process, feat: support Event beforeExit.

fibjs/src/coroutine/Fiber.cpp

@@ -7,6 +7,7 @@
 
 #include "object.h"
 #include "Fiber.h"
+#include "Trigger.h"
 #include "ifs/os.h"
 #include "ifs/process.h"
 
@@ -73,8 +74,16 @@ void JSFiber::fiber_proc(void* p)
 
             if (isolate->m_pendding.dec() == 0)
                 if (isolate->m_id == 1) {
+                    v8::HandleScope handle_scope(isolate->m_isolate);
                     JSFiber::scope s;
-                    process_base::exit(hr);
+                    JSTrigger t(isolate->m_isolate, process_base::class_info().getModule(isolate));
+                    v8::Local<v8::Value> code = v8::Number::New(isolate->m_isolate, isolate->m_exitCode);
+                    bool r;
+
+                    isolate->m_pendding.inc();
+                    t._emit("beforeExit", &code, 1, r);
+                    if (isolate->m_pendding.dec() == 0)
+                        process_base::exit(hr);
                 }
         }
 

idl/zh-cn/process.idl

@@ -4,6 +4,18 @@
  ```JavaScript
  var process = require('process');
  ```
+
+ ## 进程事件
+ process 模块对象是 EventEmitter 的实例，可以通过注册事件监听器响应进程级别的事件。
+
+ ### beforeExit
+ **当 fibjs 的任务已经为空，并且没有额外的工作被添加进来，事件 `beforeExit` 会被触发**
+ ```JavaScript
+ process.on('beforeExit', exitCode => {});
+ ```
+ 正常情况下，如果没有额外的工作被添加到任务队列，fibjs 进程会结束。但是如果 `beforeExit` 事件绑定的监听器的回调函数中，启动了一个新的任务，比如开启一个 fiber，那么 fibjs 进程会继续运行。
+
+ `process.exitCode` 作为唯一的参数值传递给 `beforeExit` 事件监听器的回调函数。如果进程由于显式的原因而将要终止，例如直接调用 `process.exit` 或抛出未捕获的异常，`beforeExit`事件不会被触发。
  */
 module process : EventEmitter
 {

test/process/exec13.js

@@ -0,0 +1,2 @@
+process.exitCode = 100;
+process.exit();

test/process/exec14.js

@@ -0,0 +1,2 @@
+process.exitCode = 100;
+process.exit(101);

test/process/exec15.js

@@ -0,0 +1,18 @@
+process.exitCode = 101;
+
+process.on('beforeExit', exitCode => {
+    console.log('beforeExit', exitCode);
+});
+
+var once = true;
+
+process.on('beforeExit', exitCode => {
+    console.log('other beforeExit', exitCode);
+
+    if (once) {
+        once = false;
+        setTimeout(() => {
+            console.log("new work", exitCode);
+        }, 10);
+    }
+});

test/process_test.js

@@ -54,6 +54,11 @@ describe('process', () => {
         assert.equal(process.run(cmd, [path.join(__dirname, 'process', 'exec.js')]), 100);
     });
 
+    it("exitCode", () => {
+        assert.equal(process.run(cmd, [path.join(__dirname, 'process', 'exec13.js')]), 100);
+        assert.equal(process.run(cmd, [path.join(__dirname, 'process', 'exec14.js')]), 101);
+    });
+
     xit("run throw error", () => {
         assert.throws(() => {
             process.run("not_exists_exec_file");
@@ -212,6 +217,19 @@ describe('process', () => {
             assert.equal(old, process.umask());
         });
     }
+
+    describe("Event", () => {
+        it("beforeExit", () => {
+            var bs = process.open(cmd, [path.join(__dirname, 'process', 'exec15.js')]);
+            assert.deepEqual(bs.readLines(), [
+                "beforeExit 101",
+                "other beforeExit 101",
+                "new work 101",
+                "beforeExit 101",
+                "other beforeExit 101"
+            ]);
+        });
+    });
 });
 
 repl && test.run(console.DEBUG);