zenon/feedback-arc-set
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Shared memory and semaphore setup

Browse Source
This commit is contained in:
zenon 2018-05-30 17:18:11 +02:00
parent 9ac6d9fbfe
commit e3095f8ce0
1 changed files with 58 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

58
supervisor.c
View File

@ -9,6 +9,8 @@
static const char *pname;
struct circ_buf *shared;
struct sigaction sa;
static volatile sig_atomic_t quit = 0;
@ -25,6 +27,40 @@ void usage(void)
exit(EXIT_FAILURE);
}
void initCircBuf()
{
shared->validItems = 0;
shared->head = 0;
shared->tail = 0;
shared->quit = 0;
for (int i = 0; i < MAX_ITEMS; i++) {
shared->data[i] = 0;
}
return;
}
int isEmpty()
{
if (shared->validItems == 0)
return 1;
else
return 0;
}
int getItem()
{
if (isEmpty())
return -1;
int value;
value = shared->data[shared->head];
shared->head = (shared->head + 1) % MAX_ITEMS;
shared->validItems--;
return value;
}
int main(int argc, char *argv[])
{
if (argc != 1)
@ -37,8 +73,30 @@ int main(int argc, char *argv[])
sigaction(SIGINT, &sa, NULL);
sigaction(SIGTERM, &sa, NULL);
int shmfd = shm_open(SHM_NAME, O_RDWR | O_CREAT, PERMISSION);
if (shmfd == -1) {
perror(pname);
exit(EXIT_FAILURE);
}
if (ftruncate(shmfd, sizeof(*shared)) == -1) {
perror(pname);
exit(EXIT_FAILURE);
}
shared = mmap(NULL, sizeof(*shared), PROT_READ | PROT_WRITE, MAP_SHARED, shmfd, 0);
if (shared == MAP_FAILED) {
perror(pname);
exit(EXIT_FAILURE);
}
sem_t *sFreeSpace = sem_open(SEM_FREE_SPACE, O_CREAT | O_EXCL, PERMISSION, MAX_ITEMS);
sem_t *sUsedSpace = sem_open(SEM_USED_SPACE, O_CREAT | O_EXCL, PERMISSION, 0);
initCircBuf();
while (quit == 0) {
}
return 0;