| [8add15e0] | 1 | /*
|
|---|
| 2 | * Copyright (c) 2019 Jaroslav Jindrak
|
|---|
| 3 | * All rights reserved.
|
|---|
| 4 | *
|
|---|
| 5 | * Redistribution and use in source and binary forms, with or without
|
|---|
| 6 | * modification, are permitted provided that the following conditions
|
|---|
| 7 | * are met:
|
|---|
| 8 | *
|
|---|
| 9 | * - Redistributions of source code must retain the above copyright
|
|---|
| 10 | * notice, this list of conditions and the following disclaimer.
|
|---|
| 11 | * - Redistributions in binary form must reproduce the above copyright
|
|---|
| 12 | * notice, this list of conditions and the following disclaimer in the
|
|---|
| 13 | * documentation and/or other materials provided with the distribution.
|
|---|
| 14 | * - The name of the author may not be used to endorse or promote products
|
|---|
| 15 | * derived from this software without specific prior written permission.
|
|---|
| 16 | *
|
|---|
| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
|
|---|
| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
|---|
| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
|
|---|
| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|---|
| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
|---|
| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|---|
| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|---|
| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|---|
| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
|---|
| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|---|
| 27 | */
|
|---|
| 28 |
|
|---|
| 29 | #ifndef LIBCPP_BITS_REFCOUNT_OBJ
|
|---|
| 30 | #define LIBCPP_BITS_REFCOUNT_OBJ
|
|---|
| 31 |
|
|---|
| 32 | namespace std::aux
|
|---|
| 33 | {
|
|---|
| 34 | /**
|
|---|
| 35 | * At the moment we do not have atomics, change this
|
|---|
| 36 | * to std::atomic<long> once we do.
|
|---|
| 37 | */
|
|---|
| 38 | using refcount_t = long;
|
|---|
| 39 |
|
|---|
| 40 | class refcount_obj
|
|---|
| 41 | {
|
|---|
| 42 | public:
|
|---|
| 43 | refcount_obj() = default;
|
|---|
| 44 |
|
|---|
| 45 | void increment() noexcept;
|
|---|
| 46 | void increment_weak() noexcept;
|
|---|
| 47 | bool decrement() noexcept;
|
|---|
| 48 | bool decrement_weak() noexcept;
|
|---|
| 49 | refcount_t refs() const noexcept;
|
|---|
| 50 | refcount_t weak_refs() const noexcept;
|
|---|
| 51 | bool expired() const noexcept;
|
|---|
| 52 |
|
|---|
| 53 | virtual ~refcount_obj() = default;
|
|---|
| 54 | virtual void destroy() = 0;
|
|---|
| 55 |
|
|---|
| 56 | protected:
|
|---|
| 57 | /**
|
|---|
| 58 | * We're using a trick where refcount_ > 0
|
|---|
| 59 | * means weak_refcount_ has 1 added to it,
|
|---|
| 60 | * this makes it easier for weak_ptrs that
|
|---|
| 61 | * can't decrement the weak_refcount_ to
|
|---|
| 62 | * zero with shared_ptrs using this object.
|
|---|
| 63 | */
|
|---|
| 64 | refcount_t refcount_{1};
|
|---|
| 65 | refcount_t weak_refcount_{1};
|
|---|
| 66 | };
|
|---|
| 67 | }
|
|---|
| 68 |
|
|---|
| 69 | #endif
|
|---|
