Update GrSemaphore to allow it to only be used once for signaling and once for waiting.

This is required for Vulkan which doesn't allow a semaphore to be waited on by
multiple things at once or signaled from multiple places.

Bug: skia:
Change-Id: Iac0cb782a6662167c2cab1fd6a2c80378834a480
Reviewed-on: https://skia-review.googlesource.com/92601
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>

14 files changed, 135 insertions, 50 deletions

diff --git a/src/gpu/GrBackendTextureImageGenerator.cpp b/src/gpu/GrBackendTextureImageGenerator.cpp
index 186ca52446..420020b0b6 100644
--- a/src/gpu/GrBackendTextureImageGenerator.cpp
+++ b/src/gpu/GrBackendTextureImageGenerator.cpp
@@ -114,7 +114,8 @@ sk_sp<GrTextureProxy> GrBackendTextureImageGenerator::onGenerateTexture(
         } else {
             // Wait on a semaphore when a new context has just started borrowing the texture. This
             // is conservative, but shouldn't be too expensive.
-            if (fSemaphore && fLastBorrowingContextID != context->uniqueID()) {
+            if (fSemaphore && !fSemaphore->hasSubmittedWait() &&
+                fLastBorrowingContextID != context->uniqueID()) {
                 context->getGpu()->waitSemaphore(fSemaphore);
                 fLastBorrowingContextID = context->uniqueID();
             }
diff --git a/src/gpu/GrGpu.cpp b/src/gpu/GrGpu.cpp
index 5b338cdfa0..3a095517b5 100644
--- a/src/gpu/GrGpu.cpp
+++ b/src/gpu/GrGpu.cpp
@@ -488,7 +488,8 @@ GrSemaphoresSubmitted GrGpu::finishFlush(int numSemaphores,
             sk_sp<GrSemaphore> semaphore;
             if (backendSemaphores[i].isInitialized()) {
                 semaphore = fContext->resourceProvider()->wrapBackendSemaphore(
-                        backendSemaphores[i], kBorrow_GrWrapOwnership);
+                        backendSemaphores[i], GrResourceProvider::SemaphoreWrapType::kWillSignal,
+                        kBorrow_GrWrapOwnership);
             } else {
                 semaphore = fContext->resourceProvider()->makeSemaphore(false);
             }
@@ -513,3 +514,49 @@ void GrGpu::dumpJSON(SkJSONWriter* writer) const {
 
     writer->endObject();
 }
+
+void GrGpu::insertSemaphore(sk_sp<GrSemaphore> semaphore, bool flush) {
+    if (!semaphore) {
+        return;
+    }
+
+    SkASSERT(!semaphore->fSignaled);
+    if (semaphore->fSignaled) {
+        this->onInsertSemaphore(nullptr, flush);
+        return;
+    }
+    this->onInsertSemaphore(semaphore, flush);
+    semaphore->fSignaled = true;
+}
+
+void GrGpu::waitSemaphore(sk_sp<GrSemaphore> semaphore) {
+    if (!semaphore) {
+        return;
+    }
+
+    SkASSERT(!semaphore->fWaitedOn);
+    if (!semaphore->fWaitedOn) {
+        this->onWaitSemaphore(semaphore);
+        semaphore->fWaitedOn = true;
+    }
+}
+
+sk_sp<GrSemaphore> GrGpu::wrapBackendSemaphore(const GrBackendSemaphore& semaphore,
+                                               GrResourceProvider::SemaphoreWrapType wrapType,
+                                               GrWrapOwnership ownership) {
+    sk_sp<GrSemaphore> grSema = this->onWrapBackendSemaphore(semaphore, ownership);
+    if (GrResourceProvider::SemaphoreWrapType::kWillSignal == wrapType) {
+        // This is a safety check to make sure we never try to wait on this semaphore since we
+        // assume the client will wait on it themselves if they've asked us to signal it.
+        grSema->fWaitedOn = true;
+    } else {
+        SkASSERT(GrResourceProvider::SemaphoreWrapType::kWillWait == wrapType);
+        // This is a safety check to make sure we never try to signal this semaphore since we assume
+        // the client will signal it themselves if they've asked us wait on it.
+        grSema->fSignaled = true;
+    }
+
+    SkASSERT(this->caps()->fenceSyncSupport());
+    return grSema;
+}
+
diff --git a/src/gpu/GrGpu.h b/src/gpu/GrGpu.h
index 3f3610898a..e8e0ab9141 100644
--- a/src/gpu/GrGpu.h
+++ b/src/gpu/GrGpu.h
@@ -377,10 +377,11 @@ public:
     virtual void deleteFence(GrFence) const = 0;
 
