docs: Move GModule documentation to Markdown

Helps: #3037
This commit is contained in:
Matthias Clasen 2023-10-09 23:25:05 +01:00 committed by Philip Withnall
parent fc29022f0b
commit 390d9a446d
4 changed files with 94 additions and 78 deletions

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@ -43,6 +43,7 @@ base_url = "https://gitlab.gnome.org/GNOME/glib/-/blob/HEAD/"
urlmap_file = "urlmap.js"
# The same order will be used when generating the index
content_files = [
"modules.md",
]
content_images = [
]

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@ -1,4 +1,5 @@
expand_content_files = [
'modules.md',
]
gmodule_gir = meson.current_source_dir() / 'GModule-2.0.gir'

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@ -0,0 +1,92 @@
Title: Dynamic Loading of Modules
## Dynamic Loading of Modules
These functions provide a portable way to dynamically load object files
(commonly known as 'plug-ins'). The current implementation supports all
systems that provide an implementation of `dlopen()` (e.g. Linux/Sun), as
well as Windows platforms via DLLs.
A program which wants to use these functions must be linked to the libraries
output by the command:
pkg-config --libs gmodule-2.0
To use them you must first determine whether dynamic loading is supported on
the platform by calling [`func@GModule.Module.supported`]. If it is, you can
open a module with [`func@GModule.Module.open`], find the module's symbols
(e.g. function names) with [`method@GModule.Module.symbol`], and later close
the module with [`method@GModule.Module.close`].
[`method@GModule.Module.name`] will return the file name of a currently
opened module.
If any of the above functions fail, the error status can be found with
[`func@GModule.Module.error`].
The `GModule` implementation features reference counting for opened modules,
and supports hook functions within a module which are called when the module
is loaded and unloaded (see [callback@GModule.ModuleCheckInit] and
[callback@GModule.ModuleUnload]).
If your module introduces static data to common subsystems in the running
program, e.g. through calling API like:
```c
static GQuark my_module_quark =
g_quark_from_static_string ("my-module-stuff");
```
it must ensure that it is never unloaded, by calling
[`method@GModule.Module.make_resident`].
### Calling a function defined in a GModule
```c
// the function signature for 'say_hello'
typedef void (* SayHelloFunc) (const char *message);
gboolean
just_say_hello (const char *filename, GError **error)
{
SayHelloFunc say_hello;
GModule *module;
module = g_module_open (filename, G_MODULE_BIND_LAZY);
if (module == NULL)
{
g_set_error (error, FOO_ERROR, FOO_ERROR_BLAH,
"%s", g_module_error ());
return FALSE;
}
if (!g_module_symbol (module, "say_hello", (gpointer *)&say_hello))
{
g_set_error (error, SAY_ERROR, SAY_ERROR_OPEN,
"%s: %s", filename, g_module_error ());
if (!g_module_close (module))
g_warning ("%s: %s", filename, g_module_error ());
return FALSE;
}
if (say_hello == NULL)
{
g_set_error (error, SAY_ERROR, SAY_ERROR_OPEN,
"symbol say_hello is NULL");
if (!g_module_close (module))
g_warning ("%s: %s", filename, g_module_error ());
return FALSE;
}
// call our function in the module
say_hello ("Hello world!");
if (!g_module_close (module))
g_warning ("%s: %s", filename, g_module_error ());
return TRUE;
}
```

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@ -52,84 +52,6 @@
#include "gmoduleconf.h"
#include "gstdio.h"
/**
* SECTION:modules
* @title: Dynamic Loading of Modules
* @short_description: portable method for dynamically loading 'plug-ins'
*
* These functions provide a portable way to dynamically load object files
* (commonly known as 'plug-ins'). The current implementation supports all
* systems that provide an implementation of dlopen() (e.g. Linux/Sun), as
* well as Windows platforms via DLLs.
*
* A program which wants to use these functions must be linked to the
* libraries output by the command `pkg-config --libs gmodule-2.0`.
*
* To use them you must first determine whether dynamic loading
* is supported on the platform by calling g_module_supported().
* If it is, you can open a module with g_module_open(),
* find the module's symbols (e.g. function names) with g_module_symbol(),
* and later close the module with g_module_close().
* g_module_name() will return the file name of a currently opened module.
*
* If any of the above functions fail, the error status can be found with
* g_module_error().
*
* The #GModule implementation features reference counting for opened modules,
* and supports hook functions within a module which are called when the
* module is loaded and unloaded (see #GModuleCheckInit and #GModuleUnload).
*
* If your module introduces static data to common subsystems in the running
* program, e.g. through calling
* `g_quark_from_static_string ("my-module-stuff")`,
* it must ensure that it is never unloaded, by calling g_module_make_resident().
*
* Example: Calling a function defined in a GModule
* |[<!-- language="C" -->
* // the function signature for 'say_hello'
* typedef void (* SayHelloFunc) (const char *message);
*
* gboolean
* just_say_hello (const char *filename, GError **error)
* {
* SayHelloFunc say_hello;
* GModule *module;
*
* module = g_module_open (filename, G_MODULE_BIND_LAZY);
* if (!module)
* {
* g_set_error (error, FOO_ERROR, FOO_ERROR_BLAH,
* "%s", g_module_error ());
* return FALSE;
* }
*
* if (!g_module_symbol (module, "say_hello", (gpointer *)&say_hello))
* {
* g_set_error (error, SAY_ERROR, SAY_ERROR_OPEN,
* "%s: %s", filename, g_module_error ());
* if (!g_module_close (module))
* g_warning ("%s: %s", filename, g_module_error ());
* return FALSE;
* }
*
* if (say_hello == NULL)
* {
* g_set_error (error, SAY_ERROR, SAY_ERROR_OPEN,
* "symbol say_hello is NULL");
* if (!g_module_close (module))
* g_warning ("%s: %s", filename, g_module_error ());
* return FALSE;
* }
*
* // call our function in the module
* say_hello ("Hello world!");
*
* if (!g_module_close (module))
* g_warning ("%s: %s", filename, g_module_error ());
* return TRUE;
* }
* ]|
*/
/**
* GModule: