diff options
Diffstat (limited to 'lib/kernel/doc/src/code.xml')
| -rw-r--r-- | lib/kernel/doc/src/code.xml | 64 |
1 files changed, 54 insertions, 10 deletions
diff --git a/lib/kernel/doc/src/code.xml b/lib/kernel/doc/src/code.xml index 3143cdc825..aff3e8133c 100644 --- a/lib/kernel/doc/src/code.xml +++ b/lib/kernel/doc/src/code.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1996</year><year>2016</year> + <year>1996</year><year>2018</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -34,26 +34,28 @@ <p>This module contains the interface to the Erlang <em>code server</em>, which deals with the loading of compiled code into a running Erlang runtime system.</p> - <p>The runtime system can be started in <em>embedded</em> or - <em>interactive</em> mode. Which one is decided by command-line + <p>The runtime system can be started in <em>interactive</em> or + <em>embedded</em> mode. Which one is decided by the command-line flag <c>-mode</c>:</p> <pre> % <input>erl -mode interactive</input></pre> <p>The modes are as follows:</p> <list type="bulleted"> <item> - <p>In embedded mode, all code is loaded during system startup - according to the boot script. (Code can also be loaded later - by explicitly ordering the code server to do so).</p> - </item> - <item> <p>In interactive mode, which is default, only some code is loaded - during system startup, basically the modules needed by the runtime + during system startup, basically the modules needed by the runtime system. Other code is dynamically loaded when first referenced. When a call to a function in a certain module is made, and the module is not loaded, the code server searches for and tries to load the module.</p> </item> + <item> + <p>In embedded mode, modules are not auto loaded. Trying to use + a module that has not been loaded results in an error. This mode is + recommended when the boot script loads all modules, as it is + typically done in OTP releases. (Code can still be loaded later + by explicitly ordering the code server to do so).</p> + </item> </list> <p>To prevent accidentally reloading of modules affecting the Erlang runtime system, directories <c>kernel</c>, <c>stdlib</c>, @@ -258,7 +260,7 @@ zip:create("mnesia-4.4.7.ez", both strings and atoms, but a future release will probably only allow the arguments that are documented.</p> - <p>As from Erlang/OTP R12B, functions in this module generally fail with an + <p>Functions in this module generally fail with an exception if they are passed an incorrect type (for example, an integer or a tuple where an atom is expected). An error tuple is returned if the argument type is correct, but there are some other errors (for example, a non-existing directory @@ -899,6 +901,48 @@ rpc:call(Node, code, load_binary, [Module, Filename, Binary]), </desc> </func> <func> + <name name="module_status" arity="1"/> + <fsummary>Return the status of the module in relation to object file on disk.</fsummary> + <desc> + <p>Returns:</p> + <taglist> + <tag><c>not_loaded</c></tag> + <item><p>If <c><anno>Module</anno></c> is not currently loaded.</p></item> + <tag><c>loaded</c></tag> + <item><p>If <c><anno>Module</anno></c> is loaded and the object file + exists and contains the same code.</p></item> + <tag><c>removed</c></tag> + <item><p>If <c><anno>Module</anno></c> is loaded but no + corresponding object file can be found in the code path.</p></item> + <tag><c>modified</c></tag> + <item><p>If <c><anno>Module</anno></c> is loaded but the object file + contains code with a different MD5 checksum.</p></item> + </taglist> + <p>Preloaded modules are always reported as <c>loaded</c>, without + inspecting the contents on disk. Cover compiled modules will always + be reported as <c>modified</c> if an object file exists, or as + <c>removed</c> otherwise. Modules whose load path is an empty string + (which is the convention for auto-generated code) will only be + reported as <c>loaded</c> or <c>not_loaded</c>.</p> + <p>For modules that have native code loaded (see + <seealso marker="#is_module_native/1"><c>is_module_native/1</c></seealso>), + the MD5 sum of the native code in the object file is used for the + comparison, if it exists; the Beam code in the file is ignored. + Reversely, for modules that do not currently have native code + loaded, any native code in the file will be ignored.</p> + <p>See also <seealso marker="#modified_modules/0"><c>modified_modules/0</c></seealso>.</p> + </desc> + </func> + <func> + <name name="modified_modules" arity="0"/> + <fsummary>Return a list of all modules modified on disk.</fsummary> + <desc> + <p>Returns the list of all currently loaded modules for which + <seealso marker="#module_status/1"><c>module_status/1</c></seealso> + returns <c>modified</c>. See also <seealso marker="#all_loaded/0"><c>all_loaded/0</c></seealso>.</p> + </desc> + </func> + <func> <name name="is_module_native" arity="1"/> <fsummary>Test if a module has native code.</fsummary> <desc> |