Add category support to JSON and SkDebugf tracing

Bug: skia:
Change-Id: I4d0bdb9d954e49b79ace0552d7b74b36a512c00d
Reviewed-on: https://skia-review.googlesource.com/25642
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Brian Osman <brianosman@google.com>

6 files changed, 79 insertions, 22 deletions

diff --git a/tools/trace/SkChromeTracingTracer.cpp b/tools/trace/SkChromeTracingTracer.cpp
index aa71ff0448..4d76d2956d 100644
--- a/tools/trace/SkChromeTracingTracer.cpp
+++ b/tools/trace/SkChromeTracingTracer.cpp
@@ -27,7 +27,7 @@ SkEventTracer::Handle SkChromeTracingTracer::addTraceEvent(char phase,
     char phaseString[2] = { phase, 0 };
     traceEvent["ph"] = phaseString;
     traceEvent["name"] = name;
-    traceEvent["cat"] = "skia"; // TODO
+    traceEvent["cat"] = this->getCategoryGroupName(categoryEnabledFlag);
     auto now = std::chrono::high_resolution_clock::now();
     std::chrono::duration<double, std::nano> ns = now.time_since_epoch();
     traceEvent["ts"] = ns.count() * 1E-3;
@@ -78,11 +78,6 @@ void SkChromeTracingTracer::updateTraceEventDuration(const uint8_t* categoryEnab
     (*traceEvent)["dur"] = us - (*traceEvent)["ts"].asDouble();
 }
 
-const uint8_t* SkChromeTracingTracer::getCategoryGroupEnabled(const char* name) {
-    static uint8_t yes = SkEventTracer::kEnabledForRecording_CategoryGroupEnabledFlags;
-    return &yes;
-}
-
 void SkChromeTracingTracer::flush() {
     SkString dirname = SkOSPath::Dirname(fFilename.c_str());
     if (!sk_exists(dirname.c_str(), kWrite_SkFILE_Flag)) {
diff --git a/tools/trace/SkChromeTracingTracer.h b/tools/trace/SkChromeTracingTracer.h
index da34205aa5..152771bef0 100644
--- a/tools/trace/SkChromeTracingTracer.h
+++ b/tools/trace/SkChromeTracingTracer.h
@@ -9,6 +9,7 @@
 #define SkChromeTracingTracer_DEFINED
 
 #include "SkEventTracer.h"
+#include "SkEventTracingPriv.h"
 #include "SkJSONCPP.h"
 #include "SkString.h"
 
@@ -34,11 +35,12 @@ public:
                                   const char* name,
                                   SkEventTracer::Handle handle) override;
 
-    const uint8_t* getCategoryGroupEnabled(const char* name) override;
+    const uint8_t* getCategoryGroupEnabled(const char* name) override {
+        return fCategories.getCategoryGroupEnabled(name);
+    }
 
     const char* getCategoryGroupName(const uint8_t* categoryEnabledFlag) override {
-        static const char* category = "category?";
-        return category;
+        return fCategories.getCategoryGroupName(categoryEnabledFlag);
     }
 
 private:
@@ -46,6 +48,7 @@ private:
 
     Json::Value fRoot;
     SkString fFilename;
+    SkEventTracingCategories fCategories;
 };
 
 #endif
diff --git a/tools/trace/SkDebugfTracer.cpp b/tools/trace/SkDebugfTracer.cpp
index 272af7827d..fe0da30b84 100644
--- a/tools/trace/SkDebugfTracer.cpp
+++ b/tools/trace/SkDebugfTracer.cpp
@@ -67,8 +67,9 @@ SkEventTracer::Handle SkDebugfTracer::addTraceEvent(char phase,
     }
     bool open = (phase == TRACE_EVENT_PHASE_COMPLETE);
     if (open) {
-        SkDebugf(
-                "[% 2d]%s %s%s #%d {\n", fIndent.size(), fIndent.c_str(), name, args.c_str(), fCnt);
+        const char* category = this->getCategoryGroupName(categoryEnabledFlag);
+        SkDebugf("[% 2d]%s <%s> %s%s #%d {\n", fIndent.size(), fIndent.c_str(), category, name,
+                 args.c_str(), fCnt);
         fIndent.append(" ");
     } else {
         SkDebugf("%s%s #%d\n", name, args.c_str(), fCnt);
@@ -83,8 +84,3 @@ void SkDebugfTracer::updateTraceEventDuration(const uint8_t* categoryEnabledFlag
     fIndent.resize(fIndent.size() - 1);
     SkDebugf("[% 2d]%s } %s\n", fIndent.size(), fIndent.c_str(), name);
 }
-
-const uint8_t* SkDebugfTracer::getCategoryGroupEnabled(const char* name) {
-    static uint8_t yes = SkEventTracer::kEnabledForRecording_CategoryGroupEnabledFlags;
-    return &yes;
-}
diff --git a/tools/trace/SkDebugfTracer.h b/tools/trace/SkDebugfTracer.h
index 4350d1ac3c..ca049d707b 100644
--- a/tools/trace/SkDebugfTracer.h
+++ b/tools/trace/SkDebugfTracer.h
@@ -9,6 +9,7 @@
 #define SkDebugfTracer_DEFINED
 
