Revision3: Corrected: RFR 8059557 (XL): Validate JVM Command-Line Flag Arguments

Gerard Ziemski gerard.ziemski at oracle.com
Tue Jun 16 21:11:16 UTC 2015 

Coleen, Dmitry, David, Kim, Derek and Bengt,

I have create an incremental webrev as requested: 
http://cr.openjdk.java.net/~gziemski/8059557_rev2_to_rev3

As per suggestion from Kim and Coleen, I will not be spinning webrev4 
unless there is a blocker in the code that we haven't found yet.

The plan right now is to check in rev3 and have 
https://bugs.openjdk.java.net/browse/JDK-8112746 track any follow up 
issues, which I already populated with comments from Coleen, Dmitry and Kim.

Can I have a final sign off on this webrev rev3 from all of you please?


cheers

On 6/14/2015 9:31 PM, David Holmes wrote:
> Hi Gerard,
>
> Any chance you could produce and incremental webrev please?
>
> Thanks,
> David
>
> On 14/06/2015 12:32 AM, Gerard Ziemski wrote:
>> hi all,
>>
>> Thank you for the reviews so far!
>>
>> Here is a revision 3 of the feature taking into account feedback from 
>> Kim Barrett, David Holmes, Derek White and Bengt Rutisson. I have 
>> also merged the changes to the latest jdk9.
>>
>> We introduce a new mechanism that allows specification of a valid 
>> range per flag that is then used to automatically validate given 
>> flag's value every time it changes. Ranges values must be constant 
>> and can not change. Optionally, a constraint can also be specified 
>> and applied every time a flag value changes for those flags whose 
>> valid value can not be trivially checked by a simple min and max (ex. 
>> whether it's power of 2, or bigger or smaller than some other flag 
>> that can also change)
>>
>> I have chosen to modify the table macros (ex. RUNTIME_FLAGS in 
>> globals.hpp) instead of using a more sophisticated solution, such as 
>> C++ templates, because even though macros were unfriendly when 
>> initially developing, once a solution was arrived at, subsequent 
>> additions to the tables of new ranges, or constraint are trivial from 
>> developer's point of view. (The intial development unfriendliness of 
>> macros was mitigated by using a pre-processor, which for those using 
>> a modern IDE like Xcode, is easily available from a menu). Using 
>> macros also allowed for more minimal code changes.
>>
>> The presented solution is based on expansion of macros using variadic 
>> functions and can be readily seen in 
>> runtime/commandLineFlagConstraintList.cpp and 
>> runtime/commandLineFlagRangeList.cpp
>>
>> In commandLineFlagConstraintList.cpp or 
>> commandLineFlagRangesList.cpp, there is bunch of classes and methods 
>> that seems to beg for C++ template to be used. I have tried, but when 
>> the compiler tries to generate code for both uintx and size_t, which 
>> happen to have the same underlying type (on BSD), it fails to compile 
>> overridden methods with same type, but different name. If someone has 
>> a way of simplifying the new code via C++ templates, however, we can 
>> file a new enhancement request to address that.
>>
>> This webrev represents only the initial range checking framework and 
>> only 100 or so flags that were ported from an existing ad hoc range 
>> checking code to this new mechanism. There are about 250 remaining 
>> flags that still need their ranges determined and ported over to this 
>> new mechanism and they are tracked by individual subtasks.
>>
>> I had to modify several existing tests to change the error message 
>> that they expected when VM refuses to run, which was changed to 
>> provide uniform error messages.
>>
>> To help with testing and subtask efforts I have introduced a new 
>> runtime flag:
>>
>>    PrintFlagsRanges: "Print VM flags and their ranges and exit VM"
>>
>> which in addition to the already existing flags: "PrintFlagsInitial" 
>> and "PrintFlagsFinal" allow for thorough examination of the flags 
>> values and their ranges.
>>
>> The code change builds and passes JPRT (-testset hotspot) and UTE 
>> (vm.quick.testlist)
>>
>>
>> References:
>>
