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  1. <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
    2. 

  2. <html>
    3. 

  3. <head>
    4. 

  4. <title>Module gproc</title>
    5. 

  5. <link rel="stylesheet" type="text/css" href="stylesheet.css" title="EDoc">
    6. 

  6. </head>
    7. 

  7. <body bgcolor="white">
    8. 

  8. <div class="navbar"><a name="#navbar_top"></a><table width="100%" border="0" cellspacing="0" cellpadding="2" summary="navigation bar"><tr><td><a href="overview-summary.html" target="overviewFrame">Overview</a></td><td><a href="http://www.erlang.org/"><img src="erlang.png" align="right" border="0" alt="erlang logo"></a></td></tr></table></div>
    9. 

  9. <hr>
    10. 

  10. 

  11. <h1>Module gproc</h1>
    12. 

  12. <ul class="index"><li><a href="#description">Description</a></li><li><a href="#types">Data Types</a></li><li><a href="#index">Function Index</a></li><li><a href="#functions">Function Details</a></li></ul>Extended process registry.
    13. 

  13. 

  14. <p><b>Behaviours:</b> <a href="gen_server.html"><tt>gen_server</tt></a>.</p>
    15. 

  15. <p><b>Authors:</b> Ulf Wiger (<a href="mailto:ulf.wiger@erlang-consulting.com"><tt>ulf.wiger@erlang-consulting.com</tt></a>).</p>
    16. 

  16. 

  17. <h2><a name="description">Description</a></h2>Extended process registry
    18. 

  18.   <p>This module implements an extended process registry</p>
    19. 

  19.   <p>For a detailed description, see
    20. 

  20.   <a href="erlang07-wiger.pdf">erlang07-wiger.pdf</a>.</p>
    21. 

  21.  
    22. 

  22. <h2><a name="types">Data Types</a></h2>
    23. 

  23. 

  24. <h3 class="typedecl"><a name="type-context">context()</a></h3>
    25. 

  25. <p><tt>context() = {<a href="#type-scope">scope()</a>, <a href="#type-type">type()</a>} | <a href="#type-type">type()</a></tt></p>
    26. 

  26. <p>Local scope is the default</p>
    27. 

  27. 

  28. <h3 class="typedecl"><a name="type-headpat">headpat()</a></h3>
    29. 

  29. <p><tt>headpat() = {<a href="#type-keypat">keypat()</a>, <a href="#type-pidpat">pidpat()</a>, ValPat}</tt></p>
    30. 

  30. 

  31. 

  32. <h3 class="typedecl"><a name="type-key">key()</a></h3>
    33. 

  33. <p><tt>key() = {<a href="#type-type">type()</a>, <a href="#type-scope">scope()</a>, any()}</tt></p>
    34. 

  34. 

  35. 

  36. <h3 class="typedecl"><a name="type-keypat">keypat()</a></h3>
    37. 

  37. <p><tt>keypat() = {<a href="#type-sel_type">sel_type()</a> | <a href="#type-sel_var">sel_var()</a>, l | g | <a href="#type-sel_var">sel_var()</a>, any()}</tt></p>
    38. 

  38. 

  39. 

  40. <h3 class="typedecl"><a name="type-pidpat">pidpat()</a></h3>
    41. 

  41. <p><tt>pidpat() = pid() | <a href="#type-sel_var">sel_var()</a></tt></p>
    42. 

  42. <p>sel_var() = DollarVar | '_'.</p>
    43. 

  43. 

  44. <h3 class="typedecl"><a name="type-scope">scope()</a></h3>
    45. 

  45. <p><tt>scope() = l | g</tt></p>
    46. 

  46. <p>l = local registration; g = global registration</p>
    47. 

  47. 

  48. <h3 class="typedecl"><a name="type-sel_pattern">sel_pattern()</a></h3>
    49. 

  49. <p><tt>sel_pattern() = [{<a href="#type-headpat">headpat()</a>, Guards, Prod}]</tt></p>
    50. 

  50. 

  51. 

  52. <h3 class="typedecl"><a name="type-sel_type">sel_type()</a></h3>
    53. 

  53. <p><tt>sel_type() = n | p | c | a | names | props | counters | aggr_counters</tt></p>
    54. 

  54. 

  55. 

  56. <h3 class="typedecl"><a name="type-type">type()</a></h3>
    57. 

  57. <p><tt>type() = n | p | c | a</tt></p>
    58. 

  58. <p>n = name; p = property; c = counter;
    59. 

  59.                                  a = aggregate_counter</p>
    60. 

  60. 

  61. <h2><a name="index">Function Index</a></h2>
    62. 

