1 /*
2  * Copyright (C) 2012 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 #ifndef _LIBS_CUTILS_TRACE_H
18 #define _LIBS_CUTILS_TRACE_H
19 
20 #include <inttypes.h>
21 #include <stdatomic.h>
22 #include <stdbool.h>
23 #include <stdint.h>
24 #include <stdio.h>
25 #include <sys/cdefs.h>
26 #include <sys/types.h>
27 #include <unistd.h>
28 
29 #include <cutils/compiler.h>
30 
31 __BEGIN_DECLS
32 
33 /**
34  * The ATRACE_TAG macro can be defined before including this header to trace
35  * using one of the tags defined below.  It must be defined to one of the
36  * following ATRACE_TAG_* macros.  The trace tag is used to filter tracing in
37  * userland to avoid some of the runtime cost of tracing when it is not desired.
38  *
39  * Defining ATRACE_TAG to be ATRACE_TAG_ALWAYS will result in the tracing always
40  * being enabled - this should ONLY be done for debug code, as userland tracing
41  * has a performance cost even when the trace is not being recorded.  Defining
42  * ATRACE_TAG to be ATRACE_TAG_NEVER or leaving ATRACE_TAG undefined will result
43  * in the tracing always being disabled.
44  *
45  * ATRACE_TAG_HAL should be bitwise ORed with the relevant tags for tracing
46  * within a hardware module.  For example a camera hardware module would set:
47  * #define ATRACE_TAG  (ATRACE_TAG_CAMERA | ATRACE_TAG_HAL)
48  *
49  * Keep these in sync with frameworks/base/core/java/android/os/Trace.java.
50  */
51 #define ATRACE_TAG_NEVER            0       // This tag is never enabled.
52 #define ATRACE_TAG_ALWAYS           (1<<0)  // This tag is always enabled.
53 #define ATRACE_TAG_GRAPHICS         (1<<1)
54 #define ATRACE_TAG_INPUT            (1<<2)
55 #define ATRACE_TAG_VIEW             (1<<3)
56 #define ATRACE_TAG_WEBVIEW          (1<<4)
57 #define ATRACE_TAG_WINDOW_MANAGER   (1<<5)
58 #define ATRACE_TAG_ACTIVITY_MANAGER (1<<6)
59 #define ATRACE_TAG_SYNC_MANAGER     (1<<7)
60 #define ATRACE_TAG_AUDIO            (1<<8)
61 #define ATRACE_TAG_VIDEO            (1<<9)
62 #define ATRACE_TAG_CAMERA           (1<<10)
63 #define ATRACE_TAG_HAL              (1<<11)
64 #define ATRACE_TAG_APP              (1<<12)
65 #define ATRACE_TAG_RESOURCES        (1<<13)
66 #define ATRACE_TAG_DALVIK           (1<<14)
67 #define ATRACE_TAG_RS               (1<<15)
68 #define ATRACE_TAG_BIONIC           (1<<16)
69 #define ATRACE_TAG_POWER            (1<<17)
70 #define ATRACE_TAG_PACKAGE_MANAGER  (1<<18)
71 #define ATRACE_TAG_SYSTEM_SERVER    (1<<19)
72 #define ATRACE_TAG_DATABASE         (1<<20)
73 #define ATRACE_TAG_LAST             ATRACE_TAG_DATABASE
74 
75 // Reserved for initialization.
76 #define ATRACE_TAG_NOT_READY        (1ULL<<63)
77 
78 #define ATRACE_TAG_VALID_MASK ((ATRACE_TAG_LAST - 1) | ATRACE_TAG_LAST)
79 
80 #ifndef ATRACE_TAG
81 #define ATRACE_TAG ATRACE_TAG_NEVER
82 #elif ATRACE_TAG > ATRACE_TAG_VALID_MASK
83 #error ATRACE_TAG must be defined to be one of the tags defined in cutils/trace.h
84 #endif
85 
86 /**
87  * Opens the trace file for writing and reads the property for initial tags.
88  * The atrace.tags.enableflags property sets the tags to trace.
89  * This function should not be explicitly called, the first call to any normal
90  * trace function will cause it to be run safely.
91  */
92 void atrace_setup();
93 
94 /**
95  * If tracing is ready, set atrace_enabled_tags to the system property
96  * debug.atrace.tags.enableflags. Can be used as a sysprop change callback.
97  */
98 void atrace_update_tags();
99 
100 /**
101  * Set whether the process is debuggable.  By default the process is not
102  * considered debuggable.  If the process is not debuggable then application-
103  * level tracing is not allowed unless the ro.debuggable system property is
104  * set to '1'.
105  */
106 void atrace_set_debuggable(bool debuggable);
107 
108 /**
109  * Set whether tracing is enabled for the current process.  This is used to
110  * prevent tracing within the Zygote process.
111  */
112 void atrace_set_tracing_enabled(bool enabled);
113 
114 /**
115  * Flag indicating whether setup has been completed, initialized to 0.
116  * Nonzero indicates setup has completed.
117  * Note: This does NOT indicate whether or not setup was successful.
118  */
119 extern atomic_bool atrace_is_ready;
120 
121 /**
122  * Set of ATRACE_TAG flags to trace for, initialized to ATRACE_TAG_NOT_READY.
123  * A value of zero indicates setup has failed.
