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 "xbt/automatonparse_promela.h"
11 #include "bugged1_liveness.h"
14 #define AMOUNT_OF_CLIENTS 2
15 #define CS_PER_PROCESS 2
17 XBT_LOG_NEW_DEFAULT_CATEGORY(bugged1_liveness, "my log messages");
32 int coordinator(int argc, char *argv[])
34 xbt_dynar_t requests = xbt_dynar_new(sizeof(char *), NULL); // dynamic vector storing requests (which are char*)
35 int CS_used = 0; // initially the CS is idle
36 int todo = AMOUNT_OF_CLIENTS * CS_PER_PROCESS; // amount of releases we are expecting
39 MSG_task_receive(&task, "coordinator");
40 const char *kind = MSG_task_get_name(task); //is it a request or a release?
41 if (!strcmp(kind, "request")) { // that's a request
42 char *req = MSG_task_get_data(task);
43 if (CS_used) { // need to push the request in the vector
44 XBT_INFO("CS already used. Queue the request of client %d", atoi(req) +1);
45 xbt_dynar_push(requests, &req);
46 } else { // can serve it immediatly
47 if(strcmp(req, "2") == 0){
48 m_task_t answer = MSG_task_create("grant", 0, 1000, NULL);
49 MSG_task_send(answer, req);
51 XBT_INFO("CS idle. Grant immediatly");
54 } else { // that's a release. Check if someone was waiting for the lock
55 if (xbt_dynar_length(requests) > 0) {
56 XBT_INFO("CS release. Grant to queued requests (queue size: %lu)", xbt_dynar_length(requests));
58 xbt_dynar_get_cpy(requests, (xbt_dynar_length(requests) - 1), &req);
59 if(strcmp(req, "2") == 0){
60 xbt_dynar_pop(requests, &req);
61 MSG_task_send(MSG_task_create("grant", 0, 1000, NULL), req);
64 xbt_dynar_pop(requests, &req);
65 MSG_task_send(MSG_task_create("notgrant", 0, 1000, NULL), req);
69 } else { // nobody wants it
70 XBT_INFO("CS release. resource now idle");
75 MSG_task_destroy(task);
77 XBT_INFO("Received all releases, quit now");
81 int client(int argc, char *argv[])
83 int my_pid = MSG_process_get_PID(MSG_process_self());
85 char *my_mailbox = bprintf("%s", argv[1]);
88 // request the CS (CS_PER_PROCESS times), sleeping a bit in between
89 for (i = 0; i < CS_PER_PROCESS; i++) {
91 XBT_INFO("Ask the request");
92 MSG_task_send(MSG_task_create("request", 0, 1000, my_mailbox), "coordinator");
94 if(strcmp(my_mailbox, "1") == 0){
97 XBT_DEBUG("Propositions changed : r=1, cs=0");
101 m_task_t grant = NULL;
102 MSG_task_receive(&grant, my_mailbox);
103 const char *kind = MSG_task_get_name(grant);
105 if((strcmp(my_mailbox, "1") == 0) && (strcmp("grant", kind) == 0)){
108 XBT_DEBUG("Propositions changed : r=0, cs=1");
112 MSG_task_destroy(grant);
113 XBT_INFO("%s got the answer. Sleep a bit and release it", argv[1]);
114 MSG_process_sleep(1);
115 MSG_task_send(MSG_task_create("release", 0, 1000, NULL), "coordinator");
117 MSG_process_sleep(my_pid);
119 if(strcmp(my_mailbox, "1") == 0){
122 XBT_DEBUG("Propositions changed : r=0, cs=0");
127 XBT_INFO("Got all the CS I wanted (%s), quit now", my_mailbox);
131 int main(int argc, char *argv[])
135 automaton = get_automaton();
136 xbt_new_propositional_symbol(automaton,"r", &predR);
137 xbt_new_propositional_symbol(automaton,"cs", &predCS);
139 MSG_global_init(&argc, argv);
140 MSG_create_environment("../msg_platform.xml");
141 MSG_function_register("coordinator", coordinator);
142 MSG_function_register("client", client);
143 MSG_launch_application("deploy_bugged1_liveness.xml");
144 MSG_main_liveness(automaton, argv[0]);