  62. <table width="100%" border="1" cellspacing="0" cellpadding="2" summary="function index"><tr><td valign="top"><a href="#add_global_aggr_counter-1">add_global_aggr_counter/1</a></td><td>Registers a global (unique) aggregated counter.</td></tr>
    63. 

  63. <tr><td valign="top"><a href="#add_global_counter-2">add_global_counter/2</a></td><td>Registers a global (non-unique) counter.</td></tr>
    64. 

  64. <tr><td valign="top"><a href="#add_global_name-1">add_global_name/1</a></td><td>Registers a global (unique) name.</td></tr>
    65. 

  65. <tr><td valign="top"><a href="#add_global_property-2">add_global_property/2</a></td><td>Registers a global (non-unique) property.</td></tr>
    66. 

  66. <tr><td valign="top"><a href="#add_local_aggr_counter-1">add_local_aggr_counter/1</a></td><td>Registers a local (unique) aggregated counter.</td></tr>
    67. 

  67. <tr><td valign="top"><a href="#add_local_counter-2">add_local_counter/2</a></td><td>Registers a local (non-unique) counter.</td></tr>
    68. 

  68. <tr><td valign="top"><a href="#add_local_name-1">add_local_name/1</a></td><td>Registers a local (unique) name.</td></tr>
    69. 

  69. <tr><td valign="top"><a href="#add_local_property-2">add_local_property/2</a></td><td>Registers a local (non-unique) property.</td></tr>
    70. 

  70. <tr><td valign="top"><a href="#await-2">await/2</a></td><td>Wait for a local name to be registered.</td></tr>
    71. 

  71. <tr><td valign="top"><a href="#cancel_wait-2">cancel_wait/2</a></td><td></td></tr>
    72. 

  72. <tr><td valign="top"><a href="#default-1">default/1</a></td><td></td></tr>
    73. 

  73. <tr><td valign="top"><a href="#first-1">first/1</a></td><td>Behaves as ets:first(Tab) for a given type of registration object.</td></tr>
    74. 

  74. <tr><td valign="top"><a href="#get_value-1">get_value/1</a></td><td>Read the value stored with a key registered to the current process.</td></tr>
    75. 

  75. <tr><td valign="top"><a href="#info-1">info/1</a></td><td>Similar to <code>process_info(Pid)</code> but with additional gproc info.</td></tr>
    76. 

  76. <tr><td valign="top"><a href="#info-2">info/2</a></td><td>Similar to process_info(Pid, Item), but with additional gproc info.</td></tr>
    77. 

  77. <tr><td valign="top"><a href="#last-1">last/1</a></td><td>Behaves as ets:last(Tab) for a given type of registration object.</td></tr>
    78. 

  78. <tr><td valign="top"><a href="#lookup_global_aggr_counter-1">lookup_global_aggr_counter/1</a></td><td>Lookup a global (unique) aggregated counter and returns its value.</td></tr>
    79. 

  79. <tr><td valign="top"><a href="#lookup_global_counters-1">lookup_global_counters/1</a></td><td>Look up all global (non-unique) instances of a given Counter.</td></tr>
    80. 

  80. <tr><td valign="top"><a href="#lookup_global_name-1">lookup_global_name/1</a></td><td>Lookup a global unique name.</td></tr>
    81. 

  81. <tr><td valign="top"><a href="#lookup_global_properties-1">lookup_global_properties/1</a></td><td>Look up all global (non-unique) instances of a given Property.</td></tr>
    82. 

  82. <tr><td valign="top"><a href="#lookup_local_aggr_counter-1">lookup_local_aggr_counter/1</a></td><td>Lookup a local (unique) aggregated counter and returns its value.</td></tr>
    83. 

  83. <tr><td valign="top"><a href="#lookup_local_counters-1">lookup_local_counters/1</a></td><td>Look up all local (non-unique) instances of a given Counter.</td></tr>
    84. 

  84. <tr><td valign="top"><a href="#lookup_local_name-1">lookup_local_name/1</a></td><td>Lookup a local unique name.</td></tr>
    85. 

  85. <tr><td valign="top"><a href="#lookup_local_properties-1">lookup_local_properties/1</a></td><td>Look up all local (non-unique) instances of a given Property.</td></tr>
    86. 

  86. <tr><td valign="top"><a href="#lookup_pid-1">lookup_pid/1</a></td><td>Lookup the Pid stored with a key.</td></tr>
    87. 

  87. <tr><td valign="top"><a href="#lookup_pids-1">lookup_pids/1</a></td><td>Returns a list of pids with the published key Key.</td></tr>
    88. 

  88. <tr><td valign="top"><a href="#lookup_values-1">lookup_values/1</a></td><td>Retrieve the <code>{Pid,Value}</code> pairs corresponding to Key.</td></tr>
    89. 

