Golang concurrency Goroutine method of Use

This is a creation in Article, where the information may have evolved or changed.

2013-12-08 WCDJ

In the Go language, you use Goroutine (a lightweight thread managed by the Go Runtime) to implement concurrent programs.

Go f (x, Y, z)

Starts a new goroutine running

f (x, Y, z)

The evaluation of,, f x y , and z happens in the current goroutine and the execution of f happens in the New Goroutine.

Goroutines run in the same address space, so access to shared memory must is synchronized. syncThe package provides useful primitives, although you won ' t need them much in Go as there is other primitives. (See the next slide, Channelshttp://tour.golang.org/#64)

A simple test case:

Package Mainimport ("FMT" "Time") Func main () {//A goroutine are a lightweight thread managed by the Go runtime//Goroutine s run in the same address space, so access to shared memory must is Synchronizedgo say ("World") Say ("Hello") fmt. Println ("---------------1") A: = []int{7, 2, 8,-9, 4, 0}//Channels is a typed conduit through which you can send and rec Eive values with the channel operator, <-//by default, sends and receives blocks until the other side are ready.  This allows Goroutines to synchronize without explicit locks or condition Variablesc: = make (chan int) go sum (A[:len (a)/2), c) Go sum (A[len (a)/2:], c) x, y: = <-c, <-c//Receive from CFMT. Println (x, y, x+y) fmt. Println ("---------------2")//Channels can be buffered. Provide the buffer length as the second argument to do to initialize a buffered CHANNELC2: = Make (chan int, 2) C2 <-1 C2 <-2//c2 <-3//error, the send buffer is full that would causes deadlock!fmt. Println (&LT;-C2) fmt. Println (&LT;-C2)//fmt. Println (&LT;-C2)//error, the receive buffer is empty that would causes deadlock too!fmt. Println ("---------------3") C3: = Make (chan int, ten) Go Fibonacci (Cap (C3), C3) for I: = range C3 {Fmt. Println (i)}fmt. Println ("---------------4") C4: = make (chan int) Quit: = Do (chan int) go func () {for i: = 0; i <; i++ {FMT. Println (&LT;-C4)}quit <-0} () fibonacci2 (C4, quit) fmt. Println ("---------------5")//The default case in a select was run if no other case was ready//use a default case to try a Send or receive without blockingtick: = time. Tick (time.millisecond) Boom: = time. After ($ * time.millisecond) for {select {case <-tick:fmt. Println ("tick.") Case <-boom:fmt. Println ("boom!") Returndefault:fmt. Println (".") Time. Sleep (Time.millisecond)}}}func say (s string) {for I: = 0; i < 5; i++ {time. Sleep (Time.millisecond) fmt. Println (s)}}func sum (a []int, C Chan int) {sum: = 0for _, V: = range a {sum + = v}c <-sum//Send sum to C}func Fibonac CI (n int, c Chan int) {x, Y: = 0, 1for i:= 0; I < n; i++ {c <-xx, y = y, x+y}//note:only the sender should close a channel, never the receiver. Sending on a closed channel would cause a panic//another note:channels aren ' t like files; You don ' t usually need to close them. Closing is only necessary when the receiver must be told there is no more values coming, such as to terminate a range loo Pclose (c)}//The SELECT statement lets a goroutine wait on multiple communication operations//a select blocks until one o F its cases can run and then it executes. It chooses one at random if multiple is Readyfunc fibonacci2 (c, quit Chan int) {x, Y: = 0, 1for {select {Case c <-x:x , y = y, x+ycase <-quit:fmt. Println ("Quit") Return}}}/*output:helloworldhelloworldhelloworldhelloworldhello---------------1world17-5----- ----------212---------------30112358132134---------------40112358132134quit---------------5   .    . Tick.     .   . Tick.     .   . Tick.     .   . Tick.     .   . boom!*/