmp(done);
bind(not_weak);
// Resolve (untagged) jobject.
movptr(value, Address(value, 0));
verify_oop(value);
bind(done);
}
void MacroAssembler::clear_jweak_tag(Register possibly_jweak) {
const int32_t inverted_jweak_mask = ~static_cast<int32_t>(JNIHandles::weak_tag_mask);
STATIC_ASSERT(inverted_jweak_mask == -2); // otherwise check this code
// The inverted mask is sign-extended
andptr(possibly_jweak, inverted_jweak_mask);
}
//////////////////////////////////////////////////////////////////////////////////
#if INCLUDE_ALL_GCS