A few simple examples of Go language test sledgehammer---

Organize the information, find the previous handwritten go language material, now paste it over.

First: Use of channel, create a random number

Package main import "FMT" Import  "Runtime" Func rand_generator_2 () chan int{out: = make (chan int) go func () {for{out< -rand. Int ()}} () return Out}func main () {rand_service_handler: = rand_generator_2 () fmt. Printf ("%d\n", <-rand_service_handler)}

Second: Implementing an example of summing through channel channels

Package MainType Nodeinterface Interface {receive (i int) run () int}type Node struct {name string in_degree int In_c H Chan int out_ch chan int inode nodeinterface}func NewNode (name string, Inode nodeinterface) *node {//Create a Node with two CH Annel return &node{name, 0, make (chan int), make (Chan int.), Inode}}func (from *node) ConnectTo (to *node) {to.in_deg ree++ go func () {i: = <-from.out_ch to.in_ch <-i} ()}func (n *node) Run () {go func () {defer func () {if x: = Recover (); X! = nil {println (n.name, "Panic with value", X) Panic (x)} println (n.    Name, "finished"); } () for N.in_degree > 0 {received: = <-n.in_ch n.inode.receive (Received) n.in_degree--} r ET: = N.inode.run () n.out_ch <-ret} ()}type doublenode struct {Data int}//creates a new Nodefunc Newdoublenode (name Stri ng, data int) *node {return NewNode (name, &doublenode{data})}func (n *doublenode) receive (i int) {}func (n *doubleno De) run () int {return n.data * 2}type sumnode struct {data int}func Newsumnode (name string) *node {return NewNode (name , &sumnode{0})}func (n *sumnode) receive (i int) {n.data + = I}func (n *sumnode) run () int {return N.data}func main ( {sum: = Newsumnode ("sum") sum. Run () for _, num: = range [5]int{1, 2, 3, 5, 6} {node: = Newdoublenode ("double", num) node. ConnectTo (sum) node. Run ()} println (<-sum.out_ch)}

  Third Example: concurrent operation of the go language, the Go language can be adapted to the CPU of the machine to achieve maximum concurrency

Package Mainimport ("FMT" "runtime") var workers = runtime. NUMCPU () type Result struct {jobname stringresultcode intresultinfo string}type Job struct {jobname stringresults chan&l t;-Result}func Main () {///GO language has this line of code at the beginning of most concurrent programs, but this line of code will eventually be superfluous,//Because the Go language runtime system becomes smart enough to automatically fit the machine runtime it runs. Gomaxprocs (runtime. NUMCPU ())//Returns the current number of processors in FMT. Println (runtime. Gomaxprocs (0))//Returns the number of logical processors or cores of the current machine FMT. Println (runtime. NUMCPU ())//simulation of 8 tasks Jobnames: = []string{"Gerry", "WCDJ", "Golang", "C + +", "Lua", "Perl", "Python", "C"}dorequest ( Jobnames)}func dorequest (jobnames []string) {//define required channels tiles jobs: = Make (chan Job, workers) Results: = Make (chan Result , Len (jobnames)) Done: = Make (chan struct{}, workers)//---------------------------------------------/* * The following is a classic framework for Go coprocessor concurrency processing *///to add tasks that require concurrent processing to Jobs ' channel go addjobs (Jobs, jobnames, results)//executes in its own goroutine//root According to the number of CPUs to start the corresponding number of goroutines from jobs scramble for the task to process for I: = 0; I < workers; i++ {Go dojobs (done, jobs)//per executes in its own goroutine}//newCreates a routine that accepts results, waits for all worker routiines to complete the result, and notifies the main Routinego awaitcompletion (done, results)// In the main routine output results processresults (results)//---------------------------------------------}func addjobs (Jobs chan<- Job, Jobnames []string, Results chan<-Result) {for _, JobName: = Range Jobnames {//Add task in channel jobs <-Job{jobnam  E, Results}}close (jobs)}func dojobs (done chan<-struct{}, Jobs <-chan job) {//Remove task in channel and calculate for job: = Range jobs {/* * Defines the type's own method to handle business logic, implementing framework and business separation */job. Do ()}//the end flag for all tasks, an empty struct slice done <-struct{}{}}//method is a class of special function func (Job Job) do () that acts on the value of a custom type. {//Prints the currently processed task name FMT. Printf ("... doing work in [%s]\n", job.jobname)//Simulation results if Job.jobname = = "Golang" {job.results <-result{job.jobname,  0, "OK"}} else {job.results <-result{job.jobname,-1, "Error"}}}func awaitcompletion (Done <-chan struct{}, results Chan Result) {for i: = 0; i < workers; i++ {<-done}close (results)}func processresults (Results <-chan Result) {fo R Result: = Range Results {Fmt. Printf ("Done:%s,%d,%s\n", Result.jobname, Result.resultcode, Result.resultinfo)}}

