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8220351: Cross-modifying code

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Reviewed-by: rrich, mdoerr, dholmes, eosterlund
This commit is contained in:
Robbin Ehn 2019-03-28 11:08:23 +01:00
parent dbe0da648a
commit 76cdc8016f
21 changed files with 96 additions and 13 deletions
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8
src/hotspot/share/runtime/thread.cpp
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@ -1836,6 +1836,10 @@ void JavaThread::run() {
// Thread is now sufficiently initialized to be handled by the safepoint code as being
// in the VM. Change thread state from _thread_new to _thread_in_vm
ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm);
// Before a thread is on the threads list it is always safe, so after leaving the
// _thread_new we should emit a instruction barrier. The distance to modified code
// from here is probably far enough, but this is consistent and safe.
OrderAccess::cross_modify_fence();
assert(JavaThread::current() == this, "sanity check");
assert(!Thread::current()->owns_locks(), "sanity check");
@ -2439,7 +2443,6 @@ int JavaThread::java_suspend_self() {
this->SR_lock()->wait(Mutex::_no_safepoint_check_flag);
}
}
return ret;
}
@ -2467,6 +2470,9 @@ void JavaThread::java_suspend_self_with_safepoint_check() {
set_thread_state(_thread_blocked);
java_suspend_self();
set_thread_state(state);
// Since we are not using a regular thread-state transition helper here,
// we must manually emit the instruction barrier after leaving a safe state.
OrderAccess::cross_modify_fence();
InterfaceSupport::serialize_thread_state_with_handler(this);
if (state != _thread_in_native) {
SafepointMechanism::block_if_requested(this);