PROTOTYPE WIP: Add thread-safe read functions to input files

src/lib/OpenEXR/ImfInputFile.cpp

@@ -899,12 +899,43 @@ InputFile::readPixels (int scanLine1, int scanLine2)
     }
 }
 
+void
+InputFile::readPixels (const FrameBuffer& frameBuffer, int scanLine1, int scanLine2)
+{
+    if (_data->compositor)
+    {
+#if ILMTHREAD_THREADING_ENABLED
+        std::lock_guard<std::mutex> lock (*_data);
+#endif
+        setFrameBuffer (frameBuffer);
+        _data->compositor->readPixels (scanLine1, scanLine2);
+    }
+    else if (_data->isTiled)
+    {
+#if ILMTHREAD_THREADING_ENABLED
+        std::lock_guard<std::mutex> lock (*_data);
+#endif
+        setFrameBuffer (frameBuffer);
+        bufferedReadPixels (_data, scanLine1, scanLine2);
+    }
+    else
+    {
+        _data->sFile->readPixels (frameBuffer, scanLine1, scanLine2);
+    }
+}
+
 void
 InputFile::readPixels (int scanLine)
 {
     readPixels (scanLine, scanLine);
 }
 
+void
+InputFile::readPixels (const FrameBuffer& frameBuffer, int scanLine)
+{
+    readPixels (frameBuffer, scanLine, scanLine);
+}
+
 void
 InputFile::rawPixelData (
     int firstScanLine, const char*& pixelData, int& pixelDataSize)

src/lib/OpenEXR/ImfInputFile.h

@@ -147,13 +147,25 @@ class IMF_EXPORT_TYPE InputFile : public GenericInputFile
     //
     // readPixels(s) calls readPixels(s,s).
     //
+    // The readPixels flavors that are passed a `FrameBuffer&` are
+    // thread-safe when called at the same time as other threads make
+    // calls to readPixels(fb,...). The reading functions that rely
+    // on saved state from a prior call to setFrameBuffer() are NOT
+    // safe to call when multiple threads are using the same InputFile.
+    //
     //---------------------------------------------------------------
 
     IMF_EXPORT
     void readPixels (int scanLine1, int scanLine2);
     IMF_EXPORT
     void readPixels (int scanLine);
 
+    IMF_EXPORT
+    void readPixels (const FrameBuffer& frameBuffer, int scanLine1, int scanLine2);
+    IMF_EXPORT
+    void readPixels (const FrameBuffer& frameBuffer, int scanLine);
+
+
     //----------------------------------------------
     // Read a block of raw pixel data from the file,
     // without uncompressing it (this function is

src/lib/OpenEXR/ImfInputPart.h

@@ -41,6 +41,10 @@ class IMF_EXPORT_TYPE InputPart
     IMF_EXPORT
     void readPixels (int scanLine);
     IMF_EXPORT
+    void readPixels (const FrameBuffer& frameBuffer, int scanLine1, int scanLine2);
+    IMF_EXPORT
+    void readPixels (const FrameBuffer& frameBuffer, int scanLine);
+    IMF_EXPORT
     void rawPixelData (
         int firstScanLine, const char*& pixelData, int& pixelDataSize);
 

src/lib/OpenEXR/ImfScanLineInputFile.cpp

@@ -1748,12 +1748,31 @@ ScanLineInputFile::readPixels (int scanLine1, int scanLine2)
     }
 }
 
+void
+ScanLineInputFile::readPixels (const FrameBuffer& frameBuffer, int scanLine1, int scanLine2)
+{
+    // FIXME: For now, this just locks, then calls setFrameBuffer() and
+    // readPixels(). It would be better to implement this function to avoid
+    // locking by not needing any saved framebuffer state.
+#if ILMTHREAD_THREADING_ENABLED
+    std::lock_guard<std::mutex> lock (*_data);
+#endif
+    setFrameBuffer(frameBuffer);
+    readPixels(scanLine1, scanLine2);
+}
+
 void
 ScanLineInputFile::readPixels (int scanLine)
 {
     readPixels (scanLine, scanLine);
 }
 
