PHP 混合 Go 協程並發

這是一個建立於 的文章，其中的資訊可能已經有所發展或是發生改變。

想法很簡單。通過設定 runtime.GOMAXPROCS(1) 讓 golang 的進程變成單線程執行的。類似python用gevent的效果。然後通過調度多個協程實現非同步I/O並發。php作為一個子函數跑在go的進程內，php需要yield到其他協程時，通過回調到golang函數來實現。從php裡調用go提供的子函數時，go保證儲存php的當前上下文。當協程執行權讓渡回來的時候，把原來的php上下文恢複。關鍵的代碼在：

// 儲存當前協程上的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)// 放棄全域的鎖，使得其他的協程可以開始執行php    engineLock.Unlock()    defer engineLock.Lock()

ServerContextGet 這幾個函數是我加的，獲得的是php的（EG/SG/PG）這三個全域context（參見：http://www.cnblogs.com/chance...）。修改過的github.com/deuill/go-php的原始碼在：https://github.com/taowen/go-...

完整的php/go混合協程的demo：

package mainimport (    "fmt"    "github.com/deuill/go-php/engine"    "os"    "runtime"    "time"    "sync")type TestObj struct{}func newTestObj(args []interface{}) interface{} {    return &TestObj{}}var engineLock *sync.Mutexfunc (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))}

