Assemblies

Code in .NET and Mono is distributed in assemblies, there are shipped typically in files with the extension .exe or .dll, and they are files that extend the Portable Executable file format to include the Common Intermediate Language metadata and portable code.

Assemblies are typically loaded either from a given file path, or using an Assembly Name to load them from the Global Assembly Cache.

The Mono Assembly API contains method for dealing with assembly names, loading assemblies, accessing assembly components, modules and some advanced features.

Assemblies contain one or more images, the actual vessels for your code. The Image API documents the functions that operate on MonoImage *.

Synopsis

#include <metadata/assembly.h> typedef struct _MonoImage MonoImage; typedef struct _MonoAssembly MonoAssembly;

Assembly Loading

mono_assembly_close
Syntax
void mono_assembly_close (MonoAssembly *assembly)

Parameters
assembly the assembly to release.
Description

This method releases a reference to the assembly. The assembly is only released when all the outstanding references to it are released.

mono_assembly_get_object
Syntax
MonoReflectionAssembly* mono_assembly_get_object (MonoDomain *domain, MonoAssembly *assembly)

Parameters
domain an app domain
assembly an assembly
Return value
a System.Reflection.Assembly object representing the MonoAssembly assembly.
mono_assembly_load
Syntax
MonoAssembly* mono_assembly_load (MonoAssemblyName *aname, const char *basedir, MonoImageOpenStatus *status)

Parameters
aname A MonoAssemblyName with the assembly name to load.
basedir A directory to look up the assembly at.
status a pointer to a MonoImageOpenStatus to return the status of the load operation
Return value
the assembly referenced by aname loaded or NULL on error. On error the value pointed by status is updated with an error code.
Description

Loads the assembly referenced by aname, if the value of basedir is not NULL, it attempts to load the assembly from that directory before probing the standard locations.

mono_assembly_load_full
Syntax
MonoAssembly* mono_assembly_load_full (MonoAssemblyName *aname, const char *basedir, MonoImageOpenStatus *status, gboolean refonly)

Parameters
aname A MonoAssemblyName with the assembly name to load.
basedir A directory to look up the assembly at.
status a pointer to a MonoImageOpenStatus to return the status of the load operation
refonly Whether this assembly is being opened in "reflection-only" mode.
Return value
the assembly referenced by aname loaded or NULL on error. On error the value pointed by status is updated with an error code.
Description

Loads the assembly referenced by aname, if the value of basedir is not NULL, it attempts to load the assembly from that directory before probing the standard locations.

If the assembly is being opened in reflection-only mode (refonly set to TRUE) then no assembly binding takes place.

mono_assembly_loaded
Syntax
MonoAssembly* mono_assembly_loaded (MonoAssemblyName *aname)

Parameters
aname an assembly to look for.
Return value
NULL If the given aname assembly has not been loaded, or a pointer to a MonoAssembly that matches the MonoAssemblyName specified.
Description

This is used to determine if the specified assembly has been loaded

mono_assembly_load_from
Syntax
MonoAssembly* mono_assembly_load_from (MonoImage *image, const char *fname, MonoImageOpenStatus *status)

Parameters
image Image to load the assembly from
fname assembly name to associate with the assembly
status return status code
Return value
A valid pointer to a MonoAssembly* on success and then status will be set to MONO_IMAGE_OK; or NULL on error.

If there is an error loading the assembly the status will indicate the reason with status being set to MONO_IMAGE_INVALID if the image did not contain an assembly reference table.

Description

If the provided image has an assembly reference, it will process the given image as an assembly with the given name.

Most likely you want to use the `api:mono_assembly_load_full` method instead.

This is equivalent to calling `api:mono_assembly_load_from_full` with the refonly parameter set to FALSE.

mono_assembly_load_from_full
Syntax
MonoAssembly* mono_assembly_load_from_full (MonoImage *image, const char*fname, MonoImageOpenStatus *status, gboolean refonly)

Parameters
image Image to load the assembly from
fname assembly name to associate with the assembly
status returns the status condition
refonly Whether this assembly is being opened in "reflection-only" mode.
Return value
A valid pointer to a MonoAssembly* on success and the status will be set to MONO_IMAGE_OK; or NULL on error.

If there is an error loading the assembly the status will indicate the reason with status being set to MONO_IMAGE_INVALID if the image did not contain an assembly reference table.

Description

If the provided image has an assembly reference, it will process the given image as an assembly with the given name.

Most likely you want to use the `api:mono_assembly_load_full` method instead.

mono_assembly_load_with_partial_name
Syntax
MonoAssembly* mono_assembly_load_with_partial_name (const char *name, MonoImageOpenStatus *status)

Parameters
name an assembly name that is then parsed by `api:mono_assembly_name_parse`.
status return status code
Return value
NULL on failure, or a pointer to a MonoAssembly on success.
Description

Loads a MonoAssembly from a name. The name is parsed using `api:mono_assembly_name_parse`, so it might contain a qualified type name, version, culture and token.

