53 lines
1.7 KiB
C++
53 lines
1.7 KiB
C++
/**
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* PANDA 3D SOFTWARE
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* Copyright (c) Carnegie Mellon University. All rights reserved.
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*
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* All use of this software is subject to the terms of the revised BSD
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* license. You should have received a copy of this license along
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* with this source code in a file named "LICENSE."
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*
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* @file completionCounter.cxx
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* @author rdb
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* @date 2025-01-24
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*/
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#include "completionCounter.h"
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/**
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* Called when a token is completed before then() is called.
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*/
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void CompletionCounter::
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initial_callback(Completable::Data *data_ptr, bool success) {
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CounterData &data = *(CounterData *)data_ptr;
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auto prev_count = data._counter.fetch_add((success ? 0 : 0x10000) - 1, std::memory_order_release);
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if ((prev_count & 0xffff) == 1) {
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// We're done early.
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auto prev_callback = data._function.exchange(nullptr, std::memory_order_acq_rel);
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nassertv(prev_callback != nullptr);
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// Someone called then() in the meantime. Call the new callback. The
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// refcount will drop below 0 when that's called but they are designed to
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// handle that.
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if (prev_callback != &initial_callback) {
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prev_callback(data_ptr, success && (prev_count & ~0xffff) == 0);
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}
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}
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}
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/**
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* Called when a token is completed after this object is destroyed without
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* then() being called.
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*/
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void CompletionCounter::
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abandon_callback(Completable::Data *data_ptr, bool success) {
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CounterData &data = *(CounterData *)data_ptr;
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auto prev_count = data._counter.fetch_sub(1, std::memory_order_relaxed);
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if ((prev_count & 0xffff) <= 1) {
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// Done.
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auto prev_callback = data._function.exchange(nullptr, std::memory_order_relaxed);
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nassertv(prev_callback != nullptr);
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nassertv(prev_callback == &abandon_callback);
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delete &data;
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}
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}
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