Updates to cothreads code, including non-working alpha. Changed things a bit, including PPC. Not having a PPC machi...

Original commit message from CVS:
Updates to cothreads code, including non-working alpha.  Changed things a
bit, including PPC.  Not having a PPC machine, I need someone to test
these changes and report back whether they worked or not.

gst/Makefile.am

@@ -101,6 +101,7 @@ noinst_HEADERS = 	\
 	gstarch.h	\
 	gsti386.h	\
 	gstppc.h	\
+	gstalpha.h	\
 	gstpropsprivate.h
 
 CFLAGS = $(LIBGST_CFLAGS)

gst/cothreads.c

@@ -29,7 +29,7 @@
 #include <sys/mman.h>
 
 /* we make too much noise for normal debugging... */
-#define GST_DEBUG_FORCE_DISABLE
+//#define GST_DEBUG_FORCE_DISABLE
 #include "gst_private.h"
 
 #include "cothreads.h"
@@ -180,7 +180,7 @@ cothread_stub (void)
   thread->pc = 0;
   thread->sp = thread->top_sp;
   GST_DEBUG_LEAVE("");
-//  printf("uh, yeah, we shouldn't be here, but we should deal anyway\n");
+  fprintf(stderr,"uh, yeah, we shouldn't be here, but we should deal anyway\n");
 }
 
 /**
@@ -258,11 +258,12 @@ cothread_switch (cothread_state *thread)
   if (current == thread) goto selfswitch;
 
   // find the number of the thread to switch to
+  GST_INFO (GST_CAT_COTHREAD_SWITCH,"switching from cothread %d to to cothread #%d\n",
+            ctx->current,thread->threadnum);
   ctx->current = thread->threadnum;
-  GST_INFO (GST_CAT_COTHREAD_SWITCH,"switching to thread #%d",ctx->current);
 
   /* save the current stack pointer, frame pointer, and pc */
-  GET_SP(current->sp);
+//  GET_SP(current->sp);
   enter = setjmp(current->jmp);
   if (enter != 0) {
     GST_DEBUG (0,"enter thread #%d %d %p<->%p (%d)\n",current->threadnum, enter, 
@@ -277,14 +278,14 @@ cothread_switch (cothread_state *thread)
   /* restore stack pointer and other stuff of new cothread */
   if (thread->flags & COTHREAD_STARTED) {
     GST_DEBUG (0,"in thread \n");
-    SET_SP(thread->sp);
+//    SET_SP(thread->sp);
     // switch to it
     longjmp(thread->jmp,1);
   } else {
     SETUP_STACK(thread->sp);
     SET_SP(thread->sp);
     // start it
-    cothread_stub();
+    CALL(cothread_stub);
     GST_DEBUG (0,"exit thread \n");
     ctx->current = 0;
   }

gst/gstalpha.h

@@ -0,0 +1,49 @@
+/* GStreamer
+ * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
+ *                    2000 Wim Taymans <wtay@chello.be>
+ *
+ * gstppc.h: Header for PPC-specific architecture issues
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifndef GST_HGUARD_GSTALPHA_H
+#define GST_HGUARD_GSTALPHA_H
+
+#warning in gstalpha.h
+
+#define GET_SP(target) \
+    __asm__("stq $30,%0" : "=m"(target) : : "30");
+
+#define SET_SP(stackpointer) \
+    __asm__("bis $31,%0,$30" : : "r"(stackpointer));
+
+#define CALL(target) \
+    __asm__( "bis $31,%0,$27\n\t" \
+             "jsr $26,($27),0" : : "r"(target) );
+
+struct minimal_ppc_stackframe {
+    unsigned long back_chain;
+    unsigned long LR_save;
+    unsigned long unused1;
+    unsigned long unused2;
+};
+
+#define SETUP_STACK(sp) \
+    sp = ((unsigned long *)(sp)) - 4; \
+    ((struct minimal_ppc_stackframe *)sp)->back_chain = 0;
+
+#endif /* GST_HGUARD_GSTALPHA_H */

gst/gstarch.h

@@ -33,8 +33,12 @@
 #ifdef HAVE_CPU_PPC
 #include "gstppc.h"
 #else
+#ifdef HAVE_CPU_ALPHA
+#include "gstalpha.h"
+#else
 #error Need to know about this architecture, or have a generic implementation
 #endif
 #endif
+#endif
 
 #endif /* __GST_GSTARCH_H__ */

gst/gsti386.h

@@ -24,13 +24,13 @@
 #define GST_HGUARD_GSTI386_H
 
 #define GET_SP(target) \
-  __asm__("movl %%esp, %0" : "=m"(target) : : "esp", "ebp");
+  __asm__( "movl %%esp, %0" : "=r"(target) : : "esp", "ebp" );
 
 #define SET_SP(source) \
-  __asm__("movl %0, %%esp\n" : "=m"(thread->sp));
+  __asm__( "movl %0, %%esp\n" : : "r"(source) );
 
-#define JUMP(target) \
-    __asm__("jmp " SYMBOL_NAME_STR(cothread_stub))
+#define CALL(target) \
+    __asm__("call *%0" : : "r"(target) );
 
 #define SETUP_STACK(sp) do ; while(0)
 

gst/gstppc.h

@@ -31,8 +31,10 @@
 #define SET_SP(source) \
     __asm__("lwz 1,%0" : "=m"(source))
 
-#define JUMP(target) \
-    __asm__("b " SYMBOL_NAME_STR(cothread_stub))
+#define CALL(target) \
+    __asm__( "mr 0,%0\n\t" \
+             "mtlr 0\n\t" \
+             "blrl" : : "r"(target) );
 
 struct minimal_ppc_stackframe {
     unsigned long back_chain;