joejulian/gio
1
0
Fork 1
mirror of https://git.sr.ht/~eliasnaur/gio synced 2026-07-07 02:15:34 +00:00
Code Issues Packages Projects Releases Wiki Activity

app: [macOS] fix display link callback race

Browse Source 
Commit c0c25b777 replaced the synchronizing of the display link callback
from a sync.Map to a cgo.Handle. However, the change didn't take into
account the lifecycle issues: a callback may happen just as the cgo.Handle
is freed, leading to a misuse crash.

This change restores the sync.Map synchronization, which avoids the
lifecycle issue.

Fixes: https://todo.sr.ht/~eliasnaur/gio/526
Signed-off-by: Elias Naur <mail@eliasnaur.com>
This commit is contained in:
Elias Naur
2023-08-22 11:01:56 -06:00
parent cc477e9ca6
commit 2e524200ab
3 changed files with 26 additions and 31 deletions
Download Patch File Download Diff File Expand all files Collapse all files
app/os_darwin.go
+18 -11
View File
@@ -6,7 +6,7 @@ package app
#include <Foundation/Foundation.h>
__attribute__ ((visibility ("hidden"))) void gio_wakeupMainThread(void);
__attribute__ ((visibility ("hidden"))) CFTypeRef gio_createDisplayLink(uintptr_t handle);
__attribute__ ((visibility ("hidden"))) CFTypeRef gio_createDisplayLink(void);
__attribute__ ((visibility ("hidden"))) void gio_releaseDisplayLink(CFTypeRef dl);
__attribute__ ((visibility ("hidden"))) int gio_startDisplayLink(CFTypeRef dl);
__attribute__ ((visibility ("hidden"))) int gio_stopDisplayLink(CFTypeRef dl);
@@ -42,7 +42,7 @@ static CFTypeRef newNSString(unichar *chars, NSUInteger length) {
import "C"
import (
"errors"
"runtime/cgo"
"sync"
"sync/atomic"
"time"
"unicode/utf16"
@@ -70,6 +70,9 @@ type displayLink struct {
running uint32
}
// displayLinks maps CFTypeRefs to *displayLinks.
var displayLinks sync.Map
var mainFuncs = make(chan func(), 1)
// runOnMain runs the function on the main thread.
@@ -128,18 +131,18 @@ func NewDisplayLink(callback func()) (*displayLink, error) {
states: make(chan bool),
dids: make(chan uint64),
}
h := cgo.NewHandle(d)
dl := C.gio_createDisplayLink(C.uintptr_t(h))
dl := C.gio_createDisplayLink()
if dl == 0 {
return nil, errors.New("app: failed to create display link")
}
go d.run(dl, h)
go d.run(dl)
return d, nil
}
func (d *displayLink) run(dl C.CFTypeRef, h cgo.Handle) {
func (d *displayLink) run(dl C.CFTypeRef) {
defer C.gio_releaseDisplayLink(dl)
defer h.Delete()
displayLinks.Store(dl, d)
defer displayLinks.Delete(dl)
var stopTimer *time.Timer
var tchan <-chan time.Time
started := false
@@ -200,10 +203,14 @@ func (d *displayLink) SetDisplayID(did uint64) {
}
//export gio_onFrameCallback
func gio_onFrameCallback(dl C.CFTypeRef, handle C.uintptr_t) {
d := cgo.Handle(handle).Value().(*displayLink)
if atomic.LoadUint32(&d.running) != 0 {
d.callback()
func gio_onFrameCallback(ref C.CFTypeRef) {
d, exists := displayLinks.Load(ref)
if !exists {
return
}
dl := d.(*displayLink)
if atomic.LoadUint32(&dl.running) != 0 {
dl.callback()
}
}