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

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

View file

@ -246,6 +246,7 @@ class LIRGenerator: public InstructionVisitor, public BlockClosure {
void do_AttemptUpdate(Intrinsic* x);
void do_NIOCheckIndex(Intrinsic* x);
void do_FPIntrinsics(Intrinsic* x);
void do_Reference_get(Intrinsic* x);
void do_UnsafePrefetch(UnsafePrefetch* x, bool is_store);
@ -260,13 +261,14 @@ class LIRGenerator: public InstructionVisitor, public BlockClosure {
// generic interface
void pre_barrier(LIR_Opr addr_opr, bool patch, CodeEmitInfo* info);
void pre_barrier(LIR_Opr addr_opr, LIR_Opr pre_val, bool do_load, bool patch, CodeEmitInfo* info);
void post_barrier(LIR_OprDesc* addr, LIR_OprDesc* new_val);
// specific implementations
// pre barriers
void G1SATBCardTableModRef_pre_barrier(LIR_Opr addr_opr, bool patch, CodeEmitInfo* info);
void G1SATBCardTableModRef_pre_barrier(LIR_Opr addr_opr, LIR_Opr pre_val,
bool do_load, bool patch, CodeEmitInfo* info);
// post barriers