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DGA video driver is now thread-safe
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Improved DGA hardware acceleration code
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Sam Lantinga committed Jul 12, 2001
1 parent 0c4b20d commit 7075c20
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Showing 3 changed files with 129 additions and 29 deletions.
2 changes: 2 additions & 0 deletions src/video/dga/SDL_dgaevents.c
View file
Expand Up @@ -97,9 +97,11 @@ static int DGA_DispatchEvent(_THIS)
void DGA_PumpEvents(_THIS)
{
/* Keep processing pending events */
LOCK_DISPLAY();
while ( X11_Pending(DGA_Display) ) {
DGA_DispatchEvent(this);
}
UNLOCK_DISPLAY();
}

void DGA_InitOSKeymap(_THIS)
Expand Down
139 changes: 111 additions & 28 deletions src/video/dga/SDL_dgavideo.c
View file
Expand Up @@ -58,7 +58,7 @@ static int DGA_SetGammaRamp(_THIS, Uint16 *ramp);
static void DGA_VideoQuit(_THIS);

/* Hardware surface functions */
static int DGA_InitHWSurfaces(_THIS, Uint8 *base, int size);
static int DGA_InitHWSurfaces(_THIS, SDL_Surface *screen, Uint8 *base, int size);
static void DGA_FreeHWSurfaces(_THIS);
static int DGA_AllocHWSurface(_THIS, SDL_Surface *surface);
static int DGA_FillHWRect(_THIS, SDL_Surface *dst, SDL_Rect *rect, Uint32 color);
Expand Down Expand Up @@ -409,6 +409,11 @@ static int DGA_VideoInit(_THIS, SDL_PixelFormat *vformat)
return(-1);
}

#ifdef LOCK_DGA_DISPLAY
/* Create the event lock so we're thread-safe.. :-/ */
event_lock = SDL_CreateMutex();
#endif /* LOCK_DGA_DISPLAY */

/* We're done! */
return(0);
}
Expand Down Expand Up @@ -535,7 +540,7 @@ SDL_Surface *DGA_SetVideoMode(_THIS, SDL_Surface *current,
if ( surfaces_len < 0 ) {
surfaces_len = 0;
}
DGA_InitHWSurfaces(this, surfaces_mem, surfaces_len);
DGA_InitHWSurfaces(this, current, surfaces_mem, surfaces_len);

/* Set the update rectangle function */
this->UpdateRects = DGA_DirectUpdate;
Expand Down Expand Up @@ -581,15 +586,36 @@ static void DGA_DumpHWSurfaces(_THIS)
}
#endif

static int DGA_InitHWSurfaces(_THIS, Uint8 *base, int size)
static int DGA_InitHWSurfaces(_THIS, SDL_Surface *screen, Uint8 *base, int size)
{
surfaces.prev = NULL;
surfaces.used = 0;
surfaces.base = base;
surfaces.size = size;
surfaces.next = NULL;
vidmem_bucket *bucket;

surfaces_memtotal = size;
surfaces_memleft = size;

if ( surfaces_memleft > 0 ) {
bucket = (vidmem_bucket *)malloc(sizeof(*bucket));
if ( bucket == NULL ) {
SDL_OutOfMemory();
return(-1);
}
bucket->prev = &surfaces;
bucket->used = 0;
bucket->dirty = 0;
bucket->base = base;
bucket->size = size;
bucket->next = NULL;
} else {
bucket = NULL;
}

surfaces.prev = NULL;
surfaces.used = 1;
surfaces.dirty = 0;
surfaces.base = screen->pixels;
surfaces.size = (unsigned int)((long)base - (long)surfaces.base);
surfaces.next = bucket;
screen->hwdata = (struct private_hwdata *)&surfaces;
return(0);
}
static void DGA_FreeHWSurfaces(_THIS)
Expand All @@ -605,11 +631,35 @@ static void DGA_FreeHWSurfaces(_THIS)
surfaces.next = NULL;
}

static __inline__ void DGA_AddDirtySurface(SDL_Surface *surface)
{
((vidmem_bucket *)surface->hwdata)->dirty = 1;
}

static __inline__ int DGA_IsSurfaceDirty(SDL_Surface *surface)
{
return ((vidmem_bucket *)surface->hwdata)->dirty;
}

static __inline__ void DGA_WaitDirtySurfaces(_THIS)
{
vidmem_bucket *bucket;

/* Wait for graphic operations to complete */
XDGASync(DGA_Display, DGA_Screen);

/* Clear all surface dirty bits */
for ( bucket=&surfaces; bucket; bucket=bucket->next ) {
bucket->dirty = 0;
}
}

static int DGA_AllocHWSurface(_THIS, SDL_Surface *surface)
{
vidmem_bucket *bucket;
int size;
int extra;
int retval = 0;

