Change of strategy, using a for loop wait

This commit is contained in:
Samuel Hawksby-Robinson 2022-10-20 16:14:09 +01:00
parent 9a7f38fcdf
commit a56e389bd1
3 changed files with 37 additions and 54 deletions

View File

@ -2,46 +2,33 @@ package server
import (
"fmt"
"sync"
"time"
"go.uber.org/zap"
)
// portManager is responsible for maintaining segregated access to the port field
// via the use of rwLock sync.RWMutex and mustRead sync.Mutex
// rwLock establishes a standard read write mutex that allows consecutive reads and exclusive writes
// mustRead forces MustGetPort to wait until port has a none 0 value
type portManger struct {
logger *zap.Logger
port int
afterPortChanged func(port int)
rwLock *sync.RWMutex
mustRead *sync.Mutex
}
// newPortManager returns a newly initialised portManager with a pre-Locked portManger.mustRead sync.Mutex
// newPortManager returns a newly initialised portManager
func newPortManager(logger *zap.Logger, afterPortChanged func(int)) portManger {
pm := portManger{
logger: logger.Named("portManger"),
afterPortChanged: afterPortChanged,
rwLock: new(sync.RWMutex),
mustRead: new(sync.Mutex),
}
pm.mustRead.Lock()
return pm
}
// SetPort sets portManger.port field to the given port value
// next triggers any given portManger.afterPortChanged function
// additionally portManger.mustRead.Unlock() is called, releasing any calls to MustGetPort
func (p *portManger) SetPort(port int) error {
l := p.logger.Named("SetPort")
l.Debug("fired", zap.Int("port", port))
p.rwLock.Lock()
defer p.rwLock.Unlock()
l.Debug("acquired rwLock.Lock")
if port == 0 {
errMsg := "port can not be `0`, use ResetPort() instead"
l.Error(errMsg)
@ -53,58 +40,41 @@ func (p *portManger) SetPort(port int) error {
l.Debug("p.afterPortChanged != nil")
p.afterPortChanged(port)
}
p.mustRead.Unlock()
l.Debug("p.mustRead.Unlock()")
return nil
}
// ResetPort attempts to reset portManger.port to 0
// if portManger.mustRead is already locked the function returns after doing nothing
// portManger.mustRead.TryLock() is called because ResetPort may be called multiple times in a row
// and calling multiple times must not cause a deadlock or an infinite hang, but the lock needs to be
// reapplied if it is not present.
// ResetPort resets portManger.port to 0
func (p *portManger) ResetPort() {
l := p.logger.Named("ResetPort")
l.Debug("fired")
p.rwLock.Lock()
defer p.rwLock.Unlock()
l.Debug("acquired rwLock.Lock")
if p.mustRead.TryLock() {
l.Debug("able to lock mustRead")
p.port = 0
return
}
l.Debug("unable to lock mustRead")
}
// GetPort gets the current value of portManager.port without any concern for the state of its value
// and therefore does not block until portManager.mustRead.Unlock() is called
// and therefore does not wait if portManager.port is 0
func (p *portManger) GetPort() int {
l := p.logger.Named("GetPort")
l.Debug("fired")
p.rwLock.RLock()
defer p.rwLock.RUnlock()
l.Debug("acquired rwLock.RLock")
return p.port
}
// MustGetPort only returns portManager.port if portManager.mustRead is unlocked.
// This presupposes that portManger.mustRead has a default state of locked and SetPort unlock portManager.mustRead
// MustGetPort only returns portManager.port if portManager.port is not 0.
func (p *portManger) MustGetPort() int {
l := p.logger.Named("MustGetPort")
l.Debug("fired")
p.mustRead.Lock()
defer p.mustRead.Unlock()
l.Debug("acquired mustRead.Lock")
p.rwLock.RLock()
defer p.rwLock.RUnlock()
l.Debug("acquired rwLock.RLock")
return p.port
for {
if p.port != 0 {
port := p.port
if port == 0 {
panic("port is zero, port has reset")
}
return port
}
l.Debug("port is zero")
time.Sleep(20 * time.Millisecond)
}
}

