My program crashed 1 time within 1000 times. Here is the debug information and stack:
437
new map 0 -603977536
address&{[<nil> 0x7fafdc0009f0 0x7fafdc000b00]} 0x7fafdc0008c0 0x7fafdc0008c8 0x7fafdc0008d0
&{1 0 0x7fafdc000900} &{1 0 0x7fafdc000a10} &{1 0 0x7fafdc000b20}
rgc map finish
438
new map 0 -603977536
address&{[<nil> 0x7fafdc0009f0 0x7fafdc000b00]} 0x7fafdc0008c0 0x7fafdc0008c8 0x7fafdc0008d0
&{1 0 0x7fafdc000900} &{1 0 0x7fafdc000a10} &{1 0 0x7fafdc000b20}
rgc map finish
439
new map 0 -603977536
address&{[<nil> 0x7fafdc0009f0 0x7fafdc000b00]} 0x7fafdc0008c0 0x7fafdc0008c8 0x7fafdc0008d0
&{1 0 0x7fafdc000900} &{1 0 0x7fafdc000a10} &{1 0 0x7fafdc000b20}
rgc map finish
440
new map 0 -603977536
address&{[<nil> 0x7fafdc0009f0 0x7fafdc000b00]} 0x7fafdc0008c0 0x7fafdc0008c8 0x7fafdc0008d0
&{1 0 0x7fafdc000900} &{1 0 0x7fafdc000a10} &{1 0 0x7fafdc000b20}
rgc map finish
441
new map 0 -536868672
fatal error: bad pointer in write barrier
runtime stack:
runtime.throw(0x53d200, 0x1c)
/home/map/.jumbo/lib/go/src/runtime/panic.go:530 +0x90
runtime.writebarrierptr_nostore.func1()
/home/map/.jumbo/lib/go/src/runtime/mbarrier.go:157 +0x2c
runtime.systemstack(0xc820024a00)
/home/map/.jumbo/lib/go/src/runtime/asm_amd64.s:291 +0x79
runtime.mstart()
/home/map/.jumbo/lib/go/src/runtime/proc.go:1048
goroutine 1 [running]:
runtime.systemstack_switch()
/home/map/.jumbo/lib/go/src/runtime/asm_amd64.s:245 fp=0xc82009ebd8 sp=0xc82009ebd0
runtime.writebarrierptr_nostore(0xc82030e010, 0x20)
/home/map/.jumbo/lib/go/src/runtime/mbarrier.go:157 +0x83 fp=0xc82009ebf0 sp=0xc82009ebd8
runtime.heapBitsBulkBarrier(0xc82030e000, 0x18)
/home/map/.jumbo/lib/go/src/runtime/mbitmap.go:437 +0x201 fp=0xc82009ec88 sp=0xc82009ebf0
runtime.typedmemmove(0x4fa700, 0xc82030e000, 0x7fafe00008c0)
/home/map/.jumbo/lib/go/src/runtime/mbarrier.go:197 +0x98 fp=0xc82009ecb8 sp=0xc82009ec88
reflect.typedmemmove(0x4fa700, 0xc82030e000, 0x7fafe00008c0)
/home/map/.jumbo/lib/go/src/runtime/mbarrier.go:202 +0x35 fp=0xc82009ecd8 sp=0xc82009ecb8
reflect.packEface(0x4fa700, 0x7fafe00008c0, 0x199, 0x0, 0x0)
/home/map/.jumbo/lib/go/src/reflect/value.go:113 +0x120 fp=0xc82009ed48 sp=0xc82009ecd8
reflect.valueInterface(0x4fa700, 0x7fafe00008c0, 0x199, 0x1, 0x0, 0x0)
/home/map/.jumbo/lib/go/src/reflect/value.go:938 +0x1ec fp=0xc82009eda0 sp=0xc82009ed48
reflect.Value.Interface(0x4fa700, 0x7fafe00008c0, 0x199, 0x0, 0x0)
/home/map/.jumbo/lib/go/src/reflect/value.go:908 +0x48 fp=0xc82009edd8 sp=0xc82009eda0
fmt.(*pp).printValue(0xc82040b380, 0x4fa700, 0x7fafe00008c0, 0x199, 0x7faf00000076, 0x1, 0x0)
/home/map/.jumbo/lib/go/src/fmt/print.go:842 +0x372 fp=0xc82009eec8 sp=0xc82009edd8
fmt.(*pp).printReflectValue(0xc82040b380, 0x4cc980, 0x7fafe00008c0, 0x16, 0x76, 0x0, 0xc82001cd00)
/home/map/.jumbo/lib/go/src/fmt/print.go:1009 +0x351e fp=0xc82009f680 sp=0xc82009eec8
fmt.(*pp).printArg(0xc82040b380, 0x4cc980, 0x7fafe00008c0, 0x76, 0x0, 0xc82009f800)
/home/map/.jumbo/lib/go/src/fmt/print.go:810 +0x540 fp=0xc82009f808 sp=0xc82009f680
fmt.(*pp).doPrint(0xc82040b380, 0xc82009fdf8, 0x2, 0x2, 0x400000)
/home/map/.jumbo/lib/go/src/fmt/print.go:1273 +0x24d fp=0xc82009f908 sp=0xc82009f808
fmt.Fprint(0x7faff5a401c0, 0xc820036010, 0xc82009fdf8, 0x2, 0x2, 0x40d75e, 0x0, 0x0)
/home/map/.jumbo/lib/go/src/fmt/print.go:222 +0x67 fp=0xc82009f950 sp=0xc82009f908
fmt.Print(0xc82009fdf8, 0x2, 0x2, 0x4d6ac0, 0x0, 0x0)
