remove support for X11 shared memory.

This simplifies the code and reduces dependencies.
We need to rewrite the video driver anyway, so simplifying it first is good.

Still compiles and runs as standalone C and wrapped from rust.

Author: diekmann

doom/build.rs

@@ -5,7 +5,6 @@ fn main() {
 
 
     // libraries which should be removed before going to wasm
-    println!("cargo:rustc-link-lib=Xext");
     println!("cargo:rustc-link-lib=X11");
     println!("cargo:rustc-link-lib=nsl");
 }

doom/linuxdoom-1.10/Makefile

@@ -13,7 +13,7 @@ AR=llvm-ar-10
 # apt install gcc-multilib libx11-dev:i386 libxext-dev:i386
 CFLAGS=-m32 -O2 -Wall -Wno-unused-const-variable -DNORMALUNIX -DLINUX
 LDFLAGS=-L/usr/X11R6/lib
-LIBS=-lXext -lX11 -lnsl
+LIBS=-lX11 -lnsl
 
 # subdirectory for objects
 O=linux

doom/linuxdoom-1.10/i_video.c

@@ -27,19 +27,11 @@ rcsid[] = "$Id: i_x.c,v 1.6 1997/02/03 22:45:10 b1 Exp $";
 #include <stdlib.h>
 #include <unistd.h>
 #include <sys/ipc.h>
-#include <sys/shm.h>
 
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
 #include <X11/keysym.h>
 
-#include <X11/extensions/XShm.h>
-// Had to dig up XShm.c for this one.
-// It is in the libXext, but not in the XFree86 headers.
-#ifdef LINUX
-int XShmGetEventBase( Display* dpy ); // problems with g++?
-#endif
-
 #include <stdarg.h>
 #include <sys/time.h>
 #include <sys/types.h>
@@ -71,12 +63,6 @@ XImage*		image;
 int		X_width;
 int		X_height;
 
-// MIT SHared Memory extension.
-boolean		doShm;
-
-XShmSegmentInfo	X_shminfo;
-int		X_shmeventtype;
-
 // Fake mouse handling.
 // This cannot work properly w/o DGA.
 // Needs an invisible mouse cursor at least.
@@ -163,14 +149,6 @@ int xlatekey(void)
 
 void I_ShutdownGraphics(void)
 {
-  // Detach from X server
-  if (!XShmDetach(X_display, &X_shminfo))
-	    I_Error("XShmDetach() failed in I_ShutdownGraphics()");
-
-  // Release shared memory.
-  shmdt(X_shminfo.shmaddr);
-  shmctl(X_shminfo.shmid, IPC_RMID, 0);
-
   // Paranoia.
   if (image){
   	image->data = NULL;
@@ -191,7 +169,6 @@ void I_StartFrame (void)
 static int	lastmousex = 0;
 static int	lastmousey = 0;
 boolean		mousemoved = false;
-boolean		shmFinished;
 
 void I_GetEvent(void)
 {
@@ -274,7 +251,6 @@ void I_GetEvent(void)
 	break;
 
       default:
-	if (doShm && X_event.type == X_shmeventtype) shmFinished = true;
 	break;
     }
 
@@ -482,28 +458,6 @@ void I_FinishUpdate (void)
   	Expand4 ((unsigned *)(screens[0]), (double *) (image->data));
     }
 
-    if (doShm)
-    {
-
-	if (!XShmPutImage(	X_display,
-				X_mainWindow,
-				X_gc,
-				image,
-				0, 0,
-				0, 0,
-				X_width, X_height,
-				True ))
-	    I_Error("XShmPutImage() failed\n");
-
-	// wait for it to finish and processes all input events
-	shmFinished = false;
-	do
-	{
-	    I_GetEvent();
-	} while (!shmFinished);
-
-    }
-    else
     {
 
