1 /* Copyright (c) 2012-2018. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
6 /***************** Centralized Mutual Exclusion Algorithm *******************/
7 /* This example implements a centralized mutual exclusion algorithm. */
8 /* Bug : CS requests of client 1 not satisfied */
9 /* LTL property checked : G(r->F(cs)); (r=request of CS, cs=CS ok) */
10 /****************************************************************************/
18 #include <simgrid/modelchecker.h>
19 #include <simgrid/msg.h>
21 XBT_LOG_NEW_DEFAULT_CATEGORY(bugged1_liveness, "my log messages");
27 /** Do not use a clean stack */
28 static void garbage_stack(void) {
29 const size_t size = 256;
30 int fd = open("/dev/urandom", O_RDONLY);
37 static int coordinator(int argc, char *argv[])
40 msg_task_t task = NULL;
41 msg_task_t answer = NULL;
42 xbt_dynar_t requests = xbt_dynar_new(sizeof(char *), NULL);
46 MSG_task_receive(&task, "coordinator");
47 const char *kind = MSG_task_get_name(task);
48 if (!strcmp(kind, "request")) {
49 req = MSG_task_get_data(task);
51 XBT_INFO("CS already used. Queue the request.");
52 xbt_dynar_push(requests, &req);
54 if(strcmp(req, "1") != 0){
55 XBT_INFO("CS idle. Grant immediatly");
56 answer = MSG_task_create("grant", 0, 1000, NULL);
57 MSG_task_send(answer, req);
63 if (!xbt_dynar_is_empty(requests)) {
64 XBT_INFO("CS release. Grant to queued requests (queue size: %lu)", xbt_dynar_length(requests));
65 xbt_dynar_shift(requests, &req);
66 if(strcmp(req, "1") != 0){
67 MSG_task_send(MSG_task_create("grant", 0, 1000, NULL), req);
69 xbt_dynar_push(requests, &req);
73 XBT_INFO("CS release. resource now idle");
77 MSG_task_destroy(task);
85 static int client(int argc, char *argv[])
87 int my_pid = MSG_process_get_PID(MSG_process_self());
89 char *my_mailbox = xbt_strdup(argv[1]);
90 msg_task_t grant = NULL;
91 msg_task_t release = NULL;
94 XBT_INFO("Ask the request");
95 MSG_task_send(MSG_task_create("request", 0, 1000, my_mailbox), "coordinator");
97 if(strcmp(my_mailbox, "1") == 0){
100 XBT_INFO("Propositions changed : r=1, cs=0");
103 MSG_task_receive(&grant, my_mailbox);
104 const char *kind = MSG_task_get_name(grant);
106 if((strcmp(my_mailbox, "1") == 0) && (strcmp("grant", kind) == 0)){
109 XBT_INFO("Propositions changed : r=0, cs=1");
112 MSG_task_destroy(grant);
116 XBT_INFO("%s got the answer. Sleep a bit and release it", argv[1]);
118 MSG_process_sleep(1);
120 release = MSG_task_create("release", 0, 1000, NULL);
121 MSG_task_send(release, "coordinator");
125 MSG_process_sleep(my_pid);
127 if(strcmp(my_mailbox, "1") == 0){
130 XBT_INFO("Propositions changed : r=0, cs=0");
137 static int raw_client(int argc, char *argv[])
140 // At this point the stack of the callee (client) is probably filled with
141 // zeros and uninitialized variables will contain 0. This call will place
142 // random byes in the stack of the callee:
145 return client(argc, argv);
148 int main(int argc, char *argv[])
150 MSG_init(&argc, argv);
152 MC_automaton_new_propositional_symbol_pointer("r", &r);
153 MC_automaton_new_propositional_symbol_pointer("cs", &cs);
155 MSG_create_environment(argv[1]);
157 MSG_function_register("coordinator", coordinator);
158 MSG_function_register("client", raw_client);
159 MSG_launch_application(argv[2]);