go-ethereum/vendor/google.golang.org/appengine/internal/net.go
Rafael Matias 388d8ccd9f
PoC: Network simulation framework (#1555)
* simv2: wip

* simulation: exec adapter start/stop

* simulation: add node status to exec adapter

* simulation: initial simulation code

* simulation: exec adapter, configure path to executable

* simulation: initial docker adapter

* simulation: wip kubernetes adapter

* simulation: kubernetes adapter proxy

* simulation: implement GetAll/StartAll/StopAll

* simulation: kuberentes adapter - set env vars and resource limits

* simulation: discovery test

* simulation: remove port definitions within docker adapter

* simulation: simplify wait for healthy loop

* simulation: get nat ip addr from interface

* simulation: pull docker images automatically

* simulation: NodeStatus -> NodeInfo

* simulation: move discovery test to example dir

* simulation: example snapshot usage

* simulation: add goclient specific simulation

* simulation: add peer connections to snapshot

* simulation: close rpc client

* simulation: don't export kubernetes proxy server

* simulation: merge simulation code

* simulation: don't export nodemap

* simulation: rename SimulationSnapshot -> Snapshot

* simulation: linting fixes

* simulation: add k8s available helper func

* simulation: vendor

* simulation: fix 'no non-test Go files' when building

* simulation: remove errors from interface methods where non were returned

* simulation: run getHealthInfo check in parallel
2019-07-24 17:00:13 +02:00

56 lines
1.2 KiB
Go

// Copyright 2014 Google Inc. All rights reserved.
// Use of this source code is governed by the Apache 2.0
// license that can be found in the LICENSE file.
package internal
// This file implements a network dialer that limits the number of concurrent connections.
// It is only used for API calls.
import (
"log"
"net"
"runtime"
"sync"
"time"
)
var limitSem = make(chan int, 100) // TODO(dsymonds): Use environment variable.
func limitRelease() {
// non-blocking
select {
case <-limitSem:
default:
// This should not normally happen.
log.Print("appengine: unbalanced limitSem release!")
}
}
func limitDial(network, addr string) (net.Conn, error) {
limitSem <- 1
// Dial with a timeout in case the API host is MIA.
// The connection should normally be very fast.
conn, err := net.DialTimeout(network, addr, 500*time.Millisecond)
if err != nil {
limitRelease()
return nil, err
}
lc := &limitConn{Conn: conn}
runtime.SetFinalizer(lc, (*limitConn).Close) // shouldn't usually be required
return lc, nil
}
type limitConn struct {
close sync.Once
net.Conn
}
func (lc *limitConn) Close() error {
defer lc.close.Do(func() {
limitRelease()
runtime.SetFinalizer(lc, nil)
})
return lc.Conn.Close()
}