windows lua 多线程 线程同步
今天在改一个程序,改成部分逻辑用lua写,这个程序是多线程的。将程序中部分逻辑改成lua之后,各种非法访问内存错误,各种奇奇怪怪的问题,不分时间,不分地点的出现崩溃。从调用堆栈来看,基本都是使用lua造成的。在多线程中使用lua_newthread得到的lus_State仍然有时候程序会崩溃。基本上可以确定为多线程中操作lua 的问题了。
前几天我转载的一篇文章,文章写了关于lua多线程的作法。作法有二
1.每一个线程函数用lua_newthread产生一个新的lua_state 以后对lua操作都用这个lua_state
2.修改lua源码使之成为支持多线程的(修改lua 源代码中lua_lock lua_unlock宏)
对于第2条,那篇文中的例子是用 pthread_mutex_t 来进行线程同步的pthread_mutex_t,我对pthread_mutex_t 不熟,网上一查才知道一般是在linux下C语言进行线程同步用的,在windows下面一般多线程都用CRITICAL_SECTION,和内核对象来进行线程同步的。于是产生了这篇文章。
修改代码如下:
1.global_State加一个成员变量 m_cs
- typedef struct global_State {
- stringtable strt; /* hash table for strings */
- lua_Alloc frealloc; /* function to reallocate memory */
- void *ud; /* auxiliary data to `frealloc' */
- lu_byte currentwhite;
- lu_byte gcstate; /* state of garbage collector */
- int sweepstrgc; /* position of sweep in `strt' */
- GCObject *rootgc; /* list of all collectable objects */
- GCObject **sweepgc; /* position of sweep in `rootgc' */
- GCObject *gray; /* list of gray objects */
- GCObject *grayagain; /* list of objects to be traversed atomically */
- GCObject *weak; /* list of weak tables (to be cleared) */
- GCObject *tmudata; /* last element of list of userdata to be GC */
- Mbuffer buff; /* temporary buffer for string concatentation */
- lu_mem GCthreshold;
- lu_mem totalbytes; /* number of bytes currently allocated */
- lu_mem estimate; /* an estimate of number of bytes actually in use */
- lu_mem gcdept; /* how much GC is `behind schedule' */
- int gcpause; /* size of pause between successive GCs */
- int gcstepmul; /* GC `granularity' */
- lua_CFunction panic; /* to be called in unprotected errors */
- TValue l_registry;
- struct lua_State *mainthread;
- UpVal uvhead; /* head of double-linked list of all open upvalues */
- struct Table *mt[NUM_TAGS]; /* metatables for basic types */
- TString *tmname[TM_N]; /* array with tag-method names */
- CRITICAL_SECTION m_cs; /*windows mutithread */
- } global_State;