abstract：通过设置 runtime.GOMAXPROCS(1) 让 golang 的进程变成单线程执行的。类似python用gevent的效果。然后通过调度多个协程实现异步I/O并发。php作为一个子函数跑在go的进程内，php需要yield到其他协程时，通过回调到golang函数来实现。从php里调用go提供的子函数时，go保证保存php的当前上下文想法很简单。通过设置 runtime.GOMAXPROC
通过设置 runtime.GOMAXPROCS(1) 让 golang 的进程变成单线程执行的。类似python用gevent的效果。然后通过调度多个协程实现异步I/O并发。php作为一个子函数跑在go的进程内，php需要yield到其他协程时，通过回调到golang函数来实现。从php里调用go提供的子函数时，go保证保存php的当前上下文
想法很简单。通过设置 runtime.GOMAXPROCS(1) 让 golang 的进程变成单线程执行的。类似python用gevent的效果。然后通过调度多个协程实现异步I/O并发。php作为一个子函数跑在go的进程内，php需要yield到其他协程时，通过回调到golang函数来实现。从php里调用go提供的子函数时，go保证保存php的当前上下文。当协程执行权让渡回来的时候，把原来的php上下文恢复。关键的代码在：
// 保存当前协程上的php上下文 oldServerCtx := engine.ServerContextGet() fmt.Println(oldServerCtx) defer engine.ServerContextSet(oldServerCtx) oldExecutorCtx := engine.ExecutorContextGet() fmt.Println(oldExecutorCtx) defer engine.ExecutorContextSet(oldExecutorCtx) oldCoreCtx := engine.CoreContextGet() fmt.Println(oldCoreCtx) defer engine.CoreContextSet(oldCoreCtx) // 放弃全局的锁，使得其他的协程可以开始执行php engineLock.Unlock() defer engineLock.Lock()
ServerContextGet 这几个函数是我加的，获得的是php的(EG/SG/PG)这三个全局context(参见：http://www.cnblogs.com/chance...)。修改过的github.com/deuill/go-php的源代码在：https://github.com/taowen/go-...
完整的php/go混合协程的demo：
package main import ( "fmt" "github.com/deuill/go-php/engine" "os" "runtime" "time" "sync" ) type TestObj struct{} func newTestObj(args []interface{}) interface{} { return &TestObj{} } var engineLock *sync.Mutex func (self *TestObj) Hello() { oldServerCtx := engine.ServerContextGet() fmt.Println(oldServerCtx) defer engine.ServerContextSet(oldServerCtx) oldExecutorCtx := engine.ExecutorContextGet() fmt.Println(oldExecutorCtx) defer engine.ExecutorContextSet(oldExecutorCtx) oldCoreCtx := engine.CoreContextGet() fmt.Println(oldCoreCtx) defer engine.CoreContextSet(oldCoreCtx) engineLock.Unlock() defer engineLock.Lock() time.Sleep(time.Second) fmt.Println("sleep done") } func main() { runtime.GOMAXPROCS(1) theEngine, err := engine.New() engineLock = &sync.Mutex{} if err != nil { fmt.Println(err) } _, err = theEngine.Define("TestObj", newTestObj) wg := &sync.WaitGroup{} wg.Add(2) before := time.Now() fmt.Println("1") go func() { engineLock.Lock() defer engineLock.Unlock() context1, err := theEngine.NewContext() if err != nil { fmt.Println(err) } context1.Output = os.Stdout if err != nil { fmt.Println(err) } fmt.Println("1 enter") _, err = context1.Eval("$testObj = new TestObj(); $testObj->Hello();") fmt.Println("1 back") if err != nil { fmt.Println(err) } //theEngine.DestroyContext(context1) fmt.Println("1 done") wg.Done() }() fmt.Println("2") go func() { engineLock.Lock() defer engineLock.Unlock() context2, err := theEngine.NewContext() if err != nil { fmt.Println(err) } if err != nil { fmt.Println(err) } context2.Output = os.Stdout fmt.Println("2 enter") _, err = context2.Eval("$testObj = new TestObj(); $testObj->Hello();") fmt.Println("2 back") if err != nil { fmt.Println(err) } //theEngine.DestroyContext(context2) fmt.Println("2 done") wg.Done() }() wg.Wait() after := time.Now() fmt.Println(after.Sub(before)) }
