Make shader and program object lifetimes match OpenGL ES spec....

gpu/command_buffer/service/shader_manager.h

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef GPU_COMMAND_BUFFER_SERVICE_SHADER_MANAGER_H_
 #define GPU_COMMAND_BUFFER_SERVICE_SHADER_MANAGER_H_
 
 #include <map>
 #include <string>
 #include "base/basictypes.h"
+#include "base/logging.h"
 #include "base/ref_counted.h"
 #include "gpu/command_buffer/service/gl_utils.h"
 #include "gpu/command_buffer/service/shader_translator.h"
 
 namespace gpu {
 namespace gles2 {
 
 // Tracks the Shaders.
 //
 // NOTE: To support shared resources an instance of this class will
 // need to be shared by multiple GLES2Decoders.
 class ShaderManager {
  public:
   // This is used to keep the source code for a shader. This is because in order
   // to emluate GLES2 the shaders will have to be re-written before passed to
   // the underlying OpenGL. But, when the user calls glGetShaderSource they
   // should get the source they passed in, not the re-written source.
   class ShaderInfo : public base::RefCounted<ShaderInfo> {
    public:
     typedef scoped_refptr<ShaderInfo> Ref;
     typedef ShaderTranslator::VariableInfo VariableInfo;
 
     explicit ShaderInfo(GLuint service_id, GLenum shader_type)
-        : service_id_(service_id),
+        : use_count_(0),
+          service_id_(service_id),
           shader_type_(shader_type),
           valid_(false) {
     }
 
     void Update(const std::string& source) {
       source_ = source;
     }
 
     GLuint service_id() const {
       return service_id_;
@@ skipping 19 matching lines @@
     }
 
     bool IsValid() const {
       return valid_;
     }
 
     bool IsDeleted() const {
       return service_id_ == 0;
     }
 
+    bool InUse() const {
+      DCHECK_GE(use_count_, 0);
+      return use_count_ != 0;
+    }
+
    private:
     typedef ShaderTranslator::VariableMap VariableMap;
 
     friend class base::RefCounted<ShaderInfo>;
     friend class ShaderManager;
     ~ShaderInfo() { }
 
+    void IncUseCount() {
+      ++use_count_;
+    }
+
+    void DecUseCount() {
+      --use_count_;
+      DCHECK_GE(use_count_, 0);
+    }
+
     void MarkAsDeleted() {
+      DCHECK_NE(service_id_, 0u);
       service_id_ = 0;
     }
 
+    int use_count_;
+
     // The shader this ShaderInfo is tracking.
     GLuint service_id_;
     // Type of shader - GL_VERTEX_SHADER or GL_FRAGMENT_SHADER.
     GLenum shader_type_;
 
     // True if compilation succeeded.
     bool valid_;
 
     // The shader source as passed to glShaderSource.
     std::string source_;
@@ skipping 14 matching lines @@
 
   // Creates a shader info for the given shader ID.
   void CreateShaderInfo(GLuint client_id,
                         GLuint service_id,
                         GLenum shader_type);
 
   // Gets an existing shader info for the given shader ID. Returns NULL if none
   // exists.
   ShaderInfo* GetShaderInfo(GLuint client_id);
 
-  // Deletes the shader info for the given shader.
-  void RemoveShaderInfo(GLuint client_id);
-
   // Gets a client id for a given service id.
   bool GetClientId(GLuint service_id, GLuint* client_id) const;
 
+  void MarkAsDeleted(ShaderInfo* info);
+
+  // Mark a shader as used
+  void UseShader(ShaderInfo* info);
+
+  // Unmark a shader as used. If it has been deleted and is not used
+  // then we free the info.
+  void UnuseShader(ShaderInfo* info);
+
  private:
   // Info for each shader by service side shader Id.
   typedef std::map<GLuint, ShaderInfo::Ref> ShaderInfoMap;
   ShaderInfoMap shader_infos_;
 
+  void RemoveShaderInfoIfUnused(ShaderInfo* info);
+
   DISALLOW_COPY_AND_ASSIGN(ShaderManager);
 };
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_SHADER_MANAGER_H_