在公司比较闲，让帮忙改一个奇怪的crash，没有任何log，才搞半天，发现是由于LoadLevelAsync 的Thread Loading，在乱七八糟的android机器上出现问题了，空指针，访问没有loading完的Additive场景里的东西。
下面的代码在Galaxy S4上直接crash，而且没有任何log，太恶心人了，如果项目代码一大堆，用最原始的排除法也让你累吐血
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | public class Boot : MonoBehaviour { class TestNULL { public void Test() { Debug.Log("########## Test"); } } TestNULL _test = null; void Start () { _test.Test(); //没有NullPointer异常？！ } |
整理了下，写了个Unity Plugin，准确定位空指针crash
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 | void print_stack(void* ptr){ ucontext_t *ucontext = (ucontext_t*)ptr; sigcontext& sig = ucontext->uc_mcontext; gprintf("reg[fp]: %p", sig.arm_fp); gprintf("reg[ip]: %p", sig.arm_ip); gprintf("reg[sp]: %p", sig.arm_sp); gprintf("reg[lr]: %p", sig.arm_lr); gprintf("reg[pc]: %p", sig.arm_pc); if(hasMono) { MonoDomain* domain = mono_get_root_domain(); mono_thread_attach(domain); gprintf("mono trace:"); gprintf("%s", mono_pmip((void*)sig.arm_pc)); MonoJitInfo* jit = mono_jit_info_table_find(domain, (char*)sig.arm_pc); if(jit) { uint32_t code_offset = (uint32_t)((uint8_t*)sig.arm_pc - (uint8_t*)jit->code_start); MonoDebugSourceLocation* source = mono_debug_lookup_source_location (jit->method, code_offset, domain); if (source) gprintf("\t %s:%d", source->source_file, source->row); } }}void signal_handler(int signum, siginfo_t *info, void * ptr){ if (info->si_addr == NULL) { gprintf("================NullPointerException Begin===================="); gprintf("\n"); print_stack(ptr); gprintf("\n"); gprintf("================NullPointerException End===================="); } else { gprintf("================UnKnownException Begin===================="); gprintf("\n"); print_stack(ptr); gprintf("\n"); gprintf("================UnKnownException End===================="); } signal(signum, SIG_DFL); //kill(getpid(), signum);} |
