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Diffstat (limited to 'system/doc/efficiency_guide')
| -rw-r--r-- | system/doc/efficiency_guide/advanced.xml | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/system/doc/efficiency_guide/advanced.xml b/system/doc/efficiency_guide/advanced.xml index 51f1b2612c..ed7a6670ed 100644 --- a/system/doc/efficiency_guide/advanced.xml +++ b/system/doc/efficiency_guide/advanced.xml @@ -199,6 +199,31 @@ On 64-bit architectures: 4 words for a reference from the current local node, an available, and operating system specific settings and limits.</item> <tag><em>Number of arguments to a function or fun</em></tag> <item>255</item> + <tag><marker id="unique_references"/><em>Unique References on a Runtime System Instance</em></tag> + <item>Each scheduler thread has its own set of references, and all + other threads have a shared set of references. Each set of references + consist of <c>2⁶⁴ - 1</c> unique references. That is the total + amount of unique references that can be produced on a runtime + system instance is <c>(NoSchedulers + 1) * (2⁶⁴ - 1)</c>. If a + scheduler thread create a new reference each nano second, + references will at earliest be reused after more than 584 years. + That is, for the foreseeable future they are unique enough.</item> + <tag><marker id="unique_integers"/><em>Unique Integers on a Runtime System Instance</em></tag> + <item>There are two types of unique integers both created using the + <seealso marker="erts:erlang#unique_integer/1">erlang:unique_integer()</seealso> + BIF. Unique integers created: + <taglist> + <tag><em>with</em> the <c>monotonic</c> modifier</tag> + <item>consist of a set of <c>2⁶⁴ - 1</c> unique integers.</item> + <tag><em>without</em> the <c>monotonic</c> modifier</tag> + <item>consist of a set of <c>2⁶⁴ - 1</c> unique integers per scheduler + thread and a set of <c>2⁶⁴ - 1</c> unique integers shared by + other threads. That is the total amount of unique integers without + the <c>monotonic</c> modifier is <c>(NoSchedulers + 1) * (2⁶⁴ - 1)</c></item> + </taglist> + If a unique integer is created each nano second, unique integers + will at earliest be reused after more than 584 years. That is, for + the foreseeable future they are unique enough.</item> </taglist> </section> </chapter> |