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path: root/src/lib/shm_du_map.c
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Diffstat (limited to 'src/lib/shm_du_map.c')
-rw-r--r--src/lib/shm_du_map.c194
1 files changed, 67 insertions, 127 deletions
diff --git a/src/lib/shm_du_map.c b/src/lib/shm_du_map.c
index 052b8868..630cfa42 100644
--- a/src/lib/shm_du_map.c
+++ b/src/lib/shm_du_map.c
@@ -34,23 +34,28 @@
#define SHM_DU_BLOCK_DATA_SIZE (SHM_DU_BUFF_BLOCK_SIZE - \
- sizeof (struct shm_block))
+ sizeof(struct shm_block))
#define SHM_BLOCKS_IN_MAP (SHM_DU_MAP_SIZE / SHM_DU_BUFF_BLOCK_SIZE)
#define SHM_BLOCKS_SIZE (SHM_DU_BUFF_BLOCK_SIZE * SHM_BLOCKS_IN_MAP)
#define SHM_BUFFS_SIZE (SHM_BLOCKS_IN_MAP * sizeof (struct shm_du_buff))
-#define SHM_MGT_MAP_SIZE (SHM_BLOCKS_IN_MAP * sizeof (uint8_t))
#define SHM_FILE_SIZE (SHM_BLOCKS_IN_MAP * (SHM_DU_BUFF_BLOCK_SIZE \
- + sizeof (struct shm_du_buff) \
- + sizeof (uint8_t)) \
+ + sizeof(struct shm_du_buff) \
+ + sizeof(uint8_t)) \
+ + 2 * sizeof (size_t) \
+ sizeof(pthread_mutex_t))
-#define idx_to_block_ptr(dum, i) ((struct shm_block *) \
+#define idx_to_block_ptr(dum, i) ((struct shm_block *) \
(dum->shm_base + i * SHM_DU_BUFF_BLOCK_SIZE))
#define idx_to_du_buff_ptr(dum, i) (dum->ptr_du_buff + i)
#define du_buff_ptr_to_idx(dum, sdb) ((sdb - dum->ptr_du_buff) / sizeof *sdb)
#define block_ptr_to_idx(dum, sdb) (((uint8_t *)sdb - dum->shm_base) \
/ SHM_DU_BUFF_BLOCK_SIZE)
+#define shm_map_used(dum) ((*(dum->ptr_head) + SHM_BLOCKS_IN_MAP - \
+ *(dum->ptr_tail)) % SHM_BLOCKS_IN_MAP)
+
+#define shm_map_free(dum, i)(shm_map_used(dum) + i < SHM_BLOCKS_IN_MAP)
+
struct shm_block {
size_t size;
long next;
@@ -64,9 +69,10 @@ struct shm_du_buff {
};
struct shm_du_map {
- uint8_t * shm_base; /* start of buffer blocks */
+ uint8_t * shm_base; /* start of blocks */
struct shm_du_buff * ptr_du_buff; /* start of du_buff structs */
- uint8_t * ptr_map; /* start of management 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 */
int fd;
};
@@ -76,9 +82,7 @@ struct shm_du_map * shm_du_map_create()
struct shm_du_map * dum;
int shm_fd;
uint8_t * shm_base;
- uint8_t * ptr;
pthread_mutexattr_t attr;
- int i;
dum = malloc(sizeof *dum);
if (dum == NULL) {
@@ -129,17 +133,19 @@ struct shm_du_map * shm_du_map_create()
dum->shm_base = shm_base;
dum->ptr_du_buff = (struct shm_du_buff *)
((uint8_t *) dum->shm_base + SHM_BLOCKS_SIZE);
- dum->ptr_map = (uint8_t *) dum->ptr_du_buff + SHM_BUFFS_SIZE;
+ dum->ptr_head = (size_t *)
+ ((uint8_t *) dum->ptr_du_buff + SHM_BUFFS_SIZE);
+ dum->ptr_tail = (size_t *)
+ ((uint8_t *) dum->ptr_head + sizeof(size_t));
dum->shm_mutex = (pthread_mutex_t *)
- ((uint8_t *) dum->ptr_map + SHM_MGT_MAP_SIZE);
+ ((uint8_t *) dum->ptr_tail + sizeof(size_t));
pthread_mutexattr_init(&attr);
pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED);
pthread_mutex_init(dum->shm_mutex, &attr);
- ptr = dum->ptr_map;
- for (i = 0; i < SHM_BLOCKS_IN_MAP; ++i)
- *(ptr++) = 0;
+ *dum->ptr_head = 0;
+ *dum->ptr_tail = 0;
dum->fd = shm_fd;
@@ -185,9 +191,12 @@ struct shm_du_map * shm_du_map_open()
