[Mesa-dev] [PATCH 4/4] mesa: don't lock hashtables that are not shared across contexts

Samuel Pitoiset samuel.pitoiset at gmail.com
Fri Apr 21 07:50:24 UTC 2017


I would definitely prefer to see _mesa_hash_table instead here. That way 
you can get rid of the unnecessary locking at the same time.

I actually use _mesa_hash_table for the resident texture/image handles 
as part of ARB_bindless_texture. Though, I use the locked hash_table 
implementation inside the shared context, of course.

Anyways, we shouldn't use any locked hash tables in the per-context object.

Can you change this?

On 04/21/2017 07:20 AM, Timothy Arceri wrote:
>  From Chapter 5 'Shared Objects and Multiple Contexts' of
> the OpenGL 4.5 spec:
> 
>     "Objects which contain references to other objects include
>     framebuffer, program pipeline, query, transform feedback,
>     and vertex array objects.   Such objects are called container
>     objects and are not shared"
> 
> For we leave locking in place for framebuffer objects because
> the EXT fbo extension allowed sharing.
> 
> We could maybe just replace the hash with an ordinary hash table
> but for now this should remove most of the unnecessary locking.
> ---
>   src/mesa/main/arrayobj.c          | 8 ++++----
>   src/mesa/main/pipelineobj.c       | 6 +++---
>   src/mesa/main/queryobj.c          | 8 ++++----
>   src/mesa/main/queryobj.h          | 2 +-
>   src/mesa/main/transformfeedback.c | 7 ++++---
>   5 files changed, 16 insertions(+), 15 deletions(-)
> 
> diff --git a/src/mesa/main/arrayobj.c b/src/mesa/main/arrayobj.c
> index 24555d9..b901a89 100644
> --- a/src/mesa/main/arrayobj.c
> +++ b/src/mesa/main/arrayobj.c
> @@ -64,21 +64,21 @@
>    * non-existent.
>    */
>   
>   struct gl_vertex_array_object *
>   _mesa_lookup_vao(struct gl_context *ctx, GLuint id)
>   {
>      if (id == 0)
>         return NULL;
>      else
>         return (struct gl_vertex_array_object *)
> -         _mesa_HashLookup(ctx->Array.Objects, id);
> +         _mesa_HashLookupLocked(ctx->Array.Objects, id);
>   }
>   
>   
>   /**
>    * Looks up the array object for the given ID.
>    *
>    * Unlike _mesa_lookup_vao, this function generates a GL_INVALID_OPERATION
>    * error if the array object does not exist. It also returns the default
>    * array object when ctx is a compatibility profile context and id is zero.
>    */
> @@ -101,21 +101,21 @@ _mesa_lookup_vao_err(struct gl_context *ctx, GLuint id, const char *caller)
>   
>         return ctx->Array.DefaultVAO;
>      } else {
>         struct gl_vertex_array_object *vao;
>   
>         if (ctx->Array.LastLookedUpVAO &&
>             ctx->Array.LastLookedUpVAO->Name == id) {
>            vao = ctx->Array.LastLookedUpVAO;
>         } else {
>            vao = (struct gl_vertex_array_object *)
> -            _mesa_HashLookup(ctx->Array.Objects, id);
> +            _mesa_HashLookupLocked(ctx->Array.Objects, id);
>   
>            /* The ARB_direct_state_access specification says:
>             *
>             *    "An INVALID_OPERATION error is generated if <vaobj> is not
>             *     [compatibility profile: zero or] the name of an existing
>             *     vertex array object."
>             */
>            if (!vao || !vao->EverBound) {
>               _mesa_error(ctx, GL_INVALID_OPERATION,
>                           "%s(non-existent vaobj=%u)", caller, id);
