1 // Copyright 2016 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef SKIA_EXT_SKIA_HISTOGRAM_H_
6 #define SKIA_EXT_SKIA_HISTOGRAM_H_
7 
8 #include <stdint.h>
9 
10 #include <atomic>
11 #include <memory>
12 
13 // This file exposes Chrome's histogram functionality to Skia, without bringing
14 // in any Chrome specific headers. To achieve the same level of optimization as
15 // is present in Chrome, we need to use an inlined atomic pointer. This macro
16 // defines a placeholder atomic which will be inlined into the call-site. This
17 // placeholder is passed to the actual histogram logic in Chrome.
18 #define SK_HISTOGRAM_POINTER_HELPER(function, ...)                   \
19   do {                                                               \
20     static std::atomic_uintptr_t atomic_histogram_pointer;           \
21     function(std::addressof(atomic_histogram_pointer), __VA_ARGS__); \
22   } while (0)
23 
24 #define SK_HISTOGRAM_BOOLEAN(name, sample) \
25   SK_HISTOGRAM_POINTER_HELPER(skia::HistogramBoolean, "Skia." name, sample)
26 
27 #define SK_HISTOGRAM_ENUMERATION(name, sample, boundary_value)          \
28   SK_HISTOGRAM_POINTER_HELPER(skia::HistogramEnumeration, "Skia." name, \
29                               sample, boundary_value)
30 
31 namespace skia {
32 
33 void HistogramBoolean(std::atomic_uintptr_t* atomic_histogram_pointer,
34                       const char* name,
35                       bool sample);
36 void HistogramEnumeration(std::atomic_uintptr_t* atomic_histogram_pointer,
37                           const char* name,
38                           int sample,
39                           int boundary_value);
40 
41 }  // namespace skia
42 
43 #endif  // SKIA_EXT_SKIA_HISTOGRAM_H_
44