OSX/libsecurity_utilities/lib/globalizer.cpp

   1 /*
   2  * Copyright (c) 2000-2004,2011-2012,2014 Apple Inc. All Rights Reserved.
   3  *
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   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
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   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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  18  * Please see the License for the specific language governing rights and
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  22  */
  23
  24
  25 //
  26 // globalizer - multiscope globalization services.
  27 //
  28 // This is a tentative, partial implementation.
  29 // Status:
  30 //      module scope: constructs, optional cleanup
  31 //      thread scope: constructs, optional cleanup
  32 //      process scope: not implemented (obsolete implementation, unused)
  33 //      system scope: not implemented (probably never will)
  34 //
  35 // @@@ Assumption: {bool,T*} atomic unless PTHREAD_STRICT
  36 //
  37 #include <security_utilities/globalizer.h>
  38 #include <security_utilities/debugging.h>
  39 #include <cstdlib>
  40 #include <stdexcept>
  41
  42 //
  43 // The Error class thrown if Nexus operations fail
  44 //
  45 GlobalNexus::Error::~Error() _NOEXCEPT
  46 {
  47 }
  48
  49 void ModuleNexusCommon::do_create(void *(*make)())
  50 {
  51     try
  52     {
  53         pointer = make();
  54     }
  55     catch (...)
  56     {
  57         pointer = NULL;
  58     }
  59 }
  60
  61
  62
  63 void *ModuleNexusCommon::create(void *(*make)())
  64 {
  65     dispatch_once(&once, ^{do_create(make);});
  66
  67     if (pointer == NULL)
  68     {
  69         ModuleNexusError::throwMe();
  70     }
  71
  72     return pointer;
  73 }
  74
  75
  76 //
  77 // Process nexus operation
  78 //
  79 ProcessNexusBase::ProcessNexusBase(const char *identifier)
  80 {
  81         const char *env = getenv(identifier);
  82         if (env == NULL) {      // perhaps we're first...
  83                 unique_ptr<Store> store(new Store);
  84                 char form[2*sizeof(Store *) + 2];
  85                 sprintf(form, "*%p", &store);
  86                 setenv(identifier, form, 0);    // do NOT overwrite...
  87                 env = getenv(identifier);               // ... and refetch to resolve races
  88                 if (sscanf(env, "*%p", &mStore) != 1)
  89                         throw std::runtime_error("environment communication failed");
  90                 if (mStore == store.get())              // we won the race...
  91                         store.release();                        // ... so keep the store
  92         } else
  93                 if (sscanf(env, "*%p", &mStore) != 1)
  94                         throw std::runtime_error("environment communication failed");
  95 }