>> Webrev:http://cr.openjdk.java.net/~gziemski/8059557_rev3
>> JEP:https://bugs.openjdk.java.net/browse/JDK-8059557
>> Compiler subtask:https://bugs.openjdk.java.net/browse/JDK-8078554
>>        GC subtask:https://bugs.openjdk.java.net/browse/JDK-8078555
>>   Runtime subtask:https://bugs.openjdk.java.net/browse/JDK-8078556
>>
>> Note: due to "awk" limit of 50 pats the Frames diff is not available 
>> for "src/share/vm/runtime/arguments.cpp” and 
>> "src/share/vm/runtime/globals.cpp”
>>
>>
>> Followup issues:
>>
>> JDK-8085866: There are 99 uses of FLAG_SET_ERGO, should they check 
>> the return value?
>> JDK-8085864: FLAG_SET_CMDLINE in TestGenCollectorPolicy() currently 
>> ignore the return values
>> JDK-8081842: Find a better place for 
>> EMIT_{CONSTRAINTS,RANGES}_FOR_GLOBALS_EXT
>> JDK-8081833: There is a large amount of code near-duplication among 
>> the various CommandLineFlagRange_<type> classes
>> JDK-8081519: Split globals.hpp to factor out the Flag values needed 
>> by JDK-8059557
>>
>>
>> hgstat:
>>
>>   src/cpu/ppc/vm/globals_ppc.hpp |    2 +-
>>   src/cpu/sparc/vm/globals_sparc.hpp |    2 +-
>>   src/cpu/x86/vm/globals_x86.hpp |    2 +-
>>   src/cpu/zero/vm/globals_zero.hpp |    3 +-
>>   src/os/aix/vm/globals_aix.hpp |    2 +-
>>   src/os/bsd/vm/globals_bsd.hpp |   29 +-
>>   src/os/linux/vm/globals_linux.hpp |    9 +-
>>   src/os/solaris/vm/globals_solaris.hpp |    4 +-
>>   src/os/windows/vm/globals_windows.hpp |    5 +-
>>   src/share/vm/c1/c1_globals.cpp |    4 +-
>>   src/share/vm/c1/c1_globals.hpp |   17 +-
>>   src/share/vm/gc/g1/g1_globals.cpp |   14 +-
>>   src/share/vm/gc/g1/g1_globals.hpp |   38 +-
>>   src/share/vm/opto/c2_globals.cpp |   12 +-
>>   src/share/vm/opto/c2_globals.hpp |   40 +-
>>   src/share/vm/prims/whitebox.cpp |   12 +-
>>   src/share/vm/runtime/arguments.cpp                          | 765 
>> ++++++----------
>>   src/share/vm/runtime/arguments.hpp |   24 +-
>>   src/share/vm/runtime/commandLineFlagConstraintList.cpp      | 286 
>> ++++++
>>   src/share/vm/runtime/commandLineFlagConstraintList.hpp |   80 +
>>   src/share/vm/runtime/commandLineFlagConstraintsCompiler.cpp |   44 +
>>   src/share/vm/runtime/commandLineFlagConstraintsCompiler.hpp |   39 +
>>   src/share/vm/runtime/commandLineFlagConstraintsGC.cpp       | 235 
>> +++++
>>   src/share/vm/runtime/commandLineFlagConstraintsGC.hpp |   58 +
>>   src/share/vm/runtime/commandLineFlagConstraintsRuntime.cpp |   65 +
>>   src/share/vm/runtime/commandLineFlagConstraintsRuntime.hpp |   41 +
>>   src/share/vm/runtime/commandLineFlagRangeList.cpp           | 367 
>> ++++++++
>>   src/share/vm/runtime/commandLineFlagRangeList.hpp |   71 +
>>   src/share/vm/runtime/globals.cpp                            | 721 
>> ++++++++++++---
>>   src/share/vm/runtime/globals.hpp                            | 343 
>> ++++++-
>>   src/share/vm/runtime/globals_extension.hpp                  | 105 +-
>>   src/share/vm/runtime/init.cpp |    5 +-
>>   src/share/vm/runtime/os_ext.hpp |    7 +-
>>   src/share/vm/runtime/thread.cpp |    6 +
>>   src/share/vm/services/attachListener.cpp |    4 +-
>>   src/share/vm/services/classLoadingService.cpp |   12 +-
>>   src/share/vm/services/diagnosticCommand.cpp |    3 +-
>>   src/share/vm/services/management.cpp |    6 +-
>>   src/share/vm/services/memoryService.cpp |    4 +-
>>   src/share/vm/services/writeableFlags.cpp                    | 183 ++-
>>   src/share/vm/services/writeableFlags.hpp |   60 +-
>>   test/compiler/c2/7200264/Test7200264.sh |    5 +-
>>   test/compiler/startup/NumCompilerThreadsCheck.java |    2 +-
>>   test/gc/arguments/TestHeapFreeRatio.java |   23 +-
>>   test/gc/arguments/TestSurvivorAlignmentInBytesOption.java |    6 +-
>>   test/gc/g1/TestStringDeduplicationTools.java |    6 +-
>>   test/runtime/CompressedOops/CompressedClassSpaceSize.java |    4 +-
>>   test/runtime/CompressedOops/ObjectAlignment.java |    9 +-
>>   test/runtime/contended/Options.java |   10 +-
>>   49 files changed, 2851 insertions(+), 943 deletions(-)
>>
>

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