From dba896b9a0ca7cbe4fb379017672bd44a0a77ef0 Mon Sep 17 00:00:00 2001 From: dimitri staessens Date: Fri, 17 Jun 2016 15:55:23 +0200 Subject: 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. --- src/lib/shm_du_map.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) (limited to 'src/lib/shm_du_map.c') 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) { -- cgit v1.2.3