+/***************** Centralized Mutual Exclusion Algorithm *********************/
+/* This example implements a centralized mutual exclusion algorithm. */
+/* CS requests of client 1 not satisfied */
+/* LTL property checked : G(r->F(cs)); (r=request of CS, cs=CS ok) */
+/******************************************************************************/
+
+#include "msg/msg.h"
+#include "mc/mc.h"
+#include "xbt/automaton.h"
+#include "xbt/automatonparse_promela.h"
+#include "bugged1_liveness.h"
+#include "y.tab.c"
+
+XBT_LOG_NEW_DEFAULT_CATEGORY(bugged1_liveness, "my log messages");
+
+int r=0;
+int cs=0;
+
+int predR(){
+ return r;
+}
+
+int predCS(){
+ return cs;
+}
+
+
+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 of client %d", atoi(req) +1);
+ xbt_dynar_push(requests, &req);
+ } else { // can serve it immediatly
+ if(strcmp(req, "2") == 0){
+ m_task_t answer = MSG_task_create("grant", 0, 1000, NULL);
+ MSG_task_send(answer, req);
+ CS_used = 1;
+ XBT_INFO("CS idle. Grant immediatly");
+ }
+ }
+ } else { // that's a release. Check if someone was waiting for the lock
+ if (xbt_dynar_length(requests) > 0) {
+ XBT_INFO("CS release. Grant to queued requests (queue size: %lu)", xbt_dynar_length(requests));
+ char *req ;
+ xbt_dynar_get_cpy(requests, (xbt_dynar_length(requests) - 1), &req);
+ if(strcmp(req, "2") == 0){
+ xbt_dynar_pop(requests, &req);
+ MSG_task_send(MSG_task_create("grant", 0, 1000, NULL), req);
+ }else{
+ xbt_dynar_pop(requests, &req);
+ MSG_task_send(MSG_task_create("notgrant", 0, 1000, NULL), req);
+ CS_used = 0;
+ }
+ } 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]);
+
+ // request the CS, sleeping a bit in between
+ while(1) {
+
+ XBT_INFO("Ask the request");
+ MSG_task_send(MSG_task_create("request", 0, 1000, my_mailbox), "coordinator");
+
+ if(strcmp(my_mailbox, "1") == 0){
+ r = 1;
+ cs = 0;
+ XBT_DEBUG("Propositions changed : r=1, cs=0");
+ }
+
+ // wait the answer
+ m_task_t grant = NULL;
+ MSG_task_receive(&grant, my_mailbox);
+ const char *kind = MSG_task_get_name(grant);
+
+ if((strcmp(my_mailbox, "1") == 0) && (strcmp("grant", kind) == 0)){
+ cs = 1;
+ r = 0;
+ XBT_DEBUG("Propositions changed : r=0, cs=1");
+ }
+
+
+ MSG_task_destroy(grant);
+ XBT_INFO("%s got the answer. Sleep a bit and release it", argv[1]);
+ MSG_process_sleep(1);
+ MSG_task_send(MSG_task_create("release", 0, 1000, NULL), "coordinator");
+
+ MSG_process_sleep(my_pid);
+
+ if(strcmp(my_mailbox, "1") == 0){
+ cs=0;
+ r=0;
+ XBT_DEBUG("Propositions changed : r=0, cs=0");
+ }
+
+ }
+
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ init();
+ yyparse();
+ automaton = get_automaton();
+ xbt_new_propositional_symbol(automaton,"r", &predR);
+ 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_bugged1_liveness.xml");
+ MSG_main_liveness(automaton, argv[0]);
+
+ return 0;
+}