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Diffstat (limited to 'lib/kernel/doc/src/error_handler.xml')
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diff --git a/lib/kernel/doc/src/error_handler.xml b/lib/kernel/doc/src/error_handler.xml new file mode 100644 index 0000000000..94824688d1 --- /dev/null +++ b/lib/kernel/doc/src/error_handler.xml @@ -0,0 +1,98 @@ +<?xml version="1.0" encoding="latin1" ?> +<!DOCTYPE erlref SYSTEM "erlref.dtd"> + +<erlref> + <header> + <copyright> + <year>1996</year> + <year>2007</year> + <holder>Ericsson AB, All Rights Reserved</holder> + </copyright> + <legalnotice> + The contents of this file are subject to the Erlang Public License, + Version 1.1, (the "License"); you may not use this file except in + compliance with the License. You should have received a copy of the + Erlang Public License along with this software. If not, it can be + retrieved online at http://www.erlang.org/. + + Software distributed under the License is distributed on an "AS IS" + basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See + the License for the specific language governing rights and limitations + under the License. + + The Initial Developer of the Original Code is Ericsson AB. + </legalnotice> + + <title>error_handler</title> + <prepared></prepared> + <docno></docno> + <date></date> + <rev></rev> + </header> + <module>error_handler</module> + <modulesummary>Default System Error Handler</modulesummary> + <description> + <p>The error handler module defines what happens when certain types + of errors occur.</p> + </description> + <funcs> + <func> + <name>undefined_function(Module, Function, Args) -> term()</name> + <fsummary>Called when an undefined function is encountered</fsummary> + <type> + <v>Module = Function = atom()</v> + <v>Args = [term()]</v> + <d>A (possibly empty) list of arguments <c>Arg1,..,ArgN</c></d> + </type> + <desc> + <p>This function is evaluated if a call is made to + <c>Module:Function(Arg1,.., ArgN)</c> and + <c>Module:Function/N</c> is undefined. Note that + <c>undefined_function/3</c> is evaluated inside the process + making the original call.</p> + <p>If <c>Module</c> is interpreted, the interpreter is invoked + and the return value of the interpreted + <c>Function(Arg1,.., ArgN)</c> call is returned.</p> + <p>Otherwise, it returns, if possible, the value of + <c>apply(Module, Function, Args)</c> after an attempt has been + made to autoload <c>Module</c>. If this is not possible, the + call to <c>Module:Function(Arg1,.., ArgN)</c> fails with + exit reason <c>undef</c>.</p> + </desc> + </func> + <func> + <name>undefined_lambda(Module, Fun, Args) -> term()</name> + <fsummary>Called when an undefined lambda (fun) is encountered</fsummary> + <type> + <v>Module = Function = atom()</v> + <v>Args = [term()]</v> + <d>A (possibly empty) list of arguments <c>Arg1,..,ArgN</c></d> + </type> + <desc> + <p>This function is evaluated if a call is made to + <c>Fun(Arg1,.., ArgN)</c> when the module defining the fun is + not loaded. The function is evaluated inside the process + making the original call.</p> + <p>If <c>Module</c> is interpreted, the interpreter is invoked + and the return value of the interpreted + <c>Fun(Arg1,.., ArgN)</c> call is returned.</p> + <p>Otherwise, it returns, if possible, the value of + <c>apply(Fun, Args)</c> after an attempt has been made to + autoload <c>Module</c>. If this is not possible, the call + fails with exit reason <c>undef</c>.</p> + </desc> + </func> + </funcs> + + <section> + <title>Notes</title> + <p>The code in <c>error_handler</c> is complex and should not be + changed without fully understanding the interaction between + the error handler, the <c>init</c> process of the code server, + and the I/O mechanism of the code.</p> + <p>Changes in the code which may seem small can cause a deadlock + as unforeseen consequences may occur. The use of <c>input</c> is + dangerous in this type of code.</p> + </section> +</erlref> + |