  89. <tr><td valign="top"><a href="#mreg-3">mreg/3</a></td><td>Register multiple {Key,Value} pairs of a given type and scope.</td></tr>
    90. 

  90. <tr><td valign="top"><a href="#nb_wait-1">nb_wait/1</a></td><td>Wait for a local name to be registered.</td></tr>
    91. 

  91. <tr><td valign="top"><a href="#next-2">next/2</a></td><td>Behaves as ets:next(Tab,Key) for a given type of registration object.</td></tr>
    92. 

  92. <tr><td valign="top"><a href="#prev-2">prev/2</a></td><td>Behaves as ets:prev(Tab,Key) for a given type of registration object.</td></tr>
    93. 

  93. <tr><td valign="top"><a href="#reg-1">reg/1</a></td><td>Equivalent to <a href="#reg-2"><tt>reg(Key, default(Key))</tt></a>.
    94. 

  94. </td></tr>
    95. 

  95. <tr><td valign="top"><a href="#reg-2">reg/2</a></td><td>Register a name or property for the current process.</td></tr>
    96. 

  96. <tr><td valign="top"><a href="#select-1">select/1</a></td><td>Equivalent to <a href="#select-2"><tt>select(all, Pat)</tt></a>.
    97. 

  97. </td></tr>
    98. 

  98. <tr><td valign="top"><a href="#select-2">select/2</a></td><td>Perform a select operation on the process registry.</td></tr>
    99. 

  99. <tr><td valign="top"><a href="#select-3">select/3</a></td><td>Like <a href="#select-2"><code>select/2</code></a> but returns Limit objects at a time.</td></tr>
    100. 

  100. <tr><td valign="top"><a href="#send-2">send/2</a></td><td>Sends a message to the process, or processes, corresponding to Key.</td></tr>
    101. 

  101. <tr><td valign="top"><a href="#set_value-2">set_value/2</a></td><td>Sets the value of the registeration entry given by Key.</td></tr>
    102. 

  102. <tr><td valign="top"><a href="#start_link-0">start_link/0</a></td><td>Starts the gproc server.</td></tr>
    103. 

  103. <tr><td valign="top"><a href="#table-1">table/1</a></td><td>Equivalent to <a href="#table-2"><tt>table(Context, [])</tt></a>.
    104. 

  104. </td></tr>
    105. 

  105. <tr><td valign="top"><a href="#table-2">table/2</a></td><td>QLC table generator for the gproc registry.</td></tr>
    106. 

  106. <tr><td valign="top"><a href="#unreg-1">unreg/1</a></td><td>Unregister a name or property.</td></tr>
    107. 

  107. <tr><td valign="top"><a href="#update_counter-2">update_counter/2</a></td><td>Updates the counter registered as Key for the current process.</td></tr>
    108. 

  108. <tr><td valign="top"><a href="#where-1">where/1</a></td><td>Returns the pid registered as Key.</td></tr>
    109. 

  109. </table>
    110. 

  110. 

  111. <h2><a name="functions">Function Details</a></h2>
    112. 

  112. 

  113. <h3 class="function"><a name="add_global_aggr_counter-1">add_global_aggr_counter/1</a></h3>
    114. 

  114. <div class="spec">
    115. 

  115. <p><tt>add_global_aggr_counter(Name) -&gt; any()</tt></p>
    116. 

  116. </div><p>Equivalent to <a href="#reg-1"><tt>reg({a, g, Name})</tt></a>.</p>
    117. 

  117. <p>Registers a global (unique) aggregated counter.</p>
    118. 

  118. 

  119. <h3 class="function"><a name="add_global_counter-2">add_global_counter/2</a></h3>
    120. 

  120. <div class="spec">
    121. 

  121. <p><tt>add_global_counter(Name, Initial) -&gt; any()</tt></p>
    122. 

  122. </div><p>Registers a global (non-unique) counter. @equiv reg({c,g,Name},Value)</p>
    123. 

  123. 

  124. <h3 class="function"><a name="add_global_name-1">add_global_name/1</a></h3>
    125. 

  125. <div class="spec">
    126. 

  126. <p><tt>add_global_name(Name) -&gt; any()</tt></p>
    127. 

  127. </div><p>Registers a global (unique) name. @equiv reg({n,g,Name})</p>
    128. 

  128. 

  129. <h3 class="function"><a name="add_global_property-2">add_global_property/2</a></h3>
    130. 

  130. <div class="spec">
    131. 

  131. <p><tt>add_global_property(Name, Value) -&gt; any()</tt></p>
    132. 

