1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
|
// Copyright 2018 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/api/api-inl.h"
#include "src/builtins/builtins-utils-inl.h"
#include "src/builtins/builtins.h"
#include "src/heap/heap-inl.h" // For ToBoolean. TODO(jkummerow): Drop.
#include "src/json/json-stringifier.h"
#include "src/logging/counters.h"
#include "src/objects/objects-inl.h"
#if defined(V8_USE_PERFETTO)
#include "protos/perfetto/trace/track_event/debug_annotation.pbzero.h"
#endif
namespace v8 {
namespace internal {
namespace {
using v8::tracing::TracedValue;
#define MAX_STACK_LENGTH 100
class MaybeUtf8 {
public:
explicit MaybeUtf8(Isolate* isolate, Handle<String> string) : buf_(data_) {
string = String::Flatten(isolate, string);
int len;
if (string->IsOneByteRepresentation()) {
// Technically this allows unescaped latin1 characters but the trace
// events mechanism currently does the same and the current consuming
// tools are tolerant of it. A more correct approach here would be to
// escape non-ascii characters but this is easier and faster.
len = string->length();
AllocateSufficientSpace(len);
if (len > 0) {
// Why copy? Well, the trace event mechanism requires null-terminated
// strings, the bytes we get from SeqOneByteString are not. buf_ is
// guaranteed to be null terminated.
DisallowHeapAllocation no_gc;
memcpy(buf_, Handle<SeqOneByteString>::cast(string)->GetChars(no_gc),
len);
}
} else {
Local<v8::String> local = Utils::ToLocal(string);
auto* v8_isolate = reinterpret_cast<v8::Isolate*>(isolate);
len = local->Utf8Length(v8_isolate);
AllocateSufficientSpace(len);
if (len > 0) {
local->WriteUtf8(v8_isolate, reinterpret_cast<char*>(buf_));
}
}
buf_[len] = 0;
}
const char* operator*() const { return reinterpret_cast<const char*>(buf_); }
private:
void AllocateSufficientSpace(int len) {
if (len + 1 > MAX_STACK_LENGTH) {
allocated_.reset(new uint8_t[len + 1]);
buf_ = allocated_.get();
}
}
// In the most common cases, the buffer here will be stack allocated.
// A heap allocation will only occur if the data is more than MAX_STACK_LENGTH
// Given that this is used primarily for trace event categories and names,
// the MAX_STACK_LENGTH should be more than enough.
uint8_t* buf_;
uint8_t data_[MAX_STACK_LENGTH];
std::unique_ptr<uint8_t> allocated_;
};
#if !defined(V8_USE_PERFETTO)
class JsonTraceValue : public ConvertableToTraceFormat {
public:
explicit JsonTraceValue(Isolate* isolate, Handle<String> object) {
// object is a JSON string serialized using JSON.stringify() from within
// the BUILTIN(Trace) method. This may (likely) contain UTF8 values so
// to grab the appropriate buffer data we have to serialize it out. We
// hold on to the bits until the AppendAsTraceFormat method is called.
MaybeUtf8 data(isolate, object);
data_ = *data;
}
void AppendAsTraceFormat(std::string* out) const override { *out += data_; }
private:
std::string data_;
};
const uint8_t* GetCategoryGroupEnabled(Isolate* isolate,
Handle<String> string) {
MaybeUtf8 category(isolate, string);
return TRACE_EVENT_API_GET_CATEGORY_GROUP_ENABLED(*category);
}
#endif // !defined(V8_USE_PERFETTO)
#undef MAX_STACK_LENGTH
} // namespace
// Builins::kIsTraceCategoryEnabled(category) : bool
BUILTIN(IsTraceCategoryEnabled) {
HandleScope scope(isolate);
Handle<Object> category = args.atOrUndefined(isolate, 1);
if (!category->IsString()) {
THROW_NEW_ERROR_RETURN_FAILURE(
isolate, NewTypeError(MessageTemplate::kTraceEventCategoryError));
}
bool enabled;
#if defined(V8_USE_PERFETTO)
MaybeUtf8 category_str(isolate, Handle<String>::cast(category));
perfetto::DynamicCategory dynamic_category{*category_str};
enabled = TRACE_EVENT_CATEGORY_ENABLED(dynamic_category);
#else
enabled = *GetCategoryGroupEnabled(isolate, Handle<String>::cast(category));
#endif
return isolate->heap()->ToBoolean(enabled);
}
// Builtins::kTrace(phase, category, name, id, data) : bool
BUILTIN(Trace) {
HandleScope handle_scope(isolate);
Handle<Object> phase_arg = args.atOrUndefined(isolate, 1);
Handle<Object> category = args.atOrUndefined(isolate, 2);
Handle<Object> name_arg = args.atOrUndefined(isolate, 3);
Handle<Object> id_arg = args.atOrUndefined(isolate, 4);
Handle<Object> data_arg = args.atOrUndefined(isolate, 5);
// Exit early if the category group is not enabled.