     virtual sk_sp<GrSemaphore> SK_WARN_UNUSED_RESULT makeSemaphore(bool isOwned = true) = 0;
-    virtual sk_sp<GrSemaphore> wrapBackendSemaphore(const GrBackendSemaphore& semaphore,
-                                                    GrWrapOwnership ownership) = 0;
-    virtual void insertSemaphore(sk_sp<GrSemaphore> semaphore, bool flush = false) = 0;
-    virtual void waitSemaphore(sk_sp<GrSemaphore> semaphore) = 0;
+    sk_sp<GrSemaphore> wrapBackendSemaphore(const GrBackendSemaphore& semaphore,
+                                            GrResourceProvider::SemaphoreWrapType wrapType,
+                                            GrWrapOwnership ownership);
+    void insertSemaphore(sk_sp<GrSemaphore> semaphore, bool flush = false);
+    void waitSemaphore(sk_sp<GrSemaphore> semaphore);
 
     /**
      *  Put this texture in a safe and known state for use across multiple GrContexts. Depending on
@@ -605,6 +606,11 @@ private:
 
     virtual void onFinishFlush(bool insertedSemaphores) = 0;
 
+    virtual void onInsertSemaphore(sk_sp<GrSemaphore> semaphore, bool flush = false) = 0;
+    virtual void onWaitSemaphore(sk_sp<GrSemaphore> semaphore) = 0;
+    virtual sk_sp<GrSemaphore> onWrapBackendSemaphore(const GrBackendSemaphore& semaphore,
+                                                      GrWrapOwnership ownership) = 0;
+
     virtual void onDumpJSON(SkJSONWriter*) const {}
 
     void resetContext() {
diff --git a/src/gpu/GrRenderTargetContext.cpp b/src/gpu/GrRenderTargetContext.cpp
index c2b25d8c33..c985e964e8 100644
--- a/src/gpu/GrRenderTargetContext.cpp
+++ b/src/gpu/GrRenderTargetContext.cpp
@@ -1428,7 +1428,8 @@ bool GrRenderTargetContext::waitOnSemaphores(int numSemaphores,
     SkTArray<sk_sp<GrSemaphore>> semaphores(numSemaphores);
     for (int i = 0; i < numSemaphores; ++i) {
         sk_sp<GrSemaphore> sema = fContext->resourceProvider()->wrapBackendSemaphore(
-                waitSemaphores[i], kAdopt_GrWrapOwnership);
+                waitSemaphores[i], GrResourceProvider::SemaphoreWrapType::kWillWait,
+                kAdopt_GrWrapOwnership);
         std::unique_ptr<GrOp> waitOp(GrSemaphoreOp::MakeWait(sema, fRenderTargetProxy.get()));
         this->getRTOpList()->addOp(std::move(waitOp), *this->caps());
     }
diff --git a/src/gpu/GrResourceProvider.cpp b/src/gpu/GrResourceProvider.cpp
index 0112b5c15c..048b87fc4e 100644
--- a/src/gpu/GrResourceProvider.cpp
+++ b/src/gpu/GrResourceProvider.cpp
@@ -472,9 +472,12 @@ sk_sp<GrSemaphore> SK_WARN_UNUSED_RESULT GrResourceProvider::makeSemaphore(bool
 }
 
