RFR: 8247536: Support for pre-generated java.lang.invoke classes in CDS static archive
sundararajan.athijegannathan at oracle.com
sundararajan.athijegannathan at oracle.com
Tue Aug 18 02:39:24 UTC 2020
Hi David.
Thanks.
-Sundar
On 18/08/20 8:04 am, David Holmes wrote:
> Hi Sundar,
>
> On 18/08/2020 12:25 pm, sundararajan.athijegannathan at oracle.com wrote:
>> Not a full review of fresh changes. But couple of comments:
>>
>> * src/hotspot/share/memory/lambdaFormInvokers.cpp and
>> src/hotspot/share/memory/lambdaFormInvokers.hpp miss "Classpath
>> exception" clause in the copyright header
>
> Hotspot files do not use the Classpath exception. That is for .java
> sources that will be"linked against" by applications.
>
> Cheers,
> David
>
>> * I had suggested a change GenerateJLIClassesPlugin.java in last
>> round of review. That's still applicable.
>>
>> https://mail.openjdk.java.net/pipermail/core-libs-dev/2020-August/068160.html
>>
>>
>> -Sundar
>>
>> On 18/08/20 1:07 am, Yumin Qi wrote:
>>> Hi, Ioi
>>>
>>> Thanks for review/suggestion. I have updated the webrev at the
>>> following link:
>>>
>>> http://cr.openjdk.java.net/~minqi/2020/8247536/webrev-02/
>>>
>>> Following changes done in this patch:
>>>
>>> 1) move regenerating holder classes into new added file:
>>> lambdaFormInvokers.[ch]pp
>>>
>>> "@lambda-form-invoker" tag only observed at jvm side.
>>>
>>> 2) remove InvokerBytecodeGeneratorHelper.java, move related
>>> functions to existing class, GenerateJLIClassesHelper.java
>>>
>>> 3) add tracing for SPECIES_RESOLVE, so archive more classes.
>>>
>>> 4) remove InvokerGenerateBytesException.java, using
>>> RuntimeException instead.
>>>
>>> 5) Changed make file to exclude the new added
>>> lamdaFormInvokers.cpp from the non-cds building list.
>>>
>>> 6) There is a bug in previous patch, jobject (typeArrayOop) should
>>> not be used directly for loading class since GC will move the java
>>> object. Fixed by copying the bytes from handle to C heap.
>>>
>>> 7) Tested with tier1,2
>>>
>>>
>>> Thanks
>>>
>>> Yumin
>>>
>>>
>>>
>>> On 8/15/20 6:27 PM, Ioi Lam wrote:
>>>> On 8/15/20 6:19 PM, Ioi Lam wrote:
>>>>> To better capture what we're trying to do in this RFE, I've
>>>>> changed the RFE title (and the subject of this email thread) to
>>>>>
>>>>> https://bugs.openjdk.java.net/browse/JDK-8247536
>>>>> Support for pre-generated java.lang.invoke classes in CDS static
>>>>> archive
>>>>>
>>>>> I also update the RFE Description to give an overview of the
>>>>> problem and the solution.
>>>>>
>>>>> The design document is also updated to reflect Yumin's latest
>>>>> implementation
>>>>>
>>>>
>>>> Oops, sent too quickly. The design doc's title is also updated:
>>>>
>>>> https://wiki.openjdk.java.net/display/HotSpot/Support+for+pre-generated+java.lang.invoke+classes+in+CDS+archive
>>>>
>>>>
>>>>> Thanks
>>>>> - Ioi
>>>>>
>>>>> On 8/12/20 11:54 AM, calvin.cheung at oracle.com wrote:
>>>>>> Hi Yumin,
>>>>>>
>>>>>> I reviewed mostly the native code. Below are my comments:
>>>>>>
>>>>>> 1) classListParser.hpp
>>>>>>
>>>>>> 71 bool _lambda_format;
>>>>>>
>>>>>> The above name is too generic. How about _lambda_form or
>>>>>> _is_lambda_form?
>>>>>> If you rename the above, please also rename the function which
>>>>>> returns the above bool.
