OSX/libsecurity_utilities/lib/cfclass.cpp

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  10  * http://www.opensource.apple.com/apsl/ and read it before using this
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  23
  24 #include <security_utilities/cfclass.h>
  25 #include <security_utilities/seccfobject.h>
  26 #include <security_utilities/threading.h>
  27 #include <CoreFoundation/CFString.h>
  28 #include <sys/time.h>
  29
  30 //
  31 // CFClass
  32 //
  33 CFClass::CFClass(const char *name)
  34 {
  35         // initialize the CFRuntimeClass structure
  36         version = 0;
  37         className = name;
  38         init = NULL;
  39         copy = NULL;
  40         finalize = finalizeType;
  41         equal = equalType;
  42         hash = hashType;
  43         copyFormattingDesc = copyFormattingDescType;
  44         copyDebugDesc = copyDebugDescType;
  45
  46     // update because we are now doing our own reference counting
  47     version |= _kCFRuntimeCustomRefCount; // see ma, no hands!
  48     refcount = refCountForType;
  49
  50         // register
  51         typeID = _CFRuntimeRegisterClass(this);
  52         assert(typeID != _kCFRuntimeNotATypeID);
  53 }
  54
  55 uint32_t
  56 CFClass::cleanupObject(intptr_t op, CFTypeRef cf, bool &zap)
  57 {
  58     // the default is to not throw away the object
  59     zap = false;
  60
  61     uint32_t currentCount;
  62     SecCFObject *obj = SecCFObject::optional(cf);
  63
  64     uint32_t oldCount;
  65     currentCount = obj->updateRetainCount(op, &oldCount);
  66
  67     if (op == 0)
  68     {
  69         return currentCount;
  70     }
  71     else if (currentCount == 0)
  72     {
  73         // we may not be able to delete if the caller has active children
  74         if (obj->mayDelete())
  75         {
  76             finalizeType(cf);
  77             zap = true; // ask the caller to release the mutex and zap the object
  78             return 0;
  79         }
  80         else
  81         {
  82             return currentCount;
  83         }
  84     }
  85     else
  86     {
  87         return 0;
  88     }
  89 }
  90
  91 uint32_t
  92 CFClass::refCountForType(intptr_t op, CFTypeRef cf) _NOEXCEPT
  93 {
  94     uint32_t result = 0;
  95     bool zap = false;
  96
  97     try
  98     {
  99         SecCFObject *obj = SecCFObject::optional(cf);
 100                 Mutex* mutex = obj->getMutexForObject();
 101                 if (mutex == NULL)
 102                 {
 103                         // if the object didn't have a mutex, it wasn't cached.
 104                         // Just clean it up and get out.
 105             result = cleanupObject(op, cf, zap);
 106                 }
 107                 else
 108         {
 109             // we have a mutex, so we need to do our cleanup operation under its control
 110             StLock<Mutex> _(*mutex);
 111             result = cleanupObject(op, cf, zap);
 112         }
 113
 114         if (zap) // did we release the object?
 115         {
 116             delete obj; // should call the overloaded delete for the object
 117         }
 118     }
 119     catch (...)
 120     {
 121     }
 122
 123     // keep the compiler happy
 124     return result;
 125 }
 126
 127
 128
 129 void
 130 CFClass::finalizeType(CFTypeRef cf) _NOEXCEPT
 131 {
 132     /*
 133         We need to control the lifetime of the object.  This means
 134         that the cache lock has to be asserted while we are determining if the
 135         object should live or die.  The mutex is recursive, which means that
 136         we won't end up with mutex inversion.
 137     */
 138
 139     SecCFObject *obj = SecCFObject::optional(cf);
 140
 141     try
 142         {
 143                 Mutex* mutex = obj->getMutexForObject();
 144                 if (mutex == NULL)
 145                 {
 146                         // if the object didn't have a mutex, it wasn't cached.
 147                         // Just clean it up and get out.
 148                         obj->aboutToDestruct(); // removes the object from its associated cache.
 149                 }
 150                 else
 151         {
 152             StLock<Mutex> _(*mutex);
 153
 154             if (obj->isNew())
 155             {
 156                 // New objects aren't in the cache.
 157                 // Just clean it up and get out.
 158                 obj->aboutToDestruct(); // removes the object from its associated cache.
 159                 return;
 160             }
 161
 162             obj->aboutToDestruct(); // removes the object from its associated cache.
 163         }
 164         }
 165         catch(...)
 166         {
 167         }
 168 }
 169
 170 Boolean
 171 CFClass::equalType(CFTypeRef cf1, CFTypeRef cf2) _NOEXCEPT
 172 {
 173         // CF checks for pointer equality and ensures type equality already
 174         try {
 175                 return SecCFObject::optional(cf1)->equal(*SecCFObject::optional(cf2));
 176         } catch (...) {
 177                 return false;
 178         }
 179 }
 180
 181 CFHashCode
 182 CFClass::hashType(CFTypeRef cf) _NOEXCEPT
 183 {
 184         try {
 185                 return SecCFObject::optional(cf)->hash();
 186         } catch (...) {
 187                 return 666; /* Beasty return for error */
 188         }
 189 }
 190
 191 CFStringRef
 192 CFClass::copyFormattingDescType(CFTypeRef cf, CFDictionaryRef dict) _NOEXCEPT
 193 {
 194         try {
 195                 return SecCFObject::optional(cf)->copyFormattingDesc(dict);
 196         } catch (...) {
 197                 return CFSTR("Exception thrown trying to format object");
 198         }
 199 }
 200
 201 CFStringRef
 202 CFClass::copyDebugDescType(CFTypeRef cf) _NOEXCEPT
 203 {
 204         try {
 205                 return SecCFObject::optional(cf)->copyDebugDesc();
 206         } catch (...) {
 207                 return CFSTR("Exception thrown trying to format object");
 208         }
 209 }
 210
 211