執行結果是

122 enter{0x2cf2930 {<nil> <nil> <nil> 0 <nil> <nil> <nil> <nil> 0 0 0 [0 0 0 0 0] <nil> <nil> <nil> <nil> <nil> <nil> <nil> 0 0 <nil> 1000 [0 0 0 0]} {{<nil> <nil> 0 16 0x7f682e819780 0 [0 0 0 0 0 0 0] <nil>} 0 1 [0 0 0] <nil> <nil>} 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 <nil> 8388608 0 1 [0 0 0] 0 {8 7 2 [0 0 0 0] 0 0x29f4520 0x29f4520 0x29f4470 0x29f4420 <nil> 1 0 0 [0 0 0 0 0]} <nil> {0 [0 0 0 0 0 0 0] <nil> <nil> <nil> <nil>} 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 [<nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil>] 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 <nil> <nil> <nil> 0x7f682f016a00 <nil> 0 0 1 [0 0 0 0 0]} 0x7ffd30bac590 22527 0 0 [0 0 0 0] 0x7f682f197640 0x29f4f80 0x29f4fd0 0x29f5070 <nil> 0x2cf2950 0x7f682f1989c0 14 0 1 [0 0 0] <nil> <nil> 0 1 [0 0 0 0 0 0] {8 0 0 [0 0 0 0] 1 <nil> <nil> <nil> 0x7f682f016a00 0x7f682e883140 0 0 1 [0 0 0 0 0]} {8 0 0 [0 0 0 0] 0 <nil> <nil> <nil> 0x7f682f016a00 0x7f682e8831d0 1 0 0 [0 0 0 0 0]} 0x7f682f167088 0 [0 0 0 0] <nil> <nil> {0 0 <nil>} {0 0 <nil> <nil> 0 [0 0 0 0 0 0 0]} {0 0 <nil> <nil> 0 [0 0 0 0 0 0 0]} 0 [0 0 0 0] <nil> 0 0 0x29fb2e0 <nil> <nil> {0x7f682f187030 2 1024 -1 [0 0 0 0]} <nil> <nil> <nil> [{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 <nil> {0 [0 0 0 0] <nil> 0 [0 0 0 0] 0 0 [0 0 0 0] <nil> 0 [0 0 0 0] <nil>} 1 [0 0 0 0 0 0 0] <nil> 0x7f682f01bde8 895 [0 0 0 0 0 0] [<nil> <nil> <nil> <nil>]}{1 [0 0 0 0 0 0 0] 0 0 0 [0 0 0 0 0 0] <nil> 0x29ff9a0 17 134217728 -1 0 0 0 1 [0 0 0 0] 1024 0 0 1 [0 0 0 0 0] 0x2a00870 <nil> 0x2a010a0 0x7f682ecc58b0 <nil> 0x7f682ecc5c23 <nil> <nil> <nil> 2097152 <nil> <nil> 0x2a00180 0x2a00230 <nil> <nil> <nil> {0x7f682ec91aa8 0x7f682ec91aa8} 0x2a00910 {0 0 0 [0 0 0 0] 0 <nil> <nil> <nil> <nil> <nil> 0 0 0 [0 0 0 0 0]} 0 0 0 [0 0 0] {0x2b6dc10 0x2b6dc10 1 8 <nil> 1 [0 0 0 0 0 0 0] <nil>} [0x7f682f197330 0x7f682f197040 0x7f682f197410 <nil> <nil> 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] <nil> <nil> 0 [0 0 0 0] 0x2cf27c0 <nil> 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] <nil> 0 [0 0 0 0 0 0 0]}1 enter{0x7f6818000aa0 {<nil> <nil> <nil> 0 <nil> <nil> <nil> <nil> 0 0 0 [0 0 0 0 0] <nil> <nil> <nil> <nil> <nil> <nil> <nil> 0 0 <nil> 1000 [0 0 0 0]} {{<nil> <nil> 0 16 0x7f682e819780 0 [0 0 0 0 0 0 0] <nil>} 0 1 [0 0 0] <nil> <nil>} 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 <nil> 8388608 0 1 [0 0 0] 0 {8 7 2 [0 0 0 0] 0 0x29f4520 0x29f4520 0x29f4470 0x29f4420 <nil> 1 0 0 [0 0 0 0 0]} <nil> {0 [0 0 0 0 0 0 0] <nil> <nil> <nil> <nil>} 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 [<nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil>] 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 <nil> <nil> <nil> 0x7f682f016a00 <nil> 0 0 1 [0 0 0 0 0]} 0x7f682a4ccce0 22527 0 0 [0 0 0 0] 0x7f682f197d28 0x29f4f80 0x29f4fd0 0x29f5070 <nil> 0x2cf2950 0x7f682f1983e8 14 0 1 [0 0 0] <nil> <nil> 0 1 [0 0 0 0 0 0] {8 0 0 [0 0 0 0] 1 <nil> <nil> <nil> 0x7f682f016a00 0x7f682e883140 0 0 1 [0 0 0 0 0]} {8 0 0 [0 0 0 0] 0 <nil> <nil> <nil> 0x7f682f016a00 0x7f682e8831d0 1 0 0 [0 0 0 0 0]} 0x7f682802f030 0 [0 0 0 0] <nil> <nil> {0 0 <nil>} {0 0 <nil> <nil> 0 [0 0 0 0 0 0 0]} {0 0 <nil> <nil> 0 [0 0 0 0 0 0 0]} 0 [0 0 0 0] <nil> 0 0 0x29fb2e0 <nil> <nil> {0x7f682804efd8 2 1024 -1 [0 0 0 0]} <nil> <nil> <nil> [{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 <nil> {0 [0 0 0 0] <nil> 0 [0 0 0 0] 0 0 [0 0 0 0] <nil> 0 [0 0 0 0] <nil>} 1 [0 0 0 0 0 0 0] <nil> 0x7f682f01bde8 895 [0 0 0 0 0 0] [<nil> <nil> <nil> <nil>]}{1 [0 0 0 0 0 0 0] 0 0 0 [0 0 0 0 0 0] <nil> 0x29ff9a0 17 134217728 -1 0 0 0 1 [0 0 0 0] 1024 0 0 1 [0 0 0 0 0] 0x2a00870 <nil> 0x2a010a0 0x7f682ecc58b0 <nil> 0x7f682ecc5c23 <nil> <nil> <nil> 2097152 <nil> <nil> 0x2a00180 0x2a00230 <nil> <nil> <nil> {0x7f682ec91aa8 0x7f682ec91aa8} 0x2a00910 {0 0 0 [0 0 0 0] 0 <nil> <nil> <nil> <nil> <nil> 0 0 0 [0 0 0 0 0]} 0 0 0 [0 0 0] {0x2b6dc10 0x2b6dc10 1 8 <nil> 1 [0 0 0 0 0 0 0] <nil>} [0x7f682f197a58 0x7f682f198ce0 0x7f682f197b38 <nil> <nil> 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] <nil> <nil> 0 [0 0 0 0] 0x2cf27c0 <nil> 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] <nil> 0 [0 0 0 0 0 0 0]}sleep done1 back1 donesleep done2 back2 done1.00099211s

可以看到兩個sleep 1s，最終只用了1.00099211s。說明協程是並發的。

一些效能指標。走http調用後端，在i7-6700k上，用ab -n 100 -c 4 可以跑出這樣的結果

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調用後端，直接php=>go返回"hello"，則可以達到

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)

這些指標只說明了協程切換的成本。實際的收益取決於後端的http服務的延遲，如果耗時很長，通過協程並發則可以收益明顯。

這個實驗說明了可以用golang實現一個代替nginx+php-fpm的應用伺服器。並且提供了一條從php向golang遷移的平滑遷移路徑。在一個應用裡混合PHP和Go兩種語言。

並且可以通過提供golang函數給php調用的方式實現I/O的非同步化。像libcurl這樣的擴充自身是支援非同步回調的，只是php是同步的所以只給php暴露了同步的execute。有了Golang之後，可以把execute變成對非同步execute+callback的封裝，從而實現基於協程的調度。

參考資料：

• https://wiki.php.net/internal...

• http://www.cunmou.com/phpbook...

• http://www.phpinternalsbook.c...

• http://www.php-internals.com/...