This will load the assembly from the file whose name is derived from the assembly name by appending the .dll extension.

The assembly is loaded from either one of the extra Global Assembly Caches specified by the extra GAC paths (specified by the MONO_GAC_PREFIX environment variable) or if that fails from the GAC.

mono_assembly_open
Syntax
MonoAssembly* mono_assembly_open (const char *filename, MonoImageOpenStatus *status)

Parameters
filename Opens the assembly pointed out by this name
status return status code
Return value
a pointer to the MonoAssembly if filename contains a valid assembly or NULL on error. Details about the error are stored in the status variable.
Description

This loads an assembly from the specified filename. The filename allows a local URL (starting with a file:// prefix). If a file prefix is used, the filename is interpreted as a URL, and the filename is URL-decoded. Otherwise the file is treated as a local path.

First, an attempt is made to load the assembly from the bundled executable (for those deployments that have been done with the mkbundle tool or for scenarios where the assembly has been registered as an embedded assembly). If this is not the case, then the assembly is loaded from disk using `api:mono_image_open_full`.

If the pointed assembly does not live in the Global Assembly Cache, a shadow copy of the assembly is made.

mono_assembly_open_full
Syntax
MonoAssembly* mono_assembly_open_full (const char *filename, MonoImageOpenStatus *status, gboolean refonly)

Parameters
filename the file to load
status return status code
refonly Whether this assembly is being opened in "reflection-only" mode.
Return value
NULL on error, with the status set to an error code, or a pointer to the assembly.
Description

This loads an assembly from the specified filename. The filename allows a local URL (starting with a file:// prefix). If a file prefix is used, the filename is interpreted as a URL, and the filename is URL-decoded. Otherwise the file is treated as a local path.

First, an attempt is made to load the assembly from the bundled executable (for those deployments that have been done with the mkbundle tool or for scenarios where the assembly has been registered as an embedded assembly). If this is not the case, then the assembly is loaded from disk using `api:mono_image_open_full`.

If the pointed assembly does not live in the Global Assembly Cache, a shadow copy of the assembly is made.

If refonly is set to true, then the assembly is loaded purely for inspection with the System.Reflection API.

mono_set_assemblies_path
Syntax
void mono_set_assemblies_path (const char* path)

Parameters
path list of paths that contain directories where Mono will look for assemblies
Description

Use this method to override the standard assembly lookup system and override any assemblies coming from the GAC. This is the method that supports the MONO_PATH variable.

Notice that MONO_PATH and this method are really a very bad idea as it prevents the GAC from working and it prevents the standard resolution mechanisms from working. Nonetheless, for some debugging situations and bootstrapping setups, this is useful to have.

mono_set_rootdir
Syntax
void mono_set_rootdir (void)

Description

Registers the root directory for the Mono runtime, for Linux and Solaris 10, this auto-detects the prefix where Mono was installed.

Working with Assemblies

mono_assembly_fill_assembly_name
Syntax
gboolean mono_assembly_fill_assembly_name (MonoImage *image, MonoAssemblyName *aname)

Parameters
image Image
aname Name
Return value
TRUE if successful
mono_assembly_foreach
Syntax
void mono_assembly_foreach (GFunc func, gpointer user_data)

Parameters
func function to invoke for each assembly loaded
user_data data passed to the callback
Description

Invokes the provided func callback for each assembly loaded into the runtime. The first parameter passed to the callback is the MonoAssembly*, and the second parameter is the user_data.

This is done for all assemblies loaded in the runtime, not just those loaded in the current application domain.

mono_assembly_get_image
Syntax
MonoImage* mono_assembly_get_image (MonoAssembly *assembly)

Parameters
assembly The assembly to retrieve the image from
Return value
the MonoImage associated with this assembly.
Description

mono_assembly_get_main
Syntax
MonoAssembly* mono_assembly_get_main (void)

Return value
the assembly for the application, the first assembly that is loaded by the VM
Description

mono_assembly_get_name
Syntax
MonoAssemblyName* mono_assembly_get_name (MonoAssembly *assembly)

Parameters
assembly The assembly to retrieve the name from
Return value
the MonoAssemblyName associated with this assembly.
Description

The returned name's lifetime is the same as assembly's.

mono_assembly_getrootdir
Syntax
G_CONST_RETURN gchar * mono_assembly_getrootdir (void)

Return value
a string with the directory, this string should not be freed.
Description

Obtains the root directory used for looking up assemblies.

mono_assembly_get_assemblyref
Syntax
void mono_assembly_get_assemblyref (MonoImage *image, int index, MonoAssemblyName *aname)

Parameters
image pointer to the MonoImage to extract the information from.
index index to the assembly reference in the image.
aname pointer to a MonoAssemblyName that will hold the returned value.
Description

Fills out the aname with the assembly name of the index assembly reference in image.

mono_assembly_loaded_full
Syntax
MonoAssembly* mono_assembly_loaded_full (MonoAssemblyName *aname, gboolean refonly)

