add initial support ofr multi-threaded execution

Review URL: https://codereview.chromium.org/27541003

git-svn-id: http://skia.googlecode.com/svn/trunk@11823 2bbb7eff-a529-9590-31e7-b0007b416f81

3 files changed, 56 insertions, 9 deletions

diff --git a/tools/skpdiff/SkDiffContext.cpp b/tools/skpdiff/SkDiffContext.cpp
index 88941cab0f..07d304b64c 100644
--- a/tools/skpdiff/SkDiffContext.cpp
+++ b/tools/skpdiff/SkDiffContext.cpp
@@ -8,8 +8,10 @@
 #include "SkBitmap.h"
 #include "SkImageDecoder.h"
 #include "SkOSFile.h"
+#include "SkRunnable.h"
 #include "SkStream.h"
 #include "SkTDict.h"
+#include "SkThreadPool.h"
 
 #include "SkDiffContext.h"
 #include "SkImageDiffer.h"
@@ -22,6 +24,7 @@ SkDiffContext::SkDiffContext() {
     fRecords = NULL;
     fDiffers = NULL;
     fDifferCount = 0;
+    fThreadCount = SkThreadPool::kThreadPerCore;
 }
 
 SkDiffContext::~SkDiffContext() {
@@ -93,8 +96,29 @@ void SkDiffContext::addDiff(const char* baselinePath, const char* testPath) {
             differ->deleteDiff(diffID);
         }
     }
+
+    // if we get a difference and we want the alpha mask then compute it here.
 }
 
+class SkThreadedDiff : public SkRunnable {
+public:
+    SkThreadedDiff() : fDiffContext(NULL) { }
+
+    void setup(SkDiffContext* diffContext, const SkString& baselinePath, const SkString& testPath) {
+        fDiffContext = diffContext;
+        fBaselinePath = baselinePath;
+        fTestPath = testPath;
+    }
+
+    virtual void run() SK_OVERRIDE {
+        fDiffContext->addDiff(fBaselinePath.c_str(), fTestPath.c_str());
+    }
+
+private:
+    SkDiffContext* fDiffContext;
+    SkString fBaselinePath;
+    SkString fTestPath;
+};
 
 void SkDiffContext::diffDirectories(const char baselinePath[], const char testPath[]) {
     // Get the files in the baseline, we will then look for those inside the test path
@@ -104,9 +128,12 @@ void SkDiffContext::diffDirectories(const char baselinePath[], const char testPa
         return;
     }
 
-    for (int baselineIndex = 0; baselineIndex < baselineEntries.count(); baselineIndex++) {
-        SkDebugf("[%i/%i] ", baselineIndex, baselineEntries.count());
-        const char* baseFilename = baselineEntries[baselineIndex].c_str();
+    SkThreadPool threadPool(fThreadCount);
+    SkTArray<SkThreadedDiff> runnableDiffs;
+    runnableDiffs.reset(baselineEntries.count());
+
+    for (int x = 0; x < baselineEntries.count(); x++) {
+        const char* baseFilename = baselineEntries[x].c_str();
 
         // Find the real location of each file to compare
         SkString baselineFile = SkOSPath::SkPathJoin(baselinePath, baseFilename);
@@ -115,11 +142,14 @@ void SkDiffContext::diffDirectories(const char baselinePath[], const char testPa
         // Check that the test file exists and is a file
         if (sk_exists(testFile.c_str()) && !sk_isdir(testFile.c_str())) {
             // Queue up the comparison with the differ
-            this->addDiff(baselineFile.c_str(), testFile.c_str());
+            runnableDiffs[x].setup(this, baselineFile, testFile);
+            threadPool.add(&runnableDiffs[x]);
         } else {
             SkDebugf("Baseline file \"%s\" has no corresponding test file\n", baselineFile.c_str());
         }
     }
+
+    threadPool.wait();
 }
 
 
@@ -144,13 +174,16 @@ void SkDiffContext::diffPatterns(const char baselinePattern[], const char testPa
         return;
     }
 
