mesa: use accessors for struct gl_debug_state

When GL_DEBUG_OUTPUT_SYNCHRONOUS is GL_TRUE, drivers are allowed to log debug
messages from other threads.  That requires gl_debug_state to be protected by
a mutex, even when it is a context state.  While we do not spawn threads in
Mesa yet, this commit makes it easier to do when we want to.

Since the definition of struct gl_debug_state is no longer needed by the rest
of the driver, move it to main/errors.c.  This should make it even harder to
use the struct incorrectly.

v2: add comments for the accessors

Signed-off-by: Chia-I Wu <olv@lunarg.com>
Reviewed-by: Brian Paul <brianp@vmware.com>

src/mesa/drivers/dri/common/dri_util.c

@@ -449,10 +449,7 @@ driContextSetFlags(struct gl_context *ctx, uint32_t flags)
     if ((flags & __DRI_CTX_FLAG_FORWARD_COMPATIBLE) != 0)
         ctx->Const.ContextFlags |= GL_CONTEXT_FLAG_FORWARD_COMPATIBLE_BIT;
     if ((flags & __DRI_CTX_FLAG_DEBUG) != 0) {
-        struct gl_debug_state *debug = _mesa_get_debug_state(ctx);
+       _mesa_set_debug_state_int(ctx, GL_DEBUG_OUTPUT, GL_TRUE);
-        if (debug) {
-            debug->DebugOutput = GL_TRUE;
-        }
         ctx->Const.ContextFlags |= GL_CONTEXT_FLAG_DEBUG_BIT;
     }
 }

src/mesa/main/enable.c

@@ -368,26 +368,11 @@ _mesa_set_enable(struct gl_context *ctx, GLenum cap, GLboolean state)
          ctx->Depth.Test = state;
          break;
       case GL_DEBUG_OUTPUT:
-         if (!_mesa_is_desktop_gl(ctx)) {
-            goto invalid_enum_error;
-         }
-         else {
-            struct gl_debug_state *debug = _mesa_get_debug_state(ctx);
-            if (debug) {
-               debug->DebugOutput = state;
-            }
-         }
-         break;
       case GL_DEBUG_OUTPUT_SYNCHRONOUS_ARB:
-         if (!_mesa_is_desktop_gl(ctx)) {
+         if (!_mesa_is_desktop_gl(ctx))
             goto invalid_enum_error;
-         }
+         else
-         else {
+            _mesa_set_debug_state_int(ctx, cap, state);
-            struct gl_debug_state *debug = _mesa_get_debug_state(ctx);
-            if (debug) {
-               debug->SyncOutput = state;
-            }
-         }
          break;
       case GL_DITHER:
          if (ctx->Color.DitherFlag == state)
@@ -1239,21 +1224,11 @@ _mesa_IsEnabled( GLenum cap )
       case GL_CULL_FACE:
          return ctx->Polygon.CullFlag;
       case GL_DEBUG_OUTPUT:
-         if (!_mesa_is_desktop_gl(ctx))
-            goto invalid_enum_error;
-         if (ctx->Debug) {
-            return ctx->Debug->DebugOutput;
-         } else {
-            return GL_FALSE;
-         }
       case GL_DEBUG_OUTPUT_SYNCHRONOUS_ARB:
          if (!_mesa_is_desktop_gl(ctx))
             goto invalid_enum_error;
-         if (ctx->Debug) {
+         else
-            return ctx->Debug->SyncOutput;
+            return (GLboolean) _mesa_get_debug_state_int(ctx, cap);
-         } else {
-            return GL_FALSE;
-         }
       case GL_DEPTH_TEST:
          return ctx->Depth.Test;
       case GL_DITHER:

src/mesa/main/errors.c

@@ -47,6 +47,45 @@ struct gl_debug_severity
    GLuint ID;
 };
 
+/**
+ * An error, warning, or other piece of debug information for an application
+ * to consume via GL_ARB_debug_output/GL_KHR_debug.
+ */
+struct gl_debug_msg
+{
+   enum mesa_debug_source source;
+   enum mesa_debug_type type;
+   GLuint id;
+   enum mesa_debug_severity severity;
+   GLsizei length;
+   GLcharARB *message;
+};
+
+struct gl_debug_namespace
+{
+   struct _mesa_HashTable *IDs;
+   unsigned ZeroID; /* a HashTable won't take zero, so store its state here */
+   /** lists of IDs in the hash table at each severity */
+   struct simple_node Severity[MESA_DEBUG_SEVERITY_COUNT];
+};
+
+struct gl_debug_state
+{
+   GLDEBUGPROC Callback;
+   const void *CallbackData;
+   GLboolean SyncOutput;
+   GLboolean DebugOutput;
+   GLboolean Defaults[MAX_DEBUG_GROUP_STACK_DEPTH][MESA_DEBUG_SEVERITY_COUNT][MESA_DEBUG_SOURCE_COUNT][MESA_DEBUG_TYPE_COUNT];
+   struct gl_debug_namespace Namespaces[MAX_DEBUG_GROUP_STACK_DEPTH][MESA_DEBUG_SOURCE_COUNT][MESA_DEBUG_TYPE_COUNT];
+   struct gl_debug_msg Log[MAX_DEBUG_LOGGED_MESSAGES];
+   struct gl_debug_msg DebugGroupMsgs[MAX_DEBUG_GROUP_STACK_DEPTH];
+   GLint GroupStackDepth;
+   GLint NumMessages;
+   GLint NextMsg;
+   GLint NextMsgLength; /* redundant, but copied here from Log[NextMsg].length
+                           for the sake of the offsetof() code in get.c */
+};
+
 static char out_of_memory[] = "Debugging error: out of memory";
 
