xaddconnectionwatch(3) [centos man page]
XAddConnectionWatch(3) XLIB FUNCTIONS XAddConnectionWatch(3) NAME
XAddConnectionWatch, XRemoveConnectionWatch, XProcessInternalConnection, XInternalConnectionNumbers - handle Xlib internal connections SYNTAX
typedef void (*XConnectionWatchProc)(Display *display, XPointer client_data, int fd, Bool opening, XPointer *watch_data); Status XAddConnectionWatch(Display *display, XWatchProc procedure, XPointer client_data); Status XRemoveConnectionWatch(Display *display, XWatchProc procedure, XPointer client_data); void XProcessInternalConnection(Display *display, int fd); Status XInternalConnectionNumbers(Display *display, int **fd_return, int *count_return); ARGUMENTS
client_data Specifies the additional client data. count_return Returns the number of file descriptors. display Specifies the connection to the X server. fd Specifies the file descriptor. fd_return Returns the file descriptors. procedure Specifies the procedure to be called. DESCRIPTION
The XAddConnectionWatch function registers a procedure to be called each time Xlib opens or closes an internal connection for the specified display. The procedure is passed the display, the specified client_data, the file descriptor for the connection, a Boolean indicating whether the connection is being opened or closed, and a pointer to a location for private watch data. If opening is True, the procedure can store a pointer to private data in the location pointed to by watch_data; when the procedure is later called for this same connection and opening is False, the location pointed to by watch_data will hold this same private data pointer. This function can be called at any time after a display is opened. If internal connections already exist, the registered procedure will immediately be called for each of them, before XAddConnectionWatch returns. XAddConnectionWatch returns a nonzero status if the procedure is successfully registered; otherwise, it returns zero. The registered procedure should not call any Xlib functions. If the procedure directly or indirectly causes the state of internal connec- tions or watch procedures to change, the result is not defined. If Xlib has been initialized for threads, the procedure is called with the display locked and the result of a call by the procedure to any Xlib function that locks the display is not defined unless the executing thread has externally locked the display using XLockDisplay. The XRemoveConnectionWatch function removes a previously registered connection watch procedure. The client_data must match the client_data used when the procedure was initially registered. The XProcessInternalConnection function processes input available on an internal connection. This function should be called for an inter- nal connection only after an operating system facility (for example, select or poll) has indicated that input is available; otherwise, the effect is not defined. The XInternalConnectionNumbers function returns a list of the file descriptors for all internal connections currently open for the speci- fied display. When the allocated list is no longer needed, free it by using XFree. This functions returns a nonzero status if the list is successfully allocated; otherwise, it returns zero. SEE ALSO
Xlib - C Language X Interface X Version 11 libX11 1.6.0 XAddConnectionWatch(3)
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XAddConnectionWatch(3) XLIB FUNCTIONS XAddConnectionWatch(3) NAME
XAddConnectionWatch, XRemoveConnectionWatch, XProcessInternalConnection, XInternalConnectionNumbers - handle Xlib internal connections SYNTAX
typedef void (*XConnectionWatchProc)(Display *display, XPointer client_data, int fd, Bool opening, XPointer *watch_data); Status XAddConnectionWatch(Display *display, XWatchProc procedure, XPointer client_data); Status XRemoveConnectionWatch(Display *display, XWatchProc procedure, XPointer client_data); void XProcessInternalConnection(Display *display, int fd); Status XInternalConnectionNumbers(Display *display, int **fd_return, int *count_return); ARGUMENTS
client_data Specifies the additional client data. count_return Returns the number of file descriptors. display Specifies the connection to the X server. fd Specifies the file descriptor. fd_return Returns the file descriptors. procedure Specifies the procedure to be called. DESCRIPTION
The XAddConnectionWatch function registers a procedure to be called each time Xlib opens or closes an internal connection for the specified display. The procedure is passed the display, the specified client_data, the file descriptor for the connection, a Boolean indicating whether the connection is being opened or closed, and a pointer to a location for private watch data. If opening is True, the procedure can store a pointer to private data in the location pointed to by watch_data; when the procedure is later called for this same connection and opening is False, the location pointed to by watch_data will hold this same private data pointer. This function can be called at any time after a display is opened. If internal connections already exist, the registered procedure will immediately be called for each of them, before XAddConnectionWatch returns. XAddConnectionWatch returns a nonzero status if the procedure is successfully registered; otherwise, it returns zero. The registered procedure should not call any Xlib functions. If the procedure directly or indirectly causes the state of internal connec- tions or watch procedures to change, the result is not defined. If Xlib has been initialized for threads, the procedure is called with the display locked and the result of a call by the procedure to any Xlib function that locks the display is not defined unless the executing thread has externally locked the display using XLockDisplay. The XRemoveConnectionWatch function removes a previously registered connection watch procedure. The client_data must match the client_data used when the procedure was initially registered. The XProcessInternalConnection function processes input available on an internal connection. This function should be called for an inter- nal connection only after an operating system facility (for example, select or poll) has indicated that input is available; otherwise, the effect is not defined. The XInternalConnectionNumbers function returns a list of the file descriptors for all internal connections currently open for the speci- fied display. When the allocated list is no longer needed, free it by using XFree. This functions returns a nonzero status if the list is successfully allocated; otherwise, it returns zero. SEE ALSO
Xlib - C Language X Interface X Version 11 libX11 1.5.0 XAddConnectionWatch(3)