main.sgml

GLib是GTK+和GNOME工程的基础底层核心程序库

</para>

@context: 
@func: 


<!-- ##### FUNCTION g_main_context_get_poll_func ##### -->
<para>

</para>

@context: 
@Returns: 


<!-- ##### USER_FUNCTION GPollFunc ##### -->
<para>
Specifies the type of function passed to g_main_set_poll_func().
The semantics of the function should match those of the
<function>poll()</function> system call.
</para>

@ufds: an array of #GPollFD elements.
@nfsd: the number of elements in @ufds.
@timeout: the maximum time to wait for an event of the file descriptors.
          A negative value indicates an infinite timeout.
@Returns: the number of #GPollFD elements which have events or errors reported,
or -1 if an error occurred.


<!-- ##### FUNCTION g_main_context_add_poll ##### -->
<para>

</para>

@context: 
@fd: 
@priority: 


<!-- ##### FUNCTION g_main_context_remove_poll ##### -->
<para>

</para>

@context: 
@fd: 


<!-- ##### MACRO g_main_set_poll_func ##### -->
<para>
Sets the function to use for the handle polling of file descriptors
for the default main context. This is a compatability macro, see
g_main_context_set_poll_func() for full details.
</para>

@func: the function to call to poll all file descriptors.


<!-- ##### FUNCTION g_timeout_source_new ##### -->
<para>

</para>

@interval: 
@Returns: 


<!-- ##### FUNCTION g_timeout_add ##### -->
<para>
</para>

@interval: 
@function: 
@data: 
@Returns: 


<!-- ##### FUNCTION g_timeout_add_full ##### -->
<para>
</para>

@priority: 
@interval: 
@function: 
@data: 
@notify: 
@Returns: 


<!-- ##### FUNCTION g_idle_source_new ##### -->
<para>

</para>

@Returns: 


<!-- ##### FUNCTION g_idle_add ##### -->
<para>
</para>

@function: 
@data: 
@Returns: 


<!-- ##### FUNCTION g_idle_add_full ##### -->
<para>
</para>

@priority: 
@function: 
@data: 
@notify: 
@Returns: 


<!-- ##### FUNCTION g_idle_remove_by_data ##### -->
<para>
</para>

@data: 
@Returns: 


<!-- ##### STRUCT GPollFD ##### -->
<para>

<informaltable pgwide=1 frame="none" role="struct">
<tgroup cols="2"><colspec colwidth="2*"><colspec colwidth="8*">
<tbody>

<row>
<entry>#gint fd;</entry>
<entry>the file descriptor to poll (or a <type>HANDLE</type> on Win32 platforms).</entry>
</row>

<row>
<entry>#gushort events;</entry>
<entry>a bitwise combination of flags from #GIOCondition, specifying which
events should be polled for. Typically for reading from a file descriptor
you would use %G_IO_IN | %G_IO_HUP | %G_IO_ERR, and for writing you would use
%G_IO_OUT | %G_IO_ERR.
</entry>
</row>

<row>
<entry>#gushort revents;</entry>
<entry>a bitwise combination of flags from #GIOCondition, returned from the
<function>poll()</function> function to indicate which events occurred.
</entry>
</row>
</tbody></tgroup></informaltable>

</para>

@fd: 
@events: 
@revents: 

<!-- ##### STRUCT GSource ##### -->
<para>
The <structname>GSource</structname> struct is an opaque data type representing
an event source.
</para>


<!-- ##### STRUCT GSourceFuncs ##### -->
<para>
The #GSourceFuncs struct contains a table of functions used to handle
event sources in a generic manner.

<informaltable pgwide=1 frame="none" role="struct">
<tgroup cols="2"><colspec colwidth="2*"><colspec colwidth="8*">
<tbody>

<row>
<entry>prepare</entry>
<entry>
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 <function>poll()</function> 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 <function>poll()</function> 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 >= 0.
</entry>
</row>

<row>
<entry>check</entry>
<entry>
Called after all the file descriptors are polled.
The source should return %TRUE if it is ready to be dispatched.
Note that some time may have passed since the previous prepare function was
called, so the source should be checked again here.
</entry>
</row>

<row>
<entry>dispatch</entry>
<entry>
Called to dispatch the event source, after it has returned %TRUE in
either its @prepare or its @check function. The @dispatch function is
passed in a callback function and data. The callback function may be
%NULL if the source was never connected using g_source_connect(). The
@dispatch function should call the callback function with data and
whatever additional parameters are needed for this type of event source.
</entry>
</row>

