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Move signal handling code to pkg/signal.Trap

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Signed-off-by: Solomon Hykes <solomon@docker.com>
This commit is contained in:
Solomon Hykes 2014-08-05 16:32:24 +00:00
parent d745067487
commit d55e3fea72
2 changed files with 58 additions and 37 deletions
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53
pkg/signal/trap.go Normal file
View file

@ -0,0 +1,53 @@
package signal
import (
"log"
"os"
gosignal "os/signal"
"sync/atomic"
"syscall"
)
// Trap sets up a simplified signal "trap", appropriate for common
// behavior expected from a vanilla unix command-line tool in general
// (and the Docker engine in particular).
//
// * If SIGINT or SIGTERM are received, `cleanup` is called, then the process is terminated.
// * If SIGINT or SIGTERM are repeated 3 times before cleanup is complete, then cleanup is
// skipped and the process terminated directly.
// * If "DEBUG" is set in the environment, SIGQUIT causes an exit without cleanup.
//
func Trap(cleanup func()) {
c := make(chan os.Signal, 1)
signals := []os.Signal{os.Interrupt, syscall.SIGTERM}
if os.Getenv("DEBUG") == "" {
signals = append(signals, syscall.SIGQUIT)
}
gosignal.Notify(c, signals...)
go func() {
interruptCount := uint32(0)
for sig := range c {
go func(sig os.Signal) {
log.Printf("Received signal '%v', starting shutdown of docker...\n", sig)
switch sig {
case os.Interrupt, syscall.SIGTERM:
// If the user really wants to interrupt, let him do so.
if atomic.LoadUint32(&interruptCount) < 3 {
atomic.AddUint32(&interruptCount, 1)
// Initiate the cleanup only once
if atomic.LoadUint32(&interruptCount) == 1 {
// Call cleanup handler
cleanup()
} else {
return
}
} else {
log.Printf("Force shutdown of docker, interrupting cleanup\n")
}
case syscall.SIGQUIT:
}
os.Exit(128 + int(sig.(syscall.Signal)))
}(sig)
}
}()
}

42
server/init.go
View file

@ -6,15 +6,11 @@ package server
import (
"fmt"
"log"
"os"
gosignal "os/signal"
"sync/atomic"
"syscall"
"github.com/docker/docker/daemon"
"github.com/docker/docker/daemonconfig"
"github.com/docker/docker/engine"
"github.com/docker/docker/pkg/signal"
"github.com/docker/docker/utils"
)
@ -50,38 +46,10 @@ func InitServer(job *engine.Job) engine.Status {
return job.Error(err)
}
job.Logf("Setting up signal traps")
c := make(chan os.Signal, 1)
signals := []os.Signal{os.Interrupt, syscall.SIGTERM}
if os.Getenv("DEBUG") == "" {
signals = append(signals, syscall.SIGQUIT)
}
gosignal.Notify(c, signals...)
go func() {
interruptCount := uint32(0)
for sig := range c {
go func(sig os.Signal) {
log.Printf("Received signal '%v', starting shutdown of docker...\n", sig)
switch sig {
case os.Interrupt, syscall.SIGTERM:
// If the user really wants to interrupt, let him do so.
if atomic.LoadUint32(&interruptCount) < 3 {
atomic.AddUint32(&interruptCount, 1)
// Initiate the cleanup only once
if atomic.LoadUint32(&interruptCount) == 1 {
utils.RemovePidFile(srv.daemon.Config().Pidfile)
srv.Close()
} else {
return
}
} else {
log.Printf("Force shutdown of docker, interrupting cleanup\n")
}
case syscall.SIGQUIT:
}
os.Exit(128 + int(sig.(syscall.Signal)))
}(sig)
}
}()
signal.Trap(func() {
utils.RemovePidFile(srv.daemon.Config().Pidfile)
srv.Close()
})
job.Eng.Hack_SetGlobalVar("httpapi.server", srv)
job.Eng.Hack_SetGlobalVar("httpapi.daemon", srv.daemon)