 #include "SkEventTracer.h"
+#include "SkEventTracingPriv.h"
 #include "SkString.h"
 
 /**
@@ -32,16 +33,18 @@ public:
                                   const char* name,
                                   SkEventTracer::Handle handle) override;
 
-    const uint8_t* getCategoryGroupEnabled(const char* name) override;
+    const uint8_t* getCategoryGroupEnabled(const char* name) override {
+        return fCategories.getCategoryGroupEnabled(name);
+    }
 
     const char* getCategoryGroupName(const uint8_t* categoryEnabledFlag) override {
-        static const char* category = "category?";
-        return category;
+        return fCategories.getCategoryGroupName(categoryEnabledFlag);
     }
 
 private:
     SkString fIndent;
     int fCnt = 0;
+    SkEventTracingCategories fCategories;
 };
 
 #endif
diff --git a/tools/trace/SkEventTracingPriv.cpp b/tools/trace/SkEventTracingPriv.cpp
index 217511ffa7..c4c793b06e 100644
--- a/tools/trace/SkEventTracingPriv.cpp
+++ b/tools/trace/SkEventTracingPriv.cpp
@@ -8,10 +8,11 @@
 #include "SkEventTracingPriv.h"
 
 #include "SkATrace.h"
-#include "SkCommandLineFlags.h"
-#include "SkEventTracer.h"
 #include "SkChromeTracingTracer.h"
+#include "SkCommandLineFlags.h"
 #include "SkDebugfTracer.h"
+#include "SkEventTracer.h"
+#include "SkTraceEventCommon.h"
 
 DEFINE_string(trace, "",
               "Log trace events in one of several modes:\n"
@@ -42,3 +43,39 @@ void initializeEventTracingForTools(int32_t* threadsFlag) {
 
     SkAssertResult(SkEventTracer::SetInstance(eventTracer));
 }
+
+uint8_t* SkEventTracingCategories::getCategoryGroupEnabled(const char* name) {

+    static_assert(0 == offsetof(CategoryState, fEnabled), "CategoryState");

+

+    // We ignore the "disabled-by-default-" prefix in our internal tools (though we could honor it)

+    if (SkStrStartsWith(name, TRACE_DISABLED_BY_DEFAULT_PREFIX)) {

+        name += strlen(TRACE_DISABLED_BY_DEFAULT_PREFIX);

+    }

+

+    // Chrome's implementation of this API does a two-phase lookup (once without a lock, then again

+    // with a lock. But the tracing macros avoid calling these functions more than once per site,

+    // so just do something simple (and easier to reason about):

+    SkAutoMutexAcquire lock(&fMutex);
+    for (int i = 0; i < fNumCategories; ++i) {
+        if (0 == strcmp(name, fCategories[i].fName)) {
+            return reinterpret_cast<uint8_t*>(&fCategories[i]);
+        }
+    }
+
+    if (fNumCategories >= kMaxCategories) {
+        SkDEBUGFAIL("Exhausted event tracing categories. Increase kMaxCategories.");
+        return reinterpret_cast<uint8_t*>(&fCategories[0]);
+    }
+
+    fCategories[fNumCategories].fEnabled =
+            SkEventTracer::kEnabledForRecording_CategoryGroupEnabledFlags;
+    fCategories[fNumCategories].fName = name;
+    return reinterpret_cast<uint8_t*>(&fCategories[fNumCategories++]);
+}
+
+const char* SkEventTracingCategories::getCategoryGroupName(const uint8_t* categoryEnabledFlag) {

+    if (categoryEnabledFlag) {
+        return reinterpret_cast<const CategoryState*>(categoryEnabledFlag)->fName;
+    }
+    return nullptr;
+}
diff --git a/tools/trace/SkEventTracingPriv.h b/tools/trace/SkEventTracingPriv.h
index 330f3f83ed..a4f04caefb 100644
--- a/tools/trace/SkEventTracingPriv.h
+++ b/tools/trace/SkEventTracingPriv.h
@@ -8,7 +8,7 @@
 #ifndef SkEventTracingPriv_DEFINED
 #define SkEventTracingPriv_DEFINED
 
-#include "SkTypes.h"
+#include "SkMutex.h"
 
 /**
  * Construct and install an SkEventTracer, based on the 'trace' command line argument.
@@ -19,4 +19,27 @@
  */
 void initializeEventTracingForTools(int32_t* threadsFlag);
 
+/**
+ * Helper class used by internal implementations of SkEventTracer to manage categories.
+ */
+class SkEventTracingCategories {
+public:
+    SkEventTracingCategories() : fNumCategories(0) {}
+
+    uint8_t* getCategoryGroupEnabled(const char* name);
+    const char* getCategoryGroupName(const uint8_t* categoryEnabledFlag);
+
+private:
+    enum { kMaxCategories = 256 };
+
+    struct CategoryState {
+        uint8_t fEnabled;
+        const char* fName;
+    };
+
+    CategoryState fCategories[kMaxCategories];
+    int fNumCategories;
+    SkMutex fMutex;
+};
+
 #endif