 	// draw the image
@@ -587,110 +541,6 @@ void I_SetPalette (byte* palette)
 }
 
 
-//
-// This function is probably redundant,
-//  if XShmDetach works properly.
-// ddt never detached the XShm memory,
-//  thus there might have been stale
-//  handles accumulating.
-//
-void grabsharedmemory(int size)
-{
-
-  int			key = ('d'<<24) | ('o'<<16) | ('o'<<8) | 'm';
-  struct shmid_ds	shminfo;
-  int			minsize = 320*200;
-  int			id;
-  int			rc;
-  // UNUSED int done=0;
-  int			pollution=5;
-  
-  // try to use what was here before
-  do
-  {
-    id = shmget((key_t) key, minsize, 0777); // just get the id
-    if (id != -1)
-    {
-      rc=shmctl(id, IPC_STAT, &shminfo); // get stats on it
-      if (!rc) 
-      {
-	if (shminfo.shm_nattch)
-	{
-	  fprintf(stderr, "User %d appears to be running "
-		  "DOOM.  Is that wise?\n", shminfo.shm_cpid);
-	  key++;
-	}
-	else
-	{
-	  if (getuid() == shminfo.shm_perm.cuid)
-	  {
-	    rc = shmctl(id, IPC_RMID, 0);
-	    if (!rc)
-	      fprintf(stderr,
-		      "Was able to kill my old shared memory\n");
-	    else
-	      I_Error("Was NOT able to kill my old shared memory");
-	    
-	    id = shmget((key_t)key, size, IPC_CREAT|0777);
-	    if (id==-1)
-	      I_Error("Could not get shared memory");
-	    
-	    rc=shmctl(id, IPC_STAT, &shminfo);
-	    
-	    break;
-	    
-	  }
-	  if (size >= shminfo.shm_segsz)
-	  {
-	    fprintf(stderr,
-		    "will use %d's stale shared memory\n",
-		    shminfo.shm_cpid);
-	    break;
-	  }
-	  else
-	  {
-	    fprintf(stderr,
-		    "warning: can't use stale "
-		    "shared memory belonging to id %d, "
-		    "key=0x%x\n",
-		    shminfo.shm_cpid, key);
-	    key++;
-	  }
-	}
-      }
-      else
-      {
-	I_Error("could not get stats on key=%d", key);
-      }
-    }
-    else
-    {
-      id = shmget((key_t)key, size, IPC_CREAT|0777);
-      if (id==-1)
-      {
-	extern int errno;
-	fprintf(stderr, "errno=%d\n", errno);
-	I_Error("Could not get any shared memory");
-      }
-      break;
-    }
-  } while (--pollution);
-  
-  if (!pollution)
-  {
-    I_Error("Sorry, system too polluted with stale "
-	    "shared memory segments.\n");
-    }	
-  
-  X_shminfo.shmid = id;
-  
-  // attach to the shared memory segment
-  image->data = X_shminfo.shmaddr = shmat(id, 0, 0);
-  
-  fprintf(stderr, "shared memory id=%d, addr=0x%x\n", id,
-	  (int) (image->data));
-}
-
 void I_InitGraphics(void)
 {
 
@@ -774,23 +624,6 @@ void I_InitGraphics(void)
 	I_Error("xdoom currently only supports 256-color PseudoColor screens");
     X_visual = X_visualinfo.visual;
 
-    // check for the MITSHM extension
-    doShm = XShmQueryExtension(X_display);
-
-    // even if it's available, make sure it's a local connection
-    if (doShm)
-    {
-	if (!displayname) displayname = (char *) getenv("DISPLAY");
-	if (displayname)
-	{
-	    d = displayname;
-	    while (*d && (*d != ':')) d++;
-	    if (*d) *d = 0;
-	    if (!(!strcasecmp(displayname, "unix") || !*displayname)) doShm = false;
-	}
-    }
-
-    fprintf(stderr, "Using MITSHM extension\n");
 
     // create the colormap
     X_cmap = XCreateColormap(X_display, RootWindow(X_display,
@@ -853,50 +686,6 @@ void I_InitGraphics(void)
 		     GrabModeAsync, GrabModeAsync,
 		     X_mainWindow, None, CurrentTime);
 
-    if (doShm)
-    {
-
-	X_shmeventtype = XShmGetEventBase(X_display) + ShmCompletion;
-
-	// create the image
-	image = XShmCreateImage(	X_display,
-					X_visual,
-					8,
-					ZPixmap,
-					0,
-					&X_shminfo,
-					X_width,
-					X_height );
-
-	grabsharedmemory(image->bytes_per_line * image->height);
-
-
-	// UNUSED
-	// create the shared memory segment
-	// X_shminfo.shmid = shmget (IPC_PRIVATE,
-	// image->bytes_per_line * image->height, IPC_CREAT | 0777);
-	// if (X_shminfo.shmid < 0)
-	// {
-	// perror("");
-	// I_Error("shmget() failed in InitGraphics()");
-	// }
-	// fprintf(stderr, "shared memory id=%d\n", X_shminfo.shmid);
-	// attach to the shared memory segment
-	// image->data = X_shminfo.shmaddr = shmat(X_shminfo.shmid, 0, 0);
-	
-
-	if (!image->data)
-	{
-	    perror("");
-	    I_Error("shmat() failed in InitGraphics()");
-	}
-
-	// get the X server to attach to it
-	if (!XShmAttach(X_display, &X_shminfo))
-	    I_Error("XShmAttach() failed in InitGraphics()");
-
-    }
-    else
     {
 	image = XCreateImage(	X_display,
     				X_visual,