ОЧЕНЬ большое спасибо, Се и VJo,
Вот модифицированная версия программы, учитывающая все ваши комментарии.
Надеюсь, это будет полезно для кого-то еще.
Bert
/*
We want Mickey to send a message to Minnie exclusively.
We want Donald to send a message to pluto exclusively.
To compile:
gcc mm.c -o mm -fno-stack-protector -pthread
Requires:
syslog enabled and started.
To test:
time ./mm | { trap "" INT; sort | uniq -c | tee stats; }
Results:
1503373 Donald sent a message to Pluto.
1 Donald thread successfully started.
1423964 Mickey sent a message to Minnie.
1 Mickey thread successfully started.
1423958 Minnie received: Hello, Minnie!
1 Minnie thread successfully started.
1503333 Pluto received: Sit, Pluto!
1 Pluto thread successfully started.
real 0m17.133s
user 0m16.053s
sys 0m5.248s
*/
#include <sys/types.h>
#include <sys/msg.h>
#include <sys/ipc.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <syslog.h>
#define MQMICKEY "/tmp/MQMickey"
#define MQDONALD "/tmp/MQDonald"
pthread_t t1,t2,t3,t4;
FILE *fMickeypointer;
FILE *fDonaldpointer;
// Mickey send
key_t ipcMickey;
int mqMickeyid;
char helloMickeymsg[] = {"Hello, Minnie!"};
struct { long type; char text[100]; } myMickeymsg;
// Minnie get
int mqMinnieid;
struct { long type; char text[100]; } myMinniemsg;
// Donald send
key_t ipcDonald;
int mqDonaldid;
char helloDonaldmsg[] = {"Sit, Pluto!"};
struct { long type; char text[100]; } myDonaldmsg;
// Pluto get
int mqPlutoid;
struct { long type; char text[100]; } myPlutomsg;
static void * DONALDthreadFunc(void *arg)
{
printf("Donald thread successfully started.\n");
char *s = (char *) arg;
while(1)
{
//send
memset(myDonaldmsg.text, 0, 100);
strncpy(myDonaldmsg.text, helloDonaldmsg, strlen(helloDonaldmsg));
myDonaldmsg.type = 1;
msgsnd(mqDonaldid, &myDonaldmsg, sizeof(myDonaldmsg), 0);
printf("Donald sent a message to Pluto.\r\n");
}
/* just a formality */
return (void *) strlen(s);
}
static void * PLUTOthreadFunc(void *arg)
{
printf("Pluto thread successfully started.\n");
char *s = (char *) arg;
while(1)
{
//receive
mqPlutoid = msgget(ipcDonald, 0);
msgrcv(mqPlutoid, &myPlutomsg, sizeof(myPlutomsg), 0, 0);
printf("Pluto received: %s\r\n", myPlutomsg.text);
}
/* just a formality */
return (void *) strlen(s);
}
static void * MICKEYthreadFunc(void *arg)
{
printf("Mickey thread successfully started.\n");
char *s = (char *) arg;
while(1)
{
//send
memset(myMickeymsg.text, 0, 100);
strncpy(myMickeymsg.text, helloMickeymsg, strlen(helloMickeymsg));
myMickeymsg.type = 1;
msgsnd(mqMickeyid, &myMickeymsg, sizeof(myMickeymsg), 0);
printf("Mickey sent a message to Minnie.\r\n");
}
/* just a formality */
return (void *) strlen(s);
}
static void * MINNIEthreadFunc(void *arg)
{
printf("Minnie thread successfully started.\n");
char *s = (char *) arg;
while(1)
{
//receive
mqMinnieid = msgget(ipcMickey, 0);
msgrcv(mqMinnieid, &myMinniemsg, sizeof(myMinniemsg), 0, 0);
printf(" Minnie received: %s\r\n", myMinniemsg.text);
}
return (void *) strlen(s);
}
int main (void)
{
/*
MUST create the target files first.
The return of ftok is -1 if file is missing. If BOTH files are missing, both ipc keys
will be -1, meaning all traffic shares the same port. Result: one queue will acquire
messages not intended for it!
*/
fMickeypointer = fopen(MQMICKEY, "a");
if(fMickeypointer == NULL)
{
printf("Failed to create Mickey queue file.\n");
/* system logging */
setlogmask (LOG_UPTO (LOG_NOTICE));
openlog ("MickeyDonald", LOG_CONS | LOG_PID | LOG_NDELAY, LOG_LOCAL1);
syslog (LOG_NOTICE, "Failed to create Mickey queue file." );
closelog ();
exit(91);
}
fDonaldpointer = fopen(MQDONALD, "a");
if(fDonaldpointer == NULL)
{
printf("Failed to create Donald queue file.\r\n");
/* system logging */
setlogmask (LOG_UPTO (LOG_NOTICE));
openlog ("MickeyDonald", LOG_CONS | LOG_PID | LOG_NDELAY, LOG_LOCAL1);
syslog (LOG_NOTICE, "Failed to create Donald queue file." );
closelog ();
exit(92);
}
ipcMickey = 0;
ipcDonald = 0;
/* make sure we assign DIFFERENT ipc values */
while(ipcMickey == ipcDonald)
{
ipcMickey = ftok(MQMICKEY, 63);
if (-1==ipcMickey)
{
printf("ipcMickey does not exist.\r\n");
/* system logging */
setlogmask (LOG_UPTO (LOG_NOTICE));
openlog ("MickeyDonald", LOG_CONS | LOG_PID | LOG_NDELAY, LOG_LOCAL1);
syslog (LOG_NOTICE, "Failed to ftok Mickey file." );
closelog ();
exit(93);
}
ipcDonald = ftok(MQDONALD, 69);
if (-1==ipcDonald)
{
printf("ipcDonald does not exist.\r\n");
/* system logging */
setlogmask (LOG_UPTO (LOG_NOTICE));
openlog ("MickeyDonald", LOG_CONS | LOG_PID | LOG_NDELAY, LOG_LOCAL1);
syslog (LOG_NOTICE, "Failed to ftok Donald file." );
closelog ();
exit(94);
}
}
mqMickeyid = msgget(ipcMickey, IPC_CREAT | 0666);
mqDonaldid = msgget(ipcDonald, IPC_CREAT | 0666);
pthread_create(&t1, NULL, MICKEYthreadFunc, "Mickey sends\n");
pthread_create(&t2, NULL, MINNIEthreadFunc, "Minnie replies\n");
pthread_create(&t3, NULL, DONALDthreadFunc, "Donald sends\n");
pthread_create(&t4, NULL, PLUTOthreadFunc, "Pluto replies\n");
long exitcounter = 0;
while(exitcounter < 100000)
{
exitcounter +=1;
usleep(100);
}
exit(0);
}