 sk_sp<GrSemaphore> GrResourceProvider::wrapBackendSemaphore(const GrBackendSemaphore& semaphore,
+                                                            SemaphoreWrapType wrapType,
                                                             GrWrapOwnership ownership) {
     ASSERT_SINGLE_OWNER
-    return this->isAbandoned() ? nullptr : fGpu->wrapBackendSemaphore(semaphore, ownership);
+    return this->isAbandoned() ? nullptr : fGpu->wrapBackendSemaphore(semaphore,
+                                                                      wrapType,
+                                                                      ownership);
 }
 
 void GrResourceProvider::takeOwnershipOfSemaphore(sk_sp<GrSemaphore> semaphore) {
diff --git a/src/gpu/GrResourceProvider.h b/src/gpu/GrResourceProvider.h
index 08da9ae0b0..bf7f28e93d 100644
--- a/src/gpu/GrResourceProvider.h
+++ b/src/gpu/GrResourceProvider.h
@@ -228,7 +228,13 @@ public:
 
     sk_sp<GrSemaphore> SK_WARN_UNUSED_RESULT makeSemaphore(bool isOwned = true);
 
+    enum class SemaphoreWrapType {
+        kWillSignal,
+        kWillWait,
+    };
+
     sk_sp<GrSemaphore> wrapBackendSemaphore(const GrBackendSemaphore&,
+                                            SemaphoreWrapType wrapType,
                                             GrWrapOwnership = kBorrow_GrWrapOwnership);
 
     // Takes the GrSemaphore and sets the ownership of the semaphore to the GrGpu object used by
diff --git a/src/gpu/GrSemaphore.h b/src/gpu/GrSemaphore.h
index fbc5a6df56..20556d27ac 100644
--- a/src/gpu/GrSemaphore.h
+++ b/src/gpu/GrSemaphore.h
@@ -13,7 +13,15 @@
 class GrBackendSemaphore;
 class GrGpu;
 
+/*
+ * Wrapper around a semaphore object which must be implemented on each backend. This semaphores can
+ * at most be signaled once and waited upon once.
+ */
 class GrSemaphore : public SkRefCnt {
+public:
+    bool hasSubmittedSignal() const { return fSignaled; }
+    bool hasSubmittedWait() const { return fWaitedOn; }
+
 private:
     // This function should only be used in the case of exporting and importing a GrSemaphore object
     // from one GrContext to another. When exporting, the GrSemaphore should be set to a null GrGpu,
@@ -26,6 +34,9 @@ private:
     // internal semaphore.
     virtual void setBackendSemaphore(GrBackendSemaphore*) const = 0;
 
+    bool fSignaled = false;
+    bool fWaitedOn = false;
+
 protected:
     explicit GrSemaphore(const GrGpu* gpu) : fGpu(gpu) {}
 
diff --git a/src/gpu/ddl/GrDDLGpu.h b/src/gpu/ddl/GrDDLGpu.h
index aa708bd02b..e97a2abf4a 100644
--- a/src/gpu/ddl/GrDDLGpu.h
+++ b/src/gpu/ddl/GrDDLGpu.h
@@ -72,17 +72,6 @@ public:
         SkASSERT(0);
         return nullptr;
     }
-    sk_sp<GrSemaphore> wrapBackendSemaphore(const GrBackendSemaphore& semaphore,
-                                            GrWrapOwnership ownership) override {
-        SkASSERT(0);
-        return nullptr;
-    }
-    void insertSemaphore(sk_sp<GrSemaphore> semaphore, bool flush) override {
-        SkASSERT(0);
-    }
-    void waitSemaphore(sk_sp<GrSemaphore> semaphore) override {
-        SkASSERT(0);
-    }
     sk_sp<GrSemaphore> prepareTextureForCrossContextUsage(GrTexture*) override {
         SkASSERT(0);
         return nullptr;
@@ -158,6 +147,18 @@ private:
 
