/***************** Centralized Mutual Exclusion Algorithm *********************/
/* This example implements a centralized mutual exclusion algorithm. */
-/* CS requests of client 1 not satisfied */
+/* Bug : CS requests of client 1 not satisfied */
/* LTL property checked : G(r->F(cs)); (r=request of CS, cs=CS ok) */
/******************************************************************************/
{
int CS_used = 0;
- msg_task_t task = NULL, answer = NULL;
+ msg_task_t task = NULL, answer = NULL;
+ xbt_dynar_t requests = xbt_dynar_new(sizeof(char *), NULL);
while(1){
MSG_task_receive(&task, "coordinator");
if (!strcmp(kind, "request")) {
char *req = MSG_task_get_data(task);
if (CS_used) {
- XBT_INFO("CS already used.");
+ XBT_INFO("CS already used. Queue the request.");
+ xbt_dynar_push(requests, &req);
} else {
if(strcmp(req, "1") != 0){
XBT_INFO("CS idle. Grant immediatly");
answer = NULL;
}
}
- } else {
- XBT_INFO("CS release. resource now idle");
- CS_used = 0;
+ } else {
+ if (!xbt_dynar_is_empty(requests)) {
+ XBT_INFO("CS release. Grant to queued requests (queue size: %lu)", xbt_dynar_length(requests));
+ char *req;
+ xbt_dynar_pop(requests, &req);
+ if(strcmp(req, "1") != 0){
+ MSG_task_send(MSG_task_create("grant", 0, 1000, NULL), req);
+ }else{
+ xbt_dynar_push(requests, &req);
+ }
+ }else{
+ XBT_INFO("CS release. resource now idle");
+ CS_used = 0;
+ }
}
MSG_task_destroy(task);
task = NULL;