door_info(3X)

NAME

door_info − return information associated with a door descriptor

SYNOPSIS

#include <door.h>
int door_info (int d, struct door_info ∗info);

DESCRIPTION

The door_info() function returns information associated with a door descriptor. door_info() obtains information about the door descriptor d and places the information that is relevant to the door in the structure pointed to by the argument info.

The contents of the info argument contains the following fields:

pid_t	di_target;	/∗ door server pid ∗/
door_ptr_t	di_proc;	/∗ server function ∗/
door_ptr_t	di_data;	/∗ data cookie for invocation ∗/
door_attr_t	di_attributes;	/∗ door attributes ∗/
door_id_t	di_uniquifier;	/∗ unique id among all doors ∗/

The values for di_attributes may be composed of the following:

DOOR_LOCAL The door descriptor refers to a service procedure in this process.

DOOR_UNREF The door has requested notification when all but the last reference remain.

DOOR_REVOKED
The door descriptor refers to a door that has been revoked.

DOOR_PRIVATE
The door has a separate pool of server threads associated with it.

The di_proc and di_data fields are returned as door_ptr_t objects rather than void ∗ pointers in order to allow clients and servers to interoperate in environments where the pointer sizes may vary in size (for example, 32-bit clients and 64-bit servers). Each door has a system-wide unique number associated with it that is set when the door is created by door_create(). This number is returned in di_uniquifier.

RETURN VALUES

Upon successful completion, 0 is returned. Upon failure, -1 is returned and errno is set to indicate the error.

ERRORS

The door_info() function fails if one or more of the following are true:

EFAULT The address of argument info is an invalid address.

EBADF d is not a door descriptor.

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