124  * Any other nonzero value indicates setup has succeeded, and tracing is on.
125  */
126 extern uint64_t atrace_enabled_tags;
127 
128 /**
129  * Handle to the kernel's trace buffer, initialized to -1.
130  * Any other value indicates setup has succeeded, and is a valid fd for tracing.
131  */
132 extern int atrace_marker_fd;
133 
134 /**
135  * atrace_init readies the process for tracing by opening the trace_marker file.
136  * Calling any trace function causes this to be run, so calling it is optional.
137  * This can be explicitly run to avoid setup delay on first trace function.
138  */
139 #define ATRACE_INIT() atrace_init()
atrace_init()140 static inline void atrace_init()
141 {
142     if (CC_UNLIKELY(!atomic_load_explicit(&atrace_is_ready, memory_order_acquire))) {
143         atrace_setup();
144     }
145 }
146 
147 /**
148  * Get the mask of all tags currently enabled.
149  * It can be used as a guard condition around more expensive trace calculations.
150  * Every trace function calls this, which ensures atrace_init is run.
151  */
152 #define ATRACE_GET_ENABLED_TAGS() atrace_get_enabled_tags()
atrace_get_enabled_tags()153 static inline uint64_t atrace_get_enabled_tags()
154 {
155     atrace_init();
156     return atrace_enabled_tags;
157 }
158 
159 /**
160  * Test if a given tag is currently enabled.
161  * Returns nonzero if the tag is enabled, otherwise zero.
162  * It can be used as a guard condition around more expensive trace calculations.
163  */
164 #define ATRACE_ENABLED() atrace_is_tag_enabled(ATRACE_TAG)
atrace_is_tag_enabled(uint64_t tag)165 static inline uint64_t atrace_is_tag_enabled(uint64_t tag)
166 {
167     return atrace_get_enabled_tags() & tag;
168 }
169 
170 /**
171  * Trace the beginning of a context.  name is used to identify the context.
172  * This is often used to time function execution.
173  */
174 #define ATRACE_BEGIN(name) atrace_begin(ATRACE_TAG, name)
atrace_begin(uint64_t tag,const char * name)175 static inline void atrace_begin(uint64_t tag, const char* name)
176 {
177     if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
178         void atrace_begin_body(const char*);
179         atrace_begin_body(name);
180     }
181 }
182 
183 /**
184  * Trace the end of a context.
185  * This should match up (and occur after) a corresponding ATRACE_BEGIN.
186  */
187 #define ATRACE_END() atrace_end(ATRACE_TAG)
atrace_end(uint64_t tag)188 static inline void atrace_end(uint64_t tag)
189 {
190     if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
191         char c = 'E';
192         write(atrace_marker_fd, &c, 1);
193     }
194 }
195 
196 /**
197  * Trace the beginning of an asynchronous event. Unlike ATRACE_BEGIN/ATRACE_END
198  * contexts, asynchronous events do not need to be nested. The name describes
199  * the event, and the cookie provides a unique identifier for distinguishing
200  * simultaneous events. The name and cookie used to begin an event must be
201  * used to end it.
202  */
203 #define ATRACE_ASYNC_BEGIN(name, cookie) \
204     atrace_async_begin(ATRACE_TAG, name, cookie)
atrace_async_begin(uint64_t tag,const char * name,int32_t cookie)205 static inline void atrace_async_begin(uint64_t tag, const char* name,
206         int32_t cookie)
207 {
208     if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
209         void atrace_async_begin_body(const char*, int32_t);
210         atrace_async_begin_body(name, cookie);
211     }
212 }
213 
214 /**
215  * Trace the end of an asynchronous event.
216  * This should have a corresponding ATRACE_ASYNC_BEGIN.
217  */
218 #define ATRACE_ASYNC_END(name, cookie) atrace_async_end(ATRACE_TAG, name, cookie)
atrace_async_end(uint64_t tag,const char * name,int32_t cookie)219 static inline void atrace_async_end(uint64_t tag, const char* name, int32_t cookie)
220 {
221     if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
222         void atrace_async_end_body(const char*, int32_t);
223         atrace_async_end_body(name, cookie);
224     }
225 }
226 
227 /**
228  * Traces an integer counter value.  name is used to identify the counter.
229  * This can be used to track how a value changes over time.
230  */
231 #define ATRACE_INT(name, value) atrace_int(ATRACE_TAG, name, value)
atrace_int(uint64_t tag,const char * name,int32_t value)232 static inline void atrace_int(uint64_t tag, const char* name, int32_t value)
233 {
234     if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
235         void atrace_int_body(const char*, int32_t);
236         atrace_int_body(name, value);
237     }
238 }
239 
240 /**
241  * Traces a 64-bit integer counter value.  name is used to identify the
242  * counter. This can be used to track how a value changes over time.
243  */
244 #define ATRACE_INT64(name, value) atrace_int64(ATRACE_TAG, name, value)
atrace_int64(uint64_t tag,const char * name,int64_t value)245 static inline void atrace_int64(uint64_t tag, const char* name, int64_t value)
246 {
247     if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
248         void atrace_int64_body(const char*, int64_t);
249         atrace_int64_body(name, value);
250     }
251 }
252 
253 __END_DECLS
254 
255 #endif // _LIBS_CUTILS_TRACE_H
256