执行结果是
1 2 2 enter {0x2cf2930 { 0 0 0 0 [0 0 0 0 0] 0 0 1000 [0 0 0 0]} {{ 0 16 0x7f682e819780 0 [0 0 0 0 0 0 0] } 0 1 [0 0 0] } 0 0 0 [0 0 0 0 0 0] {0 0 0 0 0 0 0 0 0 0 0 {0 0} {0 0} {0 0} [0 0 0]} 0x2a00270 0x2a00f60 8388608 0 1 [0 0 0] 0 {8 7 2 [0 0 0 0] 0 0x29f4520 0x29f4520 0x29f4470 0x29f4420 1 0 0 [0 0 0 0 0]} {0 [0 0 0 0 0 0 0] } 0 [0 0 0 0 0 0 0]} {0x7ffd30bac588 {[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0] 2 0 0 [0 0]} 0x7f682f01b928 {[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0] 1 0 0 [0 0]} 0x7f682f01b948 [ ] 0x7f682f01ba60 0x7f682f01b960 0x7f682f167168 0x7f682f01ba88 {64 63 5 [0 0 0 0] 0 0x7f682f1972d8 0x7f682f1972d8 0x7f682f1993f8 0x7f682f1970c8 0x7f682e862d10 0 0 1 [0 0 0 0 0]} {8 0 0 [0 0 0 0] 0 0x7f682f016a00 0 0 1 [0 0 0 0 0]} 0x7ffd30bac590 22527 0 0 [0 0 0 0] 0x7f682f197640 0x29f4f80 0x29f4fd0 0x29f5070 0x2cf2950 0x7f682f1989c0 14 0 1 [0 0 0] 0 1 [0 0 0 0 0 0] {8 0 0 [0 0 0 0] 1 0x7f682f016a00 0x7f682e883140 0 0 1 [0 0 0 0 0]} {8 0 0 [0 0 0 0] 0 0x7f682f016a00 0x7f682e8831d0 1 0 0 [0 0 0 0 0]} 0x7f682f167088 0 [0 0 0 0] {0 0 } {0 0 0 [0 0 0 0 0 0 0]} {0 0 0 [0 0 0 0 0 0 0]} 0 [0 0 0 0] 0 0 0x29fb2e0 {0x7f682f187030 2 1024 -1 [0 0 0 0]} [{0x7f682e915050 [0 0 0 0 0 0 0 0] [0 0 0 0 0 0 0 0] [0 0 0 0 0 0 0 0] 0 0 149 8 8 8} {0x7f682e915050 [0 0 0 0 0 0 0 0] [0 0 0 0 0 0 0 0] [0 0 0 0 0 0 0 0] 0 0 149 8 8 8} {0x7f682e915050 [0 0 0 0 0 0 0 0] [0 0 0 0 0 0 0 0] [0 0 0 0 0 0 0 0] 0 0 149 8 8 8}] 0x7f682f167168 {0 [0 0 0 0] 0 [0 0 0 0] 0 0 [0 0 0 0] 0 [0 0 0 0] } 1 [0 0 0 0 0 0 0] 0x7f682f01bde8 895 [0 0 0 0 0 0] [ ]} {1 [0 0 0 0 0 0 0] 0 0 0 [0 0 0 0 0 0] 0x29ff9a0 17 134217728 -1 0 0 0 1 [0 0 0 0] 1024 0 0 1 [0 0 0 0 0] 0x2a00870 0x2a010a0 0x7f682ecc58b0 0x7f682ecc5c23 2097152 0x2a00180 0x2a00230 {0x7f682ec91aa8 0x7f682ec91aa8} 0x2a00910 {0 0 0 [0 0 0 0] 0 0 0 0 [0 0 0 0 0]} 0 0 0 [0 0 0] {0x2b6dc10 0x2b6dc10 1 8 1 [0 0 0 0 0 0 0] } [0x7f682f197330 0x7f682f197040 0x7f682f197410 0x7f682f1974f0] 0 1 1 [0 0 0 0 0] 0x7f682ec9544b 0x7f682ec9544b 0 0 [0 0 0 0 0 0] 0 [0 0 0 0 0 0 0 0] 1 1 1 1 1 0 1 [0] 0 [0 0 0 0] 0 [0 0 0 0] 0x2cf27c0 0 0 [0 0 0 0 0 0] 64 1000 0 [0 0 0 0 0 0 0] 0x7f682ecc6270 300 0x2a009b0 1 [0 0 0 0 0 0 0] 0 [0 0 0 0 0 0 0]} 1 enter {0x7f6818000aa0 { 0 0 0 0 [0 0 0 0 0] 0 0 1000 [0 0 0 0]} {{ 0 16 0x7f682e819780 0 [0 0 0 0 0 0 0] } 0 1 [0 0 0] } 0 0 0 [0 0 0 0 0 0] {0 0 0 0 0 0 0 0 0 0 0 {0 0} {0 0} {0 0} [0 0 0]} 0x2a00270 0x2a00f60 8388608 0 1 [0 0 0] 0 {8 7 2 [0 