> @@ -299,35 +299,35 @@ _mesa_initialize_vao(struct gl_context *ctx,
>   
>   
>   /**
>    * Add the given array object to the array object pool.
>    */
>   static void
>   save_array_object(struct gl_context *ctx, struct gl_vertex_array_object *vao)
>   {
>      if (vao->Name > 0) {
>         /* insert into hash table */
> -      _mesa_HashInsert(ctx->Array.Objects, vao->Name, vao);
> +      _mesa_HashInsertLocked(ctx->Array.Objects, vao->Name, vao);
>      }
>   }
>   
>   
>   /**
>    * Remove the given array object from the array object pool.
>    * Do not deallocate the array object though.
>    */
>   static void
>   remove_array_object(struct gl_context *ctx, struct gl_vertex_array_object *vao)
>   {
>      if (vao->Name > 0) {
>         /* remove from hash table */
> -      _mesa_HashRemove(ctx->Array.Objects, vao->Name);
> +      _mesa_HashRemoveLocked(ctx->Array.Objects, vao->Name);
>      }
>   }
>   
>   
>   /**
>    * Updates the derived gl_vertex_arrays when a gl_vertex_attrib_array
>    * or a gl_vertex_buffer_binding has changed.
>    */
>   void
>   _mesa_update_vao_client_arrays(struct gl_context *ctx,
> diff --git a/src/mesa/main/pipelineobj.c b/src/mesa/main/pipelineobj.c
> index 9a852be..dbca3c3 100644
> --- a/src/mesa/main/pipelineobj.c
> +++ b/src/mesa/main/pipelineobj.c
> @@ -137,43 +137,43 @@ _mesa_free_pipeline_data(struct gl_context *ctx)
>    * a non-existent ID.  The spec defines ID 0 as being technically
>    * non-existent.
>    */
>   struct gl_pipeline_object *
>   _mesa_lookup_pipeline_object(struct gl_context *ctx, GLuint id)
>   {
>      if (id == 0)
>         return NULL;
>      else
>         return (struct gl_pipeline_object *)
> -         _mesa_HashLookup(ctx->Pipeline.Objects, id);
> +         _mesa_HashLookupLocked(ctx->Pipeline.Objects, id);
>   }
>   
>   /**
>    * Add the given pipeline object to the pipeline object pool.
>    */
>   static void
>   save_pipeline_object(struct gl_context *ctx, struct gl_pipeline_object *obj)
>   {
>      if (obj->Name > 0) {
> -      _mesa_HashInsert(ctx->Pipeline.Objects, obj->Name, obj);
> +      _mesa_HashInsertLocked(ctx->Pipeline.Objects, obj->Name, obj);
>      }
>   }
>   
>   /**
>    * Remove the given pipeline object from the pipeline object pool.
>    * Do not deallocate the pipeline object though.
>    */
>   static void
>   remove_pipeline_object(struct gl_context *ctx, struct gl_pipeline_object *obj)
>   {
>      if (obj->Name > 0) {
> -      _mesa_HashRemove(ctx->Pipeline.Objects, obj->Name);
> +      _mesa_HashRemoveLocked(ctx->Pipeline.Objects, obj->Name);
>      }
>   }
>   
>   /**
>    * Set ptr to obj w/ reference counting.
>    * Note: this should only be called from the _mesa_reference_pipeline_object()
>    * inline function.
>    */
>   void
>   _mesa_reference_pipeline_object_(struct gl_context *ctx,
> diff --git a/src/mesa/main/queryobj.c b/src/mesa/main/queryobj.c
> index e4edb51..46535d7 100644
> --- a/src/mesa/main/queryobj.c
> +++ b/src/mesa/main/queryobj.c
> @@ -271,21 +271,21 @@ create_queries(struct gl_context *ctx, GLenum target, GLsizei n, GLuint *ids,
>               = ctx->Driver.NewQueryObject(ctx, first + i);
>            if (!q) {
>               _mesa_error(ctx, GL_OUT_OF_MEMORY, "%s", func);
>               return;
>            } else if (dsa) {
>               /* Do the equivalent of binding the buffer with a target */