dum->shm_base = shm_base;
dum->ptr_du_buff = (struct shm_du_buff *)
((uint8_t *) dum->shm_base + SHM_BLOCKS_SIZE);
- dum->ptr_map = (uint8_t *) dum->ptr_du_buff + SHM_BUFFS_SIZE;
+ dum->ptr_head = (size_t *)
+ ((uint8_t *) dum->ptr_du_buff + SHM_BUFFS_SIZE);
+ dum->ptr_tail = (size_t *)
+ ((uint8_t *) dum->ptr_head + sizeof(size_t));
dum->shm_mutex = (pthread_mutex_t *)
- ((uint8_t *) dum->ptr_map + SHM_MGT_MAP_SIZE);
+ ((uint8_t *) dum->ptr_tail + sizeof(size_t));
return dum;
}
@@ -208,53 +217,6 @@ void shm_du_map_close(struct shm_du_map * dum)
free(dum);
}
-static struct shm_du_buff * alloc_du_buff(struct shm_du_map * dum)
-{
- uint8_t * ptr = dum->ptr_map;
-
- pthread_mutex_lock(dum->shm_mutex);
-
- while (*ptr == 1 && ptr < (uint8_t *) dum->shm_mutex)
- ++ptr;
-
- if (ptr < (uint8_t *) dum->shm_mutex) {
- *ptr = 1;
- } else {
- pthread_mutex_unlock(dum->shm_mutex);
- return NULL;
- }
-
- pthread_mutex_unlock(dum->shm_mutex);
-
- return dum->ptr_du_buff + (ptr - dum->ptr_map);
-}
-
-static struct shm_block * alloc_block(struct shm_du_map * dum)
-{
-
- pthread_mutex_lock(dum->shm_mutex);
-
- uint8_t * ptr = dum->ptr_map;
-
- while (*ptr == 1 && ptr < (uint8_t *) dum->shm_mutex)
- ++ptr;
-
- if (ptr < (uint8_t *) dum->shm_mutex) {
- *ptr = 1;
- }
- else {
- pthread_mutex_unlock(dum->shm_mutex);
- return NULL;
- }
-
- pthread_mutex_unlock(dum->shm_mutex);
-
-
- return (struct shm_block *)
- (dum->shm_base + ((ptr - dum->ptr_map)
- * SHM_DU_BUFF_BLOCK_SIZE));
-}
-
struct shm_du_buff * shm_create_du_buff(struct shm_du_map * dum,
size_t size,
size_t headspace,
@@ -262,11 +224,11 @@ struct shm_du_buff * shm_create_du_buff(struct shm_du_map * dum,
size_t len)
{
struct shm_du_buff * sdb;
- long index;
long prev_index = -1;
size_t remaining = size;
size_t ts = size - (headspace + len);
uint8_t * read_pos = data;
+ size_t blocks;
if (dum == NULL || data == NULL) {
LOG_DBGF("Bogus input, bugging out.");
@@ -288,51 +250,42 @@ struct shm_du_buff * shm_create_du_buff(struct shm_du_map * dum,
return NULL;
}
- sdb = alloc_du_buff(dum);
- if (sdb == NULL) {
+ pthread_mutex_lock(dum->shm_mutex);
+
+ blocks = size / SHM_DU_BLOCK_DATA_SIZE;
+ if (size % SHM_DU_BLOCK_DATA_SIZE > 0)
+ ++blocks;
+
+ if (!shm_map_free(dum, blocks)) {
+ pthread_mutex_unlock(dum->shm_mutex);
LOG_DBGF("Allocation failed, Out of Memory.");
return NULL;
}
- index = du_buff_ptr_to_idx(dum, sdb);
+ sdb = dum->ptr_du_buff + *dum->ptr_head;
+
sdb->size = size;
sdb->du_head = headspace;
sdb->du_tail = sdb->du_head + len;
while (remaining > 0) {
struct shm_block * shm_buf;
- unsigned long bytes_to_copy = len;
- uint8_t * write_pos;
+ long bytes_to_copy = len;
+ uint8_t * write_pos;
- if (prev_index == -1)
- shm_buf = idx_to_block_ptr(dum, index);
- else
- shm_buf = alloc_block(dum);
-
- if (shm_buf == NULL) {
- shm_release_du_buff(dum, sdb);
- return NULL;
- }
+ shm_buf = idx_to_block_ptr(dum, *(dum->ptr_head));
write_pos = (uint8_t *) shm_buf + sizeof *shm_buf;
- index = block_ptr_to_idx(dum, shm_buf);
+ shm_buf->size = remaining < SHM_DU_BLOCK_DATA_SIZE ?
