Hi Serguei,
I am not convinced this is the right way to do this - by removing the #ifdef ENABLE_ZAP_DEAD_LOCALS" (which is an COMPILER2 specific #define under an ASSERT), we have now unconditionally increased the bitsize for every oopmap entry to two (compared to one previously) - the inlined oop_map bits_size cache is predefined to hold two words. This means the oopmap bitmap cache is effectively halved unconditionally. /Markus -----Original Message----- From: Serguei Spitsyn Sent: den 27 juni 2014 00:15 To: Vladimir Ivanov; hotspot-...@openjdk.java.net Developers; serviceability-dev@openjdk.java.net Subject: Re: RFR (S) 8013942: JSR 292: assert(type() == T_OBJECT) failed: type check Thanks, Vladimir! Serguei On 6/26/14 3:02 PM, Vladimir Ivanov wrote: > Looks good. > > Best regards, > Vladimir Ivanov > > On 6/25/14 5:57 PM, serguei.spit...@oracle.com wrote: >> Please, review the fix for: >> https://bugs.openjdk.java.net/browse/JDK-8013942 >> >> >> Open webrev: >> http://cr.openjdk.java.net/~sspitsyn/webrevs/2014/hotspot/8013942-JVM >> TI-lobj.1 >> >> >> >> >> Summary: >> >> This is a Nightly Stabilization issue. >> >> The problem is that the JVMTI GetLocalObject() function is hitting >> the assert >> as the type of the local at current bci is not T_OBJECT as expected. >> It is because this local is alive only in a narrow scope of one >> condition in the method but current bci is out of this csope. >> >> A fragment from the target method: >> >> static Class<?> canonicalize(Class<?> t, int how) { >> Class<?> ct; <== The local >> if (t == Object.class) { >> // no change, ever >> } else if (!t.isPrimitive()) { >> switch (how) { >> case UNWRAP: >> ct = Wrapper.asPrimitiveType(t); <== Initialized >> here >> if (ct != t) return ct; >> break; >> case RAW_RETURN: >> case ERASE: >> return Object.class; >> } >> } else if (t == void.class) { <== The >> GetLocalObject() is called with bci in this block >> // no change, usually >> switch (how) { >> case RAW_RETURN: >> return int.class; >> case WRAP: >> return Void.class; >> } >> } else { >> . . . >> >> The local 'ct' is only alive in the block of condition "if >> (!t.isPrimitive())". >> However, it is dead local in the next block. >> >> The fix suggested in the webrev above is to use the oop_mask for >> the method's current bci. >> It tells when the local is dead in the scope of this bci. >> Return the JVMTI_ERROR_INVALID_SLOT error in such a case. >> >> The fix also includes the tweeks which are necessary to enable the >> InterpreterOopMap.is_dead() >> function in the product mode as it was originally defined only >> under "#ifdef ENABLE_ZAP_DEAD_LOCALS". >> This makes the code in the oopMapCache.?pp a little bit more simple. >> >> >> Testing: >> Running the failing tests: vm.mlvm.indy.func.jvmti >> In progress: nsk.jvmti, nsk.jdi, nsk.jdwp test runs on sparcv9 and >> amd64 >> >> >> Thanks, >> Serguei >>