View File

@ -3,6 +3,7 @@ package server
import (
"crypto/ecdsa"
"crypto/rand"
"regexp"
"testing"
"github.com/stretchr/testify/suite"
@ -21,6 +22,18 @@ func (s *PairingServerSuite) SetupTest() {
s.SetupPairingServerComponents(s.T())
}
func (s *PairingServerSuite) TestMultiBackgroundForeground() {
err := s.PS.Start()
s.Require().NoError(err)
s.PS.ToBackground()
s.PS.ToForeground()
s.PS.ToBackground()
s.PS.ToBackground()
s.PS.ToForeground()
s.PS.ToForeground()
s.Require().Regexp(regexp.MustCompile("(https://192\\.168\\.0\\.\\d+:\\d+)"), s.PS.MakeBaseURL().String())
}
func (s *PairingServerSuite) TestPairingServer_StartPairing() {
// Replace PairingServer.PayloadManager with a MockEncryptOnlyPayloadManager
pm, err := NewMockEncryptOnlyPayloadManager(s.EphemeralAES)

View File

@ -43,7 +43,7 @@ func (s *ServerURLSuite) SetupTest() {
}}
go func() {
time.Sleep(waitTime)
s.serverNoPort.mustRead.Unlock()
s.serverNoPort.port = 80
}()
s.testStart = time.Now()
@ -60,12 +60,12 @@ func (s *ServerURLSuite) testNoPort(expected string, actual string) {
func (s *ServerURLSuite) TestServer_MakeBaseURL() {
s.Require().Equal("https://127.0.0.1:1337", s.server.MakeBaseURL().String())
s.testNoPort("https://127.0.0.1:0", s.serverNoPort.MakeBaseURL().String())
s.testNoPort("https://127.0.0.1:80", s.serverNoPort.MakeBaseURL().String())
}
func (s *ServerURLSuite) TestServer_MakeImageServerURL() {
s.Require().Equal("https://127.0.0.1:1337/messages/", s.server.MakeImageServerURL())
s.testNoPort("https://127.0.0.1:0/messages/", s.serverNoPort.MakeImageServerURL())
s.testNoPort("https://127.0.0.1:80/messages/", s.serverNoPort.MakeImageServerURL())
}
func (s *ServerURLSuite) TestServer_MakeIdenticonURL() {
@ -73,7 +73,7 @@ func (s *ServerURLSuite) TestServer_MakeIdenticonURL() {
"https://127.0.0.1:1337/messages/identicons?publicKey=0xdaff0d11decade",
s.server.MakeIdenticonURL("0xdaff0d11decade"))
s.testNoPort(
"https://127.0.0.1:0/messages/identicons?publicKey=0xdaff0d11decade",
"https://127.0.0.1:80/messages/identicons?publicKey=0xdaff0d11decade",
s.serverNoPort.MakeIdenticonURL("0xdaff0d11decade"))
}
@ -82,7 +82,7 @@ func (s *ServerURLSuite) TestServer_MakeImageURL() {
"https://127.0.0.1:1337/messages/images?messageId=0x10aded70ffee",
s.server.MakeImageURL("0x10aded70ffee"))
s.testNoPort(
"https://127.0.0.1:0/messages/images?messageId=0x10aded70ffee",
"https://127.0.0.1:80/messages/images?messageId=0x10aded70ffee",
s.serverNoPort.MakeImageURL("0x10aded70ffee"))
}
@ -91,7 +91,7 @@ func (s *ServerURLSuite) TestServer_MakeAudioURL() {
"https://127.0.0.1:1337/messages/audio?messageId=0xde1e7ebee71e",
s.server.MakeAudioURL("0xde1e7ebee71e"))
s.testNoPort(
"https://127.0.0.1:0/messages/audio?messageId=0xde1e7ebee71e",
"https://127.0.0.1:80/messages/audio?messageId=0xde1e7ebee71e",
s.serverNoPort.MakeAudioURL("0xde1e7ebee71e"))
}
@ -100,6 +100,6 @@ func (s *ServerURLSuite) TestServer_MakeStickerURL() {
"https://127.0.0.1:1337/ipfs?hash=0xdeadbeef4ac0",
s.server.MakeStickerURL("0xdeadbeef4ac0"))
s.testNoPort(
"https://127.0.0.1:0/ipfs?hash=0xdeadbeef4ac0",
"https://127.0.0.1:80/ipfs?hash=0xdeadbeef4ac0",
s.serverNoPort.MakeStickerURL("0xdeadbeef4ac0"))
}