  132. </div><p>Registers a global (non-unique) property. @equiv reg({p,g,Name},Value)</p>
    133. 

  133. 

  134. <h3 class="function"><a name="add_local_aggr_counter-1">add_local_aggr_counter/1</a></h3>
    135. 

  135. <div class="spec">
    136. 

  136. <p><tt>add_local_aggr_counter(Name) -&gt; any()</tt></p>
    137. 

  137. </div><p>Equivalent to <a href="#reg-1"><tt>reg({a, l, Name})</tt></a>.</p>
    138. 

  138. <p>Registers a local (unique) aggregated counter.</p>
    139. 

  139. 

  140. <h3 class="function"><a name="add_local_counter-2">add_local_counter/2</a></h3>
    141. 

  141. <div class="spec">
    142. 

  142. <p><tt>add_local_counter(Name, Initial) -&gt; any()</tt></p>
    143. 

  143. </div><p>Registers a local (non-unique) counter. @equiv reg({c,l,Name},Value)</p>
    144. 

  144. 

  145. <h3 class="function"><a name="add_local_name-1">add_local_name/1</a></h3>
    146. 

  146. <div class="spec">
    147. 

  147. <p><tt>add_local_name(Name) -&gt; any()</tt></p>
    148. 

  148. </div><p>Registers a local (unique) name. @equiv reg({n,l,Name})</p>
    149. 

  149. 

  150. <h3 class="function"><a name="add_local_property-2">add_local_property/2</a></h3>
    151. 

  151. <div class="spec">
    152. 

  152. <p><tt>add_local_property(Name, Value) -&gt; any()</tt></p>
    153. 

  153. </div><p>Registers a local (non-unique) property. @equiv reg({p,l,Name},Value)</p>
    154. 

  154. 

  155. <h3 class="function"><a name="await-2">await/2</a></h3>
    156. 

  156. <div class="spec">
    157. 

  157. <p><tt>await(Key::<a href="#type-key">key()</a>, Timeout) -&gt; {pid(), Value}</tt>
    158. 

  158. <ul class="definitions"><li><tt>Timeout = integer() | infinity</tt></li>
    159. 

  159. </ul></p>
    160. 

  160. </div><p>Wait for a local name to be registered.
    161. 

  161.   The function raises an exception if the timeout expires. Timeout must be
    162. 

  162.   either an interger &gt; 0 or 'infinity'.</p>
    163. 

  163. 

  164. <h3 class="function"><a name="cancel_wait-2">cancel_wait/2</a></h3>
    165. 

  165. <div class="spec">
    166. 

  166. <p><tt>cancel_wait(Key, Ref) -&gt; any()</tt></p>
    167. 

  167. </div>
    168. 

  168. 

  169. <h3 class="function"><a name="default-1">default/1</a></h3>
    170. 

  170. <div class="spec">
    171. 

  171. <p><tt>default(X1) -&gt; any()</tt></p>
    172. 

  172. </div>
    173. 

  173. 

  174. <h3 class="function"><a name="first-1">first/1</a></h3>
    175. 

  175. <div class="spec">
    176. 

  176. <p><tt>first(Type::<a href="#type-type">type()</a>) -&gt; <a href="#type-key">key()</a> | '$end_of_table'</tt></p>
    177. 

  177. </div><p><p>Behaves as ets:first(Tab) for a given type of registration object.</p>
    178. 

  178.  
    179. 

  179.   See <a href="http://www.erlang.org/doc/man/ets.html#first-1" target="_top"><tt>http://www.erlang.org/doc/man/ets.html#first-1</tt></a>.
    180. 

  180.    The registry behaves as an ordered_set table.</p>
    181. 

  181. 

  182. <h3 class="function"><a name="get_value-1">get_value/1</a></h3>
    183. 

  183. <div class="spec">
    184. 

  184. <p><tt>get_value(Key) -&gt; Value</tt></p>
    185. 

  185. </div><p><p>Read the value stored with a key registered to the current process.</p>
    186. 

  186.  
    187. 

  187.   If no such key is registered to the current process, this function exits.</p>
    188. 

  188. 

  189. <h3 class="function"><a name="info-1">info/1</a></h3>
    190. 

  190. <div class="spec">
    191. 

  191. <p><tt>info(Pid::pid()) -&gt; ProcessInfo</tt>
    192. 

  192. <ul class="definitions"><li><tt>ProcessInfo = [{gproc, [{Key, Value}]} | ProcessInfo]</tt></li>
    193. 

  193. </ul></p>
    194. 

  194. </div><p><p>Similar to <code>process_info(Pid)</code> but with additional gproc info.</p>
    195. 

  195.  
    196. 