>               q->Target = target;
>               q->EverBound = GL_TRUE;
>            }
>            ids[i] = first + i;
> -         _mesa_HashInsert(ctx->Query.QueryObjects, first + i, q);
> +         _mesa_HashInsertLocked(ctx->Query.QueryObjects, first + i, q);
>         }
>      }
>   }
>   
>   void GLAPIENTRY
>   _mesa_GenQueries(GLsizei n, GLuint *ids)
>   {
>      GET_CURRENT_CONTEXT(ctx);
>      create_queries(ctx, 0, n, ids, false);
>   }
> @@ -338,21 +338,21 @@ _mesa_DeleteQueries(GLsizei n, const GLuint *ids)
>               if (q->Active) {
>                  struct gl_query_object **bindpt;
>                  bindpt = get_query_binding_point(ctx, q->Target, q->Stream);
>                  assert(bindpt); /* Should be non-null for active q. */
>                  if (bindpt) {
>                     *bindpt = NULL;
>                  }
>                  q->Active = GL_FALSE;
>                  ctx->Driver.EndQuery(ctx, q);
>               }
> -            _mesa_HashRemove(ctx->Query.QueryObjects, ids[i]);
> +            _mesa_HashRemoveLocked(ctx->Query.QueryObjects, ids[i]);
>               ctx->Driver.DeleteQuery(ctx, q);
>            }
>         }
>      }
>   }
>   
>   
>   GLboolean GLAPIENTRY
>   _mesa_IsQuery(GLuint id)
>   {
> @@ -441,21 +441,21 @@ _mesa_BeginQueryIndexed(GLenum target, GLuint index, GLuint id)
>            _mesa_error(ctx, GL_INVALID_OPERATION,
>                        "glBeginQuery{Indexed}(non-gen name)");
>            return;
>         } else {
>            /* create new object */
>            q = ctx->Driver.NewQueryObject(ctx, id);
>            if (!q) {
>               _mesa_error(ctx, GL_OUT_OF_MEMORY, "glBeginQuery{Indexed}");
>               return;
>            }
> -         _mesa_HashInsert(ctx->Query.QueryObjects, id, q);
> +         _mesa_HashInsertLocked(ctx->Query.QueryObjects, id, q);
>         }
>      }
>      else {
>         /* pre-existing object */
>         if (q->Active) {
>            _mesa_error(ctx, GL_INVALID_OPERATION,
>                        "glBeginQuery{Indexed}(query already active)");
>            return;
>         }
>   
> @@ -583,21 +583,21 @@ _mesa_QueryCounter(GLuint id, GLenum target)
>      q = _mesa_lookup_query_object(ctx, id);
>      if (!q) {
>         /* XXX the Core profile should throw INVALID_OPERATION here */
>   
>         /* create new object */
>         q = ctx->Driver.NewQueryObject(ctx, id);
>         if (!q) {
>            _mesa_error(ctx, GL_OUT_OF_MEMORY, "glQueryCounter");
>            return;
>         }
> -      _mesa_HashInsert(ctx->Query.QueryObjects, id, q);
> +      _mesa_HashInsertLocked(ctx->Query.QueryObjects, id, q);
>      }
>      else {
>         if (q->Target && q->Target != GL_TIMESTAMP) {
>            _mesa_error(ctx, GL_INVALID_OPERATION,
>                        "glQueryCounter(id has an invalid target)");
>            return;
>         }
>      }
>   
>      if (q->Active) {
> diff --git a/src/mesa/main/queryobj.h b/src/mesa/main/queryobj.h
> index d1036fc..24a8257 100644
> --- a/src/mesa/main/queryobj.h
> +++ b/src/mesa/main/queryobj.h
> @@ -28,21 +28,21 @@
>   
>   
>   #include "main/mtypes.h"
>   #include "main/hash.h"
>   
>   
>   static inline struct gl_query_object *
>   _mesa_lookup_query_object(struct gl_context *ctx, GLuint id)
>   {
>      return (struct gl_query_object *)
> -      _mesa_HashLookup(ctx->Query.QueryObjects, id);
