Files
go-admin/common/storage/initialize.go
T
zhangwenjian 047b23872c fix🐛: let a drain that finishes on the deadline count as finished
The wait was one select over done and ctx.Done(). Both can be ready when
it runs, select picks at random among ready cases, and so a queue that
drained in the same instant the budget expired was reported as an
overrun about half the times it landed there - often enough to be read
as noise, and pointing at the wrong thing when it was not. core's own
RunShutdown re-checks for this reason; this did not.

The tie-break is now a function taking channels rather than a queue,
which is what lets a test hand it a closed done and an expired ctx
together. That state is the whole of the bug and cannot be arrived at
reliably from the outside; over 1000 iterations the single-select
version fails, and the second look does not.

The test for giving up on the deadline read the call counter straight
after shutdownQueue returned, while Shutdown runs on a goroutine nobody
joins. It passed because the goroutine is scheduled promptly, not
because anything ordered the two. The fake now signals that Shutdown has
been entered and the test waits for it.

Both raised by Copilot on #918.

The first attempt at the tie-break test was wrong and is not what
landed: it asserted that an immediately-returning Shutdown always counts
as drained under an already-expired context, which is not true and
should not be - if the goroutine has not run, nothing has drained. That
test failed, correctly. What is being claimed is narrower: when both are
ready, done wins.
2026-09-07 17:21:03 +08:00

