xref: /xnu-11215/libkern/c++/OSObject.cpp (revision fad439e7)
1 /*
2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3  *
4  * @APPLE_LICENSE_HEADER_START@
5  *
6  * The contents of this file constitute Original Code as defined in and
7  * are subject to the Apple Public Source License Version 1.1 (the
8  * "License").  You may not use this file except in compliance with the
9  * License.  Please obtain a copy of the License at
10  * http://www.apple.com/publicsource and read it before using this file.
11  *
12  * This Original Code and all software distributed under the License are
13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
17  * License for the specific language governing rights and limitations
18  * under the License.
19  *
20  * @APPLE_LICENSE_HEADER_END@
21  */
22 /* OSObject.cpp created by gvdl on Fri 1998-11-17 */
23 
24 #include <libkern/c++/OSObject.h>
25 #include <libkern/c++/OSSerialize.h>
26 #include <libkern/c++/OSLib.h>
27 #include <libkern/c++/OSCPPDebug.h>
28 #include <libkern/OSAtomic.h>
29 
30 #include <libkern/c++/OSCollection.h>
31 
32 __BEGIN_DECLS
33 int debug_ivars_size;
34 __END_DECLS
35 
36 #if OSALLOCDEBUG
37 #define ACCUMSIZE(s) do { debug_ivars_size += (s); } while(0)
38 #else
39 #define ACCUMSIZE(s)
40 #endif
41 
42 // OSDefineMetaClassAndAbstractStructors(OSObject, 0);
43 /* Class global data */
44 OSObject::MetaClass OSObject::gMetaClass;
45 const OSMetaClass * const OSObject::metaClass = &OSObject::gMetaClass;
46 const OSMetaClass * const OSObject::superClass = 0;
47 
48 /* Class member functions - Can't use defaults */
49 OSObject::OSObject()			{ retainCount = 1; }
50 OSObject::OSObject(const OSMetaClass *)	{ retainCount = 1; }
51 OSObject::~OSObject()			{ }
52 const OSMetaClass * OSObject::getMetaClass() const
53     { return &gMetaClass; }
54 OSObject *OSObject::MetaClass::alloc() const { return 0; }
55 
56 /* The OSObject::MetaClass constructor */
57 OSObject::MetaClass::MetaClass()
58     : OSMetaClass("OSObject", OSObject::superClass, sizeof(OSObject))
59     { }
60 
61 // Virtual Padding
62 OSMetaClassDefineReservedUnused(OSObject,  0);
63 OSMetaClassDefineReservedUnused(OSObject,  1);
64 OSMetaClassDefineReservedUnused(OSObject,  2);
65 OSMetaClassDefineReservedUnused(OSObject,  3);
66 OSMetaClassDefineReservedUnused(OSObject,  4);
67 OSMetaClassDefineReservedUnused(OSObject,  5);
68 OSMetaClassDefineReservedUnused(OSObject,  6);
69 OSMetaClassDefineReservedUnused(OSObject,  7);
70 OSMetaClassDefineReservedUnused(OSObject,  8);
71 OSMetaClassDefineReservedUnused(OSObject,  9);
72 OSMetaClassDefineReservedUnused(OSObject, 10);
73 OSMetaClassDefineReservedUnused(OSObject, 11);
74 OSMetaClassDefineReservedUnused(OSObject, 12);
75 OSMetaClassDefineReservedUnused(OSObject, 13);
76 OSMetaClassDefineReservedUnused(OSObject, 14);
77 OSMetaClassDefineReservedUnused(OSObject, 15);
78 OSMetaClassDefineReservedUnused(OSObject, 16);
79 OSMetaClassDefineReservedUnused(OSObject, 17);
80 OSMetaClassDefineReservedUnused(OSObject, 18);
81 OSMetaClassDefineReservedUnused(OSObject, 19);
82 OSMetaClassDefineReservedUnused(OSObject, 20);
83 OSMetaClassDefineReservedUnused(OSObject, 21);
84 OSMetaClassDefineReservedUnused(OSObject, 22);
85 OSMetaClassDefineReservedUnused(OSObject, 23);
86 OSMetaClassDefineReservedUnused(OSObject, 24);
87 OSMetaClassDefineReservedUnused(OSObject, 25);
88 OSMetaClassDefineReservedUnused(OSObject, 26);
89 OSMetaClassDefineReservedUnused(OSObject, 27);
90 OSMetaClassDefineReservedUnused(OSObject, 28);
91 OSMetaClassDefineReservedUnused(OSObject, 29);
92 OSMetaClassDefineReservedUnused(OSObject, 30);
93 OSMetaClassDefineReservedUnused(OSObject, 31);
94 
95 static const char *getClassName(const OSObject *obj)
96 {
97     const OSMetaClass *meta = obj->getMetaClass();
98     return (meta) ? meta->getClassName() : "unknown class?";
99 }
100 
101 bool OSObject::init()
102     { return true; }
103 
104 void OSObject::free()
105 {
106     const OSMetaClass *meta = getMetaClass();
107 
108     if (meta)
109 	meta->instanceDestructed();
110     delete this;
111 }
112 
113 int OSObject::getRetainCount() const
114 {
115     return (int) ((UInt16) retainCount);
116 }
117 
118 void OSObject::taggedRetain(const void *tag) const
119 {
120 #if !DEBUG
121     volatile UInt32 *countP = (volatile UInt32 *) &retainCount;
122     UInt32 inc = 1;
123     UInt32 origCount;
124     UInt32 newCount;
125 
126     // Increment the collecion bucket.
