fix: use global var _KeepAlive to notice GC in shadow funcs (#145)

Co-authored-by: duanyi.aster <duanyi.aster@bytedance.com>

decoder/pools.go

@@ -60,17 +60,35 @@ type _Decoder func(
     fv uint64,
 ) (int, error)
 
+var _KeepAlive struct {
+    s string
+    i int
+    vp unsafe.Pointer
+    sb *_Stack
+    fv uint64
+    ret int
+    err error
+    frame [_FP_offs]byte
+}
+
 var errCallShadow = errors.New("DON'T CALL THIS!")
 
 //go:nosplit
 // Faker func of _Decoder, used to export its stackmap as _Decoder's
-func _Decoder_Shadow(s string, i int, vp unsafe.Pointer, sb *_Stack, fv uint64) (int, error) {
+func _Decoder_Shadow(s string, i int, vp unsafe.Pointer, sb *_Stack, fv uint64) (ret int, err error) {
     // align to assembler_amd64.go: _FP_offs
-    var stacks [_FP_offs]byte
-    runtime.KeepAlive(stacks)
+    var frame [_FP_offs]byte
+
+    // keep all args and stacks alive
+    _KeepAlive.s = s
+    _KeepAlive.i = i
+    _KeepAlive.vp = vp
+    _KeepAlive.sb = sb
+    _KeepAlive.fv = fv
+    _KeepAlive.ret = ret
+    _KeepAlive.err = err
+    _KeepAlive.frame = frame
 
-    // must keep sb noticeable to GC
-    runtime.KeepAlive(sb)
     return 0, errCallShadow
 }
 

decoder/stubs.go

@@ -1,3 +1,4 @@
+
 /*
  * Copyright 2021 ByteDance Inc.
  *

encoder/debug.go

@@ -26,7 +26,7 @@ import (
 )
 
 var (
-    debugSyncGC  = os.Getenv("SONIC_SYNC_GC")  != ""
+    debugSyncGC  = os.Getenv("SONIC_SYNC_GC") != ""
     debugAsyncGC = os.Getenv("SONIC_NO_ASYNC_GC") == ""
 )
 

encoder/pools.go

@@ -18,10 +18,9 @@ package encoder
 
 import (
     `bytes`
-    `errors`
-    `runtime`
     `sync`
     `unsafe`
+    `errors`
 
     `github.com/bytedance/sonic/internal/caching`
     `github.com/bytedance/sonic/internal/rt`
@@ -58,24 +57,34 @@ type _Encoder func(
     fv uint64,
 ) error
 
+var _KeepAlive struct {
+    rb *[]byte
+    vp unsafe.Pointer
+    sb *_Stack
+    fv uint64
+    err error
+    frame [_FP_offs]byte
+}
+
 var errCallShadow = errors.New("DON'T CALL THIS!")
 
 // Faker func of _Encoder, used to export its stackmap as _Encoder's
 //go:nosplit
-func _Encoder_Shadow(rb *[]byte, vp unsafe.Pointer, sb *_Stack, fv uint64) error {
+func _Encoder_Shadow(rb *[]byte, vp unsafe.Pointer, sb *_Stack, fv uint64) (err error) {
     // align to assembler_amd64.go: _FP_offs
-    var frames [_FP_offs]byte
-    runtime.KeepAlive(frames)
+    var frame [_FP_offs]byte
 
-    // must keep sb noticeable to GC
-    runtime.KeepAlive(sb)
-    runtime.KeepAlive(rb)
-    runtime.KeepAlive(vp)
+    // must keep all args and frames noticeable to GC
+    _KeepAlive.rb = rb
+    _KeepAlive.vp = vp
+    _KeepAlive.sb = sb
+    _KeepAlive.fv = fv
+    _KeepAlive.err = err
+    _KeepAlive.frame = frame
 
     return errCallShadow
 }
 
-
 func newBytes() []byte {
     if ret := bytesPool.Get(); ret != nil {
         return ret.([]byte)