/* Temporarily, we only allow surfaces the same width as display.
Some blitters require the pitch between two hardware surfaces
Expand All @@ -624,11 +674,13 @@ surface->pitch = SDL_VideoSurface->pitch;
#ifdef DGA_DEBUG
fprintf(stderr, "Allocating bucket of %d bytes\n", size);
#endif
LOCK_DISPLAY();

/* Quick check for available mem */
if ( size > surfaces_memleft ) {
SDL_SetError("Not enough video memory");
return(-1);
retval = -1;
goto done;
}

/* Search for an empty bucket big enough */
Expand All @@ -639,7 +691,8 @@ surface->pitch = SDL_VideoSurface->pitch;
}
if ( bucket == NULL ) {
SDL_SetError("Video memory too fragmented");
return(-1);
retval = -1;
goto done;
}

/* Create a new bucket for left-over memory */
Expand All @@ -653,7 +706,8 @@ surface->pitch = SDL_VideoSurface->pitch;
newbucket = (vidmem_bucket *)malloc(sizeof(*newbucket));
if ( newbucket == NULL ) {
SDL_OutOfMemory();
return(-1);
retval = -1;
goto done;
}
newbucket->prev = bucket;
newbucket->used = 0;
Expand All @@ -669,24 +723,24 @@ surface->pitch = SDL_VideoSurface->pitch;
/* Set the current bucket values and return it! */
bucket->used = 1;
bucket->size = size;
bucket->dirty = 0;
#ifdef DGA_DEBUG
fprintf(stderr, "Allocated %d bytes at %p\n", bucket->size, bucket->base);
#endif
surfaces_memleft -= size;
surface->flags |= SDL_HWSURFACE;
surface->pixels = bucket->base;
return(0);
surface->hwdata = (struct private_hwdata *)bucket;
done:
UNLOCK_DISPLAY();
return(retval);
}
static void DGA_FreeHWSurface(_THIS, SDL_Surface *surface)
{
vidmem_bucket *bucket, *freeable;

/* Look for the bucket in the current list */
for ( bucket=&surfaces; bucket; bucket=bucket->next ) {
if ( bucket->base == (Uint8 *)surface->pixels ) {
break;
}
}
bucket = (vidmem_bucket *)surface->hwdata;
if ( (bucket == NULL) || ! bucket->used ) {
return;
}
Expand Down Expand Up @@ -724,6 +778,7 @@ static void DGA_FreeHWSurface(_THIS, SDL_Surface *surface)
free(freeable);
}
surface->pixels = NULL;
surface->hwdata = NULL;
}

static __inline__ void dst_to_xy(_THIS, SDL_Surface *dst, int *x, int *y)
Expand All @@ -742,6 +797,7 @@ static int DGA_FillHWRect(_THIS, SDL_Surface *dst, SDL_Rect *rect, Uint32 color)
unsigned int w, h;

/* Don't fill the visible part of the screen, wait until flipped */
LOCK_DISPLAY();
if ( was_flipped && (dst == this->screen) ) {
while ( XDGAGetViewportStatus(DGA_Display, DGA_Screen) )
/* Keep waiting for the hardware ... */ ;
Expand All @@ -756,8 +812,9 @@ static int DGA_FillHWRect(_THIS, SDL_Surface *dst, SDL_Rect *rect, Uint32 color)
printf("Hardware accelerated rectangle fill: %dx%d at %d,%d\n", w, h, x, y);
#endif
XDGAFillRectangle(DGA_Display, DGA_Screen, x, y, w, h, color);
sync_needed++;
XFlush(DGA_Display);
DGA_AddDirtySurface(dst);
UNLOCK_DISPLAY();
return(0);
}

Expand All @@ -771,6 +828,7 @@ static int HWAccelBlit(SDL_Surface *src, SDL_Rect *srcrect,

this = current_video;
/* Don't blit to the visible part of the screen, wait until flipped */
LOCK_DISPLAY();
if ( was_flipped && (dst == this->screen) ) {
while ( XDGAGetViewportStatus(DGA_Display, DGA_Screen) )
/* Keep waiting for the hardware ... */ ;
Expand All @@ -794,8 +852,10 @@ static int HWAccelBlit(SDL_Surface *src, SDL_Rect *srcrect,
XDGACopyArea(DGA_Display, DGA_Screen,
srcx, srcy, w, h, dstx, dsty);
}
sync_needed++;
XFlush(DGA_Display);
DGA_AddDirtySurface(src);
DGA_AddDirtySurface(dst);
UNLOCK_DISPLAY();
return(0);
}

