archive/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2025-08-27 14:54:52 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

7009266: G1: assert(obj->is_oop_or_null(true )) failed: Error

Browse source 
A referent object that is only weakly reachable at the start of concurrent marking but is re-attached to the strongly reachable object graph during marking may not be marked as live. This can cause the reference object to be processed prematurely and leave dangling pointers to the referent object. Implement a read barrier for the java.lang.ref.Reference::referent field by intrinsifying the Reference.get() method, and intercepting accesses though JNI, reflection, and Unsafe, so that when a non-null referent object is read it is also logged in an SATB buffer.

Reviewed-by: kvn, iveresov, never, tonyp, dholmes
This commit is contained in:
John Cuthbertson 2011-04-07 09:53:20 -07:00
parent aac4647e6e
commit a08e1ce906
41 changed files with 1423 additions and 268 deletions
Download patch file Download diff file Expand all files Collapse all files

101
hotspot/src/cpu/sparc/vm/c1_CodeStubs_sparc.cpp
View file

@ -408,13 +408,20 @@ void ArrayCopyStub::emit_code(LIR_Assembler* ce) {
#ifndef SERIALGC
void G1PreBarrierStub::emit_code(LIR_Assembler* ce) {
// At this point we know that marking is in progress.
// If do_load() is true then we have to emit the
// load of the previous value; otherwise it has already
// been loaded into _pre_val.
__ bind(_entry);
assert(pre_val()->is_register(), "Precondition.");
Register pre_val_reg = pre_val()->as_register();
ce->mem2reg(addr(), pre_val(), T_OBJECT, patch_code(), info(), false /*wide*/, false /*unaligned*/);
if (do_load()) {
ce->mem2reg(addr(), pre_val(), T_OBJECT, patch_code(), info(), false /*wide*/, false /*unaligned*/);
}
if (__ is_in_wdisp16_range(_continuation)) {
__ br_on_reg_cond(Assembler::rc_z, /*annul*/false, Assembler::pt,
pre_val_reg, _continuation);
@ -431,6 +438,96 @@ void G1PreBarrierStub::emit_code(LIR_Assembler* ce) {
}
void G1UnsafeGetObjSATBBarrierStub::emit_code(LIR_Assembler* ce) {
// At this point we know that offset == referent_offset.
//
// So we might have to emit:
// if (src == null) goto continuation.
//
// and we definitely have to emit:
// if (klass(src).reference_type == REF_NONE) goto continuation
// if (!marking_active) goto continuation
// if (pre_val == null) goto continuation
// call pre_barrier(pre_val)
// goto continuation
//
__ bind(_entry);
assert(src()->is_register(), "sanity");
Register src_reg = src()->as_register();
if (gen_src_check()) {
// The original src operand was not a constant.
// Generate src == null?
if (__ is_in_wdisp16_range(_continuation)) {
__ br_on_reg_cond(Assembler::rc_z, /*annul*/false, Assembler::pt,
src_reg, _continuation);
} else {
__ cmp(src_reg, G0);
__ brx(Assembler::equal, false, Assembler::pt, _continuation);
}
__ delayed()->nop();
}
// Generate src->_klass->_reference_type() == REF_NONE)?
assert(tmp()->is_register(), "sanity");
Register tmp_reg = tmp()->as_register();
__ load_klass(src_reg, tmp_reg);
Address ref_type_adr(tmp_reg, instanceKlass::reference_type_offset_in_bytes() + sizeof(oopDesc));
__ ld(ref_type_adr, tmp_reg);
if (__ is_in_wdisp16_range(_continuation)) {
__ br_on_reg_cond(Assembler::rc_z, /*annul*/false, Assembler::pt,
tmp_reg, _continuation);
} else {
__ cmp(tmp_reg, G0);
__ brx(Assembler::equal, false, Assembler::pt, _continuation);
}
__ delayed()->nop();
// Is marking active?
assert(thread()->is_register(), "precondition");
Register thread_reg = thread()->as_register();
Address in_progress(thread_reg, in_bytes(JavaThread::satb_mark_queue_offset() +
PtrQueue::byte_offset_of_active()));
if (in_bytes(PtrQueue::byte_width_of_active()) == 4) {
__ ld(in_progress, tmp_reg);
} else {
assert(in_bytes(PtrQueue::byte_width_of_active()) == 1, "Assumption");
__ ldsb(in_progress, tmp_reg);
}
if (__ is_in_wdisp16_range(_continuation)) {
__ br_on_reg_cond(Assembler::rc_z, /*annul*/false, Assembler::pt,
tmp_reg, _continuation);
} else {
__ cmp(tmp_reg, G0);
__ brx(Assembler::equal, false, Assembler::pt, _continuation);
}
__ delayed()->nop();
// val == null?
assert(val()->is_register(), "Precondition.");
Register val_reg = val()->as_register();
if (__ is_in_wdisp16_range(_continuation)) {
__ br_on_reg_cond(Assembler::rc_z, /*annul*/false, Assembler::pt,
val_reg, _continuation);
} else {
__ cmp(val_reg, G0);
__ brx(Assembler::equal, false, Assembler::pt, _continuation);
}
__ delayed()->nop();
__ call(Runtime1::entry_for(Runtime1::Runtime1::g1_pre_barrier_slow_id));
__ delayed()->mov(val_reg, G4);
__ br(Assembler::always, false, Assembler::pt, _continuation);
__ delayed()->nop();
}
jbyte* G1PostBarrierStub::_byte_map_base = NULL;
jbyte* G1PostBarrierStub::byte_map_base_slow() {