Acquire and release Heap_lock on VM_MMTkSTWOperation #316
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wks
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This reverts commit dc3a9b4.
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This reverts commit dc3a9b4.
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This PR changes how we acquire
Heap_lockfor GC. With the changes, we acquire the lock inVM_MMTkSTWOperation::doit_prologue(), and release the lock in epilogue. We hold the lock during the entire STW. This is the same behavior as OpenJDK's GCs.We used to acquire the lock during reference enqueueing before
swap_reference_pending_list()(which requires the lock to be locked), and acquire the lock before notifying the reference handler. This causes deadlock as seen in #315 .The
has_reference_pending_listcall used for an assertion in reference enqueueing is removed, as it requires the current thread to hold the lock which cannot be satisfied.This PR should fix #315.