trace.h revision 9ede33233f97da5c9fb079ac4b373fb7eeb6a3ee 
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 <sys/cdefs.h>
21#include <sys/types.h>
22#include <stdint.h>
23#include <stdbool.h>
24#include <unistd.h>
25#include <cutils/compiler.h>
26
27#ifdef ANDROID_SMP
28#include <cutils/atomic-inline.h>
29#else
30#include <cutils/atomic.h>
31#endif
32
33__BEGIN_DECLS
34
35/**
36 * The ATRACE_TAG macro can be defined before including this header to trace
37 * using one of the tags defined below.  It must be defined to one of the
38 * following ATRACE_TAG_* macros.  The trace tag is used to filter tracing in
39 * userland to avoid some of the runtime cost of tracing when it is not desired.
40 *
41 * Defining ATRACE_TAG to be ATRACE_TAG_ALWAYS will result in the tracing always
42 * being enabled - this should ONLY be done for debug code, as userland tracing
43 * has a performance cost even when the trace is not being recorded.  Defining
44 * ATRACE_TAG to be ATRACE_TAG_NEVER or leaving ATRACE_TAG undefined will result
45 * in the tracing always being disabled.
46 *
47 * ATRACE_TAG_HAL should be bitwise ORed with the relevant tags for tracing
48 * within a hardware module.  For example a camera hardware module would set:
49 * #define ATRACE_TAG  (ATRACE_TAG_CAMERA | ATRACE_TAG_HAL)
50 *
51 * Keep these in sync with frameworks/base/core/java/android/os/Trace.java.
52 */
53#define ATRACE_TAG_NEVER            0       // This tag is never enabled.
54#define ATRACE_TAG_ALWAYS           (1<<0)  // This tag is always enabled.
55#define ATRACE_TAG_GRAPHICS         (1<<1)
56#define ATRACE_TAG_INPUT            (1<<2)
57#define ATRACE_TAG_VIEW             (1<<3)
58#define ATRACE_TAG_WEBVIEW          (1<<4)
59#define ATRACE_TAG_WINDOW_MANAGER   (1<<5)
60#define ATRACE_TAG_ACTIVITY_MANAGER (1<<6)
61#define ATRACE_TAG_SYNC_MANAGER     (1<<7)
62#define ATRACE_TAG_AUDIO            (1<<8)
63#define ATRACE_TAG_VIDEO            (1<<9)
64#define ATRACE_TAG_CAMERA           (1<<10)
65#define ATRACE_TAG_HAL              (1<<11)
66#define ATRACE_TAG_APP              (1<<12)
67#define ATRACE_TAG_RESOURCES        (1<<13)
68#define ATRACE_TAG_DALVIK           (1<<14)
69#define ATRACE_TAG_RS               (1<<15)
70#define ATRACE_TAG_LAST             ATRACE_TAG_RS
71
72// Reserved for initialization.
73#define ATRACE_TAG_NOT_READY        (1LL<<63)
74
75#define ATRACE_TAG_VALID_MASK ((ATRACE_TAG_LAST - 1) | ATRACE_TAG_LAST)
76
77#ifndef ATRACE_TAG
78#define ATRACE_TAG ATRACE_TAG_NEVER
79#elif ATRACE_TAG > ATRACE_TAG_VALID_MASK
80#error ATRACE_TAG must be defined to be one of the tags defined in cutils/trace.h
81#endif
82
83#ifdef HAVE_ANDROID_OS
84/**
85 * Maximum size of a message that can be logged to the trace buffer.
86 * Note this message includes a tag, the pid, and the string given as the name.
87 * Names should be kept short to get the most use of the trace buffer.
88 */
89#define ATRACE_MESSAGE_LENGTH 1024
90
91/**
92 * Opens the trace file for writing and reads the property for initial tags.
93 * The atrace.tags.enableflags property sets the tags to trace.
94 * This function should not be explicitly called, the first call to any normal
95 * trace function will cause it to be run safely.
96 */
97void atrace_setup();
98
99/**
100 * If tracing is ready, set atrace_enabled_tags to the system property
101 * debug.atrace.tags.enableflags. Can be used as a sysprop change callback.
102 */
103void atrace_update_tags();
104
105/**
106 * Set whether the process is debuggable.  By default the process is not
107 * considered debuggable.  If the process is not debuggable then application-
108 * level tracing is not allowed unless the ro.debuggable system property is
109 * set to '1'.
110 */
111void atrace_set_debuggable(bool debuggable);
112
113/**
114 * Set whether tracing is enabled for the current process.  This is used to
115 * prevent tracing within the Zygote process.
116 */
117void atrace_set_tracing_enabled(bool enabled);
118
119/**
120 * Flag indicating whether setup has been completed, initialized to 0.
121 * Nonzero indicates setup has completed.
122 * Note: This does NOT indicate whether or not setup was successful.
123 */
124extern volatile int32_t atrace_is_ready;
125
126/**
127 * Set of ATRACE_TAG flags to trace for, initialized to ATRACE_TAG_NOT_READY.
128 * A value of zero indicates setup has failed.
129 * Any other nonzero value indicates setup has succeeded, and tracing is on.
130 */
131extern uint64_t atrace_enabled_tags;
132
133/**
134 * Handle to the kernel's trace buffer, initialized to -1.
