POSIX Signal Handling: libxfce4util Reference Manual

POSIX Signal Handling

POSIX Signal Handling — a callback system for handling POSIX signals safely

Functions

void	(*XfcePosixSignalHandler) ()
gboolean	xfce_posix_signal_handler_init ()
void	xfce_posix_signal_handler_restore_handler ()
gboolean	xfce_posix_signal_handler_set_handler ()
void	xfce_posix_signal_handler_shutdown ()

Includes

#include <libxfce4util/libxfce4util.h>

Description

Due to reentrancy issues, there is a restricted set of functions/syscalls that are allowed to be performed inside a POSIX signal handler. In general, it's safer to defer any signal-related processing until after the signal handler has run. The functionality in this module automatically handles this, and allows you to set a handler function (with optional user data) for any signal.

Functions

XfcePosixSignalHandler ()

void
(*XfcePosixSignalHandler) (gint signal,
                           gpointer user_data);

Parameters

signal	The signal that was caught.
user_data	The `user_data` parameter passed when the handler was registered.

xfce_posix_signal_handler_init ()

gboolean
xfce_posix_signal_handler_init (GError **error);

Initializes the POSIX signal handler system. Must be called before setting any POSIX signal handlers.

Parameters

error

Location of a GError to store any possible errors.

[out][allow-none][transfer full]

Returns

TRUE on success, FALSE on failure, in which case error will be set.

xfce_posix_signal_handler_restore_handler ()

void
xfce_posix_signal_handler_restore_handler
                               (gint signal);

Restores the default handler for signal .

Parameters

signal

A POSIX signal id number.

xfce_posix_signal_handler_set_handler ()

gboolean
xfce_posix_signal_handler_set_handler (gint signal,
                                       XfcePosixSignalHandler handler,
                                       gpointer user_data,
                                       GError **error);

Sets handler to be called whenever signal is caught by the application. The user_data parameter will be passed as an argument to handler .

Parameters

signal	A POSIX signal id number.
handler	A callback function.	[scope call]
user_data	Arbitrary data that will be passed to `handler` .
error	Location of a GError to store any possible errors.	[out][allow-none][transfer full]

Returns

TRUE on success, FALSE otherwise, in which case error will be set.

xfce_posix_signal_handler_shutdown ()

void
xfce_posix_signal_handler_shutdown (void);

Frees all memory associated with the POSIX signal handling system and restores all default signal handlers.