1 //
2 //
3 // Copyright 2015 gRPC authors.
4 //
5 // Licensed under the Apache License, Version 2.0 (the "License");
6 // you may not use this file except in compliance with the License.
7 // You may obtain a copy of the License at
8 //
9 // http://www.apache.org/licenses/LICENSE-2.0
10 //
11 // Unless required by applicable law or agreed to in writing, software
12 // distributed under the License is distributed on an "AS IS" BASIS,
13 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 // See the License for the specific language governing permissions and
15 // limitations under the License.
16 //
17 //
18
19 #include "src/core/lib/debug/trace.h"
20
21 #include <grpc/grpc.h>
22 #include <grpc/support/port_platform.h>
23
24 #include <string>
25 #include <type_traits>
26 #include <utility>
27
28 #include "absl/log/log.h"
29 #include "absl/strings/match.h"
30 #include "absl/strings/str_cat.h"
31 #include "absl/strings/str_split.h"
32 #include "absl/strings/string_view.h"
33 #include "absl/strings/strip.h"
34 #include "src/core/config/config_vars.h"
35 #include "src/core/util/glob.h"
36
37 int grpc_tracer_set_enabled(const char* name, int enabled);
38
39 namespace grpc_core {
40 namespace {
LogAllTracers()41 void LogAllTracers() {
42 VLOG(2) << "available tracers:";
43 for (const auto& name : GetAllTraceFlags()) {
44 LOG(INFO) << " " << name.first;
45 }
46 }
47
48 } // namespace
49
50 // Flags register themselves on the list during construction
TraceFlag(bool default_enabled,const char * name)51 TraceFlag::TraceFlag(bool default_enabled, const char* name) : name_(name) {
52 static_assert(std::is_trivially_destructible<TraceFlag>::value,
53 "TraceFlag needs to be trivially destructible.");
54 set_enabled(default_enabled);
55 }
56
SavedTraceFlags()57 SavedTraceFlags::SavedTraceFlags() {
58 for (const auto& flag : GetAllTraceFlags()) {
59 values_[flag.first] = {flag.second->enabled(), flag.second};
60 }
61 }
62
Restore()63 void SavedTraceFlags::Restore() {
64 for (const auto& flag : values_) {
65 flag.second.second->set_enabled(flag.second.first);
66 }
67 }
68
ParseTracers(absl::string_view tracers)69 bool ParseTracers(absl::string_view tracers) {
70 std::string enabled_tracers;
71 bool some_trace_was_found = false;
72 for (auto trace_glob : absl::StrSplit(tracers, ',', absl::SkipWhitespace())) {
73 if (trace_glob == "list_tracers") {
74 LogAllTracers();
75 continue;
76 }
77 bool enabled = !absl::ConsumePrefix(&trace_glob, "-");
78 if (trace_glob == "all") trace_glob = "*";
79 if (trace_glob == "refcount") trace_glob = "*refcount*";
80 bool found = false;
81 for (const auto& flag : GetAllTraceFlags()) {
82 if (GlobMatch(flag.first, trace_glob)) {
83 flag.second->set_enabled(enabled);
84 if (enabled) absl::StrAppend(&enabled_tracers, flag.first, ", ");
85 found = true;
86 some_trace_was_found = true;
87 }
88 }
89 if (!found) LOG(ERROR) << "Unknown tracer: " << trace_glob;
90 }
91 if (!enabled_tracers.empty()) {
92 absl::string_view enabled_tracers_view(enabled_tracers);
93 absl::ConsumeSuffix(&enabled_tracers_view, ", ");
94 LOG(INFO) << "gRPC Tracers: " << enabled_tracers_view;
95 }
96 return some_trace_was_found;
97 }
98
99 } // namespace grpc_core
100
grpc_tracer_init()101 void grpc_tracer_init() {
102 grpc_core::ParseTracers(grpc_core::ConfigVars::Get().Trace());
103 }
104
grpc_tracer_set_enabled(const char * name,int enabled)105 int grpc_tracer_set_enabled(const char* name, int enabled) {
106 if (enabled != 0) return grpc_core::ParseTracers(name);
107 return grpc_core::ParseTracers(absl::StrCat("-", name));
108 }
109