ACE/ace/SV_Semaphore_Simple.cpp

   1 #include "ace/SV_Semaphore_Simple.h"
   2 #include "ace/Log_Category.h"
   3 #include "ace/ACE.h"
   4 #include "ace/os_include/sys/os_sem.h"
   5 #if defined (ACE_HAS_ALLOC_HOOKS)
   6 # include "ace/Malloc_Base.h"
   7 #endif /* ACE_HAS_ALLOC_HOOKS */
   8
   9 #if !defined (__ACE_INLINE__)
  10 #include "ace/SV_Semaphore_Simple.inl"
  11 #endif /* !__ACE_INLINE__ */
  12
  13 ACE_BEGIN_VERSIONED_NAMESPACE_DECL
  14
  15 ACE_ALLOC_HOOK_DEFINE (ACE_SV_Semaphore_Simple)
  16
  17 void
  18 ACE_SV_Semaphore_Simple::dump (void) const
  19 {
  20 #if defined (ACE_HAS_DUMP)
  21   ACE_TRACE ("ACE_SV_Semaphore_Simple::dump");
  22 #endif /* ACE_HAS_DUMP */
  23 }
  24
  25 int
  26 ACE_SV_Semaphore_Simple::control (int cmd,
  27                                   int value,
  28                                   u_short semnum) const
  29 {
  30   ACE_TRACE ("ACE_SV_Semaphore_Simple::control");
  31   if (this->internal_id_ == -1)
  32     return -1;
  33   else
  34     {
  35       semun semctl_arg;
  36
  37       semctl_arg.val = value;
  38       return ACE_OS::semctl (this->internal_id_,
  39                              semnum,
  40                              cmd,
  41                              semctl_arg);
  42     }
  43 }
  44
  45 #ifdef ACE_HAS_SYSV_IPC
  46 int
  47 ACE_SV_Semaphore_Simple::init (key_t k, int i)
  48 {
  49   ACE_TRACE ("ACE_SV_Semaphore_Simple::init");
  50   this->key_ = k;
  51   this->internal_id_ = i;
  52   return 0;
  53 }
  54 #endif
  55
  56 // General ACE_SV_Semaphore operation. Increment or decrement by a
  57 // specific amount (positive or negative; amount can`t be zero).
  58
  59 int
  60 ACE_SV_Semaphore_Simple::op (short val, u_short n, short flags) const
  61 {
  62   ACE_TRACE ("ACE_SV_Semaphore_Simple::op");
  63   sembuf op_op;
  64
  65   op_op.sem_num = n;
  66   op_op.sem_flg = flags;
  67
  68   if (this->internal_id_ == -1)
  69     return -1;
  70   else if ((op_op.sem_op = val) == 0)
  71     return -1;
  72   else
  73     return ACE_OS::semop (this->internal_id_, &op_op, 1);
  74 }
  75
  76 // Open or create one or more SV_Semaphores.  We return 0 if all is
  77 // OK, else -1.
  78
  79 int
  80 ACE_SV_Semaphore_Simple::open (key_t k,
  81                                short flags,
  82                                int initial_value,
  83                                u_short n,
  84                                mode_t perms)
  85 {
  86   ACE_TRACE ("ACE_SV_Semaphore_Simple::open");
  87   union semun ivalue;
  88
  89 #ifdef ACE_HAS_SYSV_IPC
  90   if (k == IPC_PRIVATE || k == static_cast<key_t> (ACE_INVALID_SEM_KEY))
  91     return -1;
  92 #endif
  93
  94   ivalue.val = initial_value;
  95   this->key_ = k;
  96   this->sem_number_ = n;
  97
  98   this->internal_id_ = ACE_OS::semget (this->key_, n, perms | flags);
  99
 100   if (this->internal_id_ == -1)
 101     return -1;
 102
 103   if (ACE_BIT_ENABLED (flags, IPC_CREAT))
 104     for (int i = 0; i < n; i++)
 105       if (ACE_OS::semctl (this->internal_id_, i, SETVAL, ivalue) == -1)
 106         return -1;
 107
 108   return 0;
 109 }
 110
 111 ACE_SV_Semaphore_Simple::ACE_SV_Semaphore_Simple (key_t k,
 112                                                   short flags,
 113                                                   int initial_value,
 114                                                   u_short n,
 115                                                   mode_t perms)
 116   : key_ (k)
 117 {
 118   ACE_TRACE ("ACE_SV_Semaphore_Simple::ACE_SV_Semaphore_Simple");
 119   if (this->open (k, flags, initial_value, n, perms) == -1)
 120     ACELIB_ERROR ((LM_ERROR,  ACE_TEXT ("%p\n"),  ACE_TEXT ("ACE_SV_Semaphore::ACE_SV_Semaphore")));
 121 }
 122
 123 // Convert name to key.  This function is used internally to create keys
 124 // for the semaphores.
 125 //
 126 // The method for generating names is a 32 bit CRC, but still we
 127 // measured close to collition ratio of nearly 0.1% for
 128 // ACE::unique_name()-like strings.
