RFR: 8252543: [JVMCI] Libgraal can deadlock in blocking compilation mode [v3]

[Vladimir Kozlov]

On Fri, 11 Sep 2020 08:08:22 GMT, Doug Simon <dnsimon at openjdk.org> wrote:

>> To prevent a deadlock in libgraal under `-Xcomp` or `-Xbatch` due to a lock being held in libgraal, a new mechanism is
>> added by this change that allow JVMCI compiler threads to communicate their "progress" to HotSpot:
>> * Each JVMCI compiler thread has a "compilation ticks" counter.
>> * There is also a global JVMCI compilation ticks counter.
>> * Each JVMCI VM call increments the JVMCI compiler thread-local compilation ticks counter.
>> * Every 512 increments of such a counter also increments the global counter.
>> * A thread waiting on a blocking JVMCI compilation will be unblocked if these counters indicate no progress after a
>>   defined period.
>
> Doug Simon has refreshed the contents of this pull request, and previous commits have been removed. The incremental
> views will show differences compared to the previous content of the PR. The pull request contains one new commit since
> the last revision:
>   8252543: add compilation ticks for mitigating against deadlock due to blocking JVMCI compilation

Marked as reviewed by kvn (Reviewer).

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PR: https://git.openjdk.java.net/jdk/pull/35