1XInitThreads(3)                 XLIB FUNCTIONS                 XInitThreads(3)
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NAME

6       XInitThreads, XLockDisplay, XUnlockDisplay - multi-threading support
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SYNTAX

9       Status XInitThreads(void);
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11       void XLockDisplay(Display *display);
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13       void XUnlockDisplay(Display *display);
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ARGUMENTS

16       display   Specifies the connection to the X server.
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DESCRIPTION

19       The XInitThreads function initializes Xlib support for concurrent
20       threads.  This function must be the first Xlib function a multi-
21       threaded program calls, and it must complete before any other Xlib call
22       is made.  This function returns a nonzero status if initialization was
23       successful; otherwise, it returns zero.  On systems that do not support
24       threads, this function always returns zero.
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26       It is only necessary to call this function if multiple threads might
27       use Xlib concurrently.  If all calls to Xlib functions are protected by
28       some other access mechanism (for example, a mutual exclusion lock in a
29       toolkit or through explicit client programming), Xlib thread initial‐
30       ization is not required.  It is recommended that single-threaded pro‐
31       grams not call this function.
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34       The XLockDisplay function locks out all other threads from using the
35       specified display.  Other threads attempting to use the display will
36       block until the display is unlocked by this thread.  Nested calls to
37       XLockDisplay work correctly; the display will not actually be unlocked
38       until XUnlockDisplay has been called the same number of times as XLock‐
39       Display.  This function has no effect unless Xlib was successfully ini‐
40       tialized for threads using XInitThreads.
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42       The XUnlockDisplay function allows other threads to use the specified
43       display again.  Any threads that have blocked on the display are
44       allowed to continue.  Nested locking works correctly; if XLockDisplay
45       has been called multiple times by a thread, then XUnlockDisplay must be
46       called an equal number of times before the display is actually
47       unlocked.  This function has no effect unless Xlib was successfully
48       initialized for threads using XInitThreads.
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SEE ALSO

51       Xlib - C Language X Interface
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55X Version 11                     libX11 1.3.4                  XInitThreads(3)
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