RFR: 8067247: Crash: assert(method_holder->data() == 0 ...) failed: a) MT-unsafe modification of inline cache

[Vladimir Ivanov]

> clear_inline_caches clears static stubs. i wanted this api to look more
> like cleanup_inline_caches functionality(with clean all ics). So used this.

Are you sure? WhiteBox.clearInlineCaches() should clear all ICs in alive 
nmethods. Why doesn't it work for you?

WB_ENTRY(void, WB_ClearInlineCaches(JNIEnv* env, jobject wb))
   VM_ClearICs clear_ics;
   VMThread::execute(&clear_ics);
WB_END

class VM_ClearICs: public VM_Operation {
...
   void doit()         { CodeCache::clear_inline_caches(); }
...
};

void CodeCache::clear_inline_caches() {
   assert_locked_or_safepoint(CodeCache_lock);
   NMethodIterator iter;
   while(iter.next_alive()) {
     iter.method()->clear_inline_caches();
   }
}

void nmethod::clear_inline_caches() {
   assert(SafepointSynchronize::is_at_safepoint(), "cleaning of IC's 
only allowed at safepoint");
   if (is_zombie()) {
     return;
   }

   RelocIterator iter(this);
   while (iter.next()) {
     iter.reloc()->clear_inline_cache();
   }
}

void static_call_Relocation::clear_inline_cache() {
   // Safe call site info
   CompiledStaticCall* handler = compiledStaticCall_at(this);
   handler->set_to_clean();
}

void opt_virtual_call_Relocation::clear_inline_cache() {
   // No stubs for ICs
   // Clean IC
   ResourceMark rm;
   CompiledIC* icache = CompiledIC_at(this);
   icache->set_to_clean();
}

void virtual_call_Relocation::clear_inline_cache() {
   // No stubs for ICs
   // Clean IC
   ResourceMark rm;
   CompiledIC* icache = CompiledIC_at(this);
   icache->set_to_clean();
}

Best regards,
Vladimir Ivanov

>
> Best Regards,
> Jamsheed
>
> On 3/26/2016 1:50 PM, Dean Long wrote:
>> Instead of changing cleanup_inline_caches() to take a new flag, can
>> you use the existing
>> clear_inline_caches()?
>>
>> dl
>>
>> On 3/25/2016 9:54 AM, Jamsheed C m wrote:
>>> Thank you Chris.
>>> I have updated the code.
>>>
>>> + if (method == NULL) {
>>> + return;
>>> + }
>>> + nmethod* nm = method->code();
>>> + if (nm == NULL || nm->is_unloaded()) {
>>> + return;
>>> + }
>>> + nm->cleanup_inline_caches(true);
>>> Best Regards,
>>> Jamsheed
>>>
>>> On 3/25/2016 6:58 AM, Christian Thalinger wrote:
>>>>
>>>>> On Mar 24, 2016, at 11:05 AM, Jamsheed C m
>>>>> <jamsheed.c.m at oracle.com> wrote:
>>>>>
>>>>> Hi All,
>>>>>
>>>>> Request for review,
>>>>>
>>>>> bug url: https://bugs.openjdk.java.net/browse/JDK-8067247
>>>>>
>>>>> webrevs:
>>>>> fix:
>>>>>   jdk part: http://cr.openjdk.java.net/~jcm/8067247/webrev.jdk.00/
>>>>> <http://cr.openjdk.java.net/%7Ejcm/8067247/webrev.jdk.00/>
>>>>>
>>>>> newly added test case
>>>>> hotspot part:
>>>>> http://cr.openjdk.java.net/~jcm/8067247/webrev.hs.00/
>>>>> <http://cr.openjdk.java.net/%7Ejcm/8067247/webrev.hs.00/>
>>>>> under hs-comp/test
>>>>> http://cr.openjdk.java.net/~jcm/8067247/webrev.hs_comp.00/
>>>>> <http://cr.openjdk.java.net/%7Ejcm/8067247/webrev.hs_comp.00/>
>>>>>
>>>>> Unit Test: test/compiler/jsr292/misc/gc/MHInvokeTest.java
>>>>> Testing: JPRT with new test case, with fix, without fix
>>>>>
>>>>> Problem Summary:  MH.invoke linksite take assistance of java code
>>>>> to get an adapter method. Here a new method holder class and a
>>>>> adapter method are created for a MT and lform instance is cached.
>>>>> Normally this cached lform get returned for a linksite request of
>>>>> same MT.  When these cached lform get collected(due to memory
>>>>> pressure),  a new class and method gets created for same MT(even
>>>>> though old method holder class and  adapter method are live).
>>>>> Fix Summary: Kept a strong reference to lform instance in adapter
>>>>> method holder class of  MT.
>>>>
>>>> Wow!  You found the cause for his long-standing issue?  Nice.
>>>> + if (method == NULL) { return; }
>>>> + nmethod* nm = method->code();
>>>> + if (nm == NULL) { return; }
>>>> + if (nm->is_unloaded()) { return; }
>>>> Please put the return and } on separate lines.
>>>>
>>>>>
>>>>> Best Regards,
>>>>> Jamsheed
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>
>>
>