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

Timothy Arceri tarceri at itsqueeze.com
Fri Apr 21 09:47:24 UTC 2017


On 21/04/17 17:50, Samuel Pitoiset wrote:
> 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?

This hash table does some additional things that the util hash doesn't 
provide. For now I'd rather just push this.

We really need a newbie/easy task list to add stuff like 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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