> +      _mesa_HashLookupLocked(ctx->Query.QueryObjects, id);
>   }
>   
>   
>   extern void
>   _mesa_init_query_object_functions(struct dd_function_table *driver);
>   
>   extern void
>   _mesa_init_queryobj(struct gl_context *ctx);
>   
>   extern void
> diff --git a/src/mesa/main/transformfeedback.c b/src/mesa/main/transformfeedback.c
> index 131014f..3c72674 100644
> --- a/src/mesa/main/transformfeedback.c
> +++ b/src/mesa/main/transformfeedback.c
> @@ -958,21 +958,21 @@ _mesa_lookup_transform_feedback_object(struct gl_context *ctx, GLuint name)
>   {
>      /* OpenGL 4.5 core profile, 13.2 pdf page 444: "xfb must be zero, indicating
>       * the default transform feedback object, or the name of an existing
>       * transform feedback object."
>       */
>      if (name == 0) {
>         return ctx->TransformFeedback.DefaultObject;
>      }
>      else
>         return (struct gl_transform_feedback_object *)
> -         _mesa_HashLookup(ctx->TransformFeedback.Objects, name);
> +         _mesa_HashLookupLocked(ctx->TransformFeedback.Objects, name);
>   }
>   
>   static void
>   create_transform_feedbacks(struct gl_context *ctx, GLsizei n, GLuint *ids,
>                              bool dsa)
>   {
>      GLuint first;
>      const char* func;
>   
>      if (dsa)
> @@ -993,21 +993,22 @@ create_transform_feedbacks(struct gl_context *ctx, GLsizei n, GLuint *ids,
>      if (first) {
>         GLsizei i;
>         for (i = 0; i < n; i++) {
>            struct gl_transform_feedback_object *obj
>               = ctx->Driver.NewTransformFeedback(ctx, first + i);
>            if (!obj) {
>               _mesa_error(ctx, GL_OUT_OF_MEMORY, "%s", func);
>               return;
>            }
>            ids[i] = first + i;
> -         _mesa_HashInsert(ctx->TransformFeedback.Objects, first + i, obj);
> +         _mesa_HashInsertLocked(ctx->TransformFeedback.Objects, first + i,
> +                                obj);
>            if (dsa) {
>               /* this is normally done at bind time in the non-dsa case */
>               obj->EverBound = GL_TRUE;
>            }
>         }
>      }
>      else {
>         _mesa_error(ctx, GL_OUT_OF_MEMORY, "%s", func);
>      }
>   }
> @@ -1125,21 +1126,21 @@ _mesa_DeleteTransformFeedbacks(GLsizei n, const GLuint *names)
>         if (names[i] > 0) {
>            struct gl_transform_feedback_object *obj
>               = _mesa_lookup_transform_feedback_object(ctx, names[i]);
>            if (obj) {
>               if (obj->Active) {
>                  _mesa_error(ctx, GL_INVALID_OPERATION,
>                              "glDeleteTransformFeedbacks(object %u is active)",
>                              names[i]);
>                  return;
>               }
> -            _mesa_HashRemove(ctx->TransformFeedback.Objects, names[i]);
> +            _mesa_HashRemoveLocked(ctx->TransformFeedback.Objects, names[i]);
>               /* unref, but object may not be deleted until later */
>               if (obj == ctx->TransformFeedback.CurrentObject) {
>                  reference_transform_feedback_object(
>                        &ctx->TransformFeedback.CurrentObject,
>                        ctx->TransformFeedback.DefaultObject);
>               }
>               reference_transform_feedback_object(&obj, NULL);
>            }
>         }
>      }
> 


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