+/***************** Centralized Mutual Exclusion Algorithm *********************/
+/* This example implements a centralized mutual exclusion algorithm. */
+/* LTL property checked : !(GFcs) */
+/******************************************************************************/
+
+#include "msg/msg.h"
+#include "mc/mc.h"
+#include "xbt/automaton.h"
+#include "xbt/automatonparse_promela.h"
+#include "centralized_liveness.h"
+#include "y.tab.c"
+
+XBT_LOG_NEW_DEFAULT_CATEGORY(centralized, "my log messages");
+
+int cs = 0;
+
+int predCS(){
+ return cs;
+}
+
+
+int coordinator(int argc, char **argv);
+int client(int argc, char **argv);
+
+int coordinator(int argc, char *argv[])
+{
+ xbt_dynar_t requests = xbt_dynar_new(sizeof(char *), NULL); // dynamic vector storing requests (which are char*)
+ int CS_used = 0; // initially the CS is idle
+
+ while (1) {
+ m_task_t task = NULL;
+ MSG_task_receive(&task, "coordinator");
+ const char *kind = MSG_task_get_name(task); //is it a request or a release?
+ if (!strcmp(kind, "request")) { // that's a request
+ char *req = MSG_task_get_data(task);
+ if (CS_used) { // need to push the request in the vector
+ XBT_INFO("CS already used. Queue the request");
+ xbt_dynar_push(requests, &req);
+ } else { // can serve it immediatly
+ XBT_INFO("CS idle. Grant immediatly");
+ m_task_t answer = MSG_task_create("grant", 0, 1000, NULL);
+ MSG_task_send(answer, req);
+ CS_used = 1;
+ }
+ } else { // that's a release. Check if someone was waiting for the lock
+ 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);
+ MSG_task_send(MSG_task_create("grant", 0, 1000, NULL), req);
+ } else { // nobody wants it
+ XBT_INFO("CS release. resource now idle");
+ CS_used = 0;
+ }
+ }
+ MSG_task_destroy(task);
+ }
+
+ return 0;
+}
+
+int client(int argc, char *argv[])
+{
+ int my_pid = MSG_process_get_PID(MSG_process_self());
+ char *my_mailbox = bprintf("%s", argv[1]);
+
+ while(1){
+
+ XBT_INFO("Client (%s) asks the request", my_mailbox);
+ MSG_task_send(MSG_task_create("request", 0, 1000, my_mailbox),
+ "coordinator");
+ // wait the answer
+ m_task_t grant = NULL;
+ MSG_task_receive(&grant, my_mailbox);
+
+ MSG_task_destroy(grant);
+ XBT_INFO("Client (%s) got the answer. Sleep a bit and release it", my_mailbox);
+
+ if(!strcmp(my_mailbox, "1"))
+ cs = 1;
+
+ /*MSG_process_sleep(my_pid);
+ MSG_task_send(MSG_task_create("release", 0, 1000, NULL),
+ "coordinator");
+ XBT_INFO("Client (%s) releases the CS", my_mailbox);
+
+ if(!strcmp(my_mailbox, "1"))
+ cs = 0;*/
+
+ MSG_process_sleep(my_pid);
+
+ }
+
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ init();
+ yyparse();
+ automaton = get_automaton();
+ xbt_new_propositional_symbol(automaton,"cs", &predCS);
+
+ MSG_global_init(&argc, argv);
+ MSG_create_environment("../msg_platform.xml");
+ MSG_function_register("coordinator", coordinator);
+ MSG_function_register("client", client);
+ MSG_launch_application("deploy_centralized_liveness.xml");
+ MSG_main_liveness(automaton, argv[0]);
+
+ return 0;
+
+}
