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      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_LAST             ATRACE_TAG_DALVIK
     70 
     71 // Reserved for initialization.
     72 #define ATRACE_TAG_NOT_READY        (1LL<<63)
     73 
     74 #define ATRACE_TAG_VALID_MASK ((ATRACE_TAG_LAST - 1) | ATRACE_TAG_LAST)
     75 
     76 #ifndef ATRACE_TAG
     77 #define ATRACE_TAG ATRACE_TAG_NEVER
     78 #elif ATRACE_TAG > ATRACE_TAG_VALID_MASK
     79 #error ATRACE_TAG must be defined to be one of the tags defined in cutils/trace.h
     80 #endif
     81 
     82 #ifdef HAVE_ANDROID_OS
     83 /**
     84  * Maximum size of a message that can be logged to the trace buffer.
     85  * Note this message includes a tag, the pid, and the string given as the name.
     86  * Names should be kept short to get the most use of the trace buffer.
     87  */
     88 #define ATRACE_MESSAGE_LENGTH 1024
     89 
     90 /**
     91  * Opens the trace file for writing and reads the property for initial tags.
     92  * The atrace.tags.enableflags property sets the tags to trace.
     93  * This function should not be explicitly called, the first call to any normal
     94  * trace function will cause it to be run safely.
     95  */
     96 void atrace_setup();
     97 
     98 /**
     99  * If tracing is ready, set atrace_enabled_tags to the system property
    100  * debug.atrace.tags.enableflags. Can be used as a sysprop change callback.
    101  */
    102 void atrace_update_tags();
    103 
    104 /**
    105  * Set whether the process is debuggable.  By default the process is not
    106  * considered debuggable.  If the process is not debuggable then application-
    107  * level tracing is not allowed unless the ro.debuggable system property is
    108  * set to '1'.
    109  */
    110 void atrace_set_debuggable(bool debuggable);
    111 
    112 /**
    113  * Set whether tracing is enabled for the current process.  This is used to
    114  * prevent tracing within the Zygote process.
    115  */
    116 void atrace_set_tracing_enabled(bool enabled);
    117 
    118 /**
    119  * Flag indicating whether setup has been completed, initialized to 0.
    120  * Nonzero indicates setup has completed.
    121  * Note: This does NOT indicate whether or not setup was successful.
    122  */
    123 extern volatile int32_t atrace_is_ready;
    124 
    125 /**
    126  * Set of ATRACE_TAG flags to trace for, initialized to ATRACE_TAG_NOT_READY.
    127  * A value of zero indicates setup has failed.
    128  * Any other nonzero value indicates setup has succeeded, and tracing is on.
    129  */
    130 extern uint64_t atrace_enabled_tags;
    131 
    132 /**
    133  * Handle to the kernel's trace buffer, initialized to -1.
    134  * Any other value indicates setup has succeeded, and is a valid fd for tracing.
    135  */
    136 extern int atrace_marker_fd;
    137 
    138 /**
    139  * atrace_init readies the process for tracing by opening the trace_marker file.
    140  * Calling any trace function causes this to be run, so calling it is optional.
    141  * This can be explicitly run to avoid setup delay on first trace function.
    142  */
    143 #define ATRACE_INIT() atrace_init()
    144 static inline void atrace_init()
    145 {
    146     if (CC_UNLIKELY(!android_atomic_acquire_load(&atrace_is_ready))) {
    147         atrace_setup();
    148     }
    149 }
    150 
    151 /**
    152  * Get the mask of all tags currently enabled.
    153  * It can be used as a guard condition around more expensive trace calculations.
    154  * Every trace function calls this, which ensures atrace_init is run.
    155  */
    156 #define ATRACE_GET_ENABLED_TAGS() atrace_get_enabled_tags()
    157 static inline uint64_t atrace_get_enabled_tags()
    158 {
    159     atrace_init();
    160     return atrace_enabled_tags;
    161 }
    162 
    163 /**
    164  * Test if a given tag is currently enabled.
    165  * Returns nonzero if the tag is enabled, otherwise zero.
    166  * It can be used as a guard condition around more expensive trace calculations.