  196.   Returns the same information as process_info(Pid), but with the
    197. 

  197.   addition of a <code>gproc</code> information item, containing the <code>{Key,Value}</code>
    198. 

  198.   pairs registered to the process.</p>
    199. 

  199. 

  200. <h3 class="function"><a name="info-2">info/2</a></h3>
    201. 

  201. <div class="spec">
    202. 

  202. <p><tt>info(Pid::pid(), Item::atom()) -&gt; {Item, Info}</tt></p>
    203. 

  203. </div><p><p>Similar to process_info(Pid, Item), but with additional gproc info.</p>
    204. 

  204.  
    205. 

  205.   For <code>Item = gproc</code>, this function returns a list of <code>{Key, Value}</code> pairs
    206. 

  206.   registered to the process Pid. For other values of Item, it returns the
    207. 

  207.   same as <a href="http://www.erlang.org/doc/man/erlang.html#process_info-2" target="_top"><tt>http://www.erlang.org/doc/man/erlang.html#process_info-2</tt></a>.</p>
    208. 

  208. 

  209. <h3 class="function"><a name="last-1">last/1</a></h3>
    210. 

  210. <div class="spec">
    211. 

  211. <p><tt>last(Context::<a href="#type-context">context()</a>) -&gt; <a href="#type-key">key()</a> | '$end_of_table'</tt></p>
    212. 

  212. </div><p><p>Behaves as ets:last(Tab) for a given type of registration object.</p>
    213. 

  213.  
    214. 

  214.   See <a href="http://www.erlang.org/doc/man/ets.html#last-1" target="_top"><tt>http://www.erlang.org/doc/man/ets.html#last-1</tt></a>.
    215. 

  215.   The registry behaves as an ordered_set table.</p>
    216. 

  216. 

  217. <h3 class="function"><a name="lookup_global_aggr_counter-1">lookup_global_aggr_counter/1</a></h3>
    218. 

  218. <div class="spec">
    219. 

  219. <p><tt>lookup_global_aggr_counter(Name::any()) -&gt; integer()</tt></p>
    220. 

  220. </div><p>Equivalent to <a href="#where-1"><tt>where({a, g, Name})</tt></a>.</p>
    221. 

  221. <p>Lookup a global (unique) aggregated counter and returns its value.
    222. 

  222.   Fails if there is no such object.</p>
    223. 

  223. 

  224. <h3 class="function"><a name="lookup_global_counters-1">lookup_global_counters/1</a></h3>
    225. 

  225. <div class="spec">
    226. 

  226. <p><tt>lookup_global_counters(Counter::any()) -&gt; [{pid(), Value::integer()}]</tt></p>
    227. 

  227. </div><p>Equivalent to <a href="#lookup_values-1"><tt>lookup_values({c, g, Counter})</tt></a>.</p>
    228. 

  228. <p>Look up all global (non-unique) instances of a given Counter.
    229. 

  229.   Returns a list of {Pid, Value} tuples for all matching objects.</p>
    230. 

  230. 

  231. <h3 class="function"><a name="lookup_global_name-1">lookup_global_name/1</a></h3>
    232. 

  232. <div class="spec">
    233. 

  233. <p><tt>lookup_global_name(Name::any()) -&gt; pid()</tt></p>
    234. 

  234. </div><p>Equivalent to <a href="#where-1"><tt>where({n, g, Name})</tt></a>.</p>
    235. 

  235. <p>Lookup a global unique name. Fails if there is no such name.</p>
    236. 

  236. 

  237. <h3 class="function"><a name="lookup_global_properties-1">lookup_global_properties/1</a></h3>
    238. 

  238. <div class="spec">
    239. 

  239. <p><tt>lookup_global_properties(Property::any()) -&gt; [{pid(), Value}]</tt></p>
    240. 

  240. </div><p>Equivalent to <a href="#lookup_values-1"><tt>lookup_values({p, g, Property})</tt></a>.</p>
    241. 

  241. <p>Look up all global (non-unique) instances of a given Property.
    242. 

  242.   Returns a list of {Pid, Value} tuples for all matching objects.</p>
    243. 

  243. 

  244. <h3 class="function"><a name="lookup_local_aggr_counter-1">lookup_local_aggr_counter/1</a></h3>
    245. 

  245. <div class="spec">
    246. 

  246. <p><tt>lookup_local_aggr_counter(Name::any()) -&gt; integer()</tt></p>
    247. 

  247. </div><p>Equivalent to <a href="#where-1"><tt>where({a, l, Name})</tt></a>.</p>
    248. 

  248. <p>Lookup a local (unique) aggregated counter and returns its value.
    249. 

  249.   Fails if there is no such object.</p>
    250. 

  250. 

