_fini(9E)							Driver Entry Points							 _fini(9E)

NAME

       _fini, _info, _init - loadable module configuration entry points

SYNOPSIS

       #include <sys/modctl.h>

       int _fini(void)

       int _info(struct modinfo *modinfop);

       int _init(void)

INTERFACE LEVEL

       Solaris DDI specific (Solaris DDI). These entry points are required. You must write them.

PARAMETERS

   _info()
       modinfop     A pointer to an opaque modinfo structure.

DESCRIPTION

       _init()	initializes  a	loadable module. It is called before any other routine in a loadable module. _init() returns the value returned by
       mod_install(9F). The module may optionally perform some other work before the mod_install(9F) call is performed. If  the  module  has  done
       some  setup  before  the  mod_install(9F)  function  is called, then it should be prepared to undo that setup if mod_install(9F) returns an
       error.

       _info() returns information about a loadable module. _info() returns the value returned by mod_info(9F).

       _fini() prepares a loadable module for unloading. It is called when the system wants to unload a module. If the module determines  that	it
       can  be	unloaded,  then  _fini() returns the value returned by mod_remove(9F). Upon successful return from _fini() no other routine in the
       module will be called before _init() is called.

RETURN VALUES

       _init() should return the appropriate error number if there is an error, otherwise it should return the return value from mod_install(9F).

       _info() should return the return value from mod_info(9F)

       _fini() should return the return value from mod_remove(9F). _fini() is permitted to return EBUSY prior to  calling  mod_remove(9F)  if  the
       driver  should  not be unloaded. Driver global resources, such as mutexes and calls to ddi_soft_state_fini(9F), should only be destroyed in
       _fini() after mod_remove() returns successfully.

EXAMPLES

       Example 1 Initializing and Freeing a Mutex

       The following example demonstrates how to initialize and free a mutex(9F).

	 #include <sys/modctl.h>
	 #include <sys/ddi.h>
	 #include <sys/sunddi.h>
	 static struct dev_ops	drv_ops;
	 /*
	  * Module linkage information for the kernel.
	  */
	 static struct modldrv modldrv = {
	      &mod_driverops,	  /* Type of module.  This one is a driver */
	     "Sample Driver",
	     &drv_ops	    /* driver ops */
	 };

	 static struct modlinkage modlinkage = {
		 MODREV_1,
		 &modldrv,
		 NULL
	 };

	 /*
	  * Global driver mutex
	  */
	 static kmutex_t   xx_global_mutex;

	 int
	 _init(void)
	 {
		 int	 i;

		 /*
		   * Initialize global mutex before mod_install'ing driver.
		   * If mod_install() fails, must clean up mutex initialization
		   */
		 mutex_init(&xx_global_mutex, NULL,
			 MUTEX_DRIVER, (void *)NULL);

		 if ((i = mod_install(&modlinkage)) != 0) {
			 mutex_destroy(&xx_global_mutex);
		 }

		 return (i);
	 }

	 int
	 _info(struct modinfo *modinfop)
	 {
		 return (mod_info(&modlinkage, modinfop));
	 }

	 int
	 _fini(void)
	 {
		 int	   i;

		 /*
		   * If mod_remove() is successful, we destroy our global mutex
		   */
		 if ((i = mod_remove(&modlinkage)) == 0) {
			  mutex_destroy(&xx_global_mutex);
		 }
		 return (i);
	 }

SEE ALSO

       add_drv(1M), mod_info(9F), mod_install(9F), mod_remove(9F), mutex(9F), modldrv(9S), modlinkage(9S), modlstrmod(9S)

       Writing Device Drivers

WARNINGS

       Do not change the structures referred to by the modlinkage structure after the call to mod_install(), as the  system  may  copy	or  change
       them.

NOTES

       Even  though the identifiers _fini(), _info(), and _init() appear to be declared as globals, their scope is restricted by the kernel to the
       module that they are defined in.

BUGS

       On some implementations _info() may be called before _init().

SunOS 5.11							    22 Jan 2002 							 _fini(9E)