228 lines
8.1 KiB
Go

/*
* @Author: zhangwenjian
* @Date: 2025/04/13 22:03
* @Last Modified by: zhangwenjian
* @Last Modified time: 2025/04/13 22:03
*/
package storage
import (
"context"
"log"
"sync"
"github.com/go-admin-team/go-admin-core/v2/captcha"
corelog "github.com/go-admin-team/go-admin-core/v2/logger"
"github.com/go-admin-team/go-admin-core/v2/sdk"
"github.com/go-admin-team/go-admin-core/v2/sdk/config"
)
// Setup 配置storage组件
func Setup() {
setupCache()
setupCaptcha()
setupQueue()
registerQueueDrain()
}
func setupCache() {
cacheAdapter, err := config.CacheConfig.Setup()
if err != nil {
log.Fatalf("cache setup error, %s\n", err.Error())
}
sdk.Runtime.SetCacheAdapter(cacheAdapter)
}
func setupCaptcha() {
captcha.SetStore(captcha.NewCacheStore(sdk.Runtime.GetCacheAdapter(), 600))
}
var (
queueMu sync.Mutex
// installed is the adapter setupQueue built, kept so the next reload can
// shut it down, and counted so a consumer can tell one from the next.
installed interface{ Shutdown() }
installedGen uint64
// drainRegistered records that the BeforeExit callback is on the runtime,
// so that a reload does not add another one.
drainRegistered bool
)
// setShutdown is sdk.Runtime.SetShutdown, indirected so that registering can
// be observed.
//
// It has to be: the runtime does not report how many callbacks a phase holds,
// and shutdownQueue takes the adapter on its first run, so every registration
// after the first returns immediately and changes nothing anybody can see. A
// reload adding one callback per round would therefore be invisible from the
// outside - which is exactly how it would survive.
var setShutdown = func(f func(context.Context)) { sdk.Runtime.SetShutdown(f) }
// registerQueueDrain puts shutdownQueue on the BeforeExit phase, once.
//
// Setup is one of the callbacks bootstrap.SetupConfig re-runs on every
// configuration change, so registering from it without a guard would leave one
// callback per reload - each shutting down the same adapter, each reported
// separately when the budget runs out.
//
// A flag under the existing mutex rather than a sync.Once: the tests in this
// package already save and restore installed and installedGen to keep one test
// from deciding what the next one sees, and a sync.Once cannot be put back.
func registerQueueDrain() {
queueMu.Lock()
first := !drainRegistered
drainRegistered = true
queueMu.Unlock()
if first {
setShutdown(shutdownQueue)
}
}
// drainedInTime shuts q down and reports whether it finished before ctx expired.
func drainedInTime(ctx context.Context, q interface{ Shutdown() }) bool {
done := make(chan struct{})
go func() {
defer close(done)
q.Shutdown()
}()
return finishedBeforeDeadline(ctx, done)
}
// finishedBeforeDeadline waits for done or for ctx, and resolves a tie in
// favour of done.
//
// The tie is the reason this is a function of its own rather than one select
// inline. Both channels can be ready when the select runs, select picks at
// random among ready cases, and so a single look reports an overrun for a
// drain that completed - about half the times it lands there, which is exactly
// often enough to be dismissed as noise. core's own RunShutdown re-checks for
// this reason.
//
// Taking channels rather than a queue is what makes it testable: a closed done
// and an expired ctx can be handed in together, which is the state a race
// would otherwise have to be caught in.
func finishedBeforeDeadline(ctx context.Context, done <-chan struct{}) bool {
select {
case <-done:
return true
case <-ctx.Done():
}
select {
case <-done:
return true
default:
return false
}
}
// shutdownQueue drains the queue this package installed, on the way out.
//
// Nothing used to. core's Memory.Shutdown closes the queue and waits for every
// consumer to finish what it is holding, and the legacy adapter cancels its
// context and closes the underlying queue - but neither ran at exit, so the
// process left with the login log, the operation log and the API sync still
// buffered, and left reporting success.
//
// The adapter is read here rather than captured at registration because a
// reload replaces it. Registration happens once per process; this runs against
// whatever is current when the signal arrives.
//
// Only an adapter this package installed. sdk.Runtime.GetQueueAdapter never
// returns nil - with no queue section configured the runtime wraps its own
// fallback queue - so going through that accessor would shut down a queue this
// package neither built nor started.
//
// The adapter is taken, not read: after this the package owns nothing, so a
// reload arriving mid-shutdown builds a new one instead of being handed a
// closed one to shut down again. Both implementations tolerate a second
// Shutdown, so this is about who owns it rather than about a crash.
func shutdownQueue(ctx context.Context) {
queueMu.Lock()
q := installed
installed = nil
queueMu.Unlock()
if q == nil {
return
}
if drainedInTime(ctx, q) {
corelog.Info("queue: drained")
return
}
// The wait is what the budget bounds, not the work: Shutdown takes no
// context and is still running in that goroutine. Saying so here names what
// is being lost, which the generic overrun message cannot.
corelog.Warnf("queue: the shutdown budget ran out while the queue was still draining - " +
"whatever it had not delivered goes with the process. Raise extend.shutdown.cleanup " +
"if this recurs.")
}
// QueueGeneration reports how many times this package has installed a queue
// adapter. It changes every time setupQueue builds a new one, which is on
// every configuration reload, and stays 0 for as long as the configuration has
// no queue section at all - in which case nothing is installed and callers are
// working with the runtime's own fallback queue.
//
// It exists because there is no way to ask for the adapter's identity from the
// outside. sdk.Runtime.GetQueueAdapter and GetQueuePrefix build a fresh
// runtime.Queue wrapper on every call, so comparing what two calls return
// compares two wrappers and never matches, however many times the underlying
// adapter has been replaced. This package creates the adapter, so this is the
// only place that knows. A counter rather than the adapter itself keeps the
// comparison on a uint64: an adapter type that is not comparable would panic
// an `==` between two interface values.
func QueueGeneration() uint64 {
queueMu.Lock()
defer queueMu.Unlock()
return installedGen
}
func setupQueue() {
if config.QueueConfig.Empty() {
return
}
queueMu.Lock()
defer queueMu.Unlock()
queueAdapter, err := config.QueueConfig.Setup()
if err != nil {
log.Fatalf("queue setup error, %s\n", err.Error())
}
previous := installed
sdk.Runtime.SetQueueAdapter(queueAdapter)
installed = queueAdapter
installedGen++
// The previous adapter goes down after the new one is installed, not
// before. Shutdown waits for its consumers to deliver what it still holds,
// and for that whole wait the runtime would otherwise be handing producers
// a queue that has stopped accepting: every Append in the window comes back
// ErrQueueClosed, and both call sites in common/middleware log it. Swapping
// first leaves no such window - a producer gets the new queue or the old
// one, and both work.
//
// Only an adapter this package installed. GetQueueAdapter never returns
// nil - with nothing configured the runtime falls back to its own memory
// queue and wraps that - so the `if q := GetQueueAdapter(); q != nil` this
// replaces was always true, and shut down the fallback queue on the very
// first start, before anything had used it.
if previous != nil {
previous.Shutdown()
}
// Deliberately not started here. Run has to come after the consumers have
// registered: the contract implementations refuse a registration once the
// queue is running (storage.ErrQueueAlreadyStarted), and the legacy
// adapter this repository still goes through swallows that error rather
// than reporting it - its own comment says the interface gives it no way
// to tell the caller. Starting here and registering afterwards is
// therefore a race that loses consumers in silence. Whoever registers is
// the one that starts it.
}