  251. <h3 class="function"><a name="lookup_local_counters-1">lookup_local_counters/1</a></h3>
    252. 

  252. <div class="spec">
    253. 

  253. <p><tt>lookup_local_counters(Counter::any()) -&gt; [{pid(), Value::integer()}]</tt></p>
    254. 

  254. </div><p>Equivalent to <a href="#lookup_values-1"><tt>lookup_values({c, l, Counter})</tt></a>.</p>
    255. 

  255. <p>Look up all local (non-unique) instances of a given Counter.
    256. 

  256.   Returns a list of {Pid, Value} tuples for all matching objects.</p>
    257. 

  257. 

  258. <h3 class="function"><a name="lookup_local_name-1">lookup_local_name/1</a></h3>
    259. 

  259. <div class="spec">
    260. 

  260. <p><tt>lookup_local_name(Name::any()) -&gt; pid()</tt></p>
    261. 

  261. </div><p>Equivalent to <a href="#where-1"><tt>where({n, l, Name})</tt></a>.</p>
    262. 

  262. <p>Lookup a local unique name. Fails if there is no such name.</p>
    263. 

  263. 

  264. <h3 class="function"><a name="lookup_local_properties-1">lookup_local_properties/1</a></h3>
    265. 

  265. <div class="spec">
    266. 

  266. <p><tt>lookup_local_properties(Property::any()) -&gt; [{pid(), Value}]</tt></p>
    267. 

  267. </div><p>Equivalent to <a href="#lookup_values-1"><tt>lookup_values({p, l, Property})</tt></a>.</p>
    268. 

  268. <p>Look up all local (non-unique) instances of a given Property.
    269. 

  269.   Returns a list of {Pid, Value} tuples for all matching objects.</p>
    270. 

  270. 

  271. <h3 class="function"><a name="lookup_pid-1">lookup_pid/1</a></h3>
    272. 

  272. <div class="spec">
    273. 

  273. <p><tt>lookup_pid(Key) -&gt; Pid</tt></p>
    274. 

  274. </div><p>Lookup the Pid stored with a key.
    275. 

  275.  </p>
    276. 

  276. 

  277. <h3 class="function"><a name="lookup_pids-1">lookup_pids/1</a></h3>
    278. 

  278. <div class="spec">
    279. 

  279. <p><tt>lookup_pids(Key::<a href="#type-key">key()</a>) -&gt; [pid()]</tt></p>
    280. 

  280. </div><p><p>Returns a list of pids with the published key Key</p>
    281. 

  281.  
    282. 

  282.   If the type of registration entry is either name or aggregated counter,
    283. 

  283.   this function will return either an empty list, or a list of one pid.
    284. 

  284.   For non-unique types, the return value can be a list of any length.</p>
    285. 

  285. 

  286. <h3 class="function"><a name="lookup_values-1">lookup_values/1</a></h3>
    287. 

  287. <div class="spec">
    288. 

  288. <p><tt>lookup_values(Key::<a href="#type-key">key()</a>) -&gt; [{pid(), Value}]</tt></p>
    289. 

  289. </div><p><p>Retrieve the <code>{Pid,Value}</code> pairs corresponding to Key.</p>
    290. 

  290.  
    291. 

  291.   Key refer to any type of registry object. If it refers to a unique
    292. 

  292.   object, the list will be of length 0 or 1. If it refers to a non-unique
    293. 

  293.   object, the return value can be a list of any length.</p>
    294. 

  294. 

  295. <h3 class="function"><a name="mreg-3">mreg/3</a></h3>
    296. 

  296. <div class="spec">
    297. 

  297. <p><tt>mreg(T::<a href="#type-type">type()</a>, X2::<a href="#type-scope">scope()</a>, KVL::[{Key::any(), Value::any()}]) -&gt; true</tt></p>
    298. 

  298. </div><p><p>Register multiple {Key,Value} pairs of a given type and scope.</p>
    299. 

  299.  
    300. 

  300.   This function is more efficient than calling <a href="#reg-2"><code>reg/2</code></a> repeatedly.</p>
    301. 

  301. 

  302. <h3 class="function"><a name="nb_wait-1">nb_wait/1</a></h3>
    303. 

  303. <div class="spec">
    304. 

  304. <p><tt>nb_wait(Key::<a href="#type-key">key()</a>) -&gt; Ref</tt></p>
    305. 

  305. </div><p>Wait for a local name to be registered.
    306. 

  306.   The caller can expect to receive a message,
    307. 

  307.   {gproc, Ref, registered, {Key, Pid, Value}}, once the name is registered.</p>
    308. 

  308. 