-    for (int entryIndex = 0; entryIndex < baselineEntries.count(); entryIndex++) {
-        SkDebugf("[%i/%i] ", entryIndex, baselineEntries.count());
-        const char* baselineFilename = baselineEntries[entryIndex].c_str();
-        const char* testFilename     = testEntries    [entryIndex].c_str();
+    SkThreadPool threadPool(fThreadCount);
+    SkTArray<SkThreadedDiff> runnableDiffs;
+    runnableDiffs.reset(baselineEntries.count());
 
-        this->addDiff(baselineFilename, testFilename);
+    for (int x = 0; x < baselineEntries.count(); x++) {
+        runnableDiffs[x].setup(this, baselineEntries[x], testEntries[x]);
+        threadPool.add(&runnableDiffs[x]);
     }
+
+    threadPool.wait();
 }
 
 void SkDiffContext::outputRecords(SkWStream& stream, bool useJSONP) {
@@ -164,6 +197,7 @@ void SkDiffContext::outputRecords(SkWStream& stream, bool useJSONP) {
     while (NULL != currentRecord) {
         stream.writeText("        {\n");
 
+            SkString differenceAbsPath = get_absolute_path(currentRecord->fDifferencePath);
             SkString baselineAbsPath = get_absolute_path(currentRecord->fBaselinePath);
             SkString testAbsPath = get_absolute_path(currentRecord->fTestPath);
 
@@ -181,6 +215,10 @@ void SkDiffContext::outputRecords(SkWStream& stream, bool useJSONP) {
             stream.writeText(baseName.c_str());
             stream.writeText("\",\n");
 
+            stream.writeText("            \"differencePath\": \"");
+            stream.writeText(differenceAbsPath.c_str());
+            stream.writeText("\",\n");
+
             stream.writeText("            \"baselinePath\": \"");
             stream.writeText(baselineAbsPath.c_str());
             stream.writeText("\",\n");
diff --git a/tools/skpdiff/SkDiffContext.h b/tools/skpdiff/SkDiffContext.h
index 93354e8dec..20193b3851 100644
--- a/tools/skpdiff/SkDiffContext.h
+++ b/tools/skpdiff/SkDiffContext.h
@@ -23,6 +23,8 @@ public:
     SkDiffContext();
     ~SkDiffContext();
 
+    void setThreadCount(int threadCount) { fThreadCount = threadCount; }
+
     /**
      * Sets the differs to be used in each diff. Already started diffs will not retroactively use
      * these.
@@ -104,6 +106,7 @@ private:
     };
 
     struct DiffRecord {
+        SkString           fDifferencePath;
         SkString           fBaselinePath;
         SkString               fTestPath;
         SkTArray<DiffData>        fDiffs;
@@ -117,6 +120,7 @@ private:
 
     SkImageDiffer** fDiffers;
     int fDifferCount;
+    int fThreadCount;
 };
 
 #endif
diff --git a/tools/skpdiff/skpdiff_main.cpp b/tools/skpdiff/skpdiff_main.cpp
index f89cc372c5..55640f7f0a 100644
--- a/tools/skpdiff/skpdiff_main.cpp
+++ b/tools/skpdiff/skpdiff_main.cpp
@@ -40,6 +40,7 @@ DEFINE_string2(patterns, p, "", "Use two patterns to compare images: <baseline>
 DEFINE_string2(output, o, "", "Writes the output of these diffs to output: <output>");
 DEFINE_bool(jsonp, true, "Output JSON with padding");
 DEFINE_string(csv, "", "Writes the output of these diffs to a csv file");
+DEFINE_int32(threads, -1, "run N threads in parallel [default is derived from CPUs available]");
 
 #if SK_SUPPORT_OPENCL
 /// A callback for any OpenCL errors
@@ -188,6 +189,10 @@ int tool_main(int argc, char * argv[]) {
     SkDiffContext ctx;
     ctx.setDiffers(chosenDiffers);
 
+    if (FLAGS_threads >= 0) {
+        ctx.setThreadCount(FLAGS_threads);
+    }
+
     // Perform a folder diff if one is requested
     if (!FLAGS_folders.isEmpty()) {
         ctx.diffDirectories(FLAGS_folders[0], FLAGS_folders[1]);