Revision2: Corrected: RFR 8059557 (XL): Validate JVM Command-Line Flag Arguments
Bengt Rutisson
bengt.rutisson at oracle.com
Fri May 29 06:35:56 UTC 2015
Hi Gerard,
Not a full review, but just a couple of questions.
The new constraint methods added in commandLineFlagConstraintsGC.cpp are
all just implementations of the existing constraints for the GC flags,
right? Basically these checks are just moved from arguments.cpp to the
constraint methods, or have any new ones been added?
All methods in commandLineFlagConstraintsGC.cpp and
commandLineFlagConstraintsCompiler.cpp start with this check:
if ((CommandLineFlags::finishedInitializing() == true)
Only the runtime flags, checked in
commandLineFlagConstraintsRuntime.cpp, are checked even when
initialization has not been completed. Why is it important to be able to
check the constraints even before we have finished initializing?
Wouldn't it be simpler to just call the constraint methods once after
we've reached CommandLineFlags::finishedInitializing()? Then all the
constraint methods wouldn't have to remember to check for that.
(BTW, it is error prone to use == for boolean values. Better to just use
"if (CommandLineFlags::finishedInitializing())" .)
Thanks,
Bengt
On 2015-05-27 23:28, Gerard Ziemski wrote:
> hi all,
>
> Here is a revision 2 of the feature taking into account feedback from
> Dmitry, David, Kim and Alexander.
>
> One significant change in this rev is the addition of
> runtime/commandLineFlagConstraintsCompiler.hpp/.cpp with one simple
> constraint needed by Dmitry's test framework.
>
> 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 mechansim 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_rev2
> note: due to "awk" limit of 50 pats the Frames diff is not
> available for "src/share/vm/runtime/arguments.cpp"
>
> 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
>
>
> 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_implementation/g1/g1_globals.cpp | 16 +-
> src/share/vm/gc_implementation/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 | 753
> ++++++++++++++----------------------
> src/share/vm/runtime/arguments.hpp | 24 +-
> src/share/vm/runtime/commandLineFlagConstraintList.cpp | 243
> +++++++++++
> src/share/vm/runtime/commandLineFlagConstraintList.hpp | 73 +++
> src/share/vm/runtime/commandLineFlagConstraintsCompiler.cpp | 46 ++
> src/share/vm/runtime/commandLineFlagConstraintsCompiler.hpp | 39 +
> src/share/vm/runtime/commandLineFlagConstraintsGC.cpp | 251
> ++++++++++++
> src/share/vm/runtime/commandLineFlagConstraintsGC.hpp | 59 ++
> src/share/vm/runtime/commandLineFlagConstraintsRuntime.cpp | 67 +++
> src/share/vm/runtime/commandLineFlagConstraintsRuntime.hpp | 41 ++
> src/share/vm/runtime/commandLineFlagRangeList.cpp | 304
> ++++++++++++++
> src/share/vm/runtime/commandLineFlagRangeList.hpp | 67 +++
> src/share/vm/runtime/globals.cpp | 699
> +++++++++++++++++++++++++++------
> src/share/vm/runtime/globals.hpp | 310
> ++++++++++++--
> src/share/vm/runtime/globals_extension.hpp | 101 +++-
> src/share/vm/runtime/init.cpp | 6 +-
> src/share/vm/runtime/os.hpp | 17 +
> 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 | 6 +-
> src/share/vm/services/diagnosticCommand.cpp | 3 +-
> src/share/vm/services/management.cpp | 6 +-
> src/share/vm/services/memoryService.cpp | 2 +-
> src/share/vm/services/writeableFlags.cpp | 161
> +++++--
> src/share/vm/services/writeableFlags.hpp | 52 +-
> 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 +-
> 50 files changed, 2730 insertions(+), 879 deletions(-)
>
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