135 * Any other value indicates setup has succeeded, and is a valid fd for tracing.
136 */
137extern int atrace_marker_fd;
138
139/**
140 * atrace_init readies the process for tracing by opening the trace_marker file.
141 * Calling any trace function causes this to be run, so calling it is optional.
142 * This can be explicitly run to avoid setup delay on first trace function.
143 */
144#define ATRACE_INIT() atrace_init()
145static inline void atrace_init()
146{
147    if (CC_UNLIKELY(!android_atomic_acquire_load(&atrace_is_ready))) {
148        atrace_setup();
149    }
150}
151
152/**
153 * Get the mask of all tags currently enabled.
154 * It can be used as a guard condition around more expensive trace calculations.
155 * Every trace function calls this, which ensures atrace_init is run.
156 */
157#define ATRACE_GET_ENABLED_TAGS() atrace_get_enabled_tags()
158static inline uint64_t atrace_get_enabled_tags()
159{
160    atrace_init();
161    return atrace_enabled_tags;
162}
163
164/**
165 * Test if a given tag is currently enabled.
166 * Returns nonzero if the tag is enabled, otherwise zero.
167 * It can be used as a guard condition around more expensive trace calculations.
168 */
169#define ATRACE_ENABLED() atrace_is_tag_enabled(ATRACE_TAG)
170static inline uint64_t atrace_is_tag_enabled(uint64_t tag)
171{
172    return atrace_get_enabled_tags() & tag;
173}
174
175/**
176 * Trace the beginning of a context.  name is used to identify the context.
177 * This is often used to time function execution.
178 */
179#define ATRACE_BEGIN(name) atrace_begin(ATRACE_TAG, name)
180static inline void atrace_begin(uint64_t tag, const char* name)
181{
182    if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
183        char buf[ATRACE_MESSAGE_LENGTH];
184        size_t len;
185
186        len = snprintf(buf, ATRACE_MESSAGE_LENGTH, "B|%d|%s", getpid(), name);
187        write(atrace_marker_fd, buf, len);
188    }
189}
190
191/**
192 * Trace the end of a context.
193 * This should match up (and occur after) a corresponding ATRACE_BEGIN.
194 */
195#define ATRACE_END() atrace_end(ATRACE_TAG)
196static inline void atrace_end(uint64_t tag)
197{
198    if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
199        char c = 'E';
200        write(atrace_marker_fd, &c, 1);
201    }
202}
203
204/**
205 * Trace the beginning of an asynchronous event. Unlike ATRACE_BEGIN/ATRACE_END
206 * contexts, asynchronous events do not need to be nested. The name describes
207 * the event, and the cookie provides a unique identifier for distinguishing
208 * simultaneous events. The name and cookie used to begin an event must be
209 * used to end it.
210 */
211#define ATRACE_ASYNC_BEGIN(name, cookie) \
212    atrace_async_begin(ATRACE_TAG, name, cookie)
213static inline void atrace_async_begin(uint64_t tag, const char* name,
214        int32_t cookie)
215{
216    if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
217        char buf[ATRACE_MESSAGE_LENGTH];
218        size_t len;
219
220        len = snprintf(buf, ATRACE_MESSAGE_LENGTH, "S|%d|%s|%d", getpid(),
221                name, cookie);
222        write(atrace_marker_fd, buf, len);
223    }
224}
225
226/**
227 * Trace the end of an asynchronous event.
228 * This should have a corresponding ATRACE_ASYNC_BEGIN.
229 */
230#define ATRACE_ASYNC_END(name, cookie) atrace_async_end(ATRACE_TAG, name, cookie)
231static inline void atrace_async_end(uint64_t tag, const char* name,
232        int32_t cookie)
233{
234    if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
235        char buf[ATRACE_MESSAGE_LENGTH];
236        size_t len;
237
238        len = snprintf(buf, ATRACE_MESSAGE_LENGTH, "F|%d|%s|%d", getpid(),
239                name, cookie);
240        write(atrace_marker_fd, buf, len);
241    }
242}
243
244
245/**
246 * Traces an integer counter value.  name is used to identify the counter.
247 * This can be used to track how a value changes over time.
248 */
249#define ATRACE_INT(name, value) atrace_int(ATRACE_TAG, name, value)
250static inline void atrace_int(uint64_t tag, const char* name, int32_t value)
251{
252    if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
253        char buf[ATRACE_MESSAGE_LENGTH];
254        size_t len;
255
256        len = snprintf(buf, ATRACE_MESSAGE_LENGTH, "C|%d|%s|%d",
257                getpid(), name, value);
258        write(atrace_marker_fd, buf, len);
259    }
260}
261
262#else // not HAVE_ANDROID_OS
263
264#define ATRACE_INIT()
265#define ATRACE_GET_ENABLED_TAGS()
266#define ATRACE_ENABLED() 0
267#define ATRACE_BEGIN(name)
268#define ATRACE_END()
269#define ATRACE_ASYNC_BEGIN(name, cookie)
270#define ATRACE_ASYNC_END(name, cookie)
271#define ATRACE_INT(name, value)
272
273#endif // not HAVE_ANDROID_OS
274
275__END_DECLS
276
277#endif // _LIBS_CUTILS_TRACE_H
278