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-rw-r--r--erts/doc/src/erlang.xml56
1 files changed, 49 insertions, 7 deletions
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml
index 687ff38cbf..2465f49581 100644
--- a/erts/doc/src/erlang.xml
+++ b/erts/doc/src/erlang.xml
@@ -60,6 +60,14 @@
</desc>
</datatype>
<datatype>
+ <name>iovec()</name>
+ <desc>
+ <p>A list of binaries. This datatype is useful to use
+ together with <seealso marker="erl_nif#enif_inspect_iovec">
+ <c>enif_inspect_iovec</c></seealso>.</p>
+ </desc>
+ </datatype>
+ <datatype>
<name name="message_queue_data"></name>
<desc>
<p>See <seealso marker="#process_flag_message_queue_data">
@@ -424,6 +432,16 @@ Z = erlang:adler32_combine(X,Y,iolist_size(Data2)).</code>
<seealso marker="#binary_to_atom/2"><c>binary_to_atom/2</c></seealso>,
but the atom must exist.</p>
<p>Failure: <c>badarg</c> if the atom does not exist.</p>
+ <note>
+ <p>Note that the compiler may optimize away atoms. For
+ example, the compiler will rewrite
+ <c>atom_to_list(some_atom)</c> to <c>"some_atom"</c>. If
+ that expression is the only mention of the atom
+ <c>some_atom</c> in the containing module, the atom will not
+ be created when the module is loaded, and a subsequent call
+ to <c>binary_to_existing_atom(&lt;&lt;"some_atom"&gt;&gt;, utf8)</c>
+ will fail.</p>
+ </note>
</desc>
</func>
@@ -1943,23 +1961,26 @@ os_prompt%</pre>
<item>The runtime system exits with integer value
<c><anno>Status</anno></c>
as status code to the calling environment (OS).
+ <note>
+ <p>On many platforms, the OS supports only status
+ codes 0-255. A too large status code is truncated by clearing
+ the high bits.</p>
+ </note>
</item>
<tag>string()</tag>
<item>An Erlang crash dump is produced with <c><anno>Status</anno></c>
as slogan. Then the runtime system exits with status code <c>1</c>.
- Note that only code points in the range 0-255 may be used
- and the string will be truncated if longer than 200 characters.
+ The string will be truncated if longer than 200 characters.
+ <note>
+ <p>Before ERTS 9.1 (OTP-20.1) only code points in the range 0-255
+ was accepted in the string. Now any unicode string is valid.</p>
+ </note>
</item>
<tag><c>abort</c></tag>
<item>The runtime system aborts producing a core dump, if that is
enabled in the OS.
</item>
</taglist>
- <note>
- <p>On many platforms, the OS supports only status
- codes 0-255. A too large status code is truncated by clearing
- the high bits.</p>
- </note>
<p>For integer <c><anno>Status</anno></c>, the Erlang runtime system
closes all ports and allows async threads to finish their
operations before exiting. To exit without such flushing, use
@@ -2125,6 +2146,15 @@ os_prompt%</pre>
</func>
<func>
+ <name name="iolist_to_iovec" arity="1"/>
+ <fsummary>Converts an iolist to a iovec.</fsummary>
+ <desc>
+ <p>Returns an iovec that is made from the integers and binaries in
+ <c><anno>IoListOrBinary</anno></c>.</p>
+ </desc>
+ </func>
+
+ <func>
<name name="is_alive" arity="0"/>
<fsummary>Check whether the local node is alive.</fsummary>
<desc>
@@ -2458,6 +2488,15 @@ os_prompt%</pre>
but only if there already exists such atom.</p>
<p>Failure: <c>badarg</c> if there does not already exist an atom
whose text representation is <c><anno>String</anno></c>.</p>
+ <note>
+ <p>Note that the compiler may optimize away atoms. For
+ example, the compiler will rewrite
+ <c>atom_to_list(some_atom)</c> to <c>"some_atom"</c>. If
+ that expression is the only mention of the atom
+ <c>some_atom</c> in the containing module, the atom will not
+ be created when the module is loaded, and a subsequent call
+ to <c>list_to_existing_atom("some_atom")</c> will fail.</p>
+ </note>
</desc>
</func>
@@ -6483,6 +6522,9 @@ lists:map(
<p>This is the sum of the runtime for all threads
in the Erlang runtime system and can therefore be greater
than the wall clock time.</p>
+ <warning><p>This value might wrap due to limitations in the
+ underlying functionality provided by the operating system
+ that is used.</p></warning>
<p>Example:</p>
<pre>
> <input>statistics(runtime).</input>