On 12/4/22 15:25, Adam D Ruppe wrote:
> which would trigger the write barrier. The thread isn't
> allowed to complete this operation until the GC is done.
According to my limited understanding of write barriers, the thread
moving to 800 could continue because order of memory operations may have
been satisfied. What I don't see is, what would the GC thread be waiting
for about the write to 800?
Would the GC be leaving behind writes to every page it scans, which have
barriers around so that the other thread can't continue? But then the
GC's write would finish and the other thread's write would finish.
Ok, here is the question: Is there a very long standing partial write
that the GC can perform like: "I write to 0x42, but I will finish it 2
seconds later. So, all other writes should wait?"
> The GC finishes its work and releases the barriers.
So, it really is explicit acquisition and releasing of these barriers...
I think this is provided by the CPU, not the OS. How many explicit write
barriers are there?
Ali
