1 // Copyright Joyent, Inc. and other Node contributors.
2 //
3 // Permission is hereby granted, free of charge, to any person obtaining a
4 // copy of this software and associated documentation files (the
5 // "Software"), to deal in the Software without restriction, including
6 // without limitation the rights to use, copy, modify, merge, publish,
7 // distribute, sublicense, and/or sell copies of the Software, and to permit
8 // persons to whom the Software is furnished to do so, subject to the
9 // following conditions:
10 //
11 // The above copyright notice and this permission notice shall be included
12 // in all copies or substantial portions of the Software.
13 //
14 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
15 // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
16 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
17 // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
18 // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
19 // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
20 // USE OR OTHER DEALINGS IN THE SOFTWARE.
21
22 #include "async_wrap-inl.h"
23 #include "env-inl.h"
24 #include "handle_wrap.h"
25 #include "node_external_reference.h"
26 #include "node_process-inl.h"
27 #include "util-inl.h"
28 #include "v8.h"
29
30 namespace node {
31
32 using v8::Context;
33 using v8::FunctionCallbackInfo;
34 using v8::FunctionTemplate;
35 using v8::HandleScope;
36 using v8::Integer;
37 using v8::Isolate;
38 using v8::Local;
39 using v8::Object;
40 using v8::Value;
41
42 void DecreaseSignalHandlerCount(int signum);
43
44 namespace {
45
46 static Mutex handled_signals_mutex;
47 static std::map<int, int64_t> handled_signals; // Signal -> number of handlers
48
49 class SignalWrap : public HandleWrap {
50 public:
Initialize(Local<Object> target,Local<Value> unused,Local<Context> context,void * priv)51 static void Initialize(Local<Object> target,
52 Local<Value> unused,
53 Local<Context> context,
54 void* priv) {
55 Environment* env = Environment::GetCurrent(context);
56 Isolate* isolate = env->isolate();
57 Local<FunctionTemplate> constructor = NewFunctionTemplate(isolate, New);
58 constructor->InstanceTemplate()->SetInternalFieldCount(
59 SignalWrap::kInternalFieldCount);
60 constructor->Inherit(HandleWrap::GetConstructorTemplate(env));
61
62 SetProtoMethod(isolate, constructor, "start", Start);
63 SetProtoMethod(isolate, constructor, "stop", Stop);
64
65 SetConstructorFunction(context, target, "Signal", constructor);
66 }
67
RegisterExternalReferences(ExternalReferenceRegistry * registry)68 static void RegisterExternalReferences(ExternalReferenceRegistry* registry) {
69 registry->Register(New);
70 registry->Register(Start);
71 registry->Register(Stop);
72 }
73
74 SET_NO_MEMORY_INFO()
75 SET_MEMORY_INFO_NAME(SignalWrap)
76 SET_SELF_SIZE(SignalWrap)
77
78 private:
New(const FunctionCallbackInfo<Value> & args)79 static void New(const FunctionCallbackInfo<Value>& args) {
80 // This constructor should not be exposed to public javascript.
81 // Therefore we assert that we are not trying to call this as a
82 // normal function.
83 CHECK(args.IsConstructCall());
84 Environment* env = Environment::GetCurrent(args);
85 new SignalWrap(env, args.This());
86 }
87
SignalWrap(Environment * env,Local<Object> object)88 SignalWrap(Environment* env, Local<Object> object)
89 : HandleWrap(env,
90 object,
91 reinterpret_cast<uv_handle_t*>(&handle_),
92 AsyncWrap::PROVIDER_SIGNALWRAP) {
93 int r = uv_signal_init(env->event_loop(), &handle_);
94 CHECK_EQ(r, 0);
95 }
96
Close(v8::Local<v8::Value> close_callback)97 void Close(v8::Local<v8::Value> close_callback) override {
98 if (active_) {
99 DecreaseSignalHandlerCount(handle_.signum);
100 active_ = false;
101 }
102 HandleWrap::Close(close_callback);
103 }
104
Start(const FunctionCallbackInfo<Value> & args)105 static void Start(const FunctionCallbackInfo<Value>& args) {
106 SignalWrap* wrap;
107 ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
108 Environment* env = wrap->env();
109 int signum;
110 if (!args[0]->Int32Value(env->context()).To(&signum)) return;
111 #if defined(__POSIX__) && HAVE_INSPECTOR
112 if (signum == SIGPROF) {
113 Environment* env = Environment::GetCurrent(args);
114 if (env->inspector_agent()->IsListening()) {
115 ProcessEmitWarning(env,
116 "process.on(SIGPROF) is reserved while debugging");
117 return;
118 }
119 }
120 #endif
121 int err = uv_signal_start(
122 &wrap->handle_,
123 [](uv_signal_t* handle, int signum) {
124 SignalWrap* wrap = ContainerOf(&SignalWrap::handle_, handle);
125 Environment* env = wrap->env();
126 HandleScope handle_scope(env->isolate());
127 Context::Scope context_scope(env->context());
128 Local<Value> arg = Integer::New(env->isolate(), signum);
129 wrap->MakeCallback(env->onsignal_string(), 1, &arg);
130 },
131 signum);
132
133 if (err == 0) {
134 CHECK(!wrap->active_);
135 wrap->active_ = true;
136 Mutex::ScopedLock lock(handled_signals_mutex);
137 handled_signals[signum]++;
138 }
139
140 args.GetReturnValue().Set(err);
141 }
142
Stop(const FunctionCallbackInfo<Value> & args)143 static void Stop(const FunctionCallbackInfo<Value>& args) {
144 SignalWrap* wrap;
145 ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
146
147 if (wrap->active_) {
148 wrap->active_ = false;
149 DecreaseSignalHandlerCount(wrap->handle_.signum);
150 }
151
152 int err = uv_signal_stop(&wrap->handle_);
153 args.GetReturnValue().Set(err);
154 }
155
156 uv_signal_t handle_;
157 bool active_ = false;
158 };
159
160
161 } // anonymous namespace
162
DecreaseSignalHandlerCount(int signum)163 void DecreaseSignalHandlerCount(int signum) {
164 Mutex::ScopedLock lock(handled_signals_mutex);
165 int64_t new_handler_count = --handled_signals[signum];
166 CHECK_GE(new_handler_count, 0);
167 if (new_handler_count == 0)
168 handled_signals.erase(signum);
169 }
170
HasSignalJSHandler(int signum)171 bool HasSignalJSHandler(int signum) {
172 Mutex::ScopedLock lock(handled_signals_mutex);
173 return handled_signals.find(signum) != handled_signals.end();
174 }
175 } // namespace node
176
177 NODE_BINDING_CONTEXT_AWARE_INTERNAL(signal_wrap, node::SignalWrap::Initialize)
178 NODE_BINDING_EXTERNAL_REFERENCE(signal_wrap,
179 node::SignalWrap::RegisterExternalReferences)
180