+void
+ScanLineInputFile::readPixels (const FrameBuffer& frameBuffer, int scanLine)
+{
+    readPixels (frameBuffer, scanLine, scanLine);
+}
+
 void
 ScanLineInputFile::rawPixelData (
     int firstScanLine, const char*& pixelData, int& pixelDataSize)

src/lib/OpenEXR/ImfScanLineInputFile.h

@@ -136,13 +136,24 @@ class IMF_EXPORT_TYPE ScanLineInputFile : public GenericInputFile
     // If threading is enabled, readPixels (s1, s2) tries to perform
     // decopmression of multiple scanlines in parallel.
     //
+    // The readPixels flavors that are passed a `FrameBuffer&` are
+    // thread-safe when called at the same time as other threads make
+    // calls to readPixels(fb,...). The reading functions that rely
+    // on saved state from a prior call to setFrameBuffer() are NOT
+    // safe to call when multiple threads are using the same InputFile.
+    //
     //---------------------------------------------------------------
 
     IMF_EXPORT
     void readPixels (int scanLine1, int scanLine2);
     IMF_EXPORT
     void readPixels (int scanLine);
 
+    IMF_EXPORT
+    void readPixels (const FrameBuffer& frameBuffer, int scanLine1, int scanLine2);
+    IMF_EXPORT
+    void readPixels (const FrameBuffer& frameBuffer, int scanLine);
+
     //----------------------------------------------
     // Read a block of raw pixel data from the file,
     // without uncompressing it (this function is

src/lib/OpenEXR/ImfTiledInputFile.h

@@ -317,6 +317,13 @@ class IMF_EXPORT_TYPE TiledInputFile : public GenericInputFile
     // Attempting to access a tile that is not present in the file
     // throws an InputExc exception.
     //
+    // The readTile/readTiles flavors that are passed a `FrameBuffer&`
+    // are thread-safe when called at the same time as other threads
+    // make calls to readTiles(fb,...). The reading functions that
+    // rely on saved state from a prior call to setFrameBuffer() are
+    // NOT safe to call when multiple threads are using the same
+    // TiledInputFile.
+    //
     //------------------------------------------------------------
 
     IMF_EXPORT
@@ -326,10 +333,33 @@ class IMF_EXPORT_TYPE TiledInputFile : public GenericInputFile
 
     IMF_EXPORT
     void readTiles (int dx1, int dx2, int dy1, int dy2, int lx, int ly);
-
     IMF_EXPORT
     void readTiles (int dx1, int dx2, int dy1, int dy2, int l = 0);
 
+    IMF_EXPORT
+    void readTile (const FrameBuffer& frameBuffer, int dx, int dy, int l = 0);
+    IMF_EXPORT
+    void
+    readTile (const FrameBuffer& frameBuffer, int dx, int dy, int lx, int ly);
+
+    IMF_EXPORT
+    void readTiles (
+        const FrameBuffer& frameBuffer,
+        int                dx1,
+        int                dx2,
+        int                dy1,
+        int                dy2,
+        int                lx,
+        int                ly);
+    IMF_EXPORT
+    void readTiles (
+        const FrameBuffer& frameBuffer,
+        int                dx1,
+        int                dx2,
+        int                dy1,
+        int                dy2,
+        int                l = 0);
+
     //--------------------------------------------------
     // Read a tile of raw pixel data from the file,
     // without uncompressing it (this function is

src/lib/OpenEXR/ImfTiledInputPart.h

@@ -79,6 +79,28 @@ class IMF_EXPORT_TYPE TiledInputPart
     IMF_EXPORT
     void readTiles (int dx1, int dx2, int dy1, int dy2, int l = 0);
     IMF_EXPORT
+    void readTile (const FrameBuffer& frameBuffer, int dx, int dy, int l = 0);
+    IMF_EXPORT
+    void
+    readTile (const FrameBuffer& frameBuffer, int dx, int dy, int lx, int ly);
+    IMF_EXPORT
+    void readTiles (
+        const FrameBuffer& frameBuffer,
+        int                dx1,
+        int                dx2,
+        int                dy1,
+        int                dy2,
+        int                lx,
+        int                ly);
+    IMF_EXPORT
+    void readTiles (
+        const FrameBuffer& frameBuffer,
+        int                dx1,
+        int                dx2,
+        int                dy1,
+        int                dy2,
+        int                l = 0);
+    IMF_EXPORT
     void rawTileData (
         int&         dx,
         int&         dy,