  309. <h3 class="function"><a name="next-2">next/2</a></h3>
    310. 

  310. <div class="spec">
    311. 

  311. <p><tt>next(Context::<a href="#type-context">context()</a>, Key::<a href="#type-key">key()</a>) -&gt; <a href="#type-key">key()</a> | '$end_of_table'</tt></p>
    312. 

  312. </div><p><p>Behaves as ets:next(Tab,Key) for a given type of registration object.</p>
    313. 

  313.  
    314. 

  314.   See <a href="http://www.erlang.org/doc/man/ets.html#next-2" target="_top"><tt>http://www.erlang.org/doc/man/ets.html#next-2</tt></a>.
    315. 

  315.   The registry behaves as an ordered_set table.</p>
    316. 

  316. 

  317. <h3 class="function"><a name="prev-2">prev/2</a></h3>
    318. 

  318. <div class="spec">
    319. 

  319. <p><tt>prev(Context::<a href="#type-context">context()</a>, Key::<a href="#type-key">key()</a>) -&gt; <a href="#type-key">key()</a> | '$end_of_table'</tt></p>
    320. 

  320. </div><p><p>Behaves as ets:prev(Tab,Key) for a given type of registration object.</p>
    321. 

  321.  
    322. 

  322.   See <a href="http://www.erlang.org/doc/man/ets.html#prev-2" target="_top"><tt>http://www.erlang.org/doc/man/ets.html#prev-2</tt></a>.
    323. 

  323.   The registry behaves as an ordered_set table.</p>
    324. 

  324. 

  325. <h3 class="function"><a name="reg-1">reg/1</a></h3>
    326. 

  326. <div class="spec">
    327. 

  327. <p><tt>reg(Key::<a href="#type-key">key()</a>) -&gt; true</tt></p>
    328. 

  328. </div><p>Equivalent to <a href="#reg-2"><tt>reg(Key, default(Key))</tt></a>.</p>
    329. 

  329. 

  330. 

  331. <h3 class="function"><a name="reg-2">reg/2</a></h3>
    332. 

  332. <div class="spec">
    333. 

  333. <p><tt>reg(Key::<a href="#type-key">key()</a>, Value) -&gt; true</tt></p>
    334. 

  334. </div><p><p>Register a name or property for the current process</p>
    335. 

  335.  
    336. 

  336.  </p>
    337. 

  337. 

  338. <h3 class="function"><a name="select-1">select/1</a></h3>
    339. 

  339. <div class="spec">
    340. 

  340. <p><tt>select(Pat::<a href="#type-select_pattern">select_pattern()</a>) -&gt; list(<a href="#type-sel_object">sel_object()</a>)</tt></p>
    341. 

  341. </div><p>Equivalent to <a href="#select-2"><tt>select(all, Pat)</tt></a>.</p>
    342. 

  342. 

  343. 

  344. <h3 class="function"><a name="select-2">select/2</a></h3>
    345. 

  345. <div class="spec">
    346. 

  346. <p><tt>select(Type::<a href="#type-sel_type">sel_type()</a>, Pat::<a href="#type-sel_pattern">sel_pattern()</a>) -&gt; [{Key, Pid, Value}]</tt></p>
    347. 

  347. </div><p><p>Perform a select operation on the process registry.</p>
    348. 

  348.  
    349. 

  349.   The physical representation in the registry may differ from the above,
    350. 

  350.   but the select patterns are transformed appropriately.</p>
    351. 

  351. 

  352. <h3 class="function"><a name="select-3">select/3</a></h3>
    353. 

  353. <div class="spec">
    354. 

  354. <p><tt>select(Type::<a href="#type-sel_type">sel_type()</a>, Pat::<a href="#type-sel_patten">sel_patten()</a>, Limit::integer()) -&gt; [{Key, Pid, Value}]</tt></p>
    355. 

  355. </div><p><p>Like <a href="#select-2"><code>select/2</code></a> but returns Limit objects at a time.</p>
    356. 

  356.  
    357. 

  357.   See <a href="http://www.erlang.org/doc/man/ets.html#select-3" target="_top"><tt>http://www.erlang.org/doc/man/ets.html#select-3</tt></a>.</p>
    358. 

  358. 

  359. <h3 class="function"><a name="send-2">send/2</a></h3>
    360. 

  360. <div class="spec">
    361. 

  361. <p><tt>send(Key::<a href="#type-key">key()</a>, Msg::any()) -&gt; Msg</tt></p>
    362. 

  362. </div><p><p>Sends a message to the process, or processes, corresponding to Key.</p>
    363. 

  363.  
    364. 

  364.   If Key belongs to a unique object (name or aggregated counter), this
    365. 

  365.   function will send a message to the corresponding process, or fail if there
    366. 