#if defined(V8_USE_PERFETTO)
MaybeUtf8 category_str(isolate, Handle<String>::cast(category));
perfetto::DynamicCategory dynamic_category{*category_str};
if (!TRACE_EVENT_CATEGORY_ENABLED(dynamic_category))
return ReadOnlyRoots(isolate).false_value();
#else
const uint8_t* category_group_enabled =
GetCategoryGroupEnabled(isolate, Handle<String>::cast(category));
if (!*category_group_enabled) return ReadOnlyRoots(isolate).false_value();
#endif
if (!phase_arg->IsNumber()) {
THROW_NEW_ERROR_RETURN_FAILURE(
isolate, NewTypeError(MessageTemplate::kTraceEventPhaseError));
}
char phase = static_cast<char>(DoubleToInt32(phase_arg->Number()));
if (!category->IsString()) {
THROW_NEW_ERROR_RETURN_FAILURE(
isolate, NewTypeError(MessageTemplate::kTraceEventCategoryError));
}
if (!name_arg->IsString()) {
THROW_NEW_ERROR_RETURN_FAILURE(
isolate, NewTypeError(MessageTemplate::kTraceEventNameError));
}
uint32_t flags = TRACE_EVENT_FLAG_COPY;
int32_t id = 0;
if (!id_arg->IsNullOrUndefined(isolate)) {
if (!id_arg->IsNumber()) {
THROW_NEW_ERROR_RETURN_FAILURE(
isolate, NewTypeError(MessageTemplate::kTraceEventIDError));
}
flags |= TRACE_EVENT_FLAG_HAS_ID;
id = DoubleToInt32(id_arg->Number());
}
Handle<String> name_str = Handle<String>::cast(name_arg);
if (name_str->length() == 0) {
THROW_NEW_ERROR_RETURN_FAILURE(
isolate, NewTypeError(MessageTemplate::kTraceEventNameLengthError));
}
MaybeUtf8 name(isolate, name_str);
// We support passing one additional trace event argument with the
// name "data". Any JSON serializable value may be passed.
static const char* arg_name = "data";
Handle<Object> arg_json;
int32_t num_args = 0;
if (!data_arg->IsUndefined(isolate)) {
// Serializes the data argument as a JSON string, which is then
// copied into an object. This eliminates duplicated code but
// could have perf costs. It is also subject to all the same
// limitations as JSON.stringify() as it relates to circular
// references and value limitations (e.g. BigInt is not supported).
ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
isolate, arg_json,
JsonStringify(isolate, data_arg, isolate->factory()->undefined_value(),
isolate->factory()->undefined_value()));
num_args++;
}
#if defined(V8_USE_PERFETTO)
auto trace_args = [&](perfetto::EventContext ctx) {
// TODO(skyostil): Use interned names to reduce trace size.
if (phase != TRACE_EVENT_PHASE_END) {
ctx.event()->set_name(*name);
}
if (num_args) {
MaybeUtf8 arg_contents(isolate, Handle<String>::cast(arg_json));
auto annotation = ctx.event()->add_debug_annotations();
annotation->set_name(arg_name);
annotation->set_legacy_json_value(*arg_contents);
}
if (flags & TRACE_EVENT_FLAG_HAS_ID) {
auto legacy_event = ctx.event()->set_legacy_event();
legacy_event->set_global_id(id);
}
};
switch (phase) {
case TRACE_EVENT_PHASE_BEGIN:
TRACE_EVENT_BEGIN(dynamic_category, nullptr, trace_args);
break;
case TRACE_EVENT_PHASE_END:
TRACE_EVENT_END(dynamic_category, trace_args);
break;
case TRACE_EVENT_PHASE_INSTANT:
TRACE_EVENT_INSTANT(dynamic_category, nullptr, trace_args);
break;
default:
THROW_NEW_ERROR_RETURN_FAILURE(
isolate, NewTypeError(MessageTemplate::kTraceEventPhaseError));
}
#else // !defined(V8_USE_PERFETTO)
uint8_t arg_type;
uint64_t arg_value;
if (num_args) {
std::unique_ptr<JsonTraceValue> traced_value(
new JsonTraceValue(isolate, Handle<String>::cast(arg_json)));
tracing::SetTraceValue(std::move(traced_value), &arg_type, &arg_value);
}
TRACE_EVENT_API_ADD_TRACE_EVENT(
phase, category_group_enabled, *name, tracing::kGlobalScope, id,
tracing::kNoId, num_args, &arg_name, &arg_type, &arg_value, flags);
#endif // !defined(V8_USE_PERFETTO)
return ReadOnlyRoots(isolate).true_value();
}
} // namespace internal
} // namespace v8
|