/home/map/.jumbo/lib/go/src/fmt/print.go:232 +0x73 fp=0xc82009f9a8 sp=0xc82009f950
services/newrgc.GetRgcService(0x54cb60, 0x49, 0xc8200aa330, 0x0, 0x0)
/home/map/zhanghuaizhi/tmpwork/2/nbserver/src/services/newrgc/mrgc.go:78 +0x390 fp=0xc82009fea0 sp=0xc82009f9a8
main.main()
/home/map/zhanghuaizhi/tmpwork/2/nbserver/src/services/newrgc/test/ttt.go:219 +0x163 fp=0xc82009ff40 sp=0xc82009fea0
runtime.main()
/home/map/.jumbo/lib/go/src/runtime/proc.go:188 +0x2b0 fp=0xc82009ff90 sp=0xc82009ff40
runtime.goexit()
/home/map/.jumbo/lib/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc82009ff98 sp=0xc82009ff90
goroutine 17 [syscall, locked to thread]:
runtime.goexit()
/home/map/.jumbo/lib/go/src/runtime/asm_amd64.s:1998 +0x1
The deug information is before the stack log. 437 means the 437th loop, new map 0 -603977536 is printed in C Code(NewRgcMap, the details can be found in the following content), the next two lines
address&{[<nil> 0x7fafdc0009f0 0x7fafdc000b00]} 0x7fafdc0008c0 0x7fafdc0008c8 0x7fafdc0008d0
&{1 0 0x7fafdc000900} &{1 0 0x7fafdc000a10} &{1 0 0x7fafdc000b20} is printed in Go Code(GO code line 78 and 80).
From the stack information, we can find that the error occurs in line 78. Now here is the Go code(mrgc.go)
30 type RgcService struct {
31 maps *C.struct_CRgcMap
32 }
74 func GetRgcService(cfgFile string) (svc *RgcService, err error) {
75 svc = new(RgcService)
76 // Init the skip list
77 C.NewRgcMap(&svc.maps)
78 fmt.Print("address", svc.maps)
79 //fmt.Println("\t", svc.maps.sl[0], svc.maps.sl[1], svc.maps.sl[2])
80 fmt.Println("\t", &svc.maps.sl[0], &svc.maps.sl[1], &svc.maps.sl[2])
81 C.skiplist_init(unsafe.Pointer(&svc.maps.sl[0]))
82 C.skiplist_init(unsafe.Pointer(&svc.maps.sl[1]))
83 C.skiplist_init(unsafe.Pointer(&svc.maps.sl[2]))
84 fmt.Println("\t", svc.maps.sl[0], svc.maps.sl[1], svc.maps.sl[2])
So, I probably guess the error happens because of the failure of C.NewRgcMap(&svc.maps). However, in my c code, the funciotn NewRgcMap is:
39 void NewRgcMap(CRgcMap** rgcmap) {
40 *rgcmap = NULL;
41 printf("new map %d\t", *rgcmap);
42 *rgcmap = (CRgcMap*)malloc(sizeof(CRgcMap));
43 printf("%d
", *rgcmap);
44 while(*rgcmap == NULL) {
45 *rgcmap = (CRgcMap*)malloc(sizeof(CRgcMap));
46 }
which means the rgcmap must be allocated correctly.
Another point is, from my debug information, I found that the program crashed when the log new map 0 -603977536 is changed to new map -536868672 at the first time. In more details, the debug log is exactly the same when the program crashed. new map 0 xxxxx1 shows a number of time, then when it changed to new map 0 xxxxx2, it MAY crashes(most of the time, it will not)
How to explain this crash? Moreover, I have used valgrind to test C code(Following is my C test codes)
int main() {
CRgcMap map;
int num = 0;
for(num = 0; num < 10000; num++) {
skiplist_init(&map.sl[0]);
skiplist_init(&map.sl[1]);
skiplist_init(&map.sl[2]);
int i = 0;
for(i = 0; i < 100; i++) {
skiplist_insert(map.sl[0], i, i);
skiplist_insert(map.sl[1], i, i);
//skiplist_insert(map.sl[2], i, i);
}
skiplist_test(map.sl[0]);
skiplist_test(map.sl[1]);
skiplist_test(map.sl[2]);
}
}
The report of valgrind shows that there is no memory leaks and everything is okay. But why it MAY crashes when using Golang? Is there anything related Go's GC? Or the address allocated by C is out of the space of Golang?