+ remaining : SHM_DU_BLOCK_DATA_SIZE;
- if (size > SHM_DU_BLOCK_DATA_SIZE
- && remaining - ts <= SHM_DU_BLOCK_DATA_SIZE
- && remaining != ts) {
+ bytes_to_copy = shm_buf->size;
+
+ if (remaining <= SHM_DU_BLOCK_DATA_SIZE)
+ bytes_to_copy -= ts;
+ else if (remaining - ts <= SHM_DU_BLOCK_DATA_SIZE)
shm_buf->size = remaining - ts;
- bytes_to_copy = shm_buf->size;
- } else if (size > SHM_DU_BLOCK_DATA_SIZE && remaining == ts) {
- shm_buf->size = ts;
- bytes_to_copy = 0;
- } else {
- shm_buf->size = remaining < SHM_DU_BLOCK_DATA_SIZE ?
- remaining : SHM_DU_BLOCK_DATA_SIZE;
- bytes_to_copy =shm_buf->size;
- if (remaining == shm_buf->size)
- bytes_to_copy -= ts;
- }
remaining -= shm_buf->size;
@@ -340,16 +293,17 @@ struct shm_du_buff * shm_create_du_buff(struct shm_du_map * dum,
#ifdef CONFIG_OUROBOROS_DEBUG
memset(write_pos, 0, sdb->du_head);
#endif
-
write_pos += sdb->du_head;
bytes_to_copy -= sdb->du_head;
}
if (prev_index != -1)
- idx_to_block_ptr(dum, prev_index)->next = index;
-
- memcpy(write_pos, read_pos, bytes_to_copy);
+ idx_to_block_ptr(dum, prev_index)->next =
+ *(dum->ptr_head);
+ if (len > 0) {
+ memcpy(write_pos, read_pos, bytes_to_copy);
+ }
read_pos += bytes_to_copy;
#ifdef CONFIG_OUROBOROS_DEBUG
if (remaining == 0) {
@@ -360,52 +314,38 @@ struct shm_du_buff * shm_create_du_buff(struct shm_du_map * dum,
shm_buf->next = -1;
shm_buf->prev = prev_index;
- prev_index = index;
+ prev_index = *dum->ptr_head;
+
+ *(dum->ptr_head) = (*dum->ptr_head + 1) % SHM_BLOCKS_IN_MAP;
}
+ pthread_mutex_unlock(dum->shm_mutex);
+
return sdb;
}
-void shm_release_du_buff(struct shm_du_map * dum, struct shm_du_buff * sdb)
+int shm_release_du_buff(struct shm_du_map * dum)
{
- long index = 0;
-
- if (sdb == NULL) {
- LOG_DBGF("Bogus input, bugging out.");
- return;
- }
-
- if (sdb < dum->ptr_du_buff || sdb > dum->ptr_du_buff + SHM_BUFFS_SIZE) {
- LOG_DBGF("Refused to free sdb outside of region.");
- return;
- }
-
- if ((sdb - dum->ptr_du_buff) % sizeof *sdb != 0) {
- LOG_DBGF("Refused to free sdb at incorrect offset.");
- return;
- }
-
- index = du_buff_ptr_to_idx(dum, sdb);
+ int released = 0;
pthread_mutex_lock(dum->shm_mutex);
- if (dum->ptr_map[index] == 0) {
- LOG_DBGF("Attempt to free unused sdb. Nothing to do.");
+ if (*dum->ptr_head == *dum->ptr_tail) {
+ LOG_DBGF("Attempt to free empty ringbuffer. Nothing to do.");
pthread_mutex_unlock(dum->shm_mutex);
- return;
+ return -1;
}
- /* release all blocks in the structure */
- dum->ptr_map[index] = 0;
-
- index = idx_to_block_ptr(dum, index)->next;
- while (index != -1) {
- dum->ptr_map[index] = 0;
- index = idx_to_block_ptr(dum, index)->next;
+ while (idx_to_block_ptr(dum, *dum->ptr_tail)->next != -1) {
+ *(dum->ptr_tail) = (*dum->ptr_tail + 1) % SHM_BLOCKS_IN_MAP;
+ released++;
}
+ *(dum->ptr_tail) = (*dum->ptr_tail + 1) % SHM_BLOCKS_IN_MAP;
+
pthread_mutex_unlock(dum->shm_mutex);
+ return 0;
}
uint8_t * shm_du_buff_head_alloc(struct shm_du_map * dum,
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-11 09:32:07 +0000