  Fourth: Network programming, based on go implementation ping operation, more difficult, not yet read

Copyright: The Go Authors. All rights reserved.//Use of this source code are governed by a bsd-style//license so can be found in the license file. Taken from http://golang.org/src/pkg/net/ipraw_test.gopackage pingimport ("bytes" "Errors" "NET" "OS" "Time") const (     Icmpv4echorequest = 8icmpv4echoreply = 0icmpv6echorequest = 128icmpv6echoreply = 129) type icmpmessage struct {type int//TypeCode int//codechecksum int//Checksumbody icmpmessagebody//Bo Dy}type Icmpmessagebody Interface {Len () Intmarshal () ([]byte, error)}//Marshal returns the binary enconding of the ICMP  Echo Request or//reply message M.func (M *icmpmessage) Marshal ([]byte, error) {b: = []byte{byte (M.type), Byte (M.code), 0, 0}if m.body! = nil && M.body.len ()! = 0 {MB, err: = M.body.marshal () if err! = Nil {return nil, err}b = append ( b, mb ...)} Switch M.type {case icmpv6echorequest, Icmpv6echoreply:return B, NIL}CSUMCV: = Len (b)-1//checksum CoveraGES: = UInt32 (0) for I: = 0; i < CSUMCV; i + = 2 {s + = UInt32 (b[i+1]) <<8 | UInt32 (B[i])}if csumcv&1 = 0 {s + = UInt32 (B[CSUMCV])}s = s>>16 + s&0 Xffffs = s + s>>16//place checksum back in header; Using ^= avoids the//assumption the checksum bytes is zero.b[2] ^= byte (^s & 0xFF) b[3] ^= byte (^s >> 8) return B, nil}//Parseicmpmessage parses B as an ICMP message.func parseicmpmessage (b []byte) (*icmpmessage, error) {msglen: = Le N (b) if Msglen < 4 {return nil, errors. New ("message Too Short")}m: = &icmpmessage{type:int (B[0]), Code:int (B[1]), Checksum:int (b[2]) <<8 | int (b[3]) }if Msglen > 4 {var err errorswitch m.type {case icmpv4echorequest, icmpv4echoreply, Icmpv6echorequest, icmpv6EchoReply : m.body, err = Parseicmpecho (b[4:]) if err! = Nil {return nil, Err}}}return m, nil}//Imcpecho represenets an ICMP echo req Uest or reply message body.type icmpecho struct {ID int//IDENTIFIERSEQ int//sequence numberdata []byte//Dat A}funC (P *icmpecho) Len () int {if p = = Nil {return 0}return 4 + Len (p.data)}//Marshal returns the binary enconding of the ICM P echo Request or//reply message body P.func (P *icmpecho) Marshal ([]byte, error) {b: = make ([]byte, 4+len (p.data)) b[0 ], b[1] = byte (p.id>>8), Byte (P.id&0xff) b[2], b[3] = byte (p.seq>>8), byte (p.seq&0xff) Copy (b[4:], p. Data) return B, nil}//Parseicmpecho parses B as an ICMP echo request or reply message Body.func Parseicmpecho (b []byte) (* Icmpecho, error) {bodylen: = Len (b) P: = &icmpecho{id:int (b[0]) <<8 | int (b[1]), Seq:int (b[2]) <<8 | int (b[  3])}if Bodylen > 4 {p.data = make ([]byte, bodylen-4) copy (P.data, b[4:])}return p, Nil}func Ping (address string, timeout int) (alive bool) {err: = Pinger (address, timeout) alive = Err = = Nilreturn}func Pinger (address string, timeout int) (err Error) {//dialing C, err: = Net. Dial ("ip4:icmp", address) if err! = Nil {return}//?c.setdeadline (time. Now (). ADD (time. Duration (Timeout) * time. Second)) deferC.close ()//>>typ: = Icmpv4echorequestxid, Xseq: = OS. Getpid () &0xffff, 1WB, err: = (&icmpmessage{type:typ, code:0,body: &icmpecho{id:xid, SEQ:XSEQ,DATA:BYTES.R Epeat ([]byte ("Go Go Gadget Ping!!!"), 3),},}). Marshal () if err! = Nil {Return}if _, err = C.write (WB); Err! = Nil {Return}var m *icmpmessagerb: = Make ([]byte, 20+len (WB)) for {if _, err = C.read (RB); Err! = Nil {RETURN}RB = IP V4payload (RB) if m, err = Parseicmpmessage (RB); Err! = Nil {return}switch M.type {case icmpv4echorequest, Icmpv6echorequest:continue}break}return}func ipv4Payload (b [] BYTE) []byte {if Len (b) < {return B}hdrlen: = Int (b[0]&0x0f) << 2return B[hdrlen:]}

A few simple examples of Go language test sledgehammer---