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#include "T.h"
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <pthread.h>
#include <stdio.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/socket.h>
#define QUIT(x) do { \
printf("T tracer: QUIT: %s\n", x); \
exit(1); \
} while (0)
/* array used to activate/disactivate a log */
static int T_IDs[T_NUMBER_OF_IDS];
int *T_active = T_IDs;
static int T_socket;
/* T_cache
* - the T macro picks up the head of freelist and marks it busy
* - the T sender thread periodically wakes up and sends what's to be sent
*/
volatile int _T_freelist_head;
volatile int *T_freelist_head = &_T_freelist_head;
T_cache_t *T_cache;
static void get_message(int s)
{
char t;
int l;
int id;
int is_on;
if (read(s, &t, 1) != 1) QUIT("get_message fails");
printf("T tracer: got mess %d\n", t);
switch (t) {
case 0:
/* toggle all those IDs */
/* optimze? (too much syscalls) */
if (read(s, &l, sizeof(int)) != sizeof(int)) QUIT("get_message fails");
while (l) {
if (read(s, &id, sizeof(int)) != sizeof(int)) QUIT("get_message fails");
T_IDs[id] = 1 - T_IDs[id];
l--;
}
break;
case 1:
/* set IDs as given */
/* optimize? */
if (read(s, &l, sizeof(int)) != sizeof(int)) QUIT("get_message fails");
id = 0;
while (l) {
if (read(s, &is_on, sizeof(int)) != sizeof(int))
QUIT("get_message fails");
T_IDs[id] = is_on;
id++;
l--;
}
break;
case 2: break; /* do nothing, this message is to wait for local tracer */
}
}
static void *T_receive_thread(void *_)
{
while (1) get_message(T_socket);
return NULL;
}
static void new_thread(void *(*f)(void *), void *data)
{
pthread_t t;
pthread_attr_t att;
if (pthread_attr_init(&att))
{ fprintf(stderr, "pthread_attr_init err\n"); exit(1); }
if (pthread_attr_setdetachstate(&att, PTHREAD_CREATE_DETACHED))
{ fprintf(stderr, "pthread_attr_setdetachstate err\n"); exit(1); }
if (pthread_create(&t, &att, f, data))
{ fprintf(stderr, "pthread_create err\n"); exit(1); }
if (pthread_attr_destroy(&att))
{ fprintf(stderr, "pthread_attr_destroy err\n"); exit(1); }
}
/* defined in local_tracer.c */
void T_local_tracer_main(int remote_port, int wait_for_tracer,
int local_socket);
/* We monitor the tracee and the local tracer processes.
* When one dies we forcefully kill the other.
*/
#include <sys/types.h>
#include <sys/wait.h>
static void monitor_and_kill(int child1, int child2)
{
int child;
int status;
child = wait(&status);
if (child == -1) perror("wait");
kill(child1, SIGKILL);
kill(child2, SIGKILL);
exit(0);
}
void T_init(int remote_port, int wait_for_tracer, int dont_fork)
{
int socket_pair[2];
int s;
int T_shm_fd;
int child1, child2;
if (socketpair(AF_UNIX, SOCK_STREAM, 0, socket_pair))
{ perror("socketpair"); abort(); }
/* child1 runs the local tracer and child2 (or main) runs the tracee */
child1 = fork(); if (child1 == -1) abort();
if (child1 == 0) {
close(socket_pair[1]);
T_local_tracer_main(remote_port, wait_for_tracer, socket_pair[0]);
exit(0);
}
close(socket_pair[0]);
if (dont_fork == 0) {
child2 = fork(); if (child2 == -1) abort();
if (child2 != 0) {
close(socket_pair[1]);
monitor_and_kill(child1, child2);
}
}
s = socket_pair[1];
/* wait for first message - initial list of active T events */
get_message(s);
T_socket = s;
/* setup shared memory */
T_shm_fd = shm_open(T_SHM_FILENAME, O_RDWR /*| O_SYNC*/, 0666);
shm_unlink(T_SHM_FILENAME);
if (T_shm_fd == -1) { perror(T_SHM_FILENAME); abort(); }
T_cache = mmap(NULL, T_CACHE_SIZE * sizeof(T_cache_t),
PROT_READ | PROT_WRITE, MAP_SHARED, T_shm_fd, 0);
if (T_cache == NULL)
{ perror(T_SHM_FILENAME); abort(); }
close(T_shm_fd);
new_thread(T_receive_thread, NULL);
}