### Go 1.23

Go 1.23 changed the channels created by package time to be unbuffered
(synchronous), which makes correct use of the [`Timer.Stop`](/pkg/time/#Timer.Stop)
and [`Timer.Reset`](/pkg/time/#Timer.Reset) method results much easier.
The [`asynctimerchan` setting](/pkg/time/#NewTimer) disables this change.
There are no runtime metrics for this change,

### Timer changes

Go 1.23 makes two significant changes to the implementation of
[time.Timer] and [time.Ticker].

First, `Timer`s and `Ticker`s that are no longer referred to by the program
become eligible for garbage collection immediately, even if their
`Stop` methods have not been called.
Earlier versions of Go did not collect unstopped `Timer`s until after
they had fired and never collected unstopped `Ticker`s.

pkg archive/tar, type FileInfoNames interface, Gname() (string, error) #50102
pkg archive/tar, type FileInfoNames interface, IsDir() bool #50102
pkg archive/tar, type FileInfoNames interface, ModTime() time.Time #50102
pkg archive/tar, type FileInfoNames interface, Mode() fs.FileMode #50102
pkg archive/tar, type FileInfoNames interface, Name() string #50102
pkg archive/tar, type FileInfoNames interface, Size() int64 #50102

pkg net, type KeepAliveConfig struct #62254
pkg net, type KeepAliveConfig struct, Count int #62254
pkg net, type KeepAliveConfig struct, Enable bool #62254
pkg net, type KeepAliveConfig struct, Idle time.Duration #62254
pkg net, type KeepAliveConfig struct, Interval time.Duration #62254
pkg net, type ListenConfig struct, KeepAliveConfig KeepAliveConfig #62254
pkg syscall (windows-386), const WSAENOPROTOOPT = 10042 #62254

/src/cmd/go/internal/cfg/zdefaultcc.go
/src/cmd/internal/objabi/zbootstrap.go
/src/go/build/zcgo.go
/src/go/doc/headscan
/src/internal/buildcfg/zbootstrap.go
/src/runtime/internal/sys/zversion.go
/src/unicode/maketables
/src/time/tzdata/zzipdata.go
/test.out
/test/garbage/*.out
/test/pass.out
/test/run.out
/test/times.out

# This file includes artifacts of Go build that should not be checked in.

pkg log/slog, func NewRecord(time.Time, Level, string, uintptr) Record #56345
pkg log/slog, func NewTextHandler(io.Writer, *HandlerOptions) *TextHandler #59339
pkg log/slog, func SetDefault(*Logger) #56345
pkg log/slog, func String(string, string) Attr #56345
pkg log/slog, func StringValue(string) Value #56345
pkg log/slog, func Time(string, time.Time) Attr #56345
pkg log/slog, func TimeValue(time.Time) Value #56345

## Compiler {#compiler}

The build time overhead to building with [Profile Guided Optimization](/doc/pgo) has been reduced significantly.
Previously, large builds could see 100%+ build time increase from enabling PGO.
In Go 1.23, overhead should be in the single digit percentages.

## Assembler {#assembler}