1 files changed, 91 insertions, 0 deletions
diff --git a/src/core/SkTaskGroup2D.cpp b/src/core/SkTaskGroup2D.cpp
new file mode 100644
index 0000000000..fe8a5a89be
--- /dev/null
+++ b/src/core/SkTaskGroup2D.cpp
@@ -0,0 +1,91 @@
+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkTaskGroup2D.h"
+
+void SkTaskGroup2D::start() {
+    fThreadsGroup->batch(fThreadCnt, [this](int threadId){
+        this->work(threadId);
+    });
+}
+
+void SkTaskGroup2D::addColumn() {
+    SkASSERT(!fIsFinishing); // we're not supposed to add more work after the calling of finish
+    fWidth++;
+}
+
+void SkTaskGroup2D::finish() {
+    fIsFinishing.store(true, std::memory_order_relaxed);
+    fThreadsGroup->wait();
+}
+
+void SkSpinningTaskGroup2D::work(int threadId) {
+    int& nextColumn = fRowData[threadId].fNextColumn;
+
+    while (true) {
+        SkASSERT(nextColumn <= fWidth);
+        if (this->isFinishing() && nextColumn >= fWidth) {
+            return;
+        }
+
+        if (nextColumn < fWidth) {
+            fWork(threadId, nextColumn);
+            nextColumn++;
+        }
+    }
+}
+
+SkFlexibleTaskGroup2D::SkFlexibleTaskGroup2D(Work2D&& w, int h, SkExecutor* x, int t)
+        : SkTaskGroup2D(std::move(w), h, x, t), fRowData(h), fThreadData(t) {
+    for (int i = 0; i < t; ++i) {
+        fThreadData[i].fRowIndex = i;
+    }
+}
+
+
+void SkFlexibleTaskGroup2D::work(int threadId) {
+    int failCnt = 0;
+    int& rowIndex = fThreadData[threadId].fRowIndex;
+
+    // This loop looks for work to do as long as
+    // either 1. isFinishing is false
+    // or     2. isFinishing is true but some rows still have unfinished tasks
+    while (true) {
+        RowData& rowData = fRowData[rowIndex];
+        bool processed = false;
+
+        // The Android roller somehow gets a false-positive compile warning/error about the try-lock
+        // and unlock process. Hence we disable -Wthread-safety-analysis to bypass it.
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wthread-safety-analysis"
+#endif
+        if (rowData.fMutex.try_lock()) {
+            if (rowData.fNextColumn < fWidth) {
+                fWork(rowIndex, rowData.fNextColumn);
+                rowData.fNextColumn++;
+                processed = true;
+            } else {
+                // isFinishing can never go from true to false. Once it's true, we count how many
+                // times that a row is out of work. If that count reaches fHeight, then we're out of
+                // work for the whole group.
+                failCnt += this->isFinishing();
+            }
+            rowData.fMutex.unlock();
+        }
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
+
+        if (!processed) {
+            if (failCnt >= fHeight) {
+                return;
+            }
+            rowIndex = (rowIndex + 1) % fHeight;
+        }
+    }
+}