Expand Down Expand Up @@ -826,12 +886,8 @@ static int DGA_CheckHWBlit(_THIS, SDL_Surface *src, SDL_Surface *dst)
return(accelerated);
}

static __inline__ void DGA_WaitHardware(_THIS)
static __inline__ void DGA_WaitFlip(_THIS)
{
if ( sync_needed ) {
XDGASync(DGA_Display, DGA_Screen);
sync_needed = 0;
}
if ( was_flipped ) {
while ( XDGAGetViewportStatus(DGA_Display, DGA_Screen) )
/* Keep waiting for the hardware ... */ ;
Expand All @@ -841,26 +897,42 @@ static __inline__ void DGA_WaitHardware(_THIS)

static int DGA_LockHWSurface(_THIS, SDL_Surface *surface)
{
if ( surface == SDL_VideoSurface ) {
if ( surface == this->screen ) {
SDL_mutexP(hw_lock);
DGA_WaitHardware(this);
LOCK_DISPLAY();
if ( DGA_IsSurfaceDirty(surface) ) {
DGA_WaitDirtySurfaces(this);
}
DGA_WaitFlip(this);
UNLOCK_DISPLAY();
} else {
if ( DGA_IsSurfaceDirty(surface) ) {
LOCK_DISPLAY();
DGA_WaitDirtySurfaces(this);
UNLOCK_DISPLAY();
}
}
return(0);
}
static void DGA_UnlockHWSurface(_THIS, SDL_Surface *surface)
{
if ( surface == SDL_VideoSurface ) {
if ( surface == this->screen ) {
SDL_mutexV(hw_lock);
}
}

static int DGA_FlipHWSurface(_THIS, SDL_Surface *surface)
{
/* Wait for vertical retrace and then flip display */
DGA_WaitHardware(this);
LOCK_DISPLAY();
if ( DGA_IsSurfaceDirty(this->screen) ) {
DGA_WaitDirtySurfaces(this);
}
DGA_WaitFlip(this);
XDGASetViewport(DGA_Display, DGA_Screen,
0, flip_yoffset[flip_page], XDGAFlipRetrace);
XFlush(DGA_Display);
UNLOCK_DISPLAY();
was_flipped = 1;
flip_page = !flip_page;

Expand Down Expand Up @@ -891,8 +963,10 @@ static int DGA_SetColors(_THIS, int firstcolor, int ncolors, SDL_Color *colors)
xcmap[i].blue = (colors[i].b<<8)|colors[i].b;
xcmap[i].flags = (DoRed|DoGreen|DoBlue);
}
LOCK_DISPLAY();
XStoreColors(DGA_Display, DGA_colormap, xcmap, ncolors);
XSync(DGA_Display, False);
UNLOCK_DISPLAY();

/* That was easy. :) */
return(1);
Expand Down Expand Up @@ -923,8 +997,10 @@ int DGA_SetGammaRamp(_THIS, Uint16 *ramp)
xcmap[i].blue = ramp[2*256+c];
xcmap[i].flags = (DoRed|DoGreen|DoBlue);
}
LOCK_DISPLAY();
XStoreColors(DGA_Display, DGA_colormap, xcmap, ncolors);
XSync(DGA_Display, False);
UNLOCK_DISPLAY();
return(0);
}

Expand Down Expand Up @@ -952,6 +1028,13 @@ void DGA_VideoQuit(_THIS)
SDL_DestroyMutex(hw_lock);
hw_lock = NULL;
}
#ifdef LOCK_DGA_DISPLAY
if ( event_lock != NULL ) {
SDL_DestroyMutex(event_lock);
event_lock = NULL;
}
#endif /* LOCK_DGA_DISPLAY */


/* Clean up defined video modes */
for ( i=0; i<NUM_MODELISTS; ++i ) {
Expand Down
17 changes: 16 additions & 1 deletion src/video/dga/SDL_dgavideo.h
View file
Expand Up @@ -37,11 +37,22 @@ static char rcsid =
/* Hidden "this" pointer for the video functions */
#define _THIS SDL_VideoDevice *this

/* Define this if you need the DGA driver to be thread-safe */
#define LOCK_DGA_DISPLAY
#ifdef LOCK_DGA_DISPLAY
#define LOCK_DISPLAY() SDL_mutexP(event_lock)
#define UNLOCK_DISPLAY() SDL_mutexV(event_lock)
#else
#define LOCK_DISPLAY()
#define UNLOCK_DISPLAY()
#endif


/* This is the structure we use to keep track of video memory */
typedef struct vidmem_bucket {
struct vidmem_bucket *prev;
unsigned int used;
int used;
int dirty;
Uint8 *base;
unsigned int size;
struct vidmem_bucket *next;
Expand Down Expand Up @@ -82,6 +93,9 @@ struct SDL_PrivateVideoData {

/* Used to handle DGA events */
int event_base;
#ifdef LOCK_DGA_DISPLAY
SDL_mutex *event_lock;
#endif
};
/* Old variable names */
#define DGA_Display (this->hidden->DGA_Display)
Expand All @@ -102,5 +116,6 @@ struct SDL_PrivateVideoData {
#define surfaces_memleft (this->hidden->surfaces_memleft)
#define hw_lock (this->hidden->hw_lock)
#define DGA_event_base (this->hidden->event_base)
#define event_lock (this->hidden->event_lock)

#endif /* _SDL_dgavideo_h */

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