     void onFinishFlush(bool insertedSemaphores) override { SkASSERT(0); }
 
+    sk_sp<GrSemaphore> onWrapBackendSemaphore(const GrBackendSemaphore& semaphore,
+                                            GrWrapOwnership ownership) override {
+        SkASSERT(0);
+        return nullptr;
+    }
+    void onInsertSemaphore(sk_sp<GrSemaphore> semaphore, bool flush) override {
+        SkASSERT(0);
+    }
+    void onWaitSemaphore(sk_sp<GrSemaphore> semaphore) override {
+        SkASSERT(0);
+    }
+
     GrStencilAttachment* createStencilAttachmentForRenderTarget(const GrRenderTarget*,
                                                                 int width,
                                                                 int height) override;
diff --git a/src/gpu/gl/GrGLGpu.cpp b/src/gpu/gl/GrGLGpu.cpp
index 7b66bcc8a1..fb82a54448 100644
--- a/src/gpu/gl/GrGLGpu.cpp
+++ b/src/gpu/gl/GrGLGpu.cpp
@@ -4569,26 +4569,29 @@ sk_sp<GrSemaphore> SK_WARN_UNUSED_RESULT GrGLGpu::makeSemaphore(bool isOwned) {
     return GrGLSemaphore::Make(this, isOwned);
 }
 
-sk_sp<GrSemaphore> GrGLGpu::wrapBackendSemaphore(const GrBackendSemaphore& semaphore,
-                                                 GrWrapOwnership ownership) {
+sk_sp<GrSemaphore> GrGLGpu::onWrapBackendSemaphore(const GrBackendSemaphore& semaphore,
+                                                   GrWrapOwnership ownership) {
     SkASSERT(this->caps()->fenceSyncSupport());
     return GrGLSemaphore::MakeWrapped(this, semaphore.glSync(), ownership);
 }
 
-void GrGLGpu::insertSemaphore(sk_sp<GrSemaphore> semaphore, bool flush) {
+void GrGLGpu::onInsertSemaphore(sk_sp<GrSemaphore> semaphore, bool flush) {
     GrGLSemaphore* glSem = static_cast<GrGLSemaphore*>(semaphore.get());
 
-    GrGLsync sync;
-    GL_CALL_RET(sync, FenceSync(GR_GL_SYNC_GPU_COMMANDS_COMPLETE, 0));
-    glSem->setSync(sync);
+    if (glSem) {
+        GrGLsync sync;
+        GL_CALL_RET(sync, FenceSync(GR_GL_SYNC_GPU_COMMANDS_COMPLETE, 0));
+        glSem->setSync(sync);
+    }
 
     if (flush) {
         GL_CALL(Flush());
     }
 }
 
-void GrGLGpu::waitSemaphore(sk_sp<GrSemaphore> semaphore) {
+void GrGLGpu::onWaitSemaphore(sk_sp<GrSemaphore> semaphore) {
     GrGLSemaphore* glSem = static_cast<GrGLSemaphore*>(semaphore.get());
+    SkASSERT(glSem);
 
     GL_CALL(WaitSync(glSem->sync(), 0, GR_GL_TIMEOUT_IGNORED));
 }
diff --git a/src/gpu/gl/GrGLGpu.h b/src/gpu/gl/GrGLGpu.h
index 4559d38e4a..2087356f04 100644
--- a/src/gpu/gl/GrGLGpu.h
+++ b/src/gpu/gl/GrGLGpu.h
@@ -173,10 +173,6 @@ public:
     void deleteFence(GrFence) const override;
 
     sk_sp<GrSemaphore> SK_WARN_UNUSED_RESULT makeSemaphore(bool isOwned) override;
-    sk_sp<GrSemaphore> wrapBackendSemaphore(const GrBackendSemaphore& semaphore,
-                                            GrWrapOwnership ownership) override;
-    void insertSemaphore(sk_sp<GrSemaphore> semaphore, bool flush) override;
-    void waitSemaphore(sk_sp<GrSemaphore> semaphore) override;
 
     sk_sp<GrSemaphore> prepareTextureForCrossContextUsage(GrTexture*) override;
 
@@ -290,6 +286,11 @@ private:
 
     void onFinishFlush(bool insertedSemaphores) override;
 
