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1 | // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- |
2 | // vim: ts=8 sw=2 smarttab | |
3 | /* | |
4 | * Ceph - scalable distributed file system | |
5 | * | |
6 | * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net> | |
7 | * | |
8 | * This is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU Lesser General Public | |
10 | * License version 2.1, as published by the Free Software | |
11 | * Foundation. See file COPYING. | |
12 | * | |
13 | */ | |
14 | ||
15 | #ifndef CEPH_REFCOUNTEDOBJ_H | |
16 | #define CEPH_REFCOUNTEDOBJ_H | |
17 | ||
18 | #include "common/Mutex.h" | |
19 | #include "common/Cond.h" | |
7c673cae FG |
20 | #include "common/ceph_context.h" |
21 | #include "common/valgrind.h" | |
22 | ||
7c673cae FG |
23 | // re-include our assert to clobber the system one; fix dout: |
24 | #include "include/assert.h" | |
25 | ||
26 | struct RefCountedObject { | |
27 | private: | |
31f18b77 | 28 | mutable std::atomic<uint64_t> nref; |
7c673cae FG |
29 | CephContext *cct; |
30 | public: | |
31 | RefCountedObject(CephContext *c = NULL, int n=1) : nref(n), cct(c) {} | |
32 | virtual ~RefCountedObject() { | |
31f18b77 | 33 | assert(nref == 0); |
7c673cae FG |
34 | } |
35 | ||
36 | const RefCountedObject *get() const { | |
31f18b77 | 37 | int v = ++nref; |
7c673cae FG |
38 | if (cct) |
39 | lsubdout(cct, refs, 1) << "RefCountedObject::get " << this << " " | |
40 | << (v - 1) << " -> " << v | |
41 | << dendl; | |
42 | return this; | |
43 | } | |
44 | RefCountedObject *get() { | |
31f18b77 | 45 | int v = ++nref; |
7c673cae FG |
46 | if (cct) |
47 | lsubdout(cct, refs, 1) << "RefCountedObject::get " << this << " " | |
48 | << (v - 1) << " -> " << v | |
49 | << dendl; | |
50 | return this; | |
51 | } | |
52 | void put() const { | |
53 | CephContext *local_cct = cct; | |
31f18b77 | 54 | int v = --nref; |
7c673cae FG |
55 | if (v == 0) { |
56 | ANNOTATE_HAPPENS_AFTER(&nref); | |
57 | ANNOTATE_HAPPENS_BEFORE_FORGET_ALL(&nref); | |
58 | delete this; | |
59 | } else { | |
60 | ANNOTATE_HAPPENS_BEFORE(&nref); | |
61 | } | |
62 | if (local_cct) | |
63 | lsubdout(local_cct, refs, 1) << "RefCountedObject::put " << this << " " | |
64 | << (v + 1) << " -> " << v | |
65 | << dendl; | |
66 | } | |
67 | void set_cct(CephContext *c) { | |
68 | cct = c; | |
69 | } | |
70 | ||
71 | uint64_t get_nref() const { | |
31f18b77 | 72 | return nref; |
7c673cae FG |
73 | } |
74 | }; | |
75 | ||
76 | /** | |
77 | * RefCountedCond | |
78 | * | |
79 | * a refcounted condition, will be removed when all references are dropped | |
80 | */ | |
81 | ||
82 | struct RefCountedCond : public RefCountedObject { | |
83 | bool complete; | |
84 | Mutex lock; | |
85 | Cond cond; | |
86 | int rval; | |
87 | ||
88 | RefCountedCond() : complete(false), lock("RefCountedCond"), rval(0) {} | |
89 | ||
90 | int wait() { | |
91 | Mutex::Locker l(lock); | |
92 | while (!complete) { | |
93 | cond.Wait(lock); | |
94 | } | |
95 | return rval; | |
96 | } | |
97 | ||
98 | void done(int r) { | |
99 | Mutex::Locker l(lock); | |
100 | rval = r; | |
101 | complete = true; | |
102 | cond.SignalAll(); | |
103 | } | |
104 | ||
105 | void done() { | |
106 | done(0); | |
107 | } | |
108 | }; | |
109 | ||
110 | /** | |
111 | * RefCountedWaitObject | |
112 | * | |
113 | * refcounted object that allows waiting for the object's last reference. | |
114 | * Any referrer can either put or put_wait(). A simple put() will return | |
115 | * immediately, a put_wait() will return only when the object is destroyed. | |
116 | * e.g., useful when we want to wait for a specific event completion. We | |
117 | * use RefCountedCond, as the condition can be referenced after the object | |
118 | * destruction. | |
119 | * | |
120 | */ | |
121 | struct RefCountedWaitObject { | |
31f18b77 | 122 | std::atomic<uint64_t> nref = { 1 }; |
7c673cae FG |
123 | RefCountedCond *c; |
124 | ||
31f18b77 | 125 | RefCountedWaitObject() { |
7c673cae FG |
126 | c = new RefCountedCond; |
127 | } | |
128 | virtual ~RefCountedWaitObject() { | |
129 | c->put(); | |
130 | } | |
131 | ||
132 | RefCountedWaitObject *get() { | |
31f18b77 | 133 | nref++; |
7c673cae FG |
134 | return this; |
135 | } | |
136 | ||
137 | bool put() { | |
138 | bool ret = false; | |
139 | RefCountedCond *cond = c; | |
140 | cond->get(); | |
31f18b77 | 141 | if (--nref == 0) { |
7c673cae FG |
142 | cond->done(); |
143 | delete this; | |
144 | ret = true; | |
145 | } | |
146 | cond->put(); | |
147 | return ret; | |
148 | } | |
149 | ||
150 | void put_wait() { | |
151 | RefCountedCond *cond = c; | |
152 | ||
153 | cond->get(); | |
31f18b77 | 154 | if (--nref == 0) { |
7c673cae FG |
155 | cond->done(); |
156 | delete this; | |
157 | } else { | |
158 | cond->wait(); | |
159 | } | |
160 | cond->put(); | |
161 | } | |
162 | }; | |
163 | ||
164 | void intrusive_ptr_add_ref(const RefCountedObject *p); | |
165 | void intrusive_ptr_release(const RefCountedObject *p); | |
166 | ||
167 | #endif |