/*
* Forking is a relatively cheap way to create a new client. The new
* client record shares the IO descriptors. To avoid interference, we
* limit children to only produce output by closing the input-side.
*
* If the father itself is a temporary client, let the new child depend
* on the grandfather.
*/
Client
MCforkClient(Client father)
{
Client son = NULL;
str prompt;
if (father == NULL)
return NULL;
if (father->father != NULL)
father = father->father;
if((prompt = GDKstrdup(father->prompt)) == NULL)
return NULL;
if ((son = MCinitClient(father->user, father->fdin, father->fdout))) {
son->fdin = NULL;
son->fdout = father->fdout;
son->bak = NULL;
son->yycur = 0;
son->father = father;
son->scenario = father->scenario;
if (son->prompt)
GDKfree(son->prompt);
son->prompt = prompt;
son->promptlength = strlen(prompt);
/* reuse the scopes wherever possible */
if (son->usermodule == 0) {
son->usermodule = userModule();
if(son->usermodule == 0) {
MCcloseClient(son);
return NULL;
}
}
} else {
GDKfree(prompt);
}
return son;
}
/*
* This is a phtread started function. Here we start the client. We
* need to initialize and allocate space for the global variables.
* Thereafter it is up to the scenario interpreter to process input.
*/
void
MSserveClient(void *dummy)
{
MalBlkPtr mb;
Client c = (Client) dummy;
str msg = 0;
if (!isAdministrator(c) && MCinitClientThread(c) < 0) {
MCcloseClient(c);
return;
}
/*
* A stack frame is initialized to keep track of global variables.
* The scenarios are run until we finally close the last one.
*/
mb = c->curprg->def;
if (c->glb == NULL)
c->glb = newGlobalStack(MAXGLOBALS + mb->vsize);
if (c->glb == NULL) {
showException(c->fdout, MAL, "serveClient", MAL_MALLOC_FAIL);
c->mode = FINISHCLIENT + 1; /* == RUNCLIENT */
} else {
c->glb->stktop = mb->vtop;
c->glb->blk = mb;
}
if (c->scenario == 0)
msg = defaultScenario(c);
if (msg) {
showException(c->fdout, MAL, "serveClient", "could not initialize default scenario");
c->mode = FINISHCLIENT + 1; /* == RUNCLIENT */
GDKfree(msg);
} else {
do {
do {
runScenario(c);
if (c->mode == FINISHCLIENT)
break;
resetScenario(c);
} while (c->scenario && !GDKexiting());
} while (c->scenario && c->mode != FINISHCLIENT && !GDKexiting());
}
/* pre announce our exiting: cleaning up may take a while and we
* don't want to get killed during that time for fear of
* deadlocks */
MT_exiting_thread();
/*
* At this stage we should clean out the MAL block
*/
freeMalBlk(c->curprg->def);
c->curprg->def = 0;
if (c->mode > FINISHCLIENT) {
if (isAdministrator(c) /* && moreClients(0)==0 */) {
if (c->scenario) {
exitScenario(c);
}
}
}
if (!isAdministrator(c))
MCcloseClient(c);
}