127     if ((const void *) OSTypeID(OSCollection) == tag)
128 	inc |= (1UL<<16);
129 
130     do {
131 	origCount = *countP;
132 	if (-1UL == origCount)
133 	    // @@@ Pinot: panic("Attempting to retain a freed object");
134 	    return;
135 
136 	newCount = origCount + inc;
137     } while (!OSCompareAndSwap(origCount, newCount, (UInt32 *) countP));
138 #else
139     volatile UInt32 *countP = (volatile UInt32 *) &retainCount;
140     UInt32 inc = 1;
141     UInt32 origCount;
142     UInt32 newCount;
143 
144     // Increment the collecion bucket.
145     if ((const void *) OSTypeID(OSCollection) == tag)
146 	inc |= (1UL<<16);
147 
148     do {
149 	origCount = *countP;
150 	if (-1UL == origCount)
151 	    return;	// We are freeing so leave now.
152 
153 	newCount = origCount + inc;
154     } while (!OSCompareAndSwap(origCount, newCount, (UInt32 *) countP));
155 #endif
156 }
157 
158 void OSObject::taggedRelease(const void *tag) const
159 {
160     taggedRelease(tag, 1);
161 }
162 
163 void OSObject::taggedRelease(const void *tag, const int when) const
164 {
165 #if !DEBUG
166     volatile UInt32 *countP = (volatile UInt32 *) &retainCount;
167     UInt32 dec = 1;
168     UInt32 origCount;
169     UInt32 newCount;
170     UInt32 actualCount;
171 
172     // Increment the collecion bucket.
173     if ((const void *) OSTypeID(OSCollection) == tag)
174 	dec |= (1UL<<16);
175 
176     do {
177 	origCount = *countP;
178 	if (-1UL == origCount)
179 	    return;	// We are freeing already leave now.
180 
181 	actualCount = origCount - dec;
182         if ((SInt16) actualCount < when)
183             newCount = (UInt32) -1;
184         else
185             newCount = actualCount;
186 
187     } while (!OSCompareAndSwap(origCount, newCount, (UInt32 *) countP));
188 
189     //
190     // This panic means that we have just attempted to release an object
191     // who's retain count has gone to less than the number of collections
192     // it is a member off.  Take a panic immediately.
193     // In Fact the panic MAY not be a registry corruption but it is
194     // ALWAYS the wrong thing to do.  I call it a registry corruption 'cause
195     // the registry is the biggest single use of a network of collections.
196     //
197     if ((UInt16) actualCount < (actualCount >> 16))
198 	panic("A driver releasing a(n) %s has corrupted the registry\n",
199 	    getClassName(this));
200 
201     // Check for a 'free' condition and that if we are first through
202     if ((UInt32) -1 == newCount)
203 	((OSObject *) this)->free();
204 #else
205     // @@@ Pinot:  Need to update the debug build release code.
206     volatile UInt32 *countP = (volatile UInt32 *) &retainCount;
207     UInt32 dec = 1;
208     UInt32 origCount;
209     UInt32 newCount;
210 
211     // Increment the collecion bucket.
212     if ((const void *) OSTypeID(OSCollection) == tag)
213 	dec |= (1UL<<16);
214 
215     do {
216 	origCount = *countP;
217 	if (-1UL == origCount)
218 	    return;	// We are freeing already leave now.
219 
220 	newCount = origCount - dec;
221     } while (!OSCompareAndSwap(origCount, newCount, (UInt32 *) countP));
222 
223     //
224     // This panic means that we have just attempted to release an object
225     // who's retain count has gone to less than the number of collections
226     // it is a member off.  Take a panic immediately.
227     // In Fact the panic MAY not be a registry corruption but it is
228     // ALWAYS the wrong thing to do.  I call it a registry corruption 'cause
229     // the registry is the biggest single use of a network of collections.
230     //
231     if ((UInt16) newCount < (newCount >> 16))
232 	panic("A driver releasing a(n) %s has corrupted the registry\n",
233 	    getClassName(this));
234 
235     // Check for a release too many
236     if ((SInt16) newCount < 0)
237 	panic("An object has had a release too many\n",
238 	    getClassName(this));
239 
240     // Check for a 'free' condition and that if we are first through
241     if ((SInt16) newCount < when
242     && OSCompareAndSwap(newCount, -1UL, (UInt32 *) countP))
243 	((OSObject *) this)->free();
244 #endif
245 }
246 
247 void OSObject::release() const
248 {
249     taggedRelease(0);
250 }
251 
252 void OSObject::retain() const
253 {
254     taggedRetain(0);
255 }
256 
257 void OSObject::release(int when) const
258 {
259     taggedRelease(0, when);
260 }
261 
262 bool OSObject::serialize(OSSerialize *s) const
263 {
264     if (s->previouslySerialized(this)) return true;
265 
266     if (!s->addXMLStartTag(this, "string")) return false;
267 
268     if (!s->addString(getClassName(this))) return false;
269     if (!s->addString(" is not serializable")) return false;
270 
271     return s->addXMLEndTag("string");
272 }
273 
274 void *OSObject::operator new(size_t size)
275 {
276     void *mem = (void *) kalloc(size);
277     assert(mem);
278     bzero(mem, size);
279 
280     ACCUMSIZE(size);
281 
282     return mem;
283 }
284 
285 void OSObject::operator delete(void *mem, size_t size)
286 {
287     kfree((vm_offset_t) mem, size);
288 
289     ACCUMSIZE(-size);
290 }
291