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8166188: G1 Needs pre barrier on dereference of weak JNI handles

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Add low tag to jweaks and G1 barrier for jweak loads.

Co-authored-by: Martin Doerr <martin.doerr@sap.com>
Co-authored-by: Volker Simonis <volker.simonis@sap.com>
Reviewed-by: mgerdin, mdoerr, pliden, dlong, dcubed, coleenp, aph, tschatzl
This commit is contained in:
Kim Barrett 2017-02-15 22:19:13 -05:00
parent 6a5e6f2ae1
commit 28477cf493
37 changed files with 1061 additions and 429 deletions
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33
hotspot/src/cpu/sparc/vm/sharedRuntime_sparc.cpp
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@ -1,5 +1,5 @@
/*
* Copyright (c) 2003, 2016, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2003, 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
@ -2754,15 +2754,30 @@ nmethod* SharedRuntime::generate_native_wrapper(MacroAssembler* masm,
__ verify_thread(); // G2_thread must be correct
__ reset_last_Java_frame();
// Unpack oop result
// Unbox oop result, e.g. JNIHandles::resolve value in I0.
if (ret_type == T_OBJECT || ret_type == T_ARRAY) {
Label L;
__ addcc(G0, I0, G0);
__ brx(Assembler::notZero, true, Assembler::pt, L);
__ delayed()->ld_ptr(I0, 0, I0);
__ mov(G0, I0);
__ bind(L);
__ verify_oop(I0);
Label done, not_weak;
__ br_null(I0, false, Assembler::pn, done); // Use NULL as-is.
__ delayed()->andcc(I0, JNIHandles::weak_tag_mask, G0); // Test for jweak
__ brx(Assembler::zero, true, Assembler::pt, not_weak);
__ delayed()->ld_ptr(I0, 0, I0); // Maybe resolve (untagged) jobject.
// Resolve jweak.
__ ld_ptr(I0, -JNIHandles::weak_tag_value, I0);
#if INCLUDE_ALL_GCS
if (UseG1GC) {
// Copy to O0 because macro doesn't allow pre_val in input reg.
__ mov(I0, O0);
__ g1_write_barrier_pre(noreg /* obj */,
noreg /* index */,
0 /* offset */,
O0 /* pre_val */,
G3_scratch /* tmp */,
true /* preserve_o_regs */);
}
#endif // INCLUDE_ALL_GCS
__ bind(not_weak);
__ verify_oop(I0);
__ bind(done);
}
if (CheckJNICalls) {