Struct
GLibMainContext
Description [src]
struct GMainContext {
/* No available fields */
}
The GMainContext
struct is an opaque data
type representing a set of sources to be handled in a main loop.
Functions
g_main_context_default
Returns the global-default main context. This is the main context
used for main loop functions when a main loop is not explicitly
specified, and corresponds to the “main” main loop. See also
g_main_context_get_thread_default()
.
g_main_context_get_thread_default
Gets the thread-default GMainContext
for this thread. Asynchronous
operations that want to be able to be run in contexts other than
the default one should call this method or
g_main_context_ref_thread_default()
to get a
GMainContext
to add their GSource
s to. (Note that
even in single-threaded programs applications may sometimes want to
temporarily push a non-default context, so it is not safe to assume that
this will always return NULL
if you are running in the default thread.).
since: 2.22
g_main_context_pusher_free
Pop pusher
’s main context as the thread default main context.
See g_main_context_pusher_new()
for details.
since: 2.64
g_main_context_ref_thread_default
Gets the thread-default GMainContext
for this thread, as with
g_main_context_get_thread_default()
, but also adds a reference to
it with g_main_context_ref()
. In addition, unlike
g_main_context_get_thread_default()
, if the thread-default context
is the global-default context, this will return that
GMainContext
(with a ref added to it) rather than returning
NULL
.
since: 2.32
Instance methods
g_main_context_acquire
Tries to become the owner of the specified context.
If some other thread is the owner of the context,
returns FALSE
immediately. Ownership is properly
recursive: the owner can require ownership again
and will release ownership when g_main_context_release()
is called as many times as g_main_context_acquire()
.
g_main_context_add_poll
Adds a file descriptor to the set of file descriptors polled for
this context. This will very seldom be used directly. Instead
a typical event source will use g_source_add_unix_fd
instead.
g_main_context_check
Passes the results of polling back to the main loop. You should be
careful to pass fds
and its length n_fds
as received from
g_main_context_query()
, as this functions relies on assumptions
on how fds
is filled.
g_main_context_find_source_by_funcs_user_data
Finds a source with the given source functions and user data. If multiple sources exist with the same source function and user data, the first one found will be returned.
g_main_context_find_source_by_user_data
Finds a source with the given user data for the callback. If multiple sources exist with the same user data, the first one found will be returned.
g_main_context_invoke
Invokes a function in such a way that context
is owned during the
invocation of function
.
since: 2.28
g_main_context_invoke_full
Invokes a function in such a way that context
is owned during the
invocation of function
.
since: 2.28
g_main_context_is_owner
Determines whether this thread holds the (recursive)
ownership of this GMainContext
. This is useful to
know before waiting on another thread that may be
blocking to get ownership of context
.
since: 2.10
g_main_context_iteration
Runs a single iteration for the given main loop. This involves
checking to see if any event sources are ready to be processed,
then if no events sources are ready and may_block
is TRUE
, waiting
for a source to become ready, then dispatching the highest priority
events sources that are ready. Otherwise, if may_block
is FALSE
sources are not waited to become ready, only those highest priority
events sources will be dispatched (if any), that are ready at this
given moment without further waiting.
g_main_context_pop_thread_default
Pops context
off the thread-default context stack (verifying that
it was on the top of the stack).
since: 2.22
g_main_context_prepare
Prepares to poll sources within a main loop. The resulting information
for polling is determined by calling g_main_context_query()
.
g_main_context_push_thread_default
Acquires context
and sets it as the thread-default context for the
current thread. This will cause certain asynchronous operations
(such as most [gio][gio]-based I/O) which are
started in this thread to run under context
and deliver their
results to its main loop, rather than running under the global
default main context in the main thread. Note that calling this function
changes the context returned by g_main_context_get_thread_default()
,
not the one returned by g_main_context_default()
, so it does not
affect the context used by functions like g_idle_add()
.
since: 2.22
g_main_context_pusher_new
Push main_context
as the new thread-default main context for the current
thread, using g_main_context_push_thread_default()
, and return a
new GMainContextPusher
. Pop with g_main_context_pusher_free().
Using g_main_context_pop_thread_default()
on main_context
while a
GMainContextPusher
exists for it can lead to undefined behaviour.
since: 2.64
g_main_context_query
Determines information necessary to poll this main loop. You should
be careful to pass the resulting fds
array and its length n_fds
as is when calling g_main_context_check()
, as this function relies
on assumptions made when the array is filled.
g_main_context_release
Releases ownership of a context previously acquired by this thread
with g_main_context_acquire()
. If the context was acquired multiple
times, the ownership will be released only when g_main_context_release()
is called as many times as it was acquired.
g_main_context_remove_poll
Removes file descriptor from the set of file descriptors to be polled for a particular context.
g_main_context_set_poll_func
Sets the function to use to handle polling of file descriptors. It
will be used instead of the poll()
system call
(or GLib’s replacement function, which is used where
poll()
isn’t available).
g_main_context_unref
Decreases the reference count on a GMainContext
object by one.
If
the result is zero, free the context and free all associated memory.
g_main_context_wait
Tries to become the owner of the specified context,
as with g_main_context_acquire()
. But if another thread
is the owner, atomically drop mutex
and wait on cond
until
that owner releases ownership or until cond
is signaled, then
try again (once) to become the owner.
deprecated: 2.58
g_main_context_wakeup
If context
is currently blocking in g_main_context_iteration()
waiting for a source to become ready, cause it to stop blocking
and return. Otherwise, cause the next invocation of
g_main_context_iteration()
to return without blocking.