RFR: bootstrap might exit early in debug JVM

[Doug Simon]

You are welcome to try.

> On Mar 5, 2015, at 4:15 PM, Christian Thalinger <christian.thalinger at oracle.com> wrote:
> 
> No problem.  Are you pushing it or should I do it?
> 
>> On Mar 5, 2015, at 1:32 AM, Doug Simon <doug.simon at oracle.com> wrote:
>> 
>> Looks good to me. However, getting it integrated may take a while given the current gate instability.
>> 
>>> On Mar 5, 2015, at 12:53 AM, Christian Thalinger <christian.thalinger at oracle.com> wrote:
>>> 
>>> Sometimes a debug JVM is too slow to schedule compilations in time during a bootstrap and the result is an early exit:
>>> 
>>> Bootstrapping Graal in 1000 ms (compiled 0 methods)
>>> 
>>> Here is a fix that waits until there are some methods in the queue the first time:
>>> 
>>> diff --git a/src/share/vm/graal/graalCompiler.cpp b/src/share/vm/graal/graalCompiler.cpp
>>> --- a/src/share/vm/graal/graalCompiler.cpp
>>> +++ b/src/share/vm/graal/graalCompiler.cpp
>>> @@ -85,12 +85,15 @@
>>> }
>>> 
>>> int qsize;
>>> -  jlong sleep_time = 1000;
>>> +  bool first_round = true;
>>> int z = 0;
>>> do {
>>> -    os::sleep(THREAD, sleep_time, true);
>>> -    sleep_time = 100;
>>> -    qsize = CompileBroker::queue_size(CompLevel_full_optimization);
>>> +    // Loop until there is something in the queue.
>>> +    do {
>>> +      os::sleep(THREAD, 100, true);
>>> +      qsize = CompileBroker::queue_size(CompLevel_full_optimization);
>>> +    } while (first_round && qsize == 0);
>>> +    first_round = false;
>>>   if (PrintBootstrap) {
>>>     while (z < (_methodsCompiled / 100)) {
>>>       ++z;
>>> 
>> 
>