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_process-inl.h"
26 #include "util-inl.h"
27 #include "v8.h"
28
29 namespace node {
30
31 using v8::Context;
32 using v8::FunctionCallbackInfo;
33 using v8::FunctionTemplate;
34 using v8::HandleScope;
35 using v8::Integer;
36 using v8::Local;
37 using v8::Object;
38 using v8::Value;
39
40 void DecreaseSignalHandlerCount(int signum);
41
42 namespace {
43
44 static Mutex handled_signals_mutex;
45 static std::map<int, int64_t> handled_signals; // Signal -> number of handlers
46
47 class SignalWrap : public HandleWrap {
48 public:
Initialize(Local<Object> target,Local<Value> unused,Local<Context> context,void * priv)49 static void Initialize(Local<Object> target,
50 Local<Value> unused,
51 Local<Context> context,
52 void* priv) {
53 Environment* env = Environment::GetCurrent(context);
54 Local<FunctionTemplate> constructor = env->NewFunctionTemplate(New);
55 constructor->InstanceTemplate()->SetInternalFieldCount(
56 SignalWrap::kInternalFieldCount);
57 constructor->Inherit(HandleWrap::GetConstructorTemplate(env));
58
59 env->SetProtoMethod(constructor, "start", Start);
60 env->SetProtoMethod(constructor, "stop", Stop);
61
62 env->SetConstructorFunction(target, "Signal", constructor);
63 }
64
65 SET_NO_MEMORY_INFO()
66 SET_MEMORY_INFO_NAME(SignalWrap)
67 SET_SELF_SIZE(SignalWrap)
68
69 private:
New(const FunctionCallbackInfo<Value> & args)70 static void New(const FunctionCallbackInfo<Value>& args) {
71 // This constructor should not be exposed to public javascript.
72 // Therefore we assert that we are not trying to call this as a
73 // normal function.
74 CHECK(args.IsConstructCall());
75 Environment* env = Environment::GetCurrent(args);
76 new SignalWrap(env, args.This());
77 }
78
SignalWrap(Environment * env,Local<Object> object)79 SignalWrap(Environment* env, Local<Object> object)
80 : HandleWrap(env,
81 object,
82 reinterpret_cast<uv_handle_t*>(&handle_),
83 AsyncWrap::PROVIDER_SIGNALWRAP) {
84 int r = uv_signal_init(env->event_loop(), &handle_);
85 CHECK_EQ(r, 0);
86 }
87
Close(v8::Local<v8::Value> close_callback)88 void Close(v8::Local<v8::Value> close_callback) override {
89 if (active_) {
90 DecreaseSignalHandlerCount(handle_.signum);
91 active_ = false;
92 }
93 HandleWrap::Close(close_callback);
94 }
95
Start(const FunctionCallbackInfo<Value> & args)96 static void Start(const FunctionCallbackInfo<Value>& args) {
97 SignalWrap* wrap;
98 ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
99 Environment* env = wrap->env();
100 int signum;
101 if (!args[0]->Int32Value(env->context()).To(&signum)) return;
102 #if defined(__POSIX__) && HAVE_INSPECTOR
103 if (signum == SIGPROF) {
104 Environment* env = Environment::GetCurrent(args);
105 if (env->inspector_agent()->IsListening()) {
106 ProcessEmitWarning(env,
107 "process.on(SIGPROF) is reserved while debugging");
108 return;
109 }
110 }
111 #endif
112 int err = uv_signal_start(
113 &wrap->handle_,
114 [](uv_signal_t* handle, int signum) {
115 SignalWrap* wrap = ContainerOf(&SignalWrap::handle_, handle);
116 Environment* env = wrap->env();
117 HandleScope handle_scope(env->isolate());
118 Context::Scope context_scope(env->context());
119 Local<Value> arg = Integer::New(env->isolate(), signum);
120 wrap->MakeCallback(env->onsignal_string(), 1, &arg);
121 },
122 signum);
123
124 if (err == 0) {
125 CHECK(!wrap->active_);
126 wrap->active_ = true;
127 Mutex::ScopedLock lock(handled_signals_mutex);
128 handled_signals[signum]++;
129 }
130
131 args.GetReturnValue().Set(err);
132 }
133
Stop(const FunctionCallbackInfo<Value> & args)134 static void Stop(const FunctionCallbackInfo<Value>& args) {
135 SignalWrap* wrap;
136 ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
137
138 if (wrap->active_) {
139 wrap->active_ = false;
140 DecreaseSignalHandlerCount(wrap->handle_.signum);
141 }
142
143 int err = uv_signal_stop(&wrap->handle_);
144 args.GetReturnValue().Set(err);
145 }
146
147 uv_signal_t handle_;
148 bool active_ = false;
149 };
150
151
152 } // anonymous namespace
153
DecreaseSignalHandlerCount(int signum)154 void DecreaseSignalHandlerCount(int signum) {
155 Mutex::ScopedLock lock(handled_signals_mutex);
156 int64_t new_handler_count = --handled_signals[signum];
157 CHECK_GE(new_handler_count, 0);
158 if (new_handler_count == 0)
159 handled_signals.erase(signum);
160 }
161
HasSignalJSHandler(int signum)162 bool HasSignalJSHandler(int signum) {
163 Mutex::ScopedLock lock(handled_signals_mutex);
164 return handled_signals.find(signum) != handled_signals.end();
165 }
166 } // namespace node
167
168
169 NODE_MODULE_CONTEXT_AWARE_INTERNAL(signal_wrap, node::SignalWrap::Initialize)
170