Force BackendTextureImageGenerator to work on only 1 consumer context

Bug: skia:
Change-Id: I83d3e4af6f20c877c541964fdd489434f6a62b25
Reviewed-on: https://skia-review.googlesource.com/93200
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/src/gpu/GrBackendTextureImageGenerator.h b/src/gpu/GrBackendTextureImageGenerator.h
index bebb736750..ef96e6a238 100644
--- a/src/gpu/GrBackendTextureImageGenerator.h
+++ b/src/gpu/GrBackendTextureImageGenerator.h
@@ -14,6 +14,13 @@
 
 class GrSemaphore;
 
+/*
+ * This ImageGenerator is used to wrap a texture in one GrContext and can then be used as a source
+ * in another GrContext. It holds onto a semaphore which the producing Grontext will signal and the
+ * consuming GrContext will wait on before using the texture. Only one GrContext can ever be used
+ * as a consumer (this is mostly because Vulkan can't allow multiple things to wait on the same
+ * semaphore).
+ */
 class GrBackendTextureImageGenerator : public SkImageGenerator {
 public:
     static std::unique_ptr<SkImageGenerator> Make(sk_sp<GrTexture>, GrSurfaceOrigin,
@@ -64,7 +71,6 @@ private:
     RefHelper* fRefHelper;
 
     sk_sp<GrSemaphore> fSemaphore;
-    uint32_t fLastBorrowingContextID;
 
     GrBackendTexture fBackendTexture;
     GrSurfaceOrigin fSurfaceOrigin;