+    void onInsertSemaphore(sk_sp<GrSemaphore> semaphore, bool flush) override;
+    void onWaitSemaphore(sk_sp<GrSemaphore> semaphore) override;
+    sk_sp<GrSemaphore> onWrapBackendSemaphore(const GrBackendSemaphore& semaphore,
+                                              GrWrapOwnership ownership) override;
+
     bool hasExtension(const char* ext) const { return fGLContext->hasExtension(ext); }
 
     bool copySurfaceAsDraw(GrSurface* dst, GrSurfaceOrigin dstOrigin,
diff --git a/src/gpu/mock/GrMockGpu.h b/src/gpu/mock/GrMockGpu.h
index 4567505546..359782f0c9 100644
--- a/src/gpu/mock/GrMockGpu.h
+++ b/src/gpu/mock/GrMockGpu.h
@@ -58,10 +58,6 @@ public:
     sk_sp<GrSemaphore> SK_WARN_UNUSED_RESULT makeSemaphore(bool isOwned) override {
         return nullptr;
     }
-    sk_sp<GrSemaphore> wrapBackendSemaphore(const GrBackendSemaphore& semaphore,
-                                            GrWrapOwnership ownership) override { return nullptr; }
-    void insertSemaphore(sk_sp<GrSemaphore> semaphore, bool flush) override {}
-    void waitSemaphore(sk_sp<GrSemaphore> semaphore) override {}
     sk_sp<GrSemaphore> prepareTextureForCrossContextUsage(GrTexture*) override { return nullptr; }
 
     void submitCommandBuffer(const GrMockGpuRTCommandBuffer*);
@@ -124,6 +120,11 @@ private:
 
     void onFinishFlush(bool insertedSemaphores) override {}
 
+    sk_sp<GrSemaphore> onWrapBackendSemaphore(const GrBackendSemaphore& semaphore,
+                                            GrWrapOwnership ownership) override { return nullptr; }
+    void onInsertSemaphore(sk_sp<GrSemaphore> semaphore, bool flush) override {}
+    void onWaitSemaphore(sk_sp<GrSemaphore> semaphore) override {}
+
     GrStencilAttachment* createStencilAttachmentForRenderTarget(const GrRenderTarget*,
                                                                 int width,
                                                                 int height) override;
diff --git a/src/gpu/mtl/GrMtlGpu.h b/src/gpu/mtl/GrMtlGpu.h
index 9c5ba8299a..61cbc62f71 100644
--- a/src/gpu/mtl/GrMtlGpu.h
+++ b/src/gpu/mtl/GrMtlGpu.h
@@ -67,10 +67,6 @@ public:
     sk_sp<GrSemaphore> SK_WARN_UNUSED_RESULT makeSemaphore(bool isOwned) override {
         return nullptr;
     }
-    sk_sp<GrSemaphore> wrapBackendSemaphore(const GrBackendSemaphore& semaphore,
-                                            GrWrapOwnership ownership) override { return nullptr; }
-    void insertSemaphore(sk_sp<GrSemaphore> semaphore, bool flush) override {}
-    void waitSemaphore(sk_sp<GrSemaphore> semaphore) override {}
     sk_sp<GrSemaphore> prepareTextureForCrossContextUsage(GrTexture*) override { return nullptr; }
 
 private:
@@ -133,6 +129,11 @@ private:
 
     void onFinishFlush(bool insertedSemaphores) override {}
 
+    sk_sp<GrSemaphore> onWrapBackendSemaphore(const GrBackendSemaphore& semaphore,
+                                            GrWrapOwnership ownership) override { return nullptr; }
+    void onInsertSemaphore(sk_sp<GrSemaphore> semaphore, bool flush) override {}
+    void onWaitSemaphore(sk_sp<GrSemaphore> semaphore) override {}
+
     GrStencilAttachment* createStencilAttachmentForRenderTarget(const GrRenderTarget*,
                                                                 int width,
                                                                 int height) override {
diff --git a/src/gpu/vk/GrVkGpu.cpp b/src/gpu/vk/GrVkGpu.cpp
index baf022185f..e1be99e872 100644
--- a/src/gpu/vk/GrVkGpu.cpp
+++ b/src/gpu/vk/GrVkGpu.cpp
@@ -2162,25 +2162,28 @@ sk_sp<GrSemaphore> SK_WARN_UNUSED_RESULT GrVkGpu::makeSemaphore(bool isOwned) {
     return GrVkSemaphore::Make(this, isOwned);
 }
 
