The "chm" Package
These routines are meant to provide a generic and simple to use channel
management facility (i.e. event processing on pipes, connections and
terminals).
A similar set of routines: chx_ provide identical functionality
(with the exception of the polling routine), except that they rely on the
Xt Intrinsics event dispatching system.
Library: karma
Link With: -lkarma
Functions
Prototype Functions
Functions
KManagedChannel
chm_manage ( Channel channel, void *info,
flag (*input_func) (), void (*close_func) (),
flag (*output_func) (),flag (*exception_func) () )
Manage a channel for activity by registering callback routines.
Parameters:
- channel :
The channel object to manage.
- info :
The arbitrary information pointer associated with the managed
channel. This pointer may be modified by the callback routines.
- input_func :
This routine is called when new input occurs on the channel.
If this is NULL, no callback routine is installed. The prototype function
is chm_PROTO_input_func.
- close_func :
This routine is called when the channel closes. If this is
NULL, no callback routine is installed. The prototype function is
chm_PROTO_close_func. The channel object MUST be capable of detecting
closure if this routine is supplied (i.e. this routine cannot be supplied
for dock channels). Any unread buffered data in the channel will be lost
upon closure. The call to this function is the last chance to read this
buffered data.
- output_func :
This routine is called when the channel becomes ready for
output. If this is NULL, no callback routine is installed. The prototype
function is chm_PROTO_output_func.
- exception_func :
This routine is called when exceptions occur on the
channel. If this is NULL, no callback routine is installed. The prototype
function is chm_PROTO_exception_func.
Returns: A KManagedChannel object on success, else NULL.
Multithreading Level: Unsafe
void
chm_unmanage (Channel channel)
Terminate the management of a channel for activity.
Parameters:
- channel :
The channel object to unmanage. The channel must be open.
Returns: Nothing.
Multithreading Level: Unsafe
Note: - This routine will NOT close the channel.
EXPERIMENTAL FUNCTION: subject to change without notice
void
chm_unmanage_by_handle (KManagedChannel mch)
Terminate the management of a channel for activity.
Parameters:
- mch :
The KManagedChannel object.
Returns: Nothing.
Multithreading Level: Unsafe
Note: - This routine will NOT close the channel.
Prototype Functions
flag
chm_PROTO_input_func (Channel channel, void **info)
This routine is called when new input occurs on a channel.
Parameters:
- channel :
The channel object.
- info :
A pointer to the arbitrary information pointer. This may be modified
Returns: TRUE if the channel is to remain managed and open, else FALSE
(indicating that the channel is to be unmanaged and closed).
Multithreading Level: Unsafe
Note: - This routine MUST NOT unmanage or close the channel.
- The close_func will be called if this routine returns FALSE.
void
chm_PROTO_close_func (Channel channel, void *info)
This routine is called when a channel closes.
Parameters:
- channel :
The channel object.
- info :
The arbitrary pointer for the channel.
Returns: Nothing.
Multithreading Level: Unsafe
Note: - This routine MUST NOT unmanage the channel. The channel will be
automatically unmanaged and deleted upon closure (even if no close_func
is specified).
flag
chm_PROTO_output_func (Channel channel, void **info)
This routine is called when a channel becomes ready for writing.
Parameters:
- channel :
The channel object.
- info :
A pointer to the arbitrary information pointer. This may be modified
Returns: TRUE if the channel is to remain managed and open, else FALSE
(indicating that the channel is to be unmanaged and closed).
Multithreading Level: Unsafe
Note: - This routine MUST NOT unmanage or close the channel.
- The close_func will be called if this routine returns FALSE.
flag
chm_PROTO_exception_func (Channel channel, void **info)
This routine is called when an exception occurs on channel.
Parameters:
- channel :
The channel object.
- info :
A pointer to the arbitrary information pointer. This may be modified
Returns: TRUE if the channel is to remain managed and open, else FALSE
(indicating that the channel is to be unmanaged and closed).
Multithreading Level: Unsafe
Note: - This routine MUST NOT unmanage or close the channel.
- The close_func will be called if this routine returns FALSE.
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