<row>
<entry>finalize</entry>
<entry>
Called when the source is finalized.
</entry>
</row>
</tbody></tgroup></informaltable>
</para>

<para>
For idle sources, the prepare and check functions always return %TRUE to
indicate that the source is always ready to be processed.
The prepare function also returns a timeout value of 0 to ensure that the
<function>poll()</function> call doesn't block (since that would be time 
wasted which could have been spent running the idle function).
</para>
<para>
For timeout sources, the prepare and check functions both return %TRUE if the
timeout interval has expired. The prepare function also returns a timeout 
value to ensure that the <function>poll()</function> call doesn't block too 
long and miss the next timeout.
</para>
<para>
For file descriptor sources, the prepare function typically returns %FALSE,
since it must wait until <function>poll()</function> has been called before 
it knows whether any events need to be processed. It sets the returned 
timeout to -1 to indicate that it doesn't mind how long the 
<function>poll()</function> call blocks.
In the check function, it tests the results of the <function>poll()</function>
call to see if the required condition has been met, and returns %TRUE if so.
</para>

@prepare: 
@check: 
@dispatch: 
@finalize: 
@closure_callback: 
@closure_marshal: 

<!-- ##### STRUCT GSourceCallbackFuncs ##### -->
<para>
The <structname>GSourceCallbackFuncs</structname> struct contains
functions for managing callback objects. 
</para>

@ref: Called when a reference is added to the callback object.
@unref: Called when a reference to the callback object is dropped.
@get: Called to extract the callback function and data from the callback object.

<!-- ##### USER_FUNCTION GSourceDummyMarshal ##### -->
<para>

</para>



<!-- ##### FUNCTION g_source_new ##### -->
<para>

</para>

@source_funcs: 
@struct_size: 
@Returns: 


<!-- ##### FUNCTION g_source_ref ##### -->
<para>

</para>

@source: 
@Returns: 


<!-- ##### FUNCTION g_source_unref ##### -->
<para>

</para>

@source: 


<!-- ##### FUNCTION g_source_attach ##### -->
<para>

</para>

@source: 
@context: 
@Returns: 


<!-- ##### FUNCTION g_source_destroy ##### -->
<para>

</para>

@source: 


<!-- ##### FUNCTION g_source_set_priority ##### -->
<para>

</para>

@source: 
@priority: 


<!-- ##### FUNCTION g_source_get_priority ##### -->
<para>

</para>

@source: 
@Returns: 


<!-- ##### FUNCTION g_source_set_can_recurse ##### -->
<para>

</para>

@source: 
@can_recurse: 


<!-- ##### FUNCTION g_source_get_can_recurse ##### -->
<para>

</para>

@source: 
@Returns: 


<!-- ##### FUNCTION g_source_get_id ##### -->
<para>

</para>

@source: 
@Returns: 


<!-- ##### FUNCTION g_source_get_context ##### -->
<para>

</para>

@source: 
@Returns: 


<!-- ##### FUNCTION g_source_set_callback ##### -->
<para>

</para>

@source: 
@func: 
@data: 
@notify: 


<!-- ##### USER_FUNCTION GSourceFunc ##### -->
<para>
Specifies the type of function passed to g_timeout_add(), g_timeout_add_full(),
g_idle_add(), and g_idle_add_full().
</para>

@data: data passed to the function, set when the source was created with one
of the above functions.
@Returns: it should return %FALSE if the source should be removed.


<!-- ##### FUNCTION g_source_set_callback_indirect ##### -->
<para>

</para>

@source: 
@callback_data: 
@callback_funcs: 


<!-- ##### FUNCTION g_source_add_poll ##### -->
<para>

</para>

@source: 
@fd: 


<!-- ##### FUNCTION g_source_remove_poll ##### -->
<para>

</para>

@source: 
@fd: 


<!-- ##### FUNCTION g_source_get_current_time ##### -->
<para>

</para>

@source: 
@timeval: 


<!-- ##### FUNCTION g_source_remove ##### -->
<para>
</para>

@tag: 
@Returns: 


<!-- ##### FUNCTION g_source_remove_by_funcs_user_data ##### -->
<para>
</para>

@funcs: 
@user_data: 
@Returns: 


<!-- ##### FUNCTION g_source_remove_by_user_data ##### -->
<para>
</para>

@user_data: 
@Returns: 

<!--
Local variables:
mode: sgml
sgml-parent-document: ("../glib-docs.sgml" "book" "refsect2" "")
End:
-->