-/* Centralized Mutual Exclusion Algorithm
- *
- * This constitutes the answer to the exercice 2 of the practical
- * lab on implementing mutual exclusion algorithms with SimGrid.
- *
- * YOU SHOULD TRY IMPLEMENTING IT YOURSELF BEFORE READING THE SOLUTION.
- */
+/* Copyright (c) 2010-2012. The SimGrid Team.
+ * All rights reserved. */
+
+/* This program is free software; you can redistribute it and/or modify it
+ * under the terms of the license (GNU LGPL) which comes with this package. */
+
+
+/***************** Centralized Mutual Exclusion Algorithm *********************/
+/* This example implements a centralized mutual exclusion algorithm. */
+/* There is no bug on it, it is just provided to test the state space */
+/* reduction of DPOR. */
+/******************************************************************************/
#include "msg/msg.h"
-#define AMOUNT_OF_CLIENTS 5
+#define AMOUNT_OF_CLIENTS 4
#define CS_PER_PROCESS 2
XBT_LOG_NEW_DEFAULT_CATEGORY(centralized, "my log messages");
-int coordinator(int argc, char** argv);
-int client(int argc, char** argv);
+int coordinator(int argc, char **argv);
+int client(int argc, char **argv);
-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
- int todo= AMOUNT_OF_CLIENTS*CS_PER_PROCESS; // amount of releases we are expecting
- while(todo>0) {
- m_task_t task=NULL;
- MSG_task_receive(&task,"coordinator");
+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
+ int todo = AMOUNT_OF_CLIENTS * CS_PER_PROCESS; // amount of releases we are expecting
+ while (todo > 0) {
+ msg_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
+ 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
- INFO0("CS already used. Queue the request");
- xbt_dynar_push(requests, &req);
- } else { // can serve it immediatly
- INFO0("CS idle. Grant immediatly");
- m_task_t answer = MSG_task_create("grant",0,1000,NULL);
- MSG_task_send(answer,req);
- CS_used = 1;
+ if (CS_used) { // need to push the request in the vector
+ XBT_INFO("CS already used. Queue the request");
+ xbt_dynar_push(requests, &req);
+ } else { // can serve it immediatly
+ XBT_INFO("CS idle. Grant immediatly");
+ msg_task_t answer = MSG_task_create("grant", 0, 1000, NULL);
+ MSG_task_send(answer, req);
+ CS_used = 1;
}
- } else { // that's a release. Check if someone was waiting for the lock
- if (xbt_dynar_length(requests)>0) {
- INFO1("CS release. Grant to queued requests (queue size: %lu)",xbt_dynar_length(requests));
- char *req;
- xbt_dynar_pop(requests,&req);
- MSG_task_send(MSG_task_create("grant",0,1000,NULL),req);
- todo--;
- } else { // nobody wants it
- INFO0("CS release. resource now idle");
- CS_used=0;
- todo--;
+ } else { // that's a release. Check if someone was waiting for the lock
+ if (!xbt_dynar_is_empty(requests)) {
+ XBT_INFO("CS release. Grant to queued requests (queue size: %lu)",
+ xbt_dynar_length(requests));
+ char *req;
+ xbt_dynar_shift(requests, &req);
+ MSG_task_send(MSG_task_create("grant", 0, 1000, NULL), req);
+ todo--;
+ } else { // nobody wants it
+ XBT_INFO("CS release. resource now idle");
+ CS_used = 0;
+ todo--;
}
}
- //MSG_task_destoy(task);
+ MSG_task_destroy(task);
}
- INFO0("Received all releases, quit now");
+ XBT_INFO("Received all releases, quit now");
return 0;
}
-int client(int argc, char *argv[]) {
- int my_pid=MSG_process_get_PID(MSG_process_self());
+int client(int argc, char *argv[])
+{
+ int my_pid = MSG_process_get_PID(MSG_process_self());
// use my pid as name of mailbox to contact me
- char *my_mailbox=bprintf("%d",my_pid);
+ char *my_mailbox = bprintf("%d", my_pid);
// request the CS 3 times, sleeping a bit in between
int i;
- for (i=0; i<CS_PER_PROCESS;i++) {
- INFO0("Ask the request");
- MSG_task_send(MSG_task_create("request",0,1000,my_mailbox),"coordinator");
+ for (i = 0; i < CS_PER_PROCESS; i++) {
+ XBT_INFO("Ask the request");
+ MSG_task_send(MSG_task_create("request", 0, 1000, my_mailbox),
+ "coordinator");
// wait the answer
- m_task_t grant = NULL;
- MSG_task_receive(&grant,my_mailbox);
- //MSG_task_destoy(grant);
- INFO0("got the answer. Sleep a bit and release it");
+ msg_task_t grant = NULL;
+ MSG_task_receive(&grant, my_mailbox);
+ MSG_task_destroy(grant);
+ XBT_INFO("got the answer. Sleep a bit and release it");
MSG_process_sleep(1);
- MSG_task_send(MSG_task_create("release",0,1000,NULL),"coordinator");
+ MSG_task_send(MSG_task_create("release", 0, 1000, NULL),
+ "coordinator");
MSG_process_sleep(my_pid);
}
- INFO0("Got all the CS I wanted, quit now");
+ XBT_INFO("Got all the CS I wanted, quit now");
return 0;
}
-int main(int argc, char*argv[]) {
- MSG_global_init(&argc,argv);
+int main(int argc, char *argv[])
+{
+ MSG_init(&argc, argv);
MSG_create_environment("../msg_platform.xml");
MSG_function_register("coordinator", coordinator);
MSG_function_register("client", client);
- MSG_launch_application("deploy.xml");
+ MSG_launch_application("deploy_mutex.xml");
MSG_main();
return 0;
}
