module_init.cpp File Reference

#include "precompiled.h"
#include "lib/module_init.h"
#include "lib/sysdep/cpu.h"

Go to the source code of this file.

Functions
Status	ModuleInit (volatile ModuleInitState *initState, Status(*init)())
	calls a user-defined init function if initState is zero. More...
Status	ModuleShutdown (volatile ModuleInitState *initState, void(*shutdown)())
	calls a user-defined shutdown function if initState is "initialized". More...

Variables
static const ModuleInitState	UNINITIALIZED = 0
static const ModuleInitState	BUSY = ERR::AGAIN
static const ModuleInitState	INITIALIZED = INFO::SKIPPED

Function Documentation

Status ModuleInit	(	volatile ModuleInitState *	initState,
		Status(*)()	init
	)

calls a user-defined init function if initState is zero.

Returns

INFO::SKIPPED if already initialized, a Status if the previous invocation failed, or the value returned by the callback.

postcondition: initState is "initialized" if the callback returned INFO::OK, otherwise its Status return value (which prevents shutdown from being called).

thread-safe: subsequent callers spin until the callback returns (this prevents using partially-initialized modules)

note that callbacks typically reference static data and thus do not require a function argument, but that can later be added if necessary.

Definition at line 40 of file module_init.cpp.

Status ModuleShutdown	(	volatile ModuleInitState *	initState,
		void(*)()	shutdown
	)

calls a user-defined shutdown function if initState is "initialized".

Returns

INFO::OK if shutdown occurred, INFO::SKIPPED if initState was zero (uninitialized), otherwise the Status returned by ModuleInit.

postcondition: initState remains set to the Status, or has been reset to zero to allow multiple init/shutdown pairs, e.g. in self-tests.

note: there is no provision for reference-counting because that turns out to be problematic (a user might call shutdown immediately after init; if this is the first use of the module, it will be shutdown prematurely, which is at least inefficient and possibly dangerous). instead, shutdown should only be called when cleanup is necessary (e.g. at exit before leak reporting) and it is certain that the module is no longer in use.

Definition at line 65 of file module_init.cpp.

Variable Documentation

const ModuleInitState BUSY = ERR::AGAIN

static

Definition at line 35 of file module_init.cpp.

const ModuleInitState INITIALIZED = INFO::SKIPPED

static

Definition at line 37 of file module_init.cpp.

const ModuleInitState UNINITIALIZED = 0

static

Definition at line 33 of file module_init.cpp.