1*05767d91SRobert Wu /*
2*05767d91SRobert Wu * Copyright 2017 The Android Open Source Project
3*05767d91SRobert Wu *
4*05767d91SRobert Wu * Licensed under the Apache License, Version 2.0 (the "License");
5*05767d91SRobert Wu * you may not use this file except in compliance with the License.
6*05767d91SRobert Wu * You may obtain a copy of the License at
7*05767d91SRobert Wu *
8*05767d91SRobert Wu * http://www.apache.org/licenses/LICENSE-2.0
9*05767d91SRobert Wu *
10*05767d91SRobert Wu * Unless required by applicable law or agreed to in writing, software
11*05767d91SRobert Wu * distributed under the License is distributed on an "AS IS" BASIS,
12*05767d91SRobert Wu * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13*05767d91SRobert Wu * See the License for the specific language governing permissions and
14*05767d91SRobert Wu * limitations under the License.
15*05767d91SRobert Wu */
16*05767d91SRobert Wu
17*05767d91SRobert Wu #include <dlfcn.h>
18*05767d91SRobert Wu #include "logging_macros.h"
19*05767d91SRobert Wu #include <cstdio>
20*05767d91SRobert Wu #include "trace.h"
21*05767d91SRobert Wu
22*05767d91SRobert Wu static const int TRACE_MAX_SECTION_NAME_LENGTH = 100;
23*05767d91SRobert Wu
24*05767d91SRobert Wu // Tracing functions
25*05767d91SRobert Wu static void *(*ATrace_beginSection)(const char *sectionName);
26*05767d91SRobert Wu
27*05767d91SRobert Wu static void *(*ATrace_endSection)(void);
28*05767d91SRobert Wu
29*05767d91SRobert Wu static bool *(*ATrace_isEnabled)(void);
30*05767d91SRobert Wu
31*05767d91SRobert Wu typedef void *(*fp_ATrace_beginSection)(const char *sectionName);
32*05767d91SRobert Wu
33*05767d91SRobert Wu typedef void *(*fp_ATrace_endSection)(void);
34*05767d91SRobert Wu
35*05767d91SRobert Wu typedef bool *(*fp_ATrace_isEnabled)(void);
36*05767d91SRobert Wu
37*05767d91SRobert Wu bool Trace::is_enabled_ = false;
38*05767d91SRobert Wu bool Trace::has_error_been_shown_ = false;
39*05767d91SRobert Wu
beginSection(const char * fmt,...)40*05767d91SRobert Wu void Trace::beginSection(const char *fmt, ...) {
41*05767d91SRobert Wu
42*05767d91SRobert Wu if (is_enabled_) {
43*05767d91SRobert Wu static char buff[TRACE_MAX_SECTION_NAME_LENGTH];
44*05767d91SRobert Wu va_list args;
45*05767d91SRobert Wu va_start(args, fmt);
46*05767d91SRobert Wu vsprintf(buff, fmt, args);
47*05767d91SRobert Wu va_end(args);
48*05767d91SRobert Wu ATrace_beginSection(buff);
49*05767d91SRobert Wu } else if (!has_error_been_shown_) {
50*05767d91SRobert Wu LOGE("Tracing is either not initialized (call Trace::initialize()) "
51*05767d91SRobert Wu "or not supported on this device");
52*05767d91SRobert Wu has_error_been_shown_ = true;
53*05767d91SRobert Wu }
54*05767d91SRobert Wu }
55*05767d91SRobert Wu
endSection()56*05767d91SRobert Wu void Trace::endSection() {
57*05767d91SRobert Wu
58*05767d91SRobert Wu if (is_enabled_) {
59*05767d91SRobert Wu ATrace_endSection();
60*05767d91SRobert Wu }
61*05767d91SRobert Wu }
62*05767d91SRobert Wu
initialize()63*05767d91SRobert Wu void Trace::initialize() {
64*05767d91SRobert Wu
65*05767d91SRobert Wu // Using dlsym allows us to use tracing on API 21+ without needing android/trace.h which wasn't
66*05767d91SRobert Wu // published until API 23
67*05767d91SRobert Wu void *lib = dlopen("libandroid.so", RTLD_NOW | RTLD_LOCAL);
68*05767d91SRobert Wu if (lib == nullptr) {
69*05767d91SRobert Wu LOGE("Could not open libandroid.so to dynamically load tracing symbols");
70*05767d91SRobert Wu } else {
71*05767d91SRobert Wu ATrace_beginSection =
72*05767d91SRobert Wu reinterpret_cast<fp_ATrace_beginSection >(
73*05767d91SRobert Wu dlsym(lib, "ATrace_beginSection"));
74*05767d91SRobert Wu ATrace_endSection =
75*05767d91SRobert Wu reinterpret_cast<fp_ATrace_endSection >(
76*05767d91SRobert Wu dlsym(lib, "ATrace_endSection"));
77*05767d91SRobert Wu ATrace_isEnabled =
78*05767d91SRobert Wu reinterpret_cast<fp_ATrace_isEnabled >(
79*05767d91SRobert Wu dlsym(lib, "ATrace_isEnabled"));
80*05767d91SRobert Wu
81*05767d91SRobert Wu if (ATrace_isEnabled != nullptr && ATrace_isEnabled()) {
82*05767d91SRobert Wu is_enabled_ = true;
83*05767d91SRobert Wu }
84*05767d91SRobert Wu }
85*05767d91SRobert Wu }
86