    167  */
    168 #define ATRACE_ENABLED() atrace_is_tag_enabled(ATRACE_TAG)
    169 static inline uint64_t atrace_is_tag_enabled(uint64_t tag)
    170 {
    171     return atrace_get_enabled_tags() & tag;
    172 }
    173 
    174 /**
    175  * Trace the beginning of a context.  name is used to identify the context.
    176  * This is often used to time function execution.
    177  */
    178 #define ATRACE_BEGIN(name) atrace_begin(ATRACE_TAG, name)
    179 static inline void atrace_begin(uint64_t tag, const char* name)
    180 {
    181     if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
    182         char buf[ATRACE_MESSAGE_LENGTH];
    183         size_t len;
    184 
    185         len = snprintf(buf, ATRACE_MESSAGE_LENGTH, "B|%d|%s", getpid(), name);
    186         write(atrace_marker_fd, buf, len);
    187     }
    188 }
    189 
    190 /**
    191  * Trace the end of a context.
    192  * This should match up (and occur after) a corresponding ATRACE_BEGIN.
    193  */
    194 #define ATRACE_END() atrace_end(ATRACE_TAG)
    195 static inline void atrace_end(uint64_t tag)
    196 {
    197     if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
    198         char c = 'E';
    199         write(atrace_marker_fd, &c, 1);
    200     }
    201 }
    202 
    203 /**
    204  * Trace the beginning of an asynchronous event. Unlike ATRACE_BEGIN/ATRACE_END
    205  * contexts, asynchronous events do not need to be nested. The name describes
    206  * the event, and the cookie provides a unique identifier for distinguishing
    207  * simultaneous events. The name and cookie used to begin an event must be
    208  * used to end it.
    209  */
    210 #define ATRACE_ASYNC_BEGIN(name, cookie) \
    211     atrace_async_begin(ATRACE_TAG, name, cookie)
    212 static inline void atrace_async_begin(uint64_t tag, const char* name,
    213         int32_t cookie)
    214 {
    215     if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
    216         char buf[ATRACE_MESSAGE_LENGTH];
    217         size_t len;
    218 
    219         len = snprintf(buf, ATRACE_MESSAGE_LENGTH, "S|%d|%s|%d", getpid(),
    220                 name, cookie);
    221         write(atrace_marker_fd, buf, len);
    222     }
    223 }
    224 
    225 /**
    226  * Trace the end of an asynchronous event.
    227  * This should have a corresponding ATRACE_ASYNC_BEGIN.
    228  */
    229 #define ATRACE_ASYNC_END(name, cookie) atrace_async_end(ATRACE_TAG, name, cookie)
    230 static inline void atrace_async_end(uint64_t tag, const char* name,
    231         int32_t cookie)
    232 {
    233     if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
    234         char buf[ATRACE_MESSAGE_LENGTH];
    235         size_t len;
    236 
    237         len = snprintf(buf, ATRACE_MESSAGE_LENGTH, "F|%d|%s|%d", getpid(),
    238                 name, cookie);
    239         write(atrace_marker_fd, buf, len);
    240     }
    241 }
    242 
    243 
    244 /**
    245  * Traces an integer counter value.  name is used to identify the counter.
    246  * This can be used to track how a value changes over time.
    247  */
    248 #define ATRACE_INT(name, value) atrace_int(ATRACE_TAG, name, value)
    249 static inline void atrace_int(uint64_t tag, const char* name, int32_t value)
    250 {
    251     if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
    252         char buf[ATRACE_MESSAGE_LENGTH];
    253         size_t len;
    254 
    255         len = snprintf(buf, ATRACE_MESSAGE_LENGTH, "C|%d|%s|%d",
    256                 getpid(), name, value);
    257         write(atrace_marker_fd, buf, len);
    258     }
    259 }
    260 
    261 #else // not HAVE_ANDROID_OS
    262 
    263 #define ATRACE_INIT()
    264 #define ATRACE_GET_ENABLED_TAGS()
    265 #define ATRACE_ENABLED()
    266 #define ATRACE_BEGIN(name)
    267 #define ATRACE_END()
    268 #define ATRACE_ASYNC_BEGIN(name, cookie)
    269 #define ATRACE_ASYNC_END(name, cookie)
    270 #define ATRACE_INT(name, value)
    271 
    272 #endif // not HAVE_ANDROID_OS
    273 
    274 __END_DECLS
    275 
    276 #endif // _LIBS_CUTILS_TRACE_H
    277