0 0 0] 0 0x29f4520 0x29f4520 0x29f4470 0x29f4420 1 0 0 [0 0 0 0 0]} {0 [0 0 0 0 0 0 0] } 0 [0 0 0 0 0 0 0]} {0x7f682a4cccd8 {[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0] 2 0 0 [0 0]} 0x7f682f01b928 {[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0] 1 0 0 [0 0]} 0x7f682f01b948 [ ] 0x7f682f01ba60 0x7f682f01b960 0x7f682802f110 0x7f682f01ba88 {64 63 5 [0 0 0 0] 0 0x7f682f197a00 0x7f682f197a00 0x7f682f198368 0x7f682f198fa0 0x7f682e862d10 0 0 1 [0 0 0 0 0]} {8 0 0 [0 0 0 0] 0 0x7f682f016a00 0 0 1 [0 0 0 0 0]} 0x7f682a4ccce0 22527 0 0 [0 0 0 0] 0x7f682f197d28 0x29f4f80 0x29f4fd0 0x29f5070 0x2cf2950 0x7f682f1983e8 14 0 1 [0 0 0] 0 1 [0 0 0 0 0 0] {8 0 0 [0 0 0 0] 1 0x7f682f016a00 0x7f682e883140 0 0 1 [0 0 0 0 0]} {8 0 0 [0 0 0 0] 0 0x7f682f016a00 0x7f682e8831d0 1 0 0 [0 0 0 0 0]} 0x7f682802f030 0 [0 0 0 0] {0 0 } {0 0 0 [0 0 0 0 0 0 0]} {0 0 0 [0 0 0 0 0 0 0]} 0 [0 0 0 0] 0 0 0x29fb2e0 {0x7f682804efd8 2 1024 -1 [0 0 0 0]} [{0x7f682e915050 [0 0 0 0 0 0 0 0] [0 0 0 0 0 0 0 0] [0 0 0 0 0 0 0 0] 0 0 149 8 8 8} {0x7f682e915050 [0 0 0 0 0 0 0 0] [0 0 0 0 0 0 0 0] [0 0 0 0 0 0 0 0] 0 0 149 8 8 8} {0x7f682e915050 [0 0 0 0 0 0 0 0] [0 0 0 0 0 0 0 0] [0 0 0 0 0 0 0 0] 0 0 149 8 8 8}] 0x7f682802f110 {0 [0 0 0 0] 0 [0 0 0 0] 0 0 [0 0 0 0] 0 [0 0 0 0] } 1 [0 0 0 0 0 0 0] 0x7f682f01bde8 895 [0 0 0 0 0 0] [ ]} {1 [0 0 0 0 0 0 0] 0 0 0 [0 0 0 0 0 0] 0x29ff9a0 17 134217728 -1 0 0 0 1 [0 0 0 0] 1024 0 0 1 [0 0 0 0 0] 0x2a00870 0x2a010a0 0x7f682ecc58b0 0x7f682ecc5c23 2097152 0x2a00180 0x2a00230 {0x7f682ec91aa8 0x7f682ec91aa8} 0x2a00910 {0 0 0 [0 0 0 0] 0 0 0 0 [0 0 0 0 0]} 0 0 0 [0 0 0] {0x2b6dc10 0x2b6dc10 1 8 1 [0 0 0 0 0 0 0] } [0x7f682f197a58 0x7f682f198ce0 0x7f682f197b38 0x7f682f197c18] 0 1 1 [0 0 0 0 0] 0x7f682ec9544b 0x7f682ec9544b 0 0 [0 0 0 0 0 0] 0 [0 0 0 0 0 0 0 0] 1 1 1 1 1 0 1 [0] 0 [0 0 0 0] 0 [0 0 0 0] 0x2cf27c0 0 0 [0 0 0 0 0 0] 64 1000 0 [0 0 0 0 0 0 0] 0x7f682ecc6270 300 0x2a009b0 1 [0 0 0 0 0 0 0] 0 [0 0 0 0 0 0 0]} sleep done 1 back 1 done sleep done 2 back 2 done 1.00099211s
可以看到两个sleep 1s，最终只用了1.00099211s。说明协程是并发的。
一些性能指标。走http调用后端，在i7-6700k上，用ab -n 100 -c 4 可以跑出这样的结果
Requests per second: 3183.70 [#/sec] (mean) Time per request: 1.256 [ms] (mean) Time per request: 0.314 [ms] (mean, across all concurrent requests)
如果不用http调用后端，直接php=>go返回"hello"，则可以达到
Requests per second: 10073.54 [#/sec] (mean) Time per request: 0.397 [ms] (mean) Time per request: 0.099 [ms] (mean, across all concurrent requests)
这些指标只说明了协程切换的成本。实际的收益取决于后端的http服务的延迟，如果耗时很长，通过协程并发则可以收益明显。
这个实验说明了可以用golang实现一个代替nginx+php-fpm的应用服务器。并且提供了一条从php向golang迁移的平滑迁移路径。在一个应用里混合PHP和Go两种语言。
并且可以通过提供golang函数给php调用的方式实现I/O的异步化。像libcurl这样的扩展自身是支持异步回调的，只是php是同步的所以只给php暴露了同步的execute。有了Golang之后，可以把execute变成对异步execute+callback的包装，从而实现基于协程的调度。
