/* create and schedule a new lua process */
static int luaproc_create_newproc( lua_State *L ) {
size_t len;
luaproc *lp;
luaL_Buffer buff;
const char *code;
int d;
int lt = lua_type( L, 1 );
/* check function argument type - must be function or string; in case it is
a function, dump it into a binary string */
if ( lt == LUA_TFUNCTION ) {
lua_settop( L, 1 );
luaL_buffinit( L, &buff );
d = dump( L, luaproc_buff_writer, &buff, FALSE );
if ( d != 0 ) {
lua_pushnil( L );
lua_pushfstring( L, "error %d dumping function to binary string", d );
return 2;
}
luaL_pushresult( &buff );
lua_insert( L, 1 );
} else if ( lt != LUA_TSTRING ) {
lua_pushnil( L );
lua_pushfstring( L, "cannot use '%s' to create a new process",
luaL_typename( L, 1 ));
return 2;
}
/* get pointer to code string */
code = lua_tolstring( L, 1, &len );
/* get exclusive access to recycled lua processes list */
pthread_mutex_lock( &mutex_recycle_list );
/* check if a lua process can be recycled */
if ( recyclemax > 0 ) {
lp = list_remove( &recycle_list );
/* otherwise create a new lua process */
if ( lp == NULL ) {
lp = luaproc_new( L );
}
} else {
lp = luaproc_new( L );
}
/* release exclusive access to recycled lua processes list */
pthread_mutex_unlock( &mutex_recycle_list );
/* init lua process */
lp->status = LUAPROC_STATUS_IDLE;
lp->args = 0;
lp->chan = NULL;
/* load code in lua process */
luaproc_loadbuffer( L, lp, code, len );
/* if lua process is being created from a function, copy its upvalues and
remove dumped binary string from stack */
if ( lt == LUA_TFUNCTION ) {
if ( luaproc_copyupvalues( L, lp->lstate, 2 ) == FALSE ) {
luaproc_recycle_insert( lp );
return 2;
}
lua_pop( L, 1 );
}
sched_inc_lpcount(); /* increase active lua process count */
sched_queue_proc( lp ); /* schedule lua process for execution */
lua_pushboolean( L, TRUE );
return 1;
}
/* worker thread main function */
void *workermain( void *args ) {
luaproc *lp;
int procstat;
/* main worker loop */
while ( TRUE ) {
/*
wait until instructed to wake up (because there's work to do
or because workers must be destroyed)
*/
pthread_mutex_lock( &mutex_sched );
while (( list_count( &ready_lp_list ) == 0 ) && ( destroyworkers <= 0 )) {
pthread_cond_wait( &cond_wakeup_worker, &mutex_sched );
}
if ( destroyworkers > 0 ) { /* check whether workers should be destroyed */
destroyworkers--; /* decrease workers to be destroyed count */
workerscount--; /* decrease active workers count */
/* remove worker from workers table */
lua_getglobal( workerls, LUAPROC_SCHED_WORKERS_TABLE );
lua_pushlightuserdata( workerls, (void *)pthread_self( ));
lua_pushnil( workerls );
lua_rawset( workerls, -3 );
lua_pop( workerls, 1 );
pthread_cond_signal( &cond_wakeup_worker ); /* wake other workers up */
pthread_mutex_unlock( &mutex_sched );
pthread_exit( NULL ); /* destroy itself */
}
/* remove lua process from the ready queue */
lp = list_remove( &ready_lp_list );
pthread_mutex_unlock( &mutex_sched );
/* execute the lua code specified in the lua process struct */
procstat = luaproc_resume( luaproc_get_state( lp ), NULL,
luaproc_get_numargs( lp ));
/* reset the process argument count */
luaproc_set_numargs( lp, 0 );
/* has the lua process sucessfully finished its execution? */
if ( procstat == 0 ) {
luaproc_set_status( lp, LUAPROC_STATUS_FINISHED );
luaproc_recycle_insert( lp ); /* try to recycle finished lua process */
sched_dec_lpcount(); /* decrease active lua process count */
}
/* has the lua process yielded? */
else if ( procstat == LUA_YIELD ) {
/* yield attempting to send a message */
if ( luaproc_get_status( lp ) == LUAPROC_STATUS_BLOCKED_SEND ) {
luaproc_queue_sender( lp ); /* queue lua process on channel */
/* unlock channel */
luaproc_unlock_channel( luaproc_get_channel( lp ));
}
/* yield attempting to receive a message */
else if ( luaproc_get_status( lp ) == LUAPROC_STATUS_BLOCKED_RECV ) {
luaproc_queue_receiver( lp ); /* queue lua process on channel */
/* unlock channel */
luaproc_unlock_channel( luaproc_get_channel( lp ));
}
/* yield on explicit coroutine.yield call */
else {
/* re-insert the job at the end of the ready process queue */
pthread_mutex_lock( &mutex_sched );
list_insert( &ready_lp_list, lp );
pthread_mutex_unlock( &mutex_sched );
}
}
/* or was there an error executing the lua process? */
else {
/* print error message */
fprintf( stderr, "close lua_State (error: %s)\n",
luaL_checkstring( luaproc_get_state( lp ), -1 ));
lua_close( luaproc_get_state( lp )); /* close lua state */
sched_dec_lpcount(); /* decrease active lua process count */
}
}
}
