dm: simplify parallel/serial decisions

dm/DMSrcSink.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef DMSrcSink_DEFINED
 #define DMSrcSink_DEFINED
 
@@ skipping 41 matching lines @@
     SkString fMsg;
     bool     fFatal;
 };
 
 struct SinkFlags {
     enum { kNull, kGPU, kVector, kRaster } type;
     enum { kDirect, kIndirect } approach;
 };
 
 struct Src {
-    // All Srcs must be thread safe.
     virtual ~Src() {}
     virtual Error SK_WARN_UNUSED_RESULT draw(SkCanvas*) const = 0;
     virtual SkISize size() const = 0;
     virtual Name name() const = 0;
     virtual void modifyGrContextOptions(GrContextOptions* options) const {}
     virtual bool veto(SinkFlags) const { return false; }
+
+    // Force Tasks using this Src to run on the main thread?
+    virtual bool serial() const { return false; }
 };
 
 struct Sink {
     virtual ~Sink() {}
     // You may write to either the bitmap or stream.  If you write to log, we'll print that out.
     virtual Error SK_WARN_UNUSED_RESULT draw(const Src&, SkBitmap*, SkWStream*, SkString* log)
         const = 0;
-    // Sinks in the same enclave (except kAnyThread_Enclave) will run serially on the same thread.
-    virtual int enclave() const = 0;
+
+    // Force Tasks using this Sink to run on the main thread?
+    virtual bool serial() const { return false; }
 
     // File extension for the content draw() outputs, e.g. "png", "pdf".
     virtual const char* fileExtension() const  = 0;
 
     virtual SinkFlags flags() const = 0;
 };
 
-enum { kAnyThread_Enclave, kGPU_Enclave };
-static const int kNumEnclaves = kGPU_Enclave + 1;
-
 /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
 class GMSrc : public Src {
 public:
     explicit GMSrc(skiagm::GMRegistry::Factory);
 
     Error draw(SkCanvas*) const override;
     SkISize size() const override;
     Name name() const override;
     void modifyGrContextOptions(GrContextOptions* options) const override;
@@ skipping 95 matching lines @@
     Path fPath;
 };
 
 /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
 class NullSink : public Sink {
 public:
     NullSink() {}
 
     Error draw(const Src& src, SkBitmap*, SkWStream*, SkString*) const override;
-    int enclave() const override { return kAnyThread_Enclave; }
     const char* fileExtension() const override { return ""; }
     SinkFlags flags() const override { return SinkFlags{ SinkFlags::kNull, SinkFlags::kDirect }; }
 };
 
 
 class GPUSink : public Sink {
 public:
     GPUSink(GrContextFactory::GLContextType, GrContextFactory::GLContextOptions,
             int samples, bool diText, bool threaded);
 
     Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const override;
-    int enclave() const override;
+    bool serial() const override { return !fThreaded; }
     const char* fileExtension() const override { return "png"; }
     SinkFlags flags() const override { return SinkFlags{ SinkFlags::kGPU, SinkFlags::kDirect }; }
 private:
     GrContextFactory::GLContextType    fContextType;
     GrContextFactory::GLContextOptions fContextOptions;
     int                                fSampleCount;
     bool                               fUseDIText;
     bool                               fThreaded;
 };
 
 class PDFSink : public Sink {
 public:
     PDFSink(const char* rasterizer);
 
     Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const override;
-    int enclave() const override { return kAnyThread_Enclave; }
     const char* fileExtension() const override { return "pdf"; }
     SinkFlags flags() const override { return SinkFlags{ SinkFlags::kVector, SinkFlags::kDirect }; }
 private:
     const char* fRasterizer;
 };
 
 class XPSSink : public Sink {
 public:
     XPSSink();
 
     Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const override;
-    int enclave() const override { return kAnyThread_Enclave; }
     const char* fileExtension() const override { return "xps"; }
     SinkFlags flags() const override { return SinkFlags{ SinkFlags::kVector, SinkFlags::kDirect }; }
 };
 
 class RasterSink : public Sink {
 public:
     explicit RasterSink(SkColorType);
 
     Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const override;
-    int enclave() const override { return kAnyThread_Enclave; }
     const char* fileExtension() const override { return "png"; }
     SinkFlags flags() const override { return SinkFlags{ SinkFlags::kRaster, SinkFlags::kDirect }; }
 private:
     SkColorType    fColorType;
 };
 
 class SKPSink : public Sink {
 public:
     SKPSink();
 
     Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const override;
-    int enclave() const override { return kAnyThread_Enclave; }
     const char* fileExtension() const override { return "skp"; }
     SinkFlags flags() const override { return SinkFlags{ SinkFlags::kVector, SinkFlags::kDirect }; }
 };
 
 class SVGSink : public Sink {
 public:
     SVGSink();
 
     Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const override;
-    int enclave() const override { return kAnyThread_Enclave; }
     const char* fileExtension() const override { return "svg"; }
     SinkFlags flags() const override { return SinkFlags{ SinkFlags::kVector, SinkFlags::kDirect }; }
 };
 
 
 /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
 class Via : public Sink {
 public:
     explicit Via(Sink* sink) : fSink(sink) {}
     const char* fileExtension() const override { return fSink->fileExtension(); }
-    int               enclave() const override { return fSink->enclave(); }
+    bool               serial() const override { return fSink->serial(); }
     SinkFlags flags() const override {
         SinkFlags flags = fSink->flags();
         flags.approach = SinkFlags::kIndirect;
         return flags;
     }
 protected:
     SkAutoTDelete<Sink> fSink;
 };
 
 class ViaMatrix : public Via {
@@ skipping 61 matching lines @@
 
 class ViaMojo : public Via {
 public:
     explicit ViaMojo(Sink* sink) : Via(sink) {}
     Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const override;
 };
 
 }  // namespace DM
 
 #endif//DMSrcSink_DEFINED