 static const GLenum debug_source_enums[] = {
@@ -597,7 +636,7 @@ debug_pop_group(struct gl_debug_state *debug)
  * Return debug state for the context.  The debug state will be allocated
  * and initialized upon the first call.
  */
-struct gl_debug_state *
+static struct gl_debug_state *
 _mesa_get_debug_state(struct gl_context *ctx)
 {
    if (!ctx->Debug) {
@@ -610,6 +649,102 @@ _mesa_get_debug_state(struct gl_context *ctx)
    return ctx->Debug;
 }
 
+/**
+ * Set the integer debug state specified by \p pname.  This can be called from
+ * _mesa_set_enable for example.
+ */
+bool
+_mesa_set_debug_state_int(struct gl_context *ctx, GLenum pname, GLint val)
+{
+   struct gl_debug_state *debug = _mesa_get_debug_state(ctx);
+
+   if (!debug)
+      return false;
+
+   switch (pname) {
+   case GL_DEBUG_OUTPUT:
+      debug->DebugOutput = (val != 0);
+      break;
+   case GL_DEBUG_OUTPUT_SYNCHRONOUS_ARB:
+      debug->SyncOutput = (val != 0);
+      break;
+   default:
+      assert(!"unknown debug output param");
+      break;
+   }
+
+   return true;
+}
+
+/**
+ * Query the integer debug state specified by \p pname.  This can be called
+ * _mesa_GetIntegerv for example.
+ */
+GLint
+_mesa_get_debug_state_int(struct gl_context *ctx, GLenum pname)
+{
+   struct gl_debug_state *debug;
+   GLint val;
+
+   debug = ctx->Debug;
+   if (!debug)
+      return 0;
+
+   switch (pname) {
+   case GL_DEBUG_OUTPUT:
+      val = debug->DebugOutput;
+      break;
+   case GL_DEBUG_OUTPUT_SYNCHRONOUS_ARB:
+      val = debug->SyncOutput;
+      break;
+   case GL_DEBUG_LOGGED_MESSAGES:
+      val = debug->NumMessages;
+      break;
+   case GL_DEBUG_NEXT_LOGGED_MESSAGE_LENGTH:
+      val = debug->NextMsgLength;
+      break;
+   case GL_DEBUG_GROUP_STACK_DEPTH:
+      val = debug->GroupStackDepth;
+      break;
+   default:
+      assert(!"unknown debug output param");
+      val = 0;
+      break;
+   }
+
+   return val;
+}
+
+/**
+ * Query the pointer debug state specified by \p pname.  This can be called
+ * _mesa_GetPointerv for example.
+ */
+void *
+_mesa_get_debug_state_ptr(struct gl_context *ctx, GLenum pname)
+{
+   struct gl_debug_state *debug;
+   void *val;
+
+   debug = ctx->Debug;
+   if (!debug)
+      return NULL;
+
+   switch (pname) {
+   case GL_DEBUG_CALLBACK_FUNCTION_ARB:
+      val = (void *) debug->Callback;
+      break;
+   case GL_DEBUG_CALLBACK_USER_PARAM_ARB:
+      val = (void *) debug->CallbackData;
+      break;
+   default:
+      assert(!"unknown debug output param");
+      val = NULL;
+      break;
+   }
+
+   return val;
+}
+
 
 /**
  * Log a client or driver debug message.

src/mesa/main/errors.h

@@ -83,8 +83,14 @@ _mesa_gl_debug(struct gl_context *ctx,
    }                                                                      \
 } while (0)
 
-struct gl_debug_state *
+bool
-_mesa_get_debug_state(struct gl_context *ctx);
+_mesa_set_debug_state_int(struct gl_context *ctx, GLenum pname, GLint val);
+
+GLint
+_mesa_get_debug_state_int(struct gl_context *ctx, GLenum pname);
+
+void *
+_mesa_get_debug_state_ptr(struct gl_context *ctx, GLenum pname);
 
