Richard Rauch's patch to ensure that freeglut does not use 100% CPU even while idling.

git-svn-id: https://svn.code.sf.net/p/freeglut/code/trunk@195 7f0cb862-5218-0410-a997-914c9d46530a
This commit is contained in:
puggles 2003-09-20 19:11:17 +00:00
parent 2a56a1a4b4
commit 84c2c9381e

View File

@ -399,6 +399,113 @@ void fgWarning( const char *fmt, ... )
va_end( ap ); va_end( ap );
} }
#include <limits.h>
#ifdef TARGET_HOST_UNIX_X11
#include <sys/types.h>
#include <sys/time.h>
#include <unistd.h>
#include <errno.h>
#include <sys/stat.h>
#elif TARGET_HOST_WIN32
#endif
#ifndef MAX
#define MAX(a,b) (((a)>(b)) ? (a) : (b))
#endif
#ifndef MIN
#define MIN(a,b) (((a)<(b)) ? (a) : (b))
#endif
/*
* Indicates whether Joystick events are being used by ANY window.
*
* The current mechanism is to walk all of the windows and ask if
* there is a joystick callback. Certainly in some cases, maybe
* in all cases, the joystick is attached to the system and accessed
* from ONE point by GLUT/freeglut, so this is not the right way,
* in general, to do this. However, the Joystick code is segregated
* in its own little world, so we can't access the information that
* we need in order to do that nicely.
*
* Some alternatives:
* * Store Joystick data into freeglut global state.
* * Provide NON-static functions or data from Joystick *.c file.
*
* Basically, the RIGHT way to do this requires knowing something
* about the Joystick. Right now, the Joystick code is behind
* an opaque wall.
*
*/
static void fgCheckJoystickCallback( SFG_Window* w, SFG_Enumerator* e)
{
if( w->Callbacks.Joystick )
{
e->found = TRUE;
e->data = w;
}
}
static int fgHaveJoystick( void )
{
SFG_Enumerator enumerator;
enumerator.found = FALSE;
enumerator.data = NULL;
fgEnumWindows( fgCheckJoystickCallback, &enumerator );
return !!enumerator.data;
}
/*
* Indicates whether there are any outstanding timers.
*/
static int fgHaveTimers( void )
{
return !!fgState.Timers.First;
}
/*
* Returns the number of GLUT ticks (milliseconds) till the next timer event.
*/
static long fgNextTimer( void )
{
long now = fgElapsedTime();
long ret = INT_MAX;
SFG_Timer *timer;
for( timer = (SFG_Timer *)fgState.Timers.First;
timer;
timer = (SFG_Timer *)timer->Node.Next )
ret = MIN( ret, MAX( 0, (timer->TriggerTime) - now ) );
return ret;
}
/*
* Does the magic required to relinquish the CPU until something interesting
* happens.
*/
static void fgSleepForEvents( void )
{
#ifdef TARGET_HOST_UNIX_X11
fd_set fdset;
int err;
int socket;
struct timeval wait;
long msec;
socket = ConnectionNumber( fgDisplay.Display );
FD_ZERO( &fdset );
FD_SET( socket, &fdset );
msec = fgNextTimer();
if( fgHaveJoystick() )
msec = MIN( msec, 10 );
wait.tv_sec = msec / 1000;
wait.tv_usec = (msec % 1000) * 1000;
err = select( socket+1, &fdset, NULL, NULL, &wait );
if( -1 == err )
printf( "freeglut select() error: %d\n", errno );
#elif TARGET_HOST_WIN32
#endif
}
/* -- INTERFACE FUNCTIONS -------------------------------------------------- */ /* -- INTERFACE FUNCTIONS -------------------------------------------------- */
/* /*
@ -425,7 +532,7 @@ void FGAPIENTRY glutMainLoopEvent( void )
/* /*
* Do we have any event messages pending? * Do we have any event messages pending?
*/ */
if( XPending( fgDisplay.Display ) ) while( XPending( fgDisplay.Display ) )
{ {
/* /*
* Grab the next event to be processed... * Grab the next event to be processed...
@ -976,7 +1083,7 @@ void FGAPIENTRY glutMainLoopEvent( void )
break; break;
} }
} }
else
{ {
/* /*
* Have all the timers checked. * Have all the timers checked.
@ -1008,7 +1115,7 @@ void FGAPIENTRY glutMainLoopEvent( void )
/* /*
* The windows processing is considerably smaller * The windows processing is considerably smaller
*/ */
if( PeekMessage( &stMsg, NULL, 0, 0, PM_NOREMOVE ) ) while( PeekMessage( &stMsg, NULL, 0, 0, PM_NOREMOVE ) )
{ {
/* /*
* Grab the message now, checking for WM_QUIT * Grab the message now, checking for WM_QUIT
@ -1022,7 +1129,7 @@ void FGAPIENTRY glutMainLoopEvent( void )
TranslateMessage( &stMsg ); TranslateMessage( &stMsg );
DispatchMessage( &stMsg ); DispatchMessage( &stMsg );
} }
else
{ {
/* /*
* Have all the timers checked. * Have all the timers checked.
@ -1117,6 +1224,8 @@ void FGAPIENTRY glutMainLoop( void )
*/ */
if ( fgStructure.Windows.First == NULL ) if ( fgStructure.Windows.First == NULL )
fgState.ExecState = GLUT_EXEC_STATE_STOP ; fgState.ExecState = GLUT_EXEC_STATE_STOP ;
else if( !fgState.IdleCallback )
fgSleepForEvents();
} }
{ {