>>>>>>
>>>>>> 2) jvm.cpp
>>>>>>
>>>>>> 3850 JVM_ENTRY(void, JVM_CDSTraceResolve(JNIEnv* env, jclass
>>>>>> ignore, jstring line))
>>>>>>
>>>>>> ignore -> ignored
>>>>>>
>>>>>> 3) jvm.hpp
>>>>>>
>>>>>> 210 JVM_CDSTraceResolve(JNIEnv* env, jclass ignore, jstring line);
>>>>>>
>>>>>> Same comment as for jvm.cpp
>>>>>>
>>>>>> 4) metaspaceShared.cpp
>>>>>>
>>>>>> 2017 size_t i = 0;
>>>>>> 2018 while (i < size) {
>>>>>> 2019 full_name[i++] = *start++;
>>>>>> 2020 }
>>>>>>
>>>>>> Could the above be simplified to the following?
>>>>>>
>>>>>> strncpy(full_name, start, size - 1);
>>>>>>
>>>>>> 2029 char* class_name = get_full_class_name(path_name);
>>>>>>
>>>>>> Should os::free(class_name) be called before the function returns?
>>>>>>
>>>>>> 1870 static GrowableArray<char *>* lambda_list = NULL;
>>>>>>
>>>>>> The name lambda_list is a bit generic, how about lambda_form_list?
>>>>>>
>>>>>> 2112 lambda_list->append(parser.current_line());
>>>>>>
>>>>>> Since parser.current_line() does a strdup, do those buffer need
>>>>>> to be freed after its use? (i.e. after the call to
>>>>>> regenerate_holder_classes()?)
>>>>>>
>>>>>> In MetaspaceShared::regenerate_holder_classes, before calling up
>>>>>> to java, I think it's better to strip the prefix
>>>>>> "@lambda-form-invoker" from the strings. So that the java
>>>>>> InvokerBytecodeGeneratorHelper.readTraceConfig method doesn't
>>>>>> need to handle it:
>>>>>>
>>>>>> 143 case "[LF_RESOLVE]":
>>>>>> 144 case
>>>>>> InvokerBytecodeGenerator.CDS_LOG_PREFIX:
>>>>>>
>>>>>> 5) DumpSymbolAndStringTable.java
>>>>>>
>>>>>> 37 private static final String my_string =
>>>>>> "DumpSymbolAndStringTable";
>>>>>>
>>>>>> Unused variable?
>>>>>>
>>>>>> thanks,
>>>>>>
>>>>>> Calvin
>>>>>>
>>>>>> On 8/11/20 10:36 AM, Yumin Qi wrote:
>>>>>>> Forget to send to @core-lib-dev, the patch changed jdk code.
>>>>>>>
>>>>>>>
>>>>>>> Thanks
>>>>>>>
>>>>>>> Yumin
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> -------- Forwarded Message --------
>>>>>>> Subject: RFR: 8247536: Support pre-generated MethodHandle
>>>>>>> lambda forms in CDS
>>>>>>> Date: Tue, 11 Aug 2020 07:44:34 -0700
>>>>>>> From: Yumin Qi <yumin.qi at oracle.com>
>>>>>>> To: hotspot-runtime-dev at openjdk.java.net
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Hi, Please reivew
>>>>>>>
>>>>>>> bug: https://bugs.openjdk.java.net/browse/JDK-8247536
>>>>>>> Webrev: http://cr.openjdk.java.net/~minqi/2020/8247536/webrev-01/
>>>>>>>
>>>>>>> Summary: CDS does not archive pre-generated lambda form
>>>>>>> classes for method handles:
>>>>>>>
>>>>>>> [0.142s][info][class,load]
>>>>>>> java.lang.invoke.LambdaForm$MH/0x0000000800066c40 source:
>>>>>>> __JVM_LookupDefineClass__
>>>>>>>
>>>>>>> The method handle resolution if not found in the holder class, a
>>>>>>> class with the method will be generated and loaded as vm
>>>>>>> internal created class and not archived like above. Those class
>>>>>>> names are mangled as combination of the class name and the class
>>>>>>> instance address.
>>>>>>>
>>>>>>> In this patch, collect those method holder class names and their
>>>>>>> associated methods' signatures when user specify
>>>>>>> DumpLoadedClassList, and record them in the log file in a format
>>>>>>> similar to the output format from traced by
>>>>>>> -Djava.lang.invoke.MethodHandle.TRACE_RESOLVE=true, but here use
>>>>>>> another name for CDS:
>>>>>>> -Djava.lang.invoke.MethodHandle.CDS_TRACE_RESOLVE=true instead.