  366.   is no such process. If Key is for a non-unique object type (counter or
    367. 

  367.   property), Msg will be send to all processes that have such an object.</p>
    368. 

  368. 

  369. <h3 class="function"><a name="set_value-2">set_value/2</a></h3>
    370. 

  370. <div class="spec">
    371. 

  371. <p><tt>set_value(Key::<a href="#type-key">key()</a>, Value) -&gt; true</tt></p>
    372. 

  372. </div><p><p>Sets the value of the registeration entry given by Key</p>
    373. 

  373.  
    374. 

  374.   <p>Key is assumed to exist and belong to the calling process.  
    375. 

  375. If it doesn't, this function will exit.</p>
    376. 

  376.  
    377. 

  377.   Value can be any term, unless the object is a counter, in which case
    378. 

  378.   it must be an integer.</p>
    379. 

  379. 

  380. <h3 class="function"><a name="start_link-0">start_link/0</a></h3>
    381. 

  381. <div class="spec">
    382. 

  382. <p><tt>start_link() -&gt; {ok, pid()}</tt></p>
    383. 

  383. </div><p><p>Starts the gproc server.</p>
    384. 

  384.  
    385. 

  385.   This function is intended to be called from gproc_sup, as part of
    386. 

  386.   starting the gproc application.</p>
    387. 

  387. 

  388. <h3 class="function"><a name="table-1">table/1</a></h3>
    389. 

  389. <div class="spec">
    390. 

  390. <p><tt>table(Context::<a href="#type-context">context()</a>) -&gt; any()</tt></p>
    391. 

  391. </div><p>Equivalent to <a href="#table-2"><tt>table(Context, [])</tt></a>.</p>
    392. 

  392. 

  393. 

  394. <h3 class="function"><a name="table-2">table/2</a></h3>
    395. 

  395. <div class="spec">
    396. 

  396. <p><tt>table(Context::<a href="#type-context">context()</a>, Opts) -&gt; any()</tt></p>
    397. 

  397. </div><p>QLC table generator for the gproc registry.
    398. 

  398.   Context specifies which subset of the registry should be queried.
    399. 

  399.   See <a href="http://www.erlang.org/doc/man/qlc.html" target="_top"><tt>http://www.erlang.org/doc/man/qlc.html</tt></a>.</p>
    400. 

  400. 

  401. <h3 class="function"><a name="unreg-1">unreg/1</a></h3>
    402. 

  402. <div class="spec">
    403. 

  403. <p><tt>unreg(Key::<a href="#type-key">key()</a>) -&gt; true</tt></p>
    404. 

  404. </div><p>Unregister a name or property.</p>
    405. 

  405. 

  406. <h3 class="function"><a name="update_counter-2">update_counter/2</a></h3>
    407. 

  407. <div class="spec">
    408. 

  408. <p><tt>update_counter(Key::<a href="#type-key">key()</a>, Incr::integer()) -&gt; integer()</tt></p>
    409. 

  409. </div><p><p>Updates the counter registered as Key for the current process.</p>
    410. 

  410.  
    411. 

  411.   This function works like ets:update_counter/3
    412. 

  412.   (see <a href="http://www.erlang.org/doc/man/ets.html#update_counter-3" target="_top"><tt>http://www.erlang.org/doc/man/ets.html#update_counter-3</tt></a>), but
    413. 

  413.   will fail if the type of object referred to by Key is not a counter.</p>
    414. 

  414. 

  415. <h3 class="function"><a name="where-1">where/1</a></h3>
    416. 

  416. <div class="spec">
    417. 

  417. <p><tt>where(Key::<a href="#type-key">key()</a>) -&gt; pid()</tt></p>
    418. 

  418. </div><p><p>Returns the pid registered as Key</p>
    419. 

  419.  
    420. 

  420.   The type of registration entry must be either name or aggregated counter.
    421. 

  421.   Otherwise this function will exit. Use <a href="#lookup_pids-1"><code>lookup_pids/1</code></a> in these
    422. 

  422.   cases.</p>
    423. 

  423. <hr>
    424. 

  424. 

  425. <div class="navbar"><a name="#navbar_bottom"></a><table width="100%" border="0" cellspacing="0" cellpadding="2" summary="navigation bar"><tr><td><a href="overview-summary.html" target="overviewFrame">Overview</a></td><td><a href="http://www.erlang.org/"><img src="erlang.png" align="right" border="0" alt="erlang logo"></a></td></tr></table></div>
    426. 

  426. <p><i>Generated by EDoc, Feb 11 2010, 05:33:39.</i></p>
    427. 

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    428. 

  428. </html>
    429.