executor: add heap object can move check for hash join v2 (#55200)

ref #53127

pkg/executor/join/BUILD.bazel

@@ -79,7 +79,7 @@ go_test(
     ],
     embed = [":join"],
     flaky = True,
-    shard_count = 48,
+    shard_count = 49,
     deps = [
         "//pkg/config",
         "//pkg/domain",

pkg/executor/join/hash_join_v2.go

@@ -53,7 +53,7 @@ func IsHashJoinV2Enabled() bool {
 	// sizeOfUintptr should always equal to sizeOfUnsafePointer, because according to golang's doc,
 	// a Pointer can be converted to an uintptr. Add this check here in case in the future go runtime
 	// change this
-	return enableHashJoinV2.Load() && sizeOfUintptr >= sizeOfUnsafePointer
+	return !heapObjectsCanMove() && enableHashJoinV2.Load() && sizeOfUintptr >= sizeOfUnsafePointer
 }
 
 // SetEnableHashJoinV2 enable/disable hash join v2

pkg/executor/join/join_row_table.go

@@ -38,6 +38,9 @@ const sizeOfUintptr = int(unsafe.Sizeof(uintptr(0)))
 
 var fakeAddrPlaceHolder = []byte{0, 0, 0, 0, 0, 0, 0, 0}
 
+//go:linkname heapObjectsCanMove runtime.heapObjectsCanMove
+func heapObjectsCanMove() bool
+
 type rowTableSegment struct {
 	/*
 	   The row storage used in hash join, the layout is
@@ -108,7 +111,7 @@ func setNextRowAddress(rowStart unsafe.Pointer, nextRowAddress unsafe.Pointer) {
 	// Save unsafe.Pointer into current Row header. Generally speaking it is unsafe or even illegal in go
 	// since after save the value of unsafe.Pointer into row header, it has no pointer semantics the value
 	// in the row header may become invalid after GC. It is ok to save unsafe.Pointer so far because
-	// 1. Go has a non-moving GC(https://tip.golang.org/doc/gc-guide), which means if the object is in heap, the address will not be changed after GC
+	// 1. the check of heapObjectsCanMove makes sure that if the object is in heap, the address will not be changed after GC
 	// 2. `rowStart` only points to a valid address in `rawData`. `rawData` is a slice in `rowTableSegment`, and it will be used by multiple goroutines,
 	//    and its size will be runtime expanded, this kind of slice will always be allocated in heap
 	*(*unsafe.Pointer)(rowStart) = nextRowAddress

pkg/executor/join/join_row_table_test.go

@@ -24,6 +24,10 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+func TestHeapObjectCanMove(t *testing.T) {
+	require.Equal(t, false, heapObjectsCanMove())
+}
+
 func TestFixedOffsetInRowLayout(t *testing.T) {
 	require.Equal(t, 8, sizeOfNextPtr)
 	require.Equal(t, 8, sizeOfLengthField)