Parameters
aname an assembly to look for.
refonly Whether this assembly is being opened in "reflection-only" mode.
Return value
NULL If the given aname assembly has not been loaded, or a pointer to a MonoAssembly that matches the MonoAssemblyName specified.
Description

This is used to determine if the specified assembly has been loaded

mono_assembly_load_reference
Syntax
void mono_assembly_load_reference (MonoImage *image, int index)

mono_assembly_load_references

Deprecated: There is no reason to use this method anymore, it does nothing
Syntax
void mono_assembly_load_references (MonoImage *image, MonoImageOpenStatus *status)

Parameters
image
status
Description

This method is now a no-op, it does nothing other than setting the status to MONO_IMAGE_OK

mono_assembly_load_module
Syntax
MonoImage* mono_assembly_load_module (MonoAssembly *assembly, guint32 idx)

mono_assembly_invoke_load_hook
Syntax
void mono_assembly_invoke_load_hook (MonoAssembly *ass)

mono_assembly_invoke_search_hook
Syntax
MonoAssembly* mono_assembly_invoke_search_hook (MonoAssemblyName *aname)

mono_assembly_set_main
Syntax
void mono_assembly_set_main (MonoAssembly *assembly)

mono_assembly_setrootdir
Syntax
void mono_assembly_setrootdir (const char *root_dir)

Parameters
root_dir The pathname of the root directory where we will locate assemblies
Description

This routine sets the internal default root directory for looking up assemblies.

This is used by Windows installations to compute dynamically the place where the Mono assemblies are located.

mono_register_config_for_assembly
Syntax
void mono_register_config_for_assembly (const char* assembly_name, const char* config_xml)

mono_register_symfile_for_assembly
Syntax
void mono_register_symfile_for_assembly (const char *assembly_name, const mono_byte *raw_contents, int size)

Assembly Names

The MonoAssemblyName contains the full identity of an assembly (name, culture, public key, public key token, version and any other flags).

These unmanaged objects represent the System.Reflection.AssemblyName managed type.

mono_assembly_name_new
Syntax
MonoAssemblyName* mono_assembly_name_new (const char *name)

Parameters
name name to parse
Return value
a newly allocated structure or NULL if there was any failure.
Description

Allocate a new MonoAssemblyName and fill its values from the passed name.

mono_assembly_name_get_name
Syntax
const char* mono_assembly_name_get_name (MonoAssemblyName *aname)

mono_assembly_name_get_culture
Syntax
const char* mono_assembly_name_get_culture (MonoAssemblyName *aname)

mono_assembly_name_get_version
Syntax
uint16_t mono_assembly_name_get_version (MonoAssemblyName *aname, uint16_t *minor, uint16_t *build, uint16_t *revision)

mono_assembly_name_get_pubkeytoken
Syntax
mono_byte* mono_assembly_name_get_pubkeytoken (MonoAssemblyName *aname)

mono_assembly_name_free
Syntax
void mono_assembly_name_free (MonoAssemblyName *aname)

Parameters
aname assembly name to free
Description

Frees the provided assembly name object. (it does not frees the object itself, only the name members).

mono_stringify_assembly_name
Syntax
char* mono_stringify_assembly_name (MonoAssemblyName *aname)

Parameters
aname the assembly name.
Return value
a newly allocated string with a string representation of the assembly name.
Description

Convert aname into its string format. The returned string is dynamically allocated and should be freed by the caller.

mono_assembly_names_equal
Syntax
gboolean mono_assembly_names_equal (MonoAssemblyName *l, MonoAssemblyName *r)

Parameters
l first assembly
r second assembly.
Return value
TRUE if both assembly names are equal.
Description

Compares two MonoAssemblyName instances and returns whether they are equal.

This compares the names, the cultures, the release version and their public tokens.

Modules

An assembly is made up of one or more modules.

mono_module_file_get_object
Syntax
MonoReflectionModule* mono_module_file_get_object (MonoDomain *domain, MonoImage *image, int table_index)

mono_module_get_object
Syntax
MonoReflectionModule* mono_module_get_object (MonoDomain *domain, MonoImage *image)

Advanced

mono_install_assembly_load_hook
Syntax
void mono_install_assembly_load_hook (MonoAssemblyLoadFunc func, gpointer user_data)

mono_install_assembly_search_hook
Syntax
void mono_install_assembly_search_hook (MonoAssemblySearchFunc func, gpointer user_data)

mono_install_assembly_refonly_search_hook
Syntax
void mono_install_assembly_refonly_search_hook (MonoAssemblySearchFunc func, gpointer user_data)

mono_install_assembly_preload_hook
Syntax
void mono_install_assembly_preload_hook (MonoAssemblyPreLoadFunc func, gpointer user_data)

mono_install_assembly_refonly_preload_hook
Syntax
void mono_install_assembly_refonly_preload_hook (MonoAssemblyPreLoadFunc func, gpointer user_data)

mono_install_assembly_postload_search_hook
Syntax
void mono_install_assembly_postload_search_hook (MonoAssemblySearchFunc func, gpointer user_data)