1 /***************** Centralized Mutual Exclusion Algorithm *********************/
2 /* This example implements a centralized mutual exclusion algorithm. */
3 /* LTL property checked : !(GFcs) */
4 /******************************************************************************/
8 #include "xbt/automaton.h"
9 #include "xbt/automatonparse_promela.h"
10 #include "centralized_liveness.h"
13 XBT_LOG_NEW_DEFAULT_CATEGORY(centralized, "my log messages");
22 int coordinator(int argc, char **argv);
23 int client(int argc, char **argv);
25 int coordinator(int argc, char *argv[])
27 int CS_used = 0; // initially the CS is idle
31 MSG_task_receive(&task, "coordinator");
32 const char *kind = MSG_task_get_name(task); //is it a request or a release?
33 if (!strcmp(kind, "request")) { // that's a request
34 char *req = MSG_task_get_data(task);
36 XBT_INFO("CS already used.");
37 m_task_t answer = MSG_task_create("not grant", 0, 1000, NULL);
38 MSG_task_send(answer, req);
39 } else { // can serve it immediatly
40 XBT_INFO("CS idle. Grant immediatly");
41 m_task_t answer = MSG_task_create("grant", 0, 1000, NULL);
42 MSG_task_send(answer, req);
45 } else { // that's a release. Check if someone was waiting for the lock
46 XBT_INFO("CS release. resource now idle");
49 MSG_task_destroy(task);
55 int client(int argc, char *argv[])
57 int my_pid = MSG_process_get_PID(MSG_process_self());
58 char *my_mailbox = bprintf("%s", argv[1]);
63 XBT_INFO("Client (%s) asks the request", my_mailbox);
64 MSG_task_send(MSG_task_create("request", 0, 1000, my_mailbox),
67 m_task_t answer = NULL;
68 MSG_task_receive(&answer, my_mailbox);
70 kind = MSG_task_get_name(answer);
72 if (!strcmp(kind, "grant")) {
74 XBT_INFO("Client (%s) got the answer (grant). Sleep a bit and release it", my_mailbox);
76 if(!strcmp(my_mailbox, "1"))
79 /*MSG_process_sleep(my_pid);
80 MSG_task_send(MSG_task_create("release", 0, 1000, NULL),
82 XBT_INFO("Client (%s) releases the CS", my_mailbox);
84 if(!strcmp(my_mailbox, "1"))
89 XBT_INFO("Client (%s) got the answer (not grant). Try again", my_mailbox);
93 MSG_task_destroy(answer);
95 MSG_process_sleep(my_pid);
101 int main(int argc, char *argv[])
105 automaton = get_automaton();
106 xbt_new_propositional_symbol(automaton,"cs", &predCS);
108 MSG_global_init(&argc, argv);
109 MSG_create_environment("../msg_platform.xml");
110 MSG_function_register("coordinator", coordinator);
111 MSG_function_register("client", client);
112 MSG_launch_application("deploy_centralized_liveness.xml");
113 MSG_main_liveness(automaton);