SourceFuncsPrepareFunc

Checks the source for readiness.

Called before all the file descriptors are polled. If the source can determine that it is ready here (without waiting for the results of the poll call) it should return true. It can also return a @timeout_ value which should be the maximum timeout (in milliseconds) which should be passed to the poll call. The actual timeout used will be -1 if all sources returned -1, or it will be the minimum of all the @timeout_ values returned which were greater than or equal to 0. If the prepare function returns a timeout and the source also has a ready time set, then the lower of the two will be used.

Since 2.36 this may be NULL, in which case the effect is as if the function always returns FALSE with a timeout of -1.

• param source The #GSource

• return true if the source is ready, false otherwise