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Table of Contents
XInitThreads, XLockDisplay,
XUnlockDisplay - multi-threading support
- Status XInitThreads(void);
- void XLockDisplay(Display *display);
- void XUnlockDisplay(Display *display);
- display
- Specifies the connection to the X server.
The
XInitThreads function initializes Xlib support for concurrent threads.
This function must be the first Xlib function a multi-threaded program calls,
and it must complete before any other Xlib call is made. This function returns
a nonzero status if initialization was successful; otherwise, it returns
zero. On systems that do not support threads, this function always returns
zero.
It is only necessary to call this function if multiple threads might
use Xlib concurrently. If all calls to Xlib functions are protected by
some other access mechanism (for example, a mutual exclusion lock in a
toolkit or through explicit client programming), Xlib thread initialization
is not required. It is recommended that single-threaded programs not call
this function.
The XLockDisplay function locks out all other threads
from using the specified display. Other threads attempting to use the display
will block until the display is unlocked by this thread. Nested calls to
XLockDisplay work correctly; the display will not actually be unlocked
until XUnlockDisplay has been called the same number of times as XLockDisplay.
This function has no effect unless Xlib was successfully initialized
for threads using XInitThreads.
The XUnlockDisplay function allows other
threads to use the specified display again. Any threads that have blocked
on the display are allowed to continue. Nested locking works correctly;
if XLockDisplay has been called multiple times by a thread, then XUnlockDisplay
must be called an equal number of times before the display is actually
unlocked. This function has no effect unless Xlib was successfully initialized
for threads using XInitThreads.
Xlib - C Language X Interface
Table of Contents
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