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src/hotspot/os/bsd/os_bsd.cpp

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*** 928,938 **** const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom; const uint64_t prev = Bsd::_max_abstime; if (now <= prev) { return prev; // same or retrograde time; } ! const uint64_t obsv = Atomic::cmpxchg(now, &Bsd::_max_abstime, prev); assert(obsv >= prev, "invariant"); // Monotonicity // If the CAS succeeded then we're done and return "now". // If the CAS failed and the observed value "obsv" is >= now then // we should return "obsv". If the CAS failed and now > obsv > prv then // some other thread raced this thread and installed a new value, in which case --- 928,938 ---- const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom; const uint64_t prev = Bsd::_max_abstime; if (now <= prev) { return prev; // same or retrograde time; } ! const uint64_t obsv = Atomic::cmpxchg(&Bsd::_max_abstime, prev, now); assert(obsv >= prev, "invariant"); // Monotonicity // If the CAS succeeded then we're done and return "now". // If the CAS failed and the observed value "obsv" is >= now then // we should return "obsv". If the CAS failed and now > obsv > prv then // some other thread raced this thread and installed a new value, in which case
*** 1831,1841 **** static int check_pending_signals() { for (;;) { for (int i = 0; i < NSIG + 1; i++) { jint n = pending_signals[i]; ! if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { return i; } } JavaThread *thread = JavaThread::current(); ThreadBlockInVM tbivm(thread); --- 1831,1841 ---- static int check_pending_signals() { for (;;) { for (int i = 0; i < NSIG + 1; i++) { jint n = pending_signals[i]; ! if (n > 0 && n == Atomic::cmpxchg(&pending_signals[i], n, n - 1)) { return i; } } JavaThread *thread = JavaThread::current(); ThreadBlockInVM tbivm(thread);
*** 3235,3245 **** for (uint i = 0; i < max_apic_ids; ++i) { mapping[i] = -1; } ! if (!Atomic::replace_if_null(mapping, &apic_to_processor_mapping)) { FREE_C_HEAP_ARRAY(int, mapping); mapping = Atomic::load_acquire(&apic_to_processor_mapping); } } --- 3235,3245 ---- for (uint i = 0; i < max_apic_ids; ++i) { mapping[i] = -1; } ! if (!Atomic::replace_if_null(&apic_to_processor_mapping, mapping)) { FREE_C_HEAP_ARRAY(int, mapping); mapping = Atomic::load_acquire(&apic_to_processor_mapping); } }
*** 3261,3271 **** uint apic_id = edx; int processor_id = Atomic::load(&mapping[apic_id]); while (processor_id < 0) { ! if (Atomic::cmpxchg(-2, &mapping[apic_id], -1)) { Atomic::store(&mapping[apic_id], Atomic::add(&next_processor_id, 1) - 1); } processor_id = Atomic::load(&mapping[apic_id]); } --- 3261,3271 ---- uint apic_id = edx; int processor_id = Atomic::load(&mapping[apic_id]); while (processor_id < 0) { ! if (Atomic::cmpxchg(&mapping[apic_id], -1, -2)) { Atomic::store(&mapping[apic_id], Atomic::add(&next_processor_id, 1) - 1); } processor_id = Atomic::load(&mapping[apic_id]); }
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