1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 /**
18  * @file trace.h
19  * @brief Writes trace events to the system trace buffer.
20  *
21  * These trace events can be collected and visualized using the Systrace tool.
22  * For information about using the Systrace tool, read <a href="https://developer.android.com/studio/profile/systrace.html">Analyzing UI Performance with Systrace</a>.
23  */
24 
25 #ifndef ANDROID_NATIVE_TRACE_H
26 #define ANDROID_NATIVE_TRACE_H
27 
28 #include <stdbool.h>
29 #include <sys/cdefs.h>
30 
31 #ifdef __cplusplus
32 extern "C" {
33 #endif
34 
35 #if __ANDROID_API__ >= 23
36 
37 /**
38  * Returns true if tracing is enabled. Use this signal to avoid expensive computation only necessary
39  * when tracing is enabled.
40  */
41 bool ATrace_isEnabled();
42 
43 /**
44  * Writes a tracing message to indicate that the given section of code has begun. This call must be
45  * followed by a corresponding call to endSection() on the same thread.
46  *
47  * Note: At this time the vertical bar character '|' and newline character '\n' are used internally
48  * by the tracing mechanism. If sectionName contains these characters they will be replaced with a
49  * space character in the trace.
50  */
51 void ATrace_beginSection(const char* sectionName);
52 
53 /**
54  * Writes a tracing message to indicate that a given section of code has ended. This call must be
55  * preceeded by a corresponding call to beginSection(char*) on the same thread. Calling this method
56  * will mark the end of the most recently begun section of code, so care must be taken to ensure
57  * that beginSection / endSection pairs are properly nested and called from the same thread.
58  */
59 void ATrace_endSection();
60 
61 #endif /* __ANDROID_API__ >= 23 */
62 
63 #ifdef __cplusplus
64 };
65 #endif
66 
67 #endif // ANDROID_NATIVE_TRACE_H
68