11.8.1 Enabling or Disabling Synchronization
When debugging X applications,
it often is very convenient to require Xlib to behave synchronously
so that errors are reported as they occur.
The following function lets you disable or enable synchronous behavior.
Note that graphics may occur 30 or more times more slowly when
synchronization is enabled.
On POSIX-conformant systems,
there is also a global variable
that, if set to nonzero before starting a program under a debugger, will force
synchronous library behavior.
After completing their work,
all Xlib functions that generate protocol requests call what is known as
an after function.
sets which function is to be called.
To enable or disable synchronization, use
Christophe Tronche, email@example.com