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authordimitri staessens <dimitri.staessens@intec.ugent.be>2016-06-17 15:55:23 +0200
committerdimitri staessens <dimitri.staessens@intec.ugent.be>2016-06-17 16:01:20 +0200
commitdba896b9a0ca7cbe4fb379017672bd44a0a77ef0 (patch)
tree5aeee1a6f05aa4a35ceab97ba6a7da16979555a5 /src/lib
parent1d196cfc0d87b6fd41ba15a3a7d17669711ed202 (diff)
downloadouroboros-dba896b9a0ca7cbe4fb379017672bd44a0a77ef0.tar.gz
ouroboros-dba896b9a0ca7cbe4fb379017672bd44a0a77ef0.zip
irmd, lib: use shm_du_map as lockfile.
Added the pid of the irmd to the shm_du_map. The IRMd will check for an existing shm_du_map. If there is an existing file, it will exit if the owner IRMd is running or remove it if the owner IRMd is not running. Also simplifies calculation of the shm_du_map pointers and corrects exiting calls for the IRMd. Fixes #8.
Diffstat (limited to 'src/lib')
-rw-r--r--src/lib/shm_du_map.c24
1 files changed, 15 insertions, 9 deletions
diff --git a/src/lib/shm_du_map.c b/src/lib/shm_du_map.c
index f63ce32d..0ce6bdcd 100644
--- a/src/lib/shm_du_map.c
+++ b/src/lib/shm_du_map.c
@@ -34,7 +34,7 @@
#define SHM_BLOCKS_SIZE (SHM_BLOCKS_IN_MAP * SHM_DU_BUFF_BLOCK_SIZE)
#define SHM_FILE_SIZE (SHM_BLOCKS_SIZE + 2 * sizeof (size_t) \
- + sizeof(pthread_mutex_t))
+ + sizeof(pthread_mutex_t)) + sizeof(pid_t)
#define get_head_ptr(dum) \
((struct shm_du_buff *)(dum->shm_base + (*dum->ptr_head * \
@@ -71,6 +71,7 @@ struct shm_du_map {
size_t * ptr_head; /* start of ringbuffer head */
size_t * ptr_tail; /* start of ringbuffer tail */
pthread_mutex_t * shm_mutex; /* lock all free space in shm */
+ pid_t * pid; /* pid of the irmd owner */
int fd;
};
@@ -126,10 +127,9 @@ struct shm_du_map * shm_du_map_create()
dum->shm_base = shm_base;
dum->ptr_head = (size_t *)
((uint8_t *) dum->shm_base + SHM_BLOCKS_SIZE);
- dum->ptr_tail = (size_t *)
- ((uint8_t *) dum->ptr_head + sizeof(size_t));
- dum->shm_mutex = (pthread_mutex_t *)
- ((uint8_t *) dum->ptr_tail + sizeof(size_t));
+ dum->ptr_tail = dum->ptr_head + 1;
+ dum->shm_mutex = (pthread_mutex_t *) (dum->ptr_tail + 1);
+ dum->pid = (pid_t *) (dum->shm_mutex + 1);
pthread_mutexattr_init(&attr);
pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED);
@@ -138,6 +138,8 @@ struct shm_du_map * shm_du_map_create()
*dum->ptr_head = 0;
*dum->ptr_tail = 0;
+ *dum->pid = getpid();
+
dum->fd = shm_fd;
return dum;
@@ -181,16 +183,20 @@ struct shm_du_map * shm_du_map_open()
dum->shm_base = shm_base;
dum->ptr_head = (size_t *)
((uint8_t *) dum->shm_base + SHM_BLOCKS_SIZE);
- dum->ptr_tail = (size_t *)
- ((uint8_t *) dum->ptr_head + sizeof(size_t));
- dum->shm_mutex = (pthread_mutex_t *)
- ((uint8_t *) dum->ptr_tail + sizeof(size_t));
+ dum->ptr_tail = dum->ptr_head + 1;
+ dum->shm_mutex = (pthread_mutex_t *) (dum->ptr_tail + 1);
+ dum->pid = (pid_t *) (dum->shm_mutex + 1);
dum->fd = shm_fd;
return dum;
}
+pid_t shm_du_map_owner(struct shm_du_map * dum)
+{
+ return *dum->pid;
+}
+
void shm_du_map_close(struct shm_du_map * dum)
{
if (dum == NULL) {