>>>>>>> The line prefix also changed from "[LF_RESOLVE]" to
>>>>>>> "@lambda-invoke-handle". At dump time, regenerate the holder
>>>>>>> class with those methods and replace the existing holder class
>>>>>>> and archived it. At runtime, the resolution of the holder class
>>>>>>> which contains those methods are loaded from CDS archive so
>>>>>>> avoid regenerating them again. The patch reorganized the code
>>>>>>> for Jlink plugin, so the new added
>>>>>>> InvokerBytecodeGeneratorHelper can be shared both by JLink
>>>>>>> plugin and CDS code. Also change made to the mangled generated
>>>>>>> class name at static dump, the class name combining the class
>>>>>>> name and a sequentially ordered number instead of the class
>>>>>>> instance address, which looks like a random.
>>>>>>>
>>>>>>>
>>>>>>> To use this feature, one can do the dump/run just like done for
>>>>>>> a static dump/run, so no extra steps required.
>>>>>>>
>>>>>>> 1) java -XX:DumpLoadedClassList=myclasslist JavaApp
>>>>>>>
>>>>>>> DumpLoadedClassList will turn on
>>>>>>> -Djava.lang.invoke.MethodHandle.CDS_TRACE_RESOLVE=true
>>>>>>>
>>>>>>> 2) java -Xshare:dump -XX:SharedClassListFile=myclasslist
>>>>>>> -XX:SharedArchiveFile=my.jsa JavaApp
>>>>>>>
>>>>>>> 3) java -Xshare:on -XX:SharedArchiveFile=my.jsa JavaApp
>>>>>>>
>>>>>>> The performance on javac HelloWorld.java (javac-benchmark), no
>>>>>>> patch vs patch:
>>>>>>>
>>>>>>> 1: 2689285002 2641821474 (-47463528) ---- 391.720
>>>>>>> 382.990 ( -8.730) ----
>>>>>>> 2: 2687495085 2632969688 (-54525397) ---- 391.030
>>>>>>> 381.480 ( -9.550) -----
>>>>>>> 3: 2694664066 2636523114 (-58140952) ----- 390.610
>>>>>>> 382.550 ( -8.060) ----
>>>>>>> 4: 2686554164 2639355233 (-47198931) ---- 390.700
>>>>>>> 383.390 ( -7.310) ---
>>>>>>> 5: 2691072338 2633016687 (-58055651) ----- 388.990
>>>>>>> 382.360 ( -6.630) ---
>>>>>>> 6: 2684448174 2644191854 (-40256320) --- 389.450
>>>>>>> 382.990 ( -6.460) ---
>>>>>>> 7: 2694921227 2630505090 (-64416137) ----- 389.300
>>>>>>> 383.160 ( -6.140) ---
>>>>>>> 8: 2685209712 2639334320 (-45875392) ---- 388.370
>>>>>>> 381.060 ( -7.310) ---
>>>>>>> 9: 2695885942 2640618655 (-55267287) ---- 389.560
>>>>>>> 381.100 ( -8.460) ----
>>>>>>> 10: 2689162942 2635658943 (-53503999) ---- 389.690
>>>>>>> 379.110 (-10.580) -----
>>>>>>> ============================================================
>>>>>>> 2689866989 2637396210 (-52470778) ---- 389.941
>>>>>>> 382.017 ( -7.924) ----
>>>>>>>
>>>>>>> instr delta = -52470778 -1.9507%
>>>>>>>
>>>>>>> time delta = -7.924 ms -2.0321%
>>>>>>>
>>>>>>> It will show much more improvement if compare with the default
>>>>>>> archive:
>>>>>>>
>>>>>>> no patch patch
>>>>>>>
>>>>>>> instr 3,996,847,605 3,320,928,995
>>>>>>>
>>>>>>> time(s). 0.686835162 0.474933546
>>>>>>>
>>>>>>>
>>>>>>> Tests:
>>>>>>>
>>>>>>> 1)jtreg on jdk/tools and hotspot/runtime local.
>>>>>>>
>>>>>>> 2) mach5 ter1,2
>>>>>>>
>>>>>>>
>>>>>>> Thanks
>>>>>>>
>>>>>>> Yumin
>>>>>>>
>>>>>>> `
>>>>>
>>>>
More information about the hotspot-runtime-dev
mailing list