 extern void
 _mesa_shader_debug(struct gl_context *ctx, GLenum type, GLuint *id,

src/mesa/main/get.c

@@ -989,24 +989,10 @@ find_custom_value(struct gl_context *ctx, const struct value_desc *d, union valu
       break;
    /* GL_KHR_DEBUG */
    case GL_DEBUG_LOGGED_MESSAGES:
-      {
-         struct gl_debug_state *debug = _mesa_get_debug_state(ctx);
-         v->value_int = debug ? debug->NumMessages : 0;
-      }
-      break;
    case GL_DEBUG_NEXT_LOGGED_MESSAGE_LENGTH:
-      {
-         struct gl_debug_state *debug = _mesa_get_debug_state(ctx);
-         v->value_int = debug ? debug->NextMsgLength : 0;
-      }
-      break;
    case GL_DEBUG_GROUP_STACK_DEPTH:
-      {
+      v->value_int = _mesa_get_debug_state_int(ctx, d->pname);
-         struct gl_debug_state *debug = _mesa_get_debug_state(ctx);
-         v->value_int = debug ? debug->GroupStackDepth : 0;
-      }
       break;
-
    /* GL_ARB_shader_atomic_counters */
    case GL_ATOMIC_COUNTER_BUFFER_BINDING:
       v->value_int = ctx->AtomicBuffer->Name;

src/mesa/main/getstring.c

@@ -253,22 +253,11 @@ _mesa_GetPointerv( GLenum pname, GLvoid **params )
          *params = (GLvoid *) ctx->Array.VAO->VertexAttrib[VERT_ATTRIB_POINT_SIZE].Ptr;
          break;
       case GL_DEBUG_CALLBACK_FUNCTION_ARB:
-         if (!_mesa_is_desktop_gl(ctx)) {
-            goto invalid_pname;
-         }
-         else {
-            struct gl_debug_state *debug = _mesa_get_debug_state(ctx);
-            *params = debug ? (void *) debug->Callback : NULL;
-         }
-         break;
       case GL_DEBUG_CALLBACK_USER_PARAM_ARB:
-         if (!_mesa_is_desktop_gl(ctx)) {
+         if (!_mesa_is_desktop_gl(ctx))
             goto invalid_pname;
-         }
+         else
-         else {
+            *params = _mesa_get_debug_state_ptr(ctx, pname);
-            struct gl_debug_state *debug = _mesa_get_debug_state(ctx);
-            *params = debug ? (void *) debug->CallbackData : NULL;
-         }
          break;
       default:
          goto invalid_pname;

src/mesa/main/mtypes.h

@@ -76,6 +76,7 @@ struct gl_list_extensions;
 struct gl_meta_state;
 struct gl_program_cache;
 struct gl_texture_object;
+struct gl_debug_state;
 struct gl_context;
 struct st_context;
 struct gl_uniform_storage;
@@ -3821,45 +3822,6 @@ enum mesa_debug_severity {
 
 /** @} */
 
-/**
- * An error, warning, or other piece of debug information for an application
- * to consume via GL_ARB_debug_output/GL_KHR_debug.
- */
-struct gl_debug_msg
-{
-   enum mesa_debug_source source;
-   enum mesa_debug_type type;
-   GLuint id;
-   enum mesa_debug_severity severity;
-   GLsizei length;
-   GLcharARB *message;
-};
-
-struct gl_debug_namespace
-{
-   struct _mesa_HashTable *IDs;
-   unsigned ZeroID; /* a HashTable won't take zero, so store its state here */
-   /** lists of IDs in the hash table at each severity */
-   struct simple_node Severity[MESA_DEBUG_SEVERITY_COUNT];
-};
-
-struct gl_debug_state
-{
-   GLDEBUGPROC Callback;
-   const void *CallbackData;
-   GLboolean SyncOutput;
-   GLboolean DebugOutput;
-   GLboolean Defaults[MAX_DEBUG_GROUP_STACK_DEPTH][MESA_DEBUG_SEVERITY_COUNT][MESA_DEBUG_SOURCE_COUNT][MESA_DEBUG_TYPE_COUNT];
-   struct gl_debug_namespace Namespaces[MAX_DEBUG_GROUP_STACK_DEPTH][MESA_DEBUG_SOURCE_COUNT][MESA_DEBUG_TYPE_COUNT];
-   struct gl_debug_msg Log[MAX_DEBUG_LOGGED_MESSAGES];
-   struct gl_debug_msg DebugGroupMsgs[MAX_DEBUG_GROUP_STACK_DEPTH];
-   GLint GroupStackDepth;
-   GLint NumMessages;
-   GLint NextMsg;
-   GLint NextMsgLength; /* redundant, but copied here from Log[NextMsg].length
-                           for the sake of the offsetof() code in get.c */
-};
-
 /**
  * Enum for the OpenGL APIs we know about and may support.
  *

src/mesa/state_tracker/st_manager.c

@@ -663,13 +663,11 @@ st_api_create_context(struct st_api *stapi, struct st_manager *smapi,
    }
 
    if (attribs->flags & ST_CONTEXT_FLAG_DEBUG){
-      struct gl_debug_state *debug = _mesa_get_debug_state(st->ctx);
+      if (!_mesa_set_debug_state_int(st->ctx, GL_DEBUG_OUTPUT, GL_TRUE)) {
-      if (!debug) {
          *error = ST_CONTEXT_ERROR_NO_MEMORY;
          return NULL;
       }
       st->ctx->Const.ContextFlags |= GL_CONTEXT_FLAG_DEBUG_BIT;
-      debug->DebugOutput = GL_TRUE;
    }
 
    if (attribs->flags & ST_CONTEXT_FLAG_FORWARD_COMPATIBLE)