RFR(S) 8134898: Small fixes found during JVMCI work (original) (raw)

Vladimir Kozlov vladimir.kozlov at oracle.com
Wed Sep 2 04:19:48 UTC 2015

To resolve the incompatibility, you can simply remove CHECK_UNHANDLED_OOPS around the field in Thread, and put it under #ifndef PRODUCT.

Wonderful! :) I thought it requires #ifdef CHECK_UNHANDLED_OOPS.

Please, look on new changes:

http://cr.openjdk.java.net/~kvn/8134898/webrev.01/

Thanks, Vladimir

On 9/1/15 8:55 PM, Coleen Phillimore wrote:

On 9/1/15 7:59 PM, Vladimir Kozlov wrote: http://cr.openjdk.java.net/~kvn/8134898/webrev/ https://bugs.openjdk.java.net/browse/JDK-8134898

During review of JVMCI changes we were asked to push not related small changes separately. Removed jre/ from jdk paths in makefiles since jdk9 does not have it anymore. Solaris vm.make and buildtree.make missed changes other unix platforms have. Fix type in doc. Added -DCHECKUNHANDLEDOOPS to debug build. I very strongly want to do that. Adding -DCHECKUNHANDLEDOOPS to the debug build adds a level of indirection to the oops that are somewhat annoying during debugging: eg. 692 void javalangClass::setcomponentmirror(oop javaclass, oop compmirror) { 693 assert(componentmirroroffset != 0, "must be set"); 694 javaclass->objfieldput(componentmirroroffset, compmirror); 695 } (gdb) print javaclass $7 = {o = 0x8cb003b8} (gdb) print javamirror No symbol "javamirror" in current context. (gdb) print compmirror $8 = {o = 0x8cb001b0} (gdb) call hsfind(javaclass.o) warning: Using non-standard conversion to match function hsfind to supplied arguments "Executing hsfind" 0x000000008cb003b8 is an oop java.lang.Class - klass: 'java/lang/Class' - ---- fields (total size 13 words): ... vs. 693 assert(componentmirroroffset != 0, "must be set"); (gdb) print javaclass $1 = (oop) 0x8cb003b8 (gdb) print compmirror $2 = (oop) 0x8cb001b0 (gdb) print hsfind(javaclass) warning: Using non-standard conversion to match function hsfind to supplied arguments "Executing hsfind" 0x000000008cb003b8 is an oop java.lang.Class - klass: 'java/lang/Class' - ---- fields (total size 13 words): ... The GC people deal with far more 'oop' objects in their debugging, which is why they asked me originally not to enable CHECKUNHANDLEDOOPS in the debug build. To resolve the incompatibility, you can simply remove CHECKUNHANDLEDOOPS around the field in Thread, and put it under #ifndef PRODUCT. Coleen It is the only incompatibility in memory layout between fastdebug and debug VM. We maintained such compatibility for long time and it was broken with 7195622 changes. For AOT project it is very important to keep compatibility because we use fastdebug VM for JAOTC tool to compile aot code and we want to be able use debug VM to debug execution of aot code. Note, using debug VM with JAOTC will take 5-10 times longer to compile. Thanks, Vladimir

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