Check core dumping is enabled when set CrashOnOutOfMemoryError

[David Holmes]

Hi,

On 13/03/2016 12:46 AM, KUBOTA Yuji wrote:
> Hi everyone.
>
> When set -XX:+CrashOnOutOfMemoryError, I think we should know
> whether core dumping has been enabled or not before launching
> process to prevent lack of information for after-the-fact analysis.

First I'm not convinced that you necessarily want to enable core dumps 
just because you want to crash on OOM.

Second I think anyone setting CrashOnOutOfMemoryError can easily 
remember to set CreateCoredumpOnCrash if they want it.

Third if I was going to force this on then I would do it directly in 
arguments.cpp, not by adding a constraint function.

Thanks,
David
-----

> So I create a patch to check the core dumping, please review it.
> I do not have an account of openjdk, so I need sponsor.
>
> I send to serviceability-dev because JDK-8138745 [1] has been
> reviewed here. If unfit, please let me know.
>
> [1]:Implement ExitOnOutOfMemory and CrashOnOutOfMemory in HotSpot
>       https://bugs.openjdk.java.net/browse/JDK-8138745
>
> diff --git a/src/share/vm/runtime/commandLineFlagConstraintsRuntime.cpp
> b/src/share/vm/runtime/commandLineFlagConstraintsRuntime.cpp
> --- a/src/share/vm/runtime/commandLineFlagConstraintsRuntime.cpp
> +++ b/src/share/vm/runtime/commandLineFlagConstraintsRuntime.cpp
> @@ -119,6 +119,17 @@
>     }
>   }
>
> +Flag::Error CrashOnOutOfMemoryErrorFunc(bool value, bool verbose) {
> +  char buffer[O_BUFLEN];
> +  os::check_dump_limit(buffer, sizeof(buffer));
> +  if (!VMError::coredump_status) {
> +    CommandLineError::print(verbose,
> +                            "%s\n", VMError::coredump_message);
> +    return Flag::VIOLATES_CONSTRAINT;
> +  }
> +  return Flag::SUCCESS;
> +}
> +
>   Flag::Error PerfDataSamplingIntervalFunc(intx value, bool verbose) {
>     if ((value % PeriodicTask::interval_gran != 0)) {
>       CommandLineError::print(verbose,
> diff --git a/src/share/vm/runtime/commandLineFlagConstraintsRuntime.hpp
> b/src/share/vm/runtime/commandLineFlagConstraintsRuntime.hpp
> --- a/src/share/vm/runtime/commandLineFlagConstraintsRuntime.hpp
> +++ b/src/share/vm/runtime/commandLineFlagConstraintsRuntime.hpp
> @@ -43,6 +43,8 @@
>   Flag::Error BiasedLockingBulkRevokeThresholdFunc(intx value, bool verbose);
>   Flag::Error BiasedLockingDecayTimeFunc(intx value, bool verbose);
>
> +Flag::Error CrashOnOutOfMemoryErrorFunc(bool value, bool verbose);
> +
>   Flag::Error PerfDataSamplingIntervalFunc(intx value, bool verbose);
>
>   #endif /* SHARE_VM_RUNTIME_COMMANDLINEFLAGCONSTRAINTSRUNTIME_HPP */
> diff --git a/src/share/vm/runtime/globals.hpp b/src/share/vm/runtime/globals.hpp
> --- a/src/share/vm/runtime/globals.hpp
> +++ b/src/share/vm/runtime/globals.hpp
> @@ -1401,6 +1401,7 @@
>     product(bool, CrashOnOutOfMemoryError, false,                             \
>             "JVM aborts, producing an error log and core/mini dump, on the "  \
>             "first occurrence of an out-of-memory error")                     \
> +          constraint(CrashOnOutOfMemoryErrorFunc,AfterErgo)                 \
>                                                                               \
>     /* tracing */                                                             \
>                                                                               \
> diff --git a/src/share/vm/utilities/vmError.hpp
> b/src/share/vm/utilities/vmError.hpp
> --- a/src/share/vm/utilities/vmError.hpp
> +++ b/src/share/vm/utilities/vmError.hpp
> @@ -65,14 +65,6 @@
>     // so use thread id instead of Thread* to identify thread.
>     static volatile intptr_t first_error_tid;
>
> -  // Core dump status, false if we have been unable to write a
> core/minidump for some reason
> -  static bool coredump_status;
> -
> -  // When coredump_status is set to true this will contain the
> name/path to the core/minidump,
> -  // if coredump_status if false, this will (hopefully) contain a
> useful error explaining why
> -  // no core/minidump has been written to disk
> -  static char coredump_message[O_BUFLEN];
> -
>
>     // set signal handlers on Solaris/Linux or the default exception filter
>     // on Windows, to handle recursive crashes.
> @@ -111,6 +103,14 @@
>     // Record status of core/minidump
>     static void record_coredump_status(const char* message, bool status);
>
> +  // Core dump status, false if we have been unable to write a
> core/minidump for some reason
> +  static bool coredump_status;
> +
> +  // When coredump_status is set to true this will contain the
> name/path to the core/minidump,
> +  // if coredump_status if false, this will (hopefully) contain a
> useful error explaining why
> +  // no core/minidump has been written to disk
> +  static char coredump_message[O_BUFLEN];
> +
>     // support for VM.info diagnostic command
>     static void print_vm_info(outputStream* st);
>
>
> Thanks,
> Yuji
>