i965g: add lots of error checks and early returns

Any allocation that may fail should be checked, and propogate the
error upwards.  At the highest level we will flush batch and retry.

This is an alternate strategy to what the original DRI driver did of
attempting to flush batch from the lowest levels (eg inside
BEGIN_BATCH).  The trouble with that strategy was that flushes could
occur at unexpected times, and additionally there was a need for a
wierd notification mechanism to propogate the 'lost context' state
back up to higher levels.

Propogating the errors directly gives us a lot of flexibility how to
deal with these states, at the expense of a lot more checking in the
code.

Will add some sanity checks later to make sure that out-of-memory
conditions are properly escalated and not lost halfway up the stack.

1 files changed, 39 insertions, 21 deletions

diff --git a/src/gallium/drivers/i965/brw_clip.c b/src/gallium/drivers/i965/brw_clip.c
index 1a52fa771b..35e1d2fdbd 100644
--- a/src/gallium/drivers/i965/brw_clip.c
+++ b/src/gallium/drivers/i965/brw_clip.c
@@ -48,9 +48,12 @@
 #define BACK_UNFILLED_BIT   0x2
 
 
-static void compile_clip_prog( struct brw_context *brw,
-			     struct brw_clip_prog_key *key )
+static enum pipe_error
+compile_clip_prog( struct brw_context *brw,
+                   struct brw_clip_prog_key *key,
+                   struct brw_winsys_buffer **bo_out )
 {
+   enum pipe_error ret;
    struct brw_clip_compile c;
    const GLuint *program;
    GLuint program_size;
@@ -123,31 +126,39 @@ static void compile_clip_prog( struct brw_context *brw,
       break;
    default:
       assert(0);
-      return;
+      return PIPE_ERROR_BAD_INPUT;
    }
 
 	 
 
    /* get the program
     */
-   program = brw_get_program(&c.func, &program_size);
+   ret = brw_get_program(&c.func, &program, &program_size);
+   if (ret)
+      return ret;
 
    /* Upload
     */
-   brw->sws->bo_unreference(brw->clip.prog_bo);
-   brw->clip.prog_bo = brw_upload_cache( &brw->cache,
-					 BRW_CLIP_PROG,
-					 &c.key, sizeof(c.key),
-					 NULL, 0,
-					 program, program_size,
-					 &c.prog_data,
-					 &brw->clip.prog_data );
+   ret = brw_upload_cache( &brw->cache,
+                           BRW_CLIP_PROG,
+                           &c.key, sizeof(c.key),
+                           NULL, 0,
+                           program, program_size,
+                           &c.prog_data,
+                           &brw->clip.prog_data,
+                           bo_out );
+   if (ret)
+      return ret;
+
+   return PIPE_OK;
 }
 
 /* Calculate interpolants for triangle and line rasterization.
  */
-static int upload_clip_prog(struct brw_context *brw)
+static enum pipe_error
+upload_clip_prog(struct brw_context *brw)
 {
+   enum pipe_error ret;
    struct brw_clip_prog_key key;
 
    /* Populate the key, starting from the almost-complete version from
@@ -166,15 +177,22 @@ static int upload_clip_prog(struct brw_context *brw)
    /* PIPE_NEW_CLIP */
    key.nr_userclip = brw->curr.ucp.nr;
 
-   brw->sws->bo_unreference(brw->clip.prog_bo);
-   brw->clip.prog_bo = brw_search_cache(&brw->cache, BRW_CLIP_PROG,
-					&key, sizeof(key),
-					NULL, 0,
-					&brw->clip.prog_data);
-   if (brw->clip.prog_bo == NULL)
-      compile_clip_prog( brw, &key );
+   /* Already cached?
+    */
+   if (brw_search_cache(&brw->cache, BRW_CLIP_PROG,
+                        &key, sizeof(key),
+                        NULL, 0,
+                        &brw->clip.prog_data,
+                        &brw->clip.prog_bo))
+      return PIPE_OK;
+
+   /* Compile new program:
+    */
+   ret = compile_clip_prog( brw, &key, &brw->clip.prog_bo );
+   if (ret)
+      return ret;
 
-   return 0;
+   return PIPE_OK;
 }