-sk_sp<GrSemaphore> GrVkGpu::wrapBackendSemaphore(const GrBackendSemaphore& semaphore,
-                                                 GrWrapOwnership ownership) {
+sk_sp<GrSemaphore> GrVkGpu::onWrapBackendSemaphore(const GrBackendSemaphore& semaphore,
+                                                   GrWrapOwnership ownership) {
     return GrVkSemaphore::MakeWrapped(this, semaphore.vkSemaphore(), ownership);
 }
 
-void GrVkGpu::insertSemaphore(sk_sp<GrSemaphore> semaphore, bool flush) {
+void GrVkGpu::onInsertSemaphore(sk_sp<GrSemaphore> semaphore, bool flush) {
     GrVkSemaphore* vkSem = static_cast<GrVkSemaphore*>(semaphore.get());
 
-    const GrVkSemaphore::Resource* resource = vkSem->getResource();
-    resource->ref();
-    fSemaphoresToSignal.push_back(resource);
+    if (vkSem) {
+        const GrVkSemaphore::Resource* resource = vkSem->getResource();
+        resource->ref();
+        fSemaphoresToSignal.push_back(resource);
+    }
 
     if (flush) {
         this->submitCommandBuffer(kSkip_SyncQueue);
     }
 }
 
-void GrVkGpu::waitSemaphore(sk_sp<GrSemaphore> semaphore) {
+void GrVkGpu::onWaitSemaphore(sk_sp<GrSemaphore> semaphore) {
     GrVkSemaphore* vkSem = static_cast<GrVkSemaphore*>(semaphore.get());
+    SkASSERT(vkSem);
 
     const GrVkSemaphore::Resource* resource = vkSem->getResource();
     resource->ref();
diff --git a/src/gpu/vk/GrVkGpu.h b/src/gpu/vk/GrVkGpu.h
index 95d96b1196..e3055945bc 100644
--- a/src/gpu/vk/GrVkGpu.h
+++ b/src/gpu/vk/GrVkGpu.h
@@ -135,11 +135,6 @@ public:
     void deleteFence(GrFence) const override;
 
     sk_sp<GrSemaphore> SK_WARN_UNUSED_RESULT makeSemaphore(bool isOwned) override;
-    sk_sp<GrSemaphore> wrapBackendSemaphore(const GrBackendSemaphore& semaphore,
-                                            GrWrapOwnership ownership) override;
-    void insertSemaphore(sk_sp<GrSemaphore> semaphore, bool flush) override;
-    void waitSemaphore(sk_sp<GrSemaphore> semaphore) override;
-
     sk_sp<GrSemaphore> prepareTextureForCrossContextUsage(GrTexture*) override;
 
     void generateMipmap(GrVkTexture* tex, GrSurfaceOrigin texOrigin);
@@ -209,6 +204,11 @@ private:
 
     void onFinishFlush(bool insertedSemaphores) override;
 
+    void onInsertSemaphore(sk_sp<GrSemaphore> semaphore, bool flush) override;
+    void onWaitSemaphore(sk_sp<GrSemaphore> semaphore) override;
+    sk_sp<GrSemaphore> onWrapBackendSemaphore(const GrBackendSemaphore& semaphore,
+                                              GrWrapOwnership ownership) override;
+
     // Ends and submits the current command buffer to the queue and then creates a new command
     // buffer and begins it. If sync is set to kForce_SyncQueue, the function will wait for all
     // work in the queue to finish before returning. If this GrVkGpu object has any semaphores in