1 /***************** Centralized Mutual Exclusion Algorithm *********************/
2 /* This example implements a centralized mutual exclusion algorithm. */
3 /* CS requests of client 1 not satisfied */
4 /* LTL property checked : G(r->F(cs)); (r=request of CS, cs=CS ok) */
5 /******************************************************************************/
9 #include "xbt/automaton.h"
10 #include "bugged1_liveness.h"
12 XBT_LOG_NEW_DEFAULT_CATEGORY(bugged1_liveness, "my log messages");
26 int coordinator(int argc, char *argv[])
28 xbt_dynar_t requests = xbt_dynar_new(sizeof(char *), NULL); // dynamic vector storing requests (which are char*)
29 int CS_used = 0; // initially the CS is idle
32 MSG_task_receive(&task, "coordinator");
33 const char *kind = MSG_task_get_name(task); //is it a request or a release?
34 if (!strcmp(kind, "request")) { // that's a request
35 char *req = MSG_task_get_data(task);
36 if (CS_used) { // need to push the request in the vector
37 XBT_INFO("CS already used. Queue the request of client %d", atoi(req) +1);
38 xbt_dynar_push(requests, &req);
39 } else { // can serve it immediatly
40 if(strcmp(req, "2") == 0){
41 m_task_t answer = MSG_task_create("grant", 0, 1000, NULL);
42 MSG_task_send(answer, req);
44 XBT_INFO("CS idle. Grant immediatly");
47 } else { // that's a release. Check if someone was waiting for the lock
48 if (xbt_dynar_length(requests) > 0) {
49 XBT_INFO("CS release. Grant to queued requests (queue size: %lu)", xbt_dynar_length(requests));
51 xbt_dynar_get_cpy(requests, (xbt_dynar_length(requests) - 1), &req);
52 if(strcmp(req, "2") == 0){
53 xbt_dynar_pop(requests, &req);
54 MSG_task_send(MSG_task_create("grant", 0, 1000, NULL), req);
56 xbt_dynar_pop(requests, &req);
57 MSG_task_send(MSG_task_create("notgrant", 0, 1000, NULL), req);
60 } else { // nobody wants it
61 XBT_INFO("CS release. resource now idle");
65 MSG_task_destroy(task);
71 int client(int argc, char *argv[])
73 int my_pid = MSG_process_get_PID(MSG_process_self());
75 char *my_mailbox = bprintf("%s", argv[1]);
77 // request the CS, sleeping a bit in between
80 XBT_INFO("Ask the request");
81 MSG_task_send(MSG_task_create("request", 0, 1000, my_mailbox), "coordinator");
83 if(strcmp(my_mailbox, "1") == 0){
86 XBT_INFO("Propositions changed : r=1, cs=0");
90 m_task_t grant = NULL;
91 MSG_task_receive(&grant, my_mailbox);
92 const char *kind = MSG_task_get_name(grant);
94 if((strcmp(my_mailbox, "1") == 0) && (strcmp("grant", kind) == 0)){
97 XBT_INFO("Propositions changed : r=0, cs=1");
101 MSG_task_destroy(grant);
102 XBT_INFO("%s got the answer. Sleep a bit and release it", argv[1]);
103 MSG_process_sleep(1);
104 MSG_task_send(MSG_task_create("release", 0, 1000, NULL), "coordinator");
106 MSG_process_sleep(my_pid);
108 if(strcmp(my_mailbox, "1") == 0){
111 XBT_INFO("Propositions changed : r=0, cs=0");
119 int main(int argc, char *argv[])
122 xbt_automaton_t a = MC_create_automaton("promela1_bugged1_liveness");
123 xbt_new_propositional_symbol(a,"r", &predR);
124 xbt_new_propositional_symbol(a,"cs", &predCS);
126 MSG_global_init(&argc, argv);
127 MSG_create_environment("../msg_platform.xml");
128 MSG_function_register("coordinator", coordinator);
129 MSG_function_register("client", client);
130 MSG_launch_application("deploy_bugged1_liveness.xml");
131 MSG_main_liveness(a);