 129
 130 key_t
 131 ACE_SV_Semaphore_Simple::name_2_key (const char *name)
 132 {
 133   ACE_TRACE ("ACE_SV_Semaphore_Simple::name_2_key");
 134
 135   if (name == 0)
 136     {
 137       errno = EINVAL;
 138 #ifdef ACE_HAS_SYSV_IPC
 139       return static_cast<key_t> (ACE_INVALID_SEM_KEY);
 140 #else
 141       key_t ret = ACE_DEFAULT_SEM_KEY;
 142       return ret;
 143 #endif
 144     }
 145
 146   // Basically "hash" the values in the <name>.  This won't
 147   // necessarily guarantee uniqueness of all keys.
 148   // But (IMHO) CRC32 is good enough for most purposes (Carlos)
 149 #if defined (ACE_WIN32) && defined (_MSC_VER)
 150   // The cast below is legit...
 151 #  pragma warning(push)
 152 #  pragma warning(disable : 4312)
 153 #endif /* defined (ACE_WIN32) && defined (_MSC_VER) */
 154
 155 #ifdef ACE_HAS_SYSV_IPC
 156   return (key_t) ACE::crc32 (name);
 157 #else
 158   key_t ret = ACE_DEFAULT_SEM_KEY;
 159   return ret;
 160 #endif
 161
 162 #if defined (ACE_WIN32) && defined (_MSC_VER)
 163 #  pragma warning(pop)
 164 #endif /* defined (ACE_WIN32) && defined (_MSC_VER) */
 165 }
 166
 167 // Open or create a ACE_SV_Semaphore.  We return 1 if all is OK, else
 168 // 0.
 169
 170 int
 171 ACE_SV_Semaphore_Simple::open (const char *name,
 172                                short flags,
 173                                int initial_value,
 174                                u_short n,
 175                                mode_t perms)
 176 {
 177   ACE_TRACE ("ACE_SV_Semaphore_Simple::open");
 178
 179   key_t key = ACE_DEFAULT_SEM_KEY;
 180
 181 #ifdef ACE_HAS_SYSV_IPC
 182   if (name != 0)
 183     key = this->name_2_key (name);
 184 #else
 185   ACE_UNUSED_ARG (name);
 186 #endif
 187
 188   return this->open (key, flags, initial_value, n, perms);
 189 }
 190
 191 ACE_SV_Semaphore_Simple::ACE_SV_Semaphore_Simple (const char *name,
 192                                                   short flags,
 193                                                   int initial_value,
 194                                                   u_short n,
 195                                                   mode_t perms)
 196 {
 197   ACE_TRACE ("ACE_SV_Semaphore_Simple::ACE_SV_Semaphore_Simple");
 198   if (this->open (name,
 199                   flags,
 200                   initial_value,
 201                   n,
 202                   perms) == -1)
 203     ACELIB_ERROR ((LM_ERROR,
 204                 ACE_TEXT ("%p\n"),
 205                 ACE_TEXT ("ACE_SV_Semaphore_Simple::ACE_SV_Semaphore_Simple")));
 206 }
 207
 208 #if defined (ACE_HAS_WCHAR)
 209 ACE_SV_Semaphore_Simple::ACE_SV_Semaphore_Simple (const wchar_t *name,
 210                                                   short flags,
 211                                                   int initial_value,
 212                                                   u_short nsems,
 213                                                   mode_t perms)
 214 {
 215   ACE_TRACE ("ACE_SV_Semaphore_Simple::ACE_SV_Semaphore_Simple(wchar_t)");
 216   if (this->open (ACE_Wide_To_Ascii (name).char_rep (),
 217                   flags,
 218                   initial_value,
 219                   nsems,
 220                   perms) == -1)
 221     ACELIB_ERROR ((LM_ERROR,
 222                 ACE_TEXT ("%p\n"),
 223                 ACE_TEXT ("ACE_SV_Semaphore_Simple::ACE_SV_Semaphore_Simple")));
 224 }
 225 #endif /* ACE_HAS_WCHAR */
 226
 227 ACE_SV_Semaphore_Simple::~ACE_SV_Semaphore_Simple (void)
 228 {
 229   ACE_TRACE ("ACE_SV_Semaphore_Simple::~ACE_SV_Semaphore_Simple");
 230   this->close ();
 231 }
 232
 233 ACE_SV_Semaphore_Simple::ACE_SV_Semaphore_Simple (void) :
 234   sem_number_ (0)
 235 {
 236   ACE_TRACE ("ACE_SV_Semaphore_Simple::ACE_SV_Semaphore_Simple");
 237 #ifdef ACE_HAS_SYSV_IPC
 238   this->init ();
 239 #endif
 240 }
 241
 242 // Remove all SV_Semaphores associated with a particular key.  This
 243 // call is intended to be called from a server, for example, when it
 244 // is being shut down, as we do an IPC_RMID on the ACE_SV_Semaphore,
 245 // regardless of whether other processes may be using it or not.  Most
 246 // other processes should use close() below.
 247
 248 int
 249 ACE_SV_Semaphore_Simple::remove (void) const
 250 {
 251   ACE_TRACE ("ACE_SV_Semaphore_Simple::remove");
 252   int const result = this->control (IPC_RMID);
 253 #ifdef ACE_HAS_SYSV_IPC
 254   ((ACE_SV_Semaphore_Simple *) this)->init ();
 255 #endif
 256   return result;
 257 }
 258
 259 ACE_END_VERSIONED_NAMESPACE_DECL