lib: Refactor shm_rdrbuff and shm_rbuff

This refactors the creation of shm_rdrbuff and shm_rbuff elements. All
cleanup is now handled and the common code between the _open() and
_create() calls is moved to a static function. Common code between the
pthread and lockless rbuff implementations was moved to shm_rbuff.c

Signed-off-by: Dimitri Staessens <[email protected]>
Signed-off-by: Sander Vrijders <[email protected]>

1 files changed, 175 insertions, 0 deletions

diff --git a/src/lib/shm_rbuff.c b/src/lib/shm_rbuff.c
index 93108332..00f0b92b 100644
--- a/src/lib/shm_rbuff.c
+++ b/src/lib/shm_rbuff.c
@@ -24,6 +24,181 @@
 
 #include "config.h"
 
+#include <ouroboros/shm_rbuff.h>
+#include <ouroboros/lockfile.h>
+#include <ouroboros/time_utils.h>
+#include <ouroboros/errno.h>
+#include <ouroboros/fccntl.h>
+
+#include <pthread.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <signal.h>
+#include <sys/stat.h>
+#include <assert.h>
+#include <stdbool.h>
+
+#define FN_MAX_CHARS 255
+
+#define SHM_RB_FILE_SIZE ((SHM_BUFFER_SIZE) * sizeof(ssize_t)          \
+                          + 3 * sizeof(size_t)                          \
+                          + sizeof(pthread_mutex_t)                     \
+                          + 2 * sizeof (pthread_cond_t))
+
+#define shm_rbuff_used(rb) ((*rb->head + (SHM_BUFFER_SIZE) - *rb->tail)   \
+                            & ((SHM_BUFFER_SIZE) - 1))
+#define shm_rbuff_free(rb) (shm_rbuff_used(rb) + 1 < (SHM_BUFFER_SIZE))
+#define shm_rbuff_empty(rb) (*rb->head == *rb->tail)
+#define head_el_ptr(rb) (rb->shm_base + *rb->head)
+#define tail_el_ptr(rb) (rb->shm_base + *rb->tail)
+
+struct shm_rbuff {
+        ssize_t *         shm_base; /* start of entry                */
+        size_t *          head;     /* start of ringbuffer head      */
+        size_t *          tail;     /* start of ringbuffer tail      */
+        size_t *          acl;      /* access control                */
+        pthread_mutex_t * lock;     /* lock all free space in shm    */
+        pthread_cond_t *  add;      /* SDU arrived                   */
+        pthread_cond_t *  del;      /* SDU removed                   */
+        pid_t             api;      /* api of the owner              */
+        int               port_id;  /* port_id of the flow           */
+};
+
+void shm_rbuff_close(struct shm_rbuff * rb)
+{
+        assert(rb);
+
+        munmap(rb->shm_base, SHM_RB_FILE_SIZE);
+
+        free(rb);
+}
+
+#define MM_FLAGS (PROT_READ | PROT_WRITE)
+
+struct shm_rbuff * rbuff_create(pid_t api, int port_id, int flags)
+{
+        struct shm_rbuff * rb;
+        int                fd;
+        ssize_t *          shm_base;
+        char               fn[FN_MAX_CHARS];
+
+        sprintf(fn, SHM_RBUFF_PREFIX "%d.%d", api, port_id);
+
+        rb = malloc(sizeof(*rb));
+        if (rb == NULL)
+                goto fail_malloc;
+
+        fd = shm_open(fn, flags, 0666);
+        if (fd == -1)
+                goto fail_open;
+
+        if ((flags & O_CREAT) && ftruncate(fd, SHM_RB_FILE_SIZE - 1) < 0)
+                goto fail_truncate;
+
+        shm_base = mmap(NULL, SHM_RB_FILE_SIZE, MM_FLAGS, MAP_SHARED, fd, 0);
+        if (shm_base == MAP_FAILED)
+                goto fail_truncate;
+
+        close(fd);
+
+        rb->shm_base = shm_base;
+        rb->head     = (size_t *) (rb->shm_base + (SHM_BUFFER_SIZE));
+        rb->tail     = rb->head + 1;
+        rb->acl      = rb->tail + 1;
+        rb->lock     = (pthread_mutex_t *) (rb->acl + 1);
+        rb->add      = (pthread_cond_t *) (rb->lock + 1);
+        rb->del      = rb->add + 1;
+
+        rb->api = api;
+        rb->port_id = port_id;
+
+        return rb;
+
+ fail_truncate:
+        close(fd);
+        if (flags & O_CREAT)
+                shm_unlink(fn);
+ fail_open:
+        free(rb);
+ fail_malloc:
+        return NULL;
+}
+
+struct shm_rbuff * shm_rbuff_create(pid_t api, int port_id)
+{
+        struct shm_rbuff *  rb;
+        pthread_mutexattr_t mattr;
+        pthread_condattr_t  cattr;
+        mode_t              mask;
+
+        mask = umask(0);
+
+        rb = rbuff_create(api, port_id, O_CREAT | O_EXCL | O_RDWR);
+
+        umask(mask);
+
+        if (rb == NULL)
+                goto fail_rb;
+
+        if (pthread_mutexattr_init(&mattr))
+                goto fail_mattr;
+
+        pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED);
+#ifdef HAVE_ROBUST_MUTEX
+        pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST);
+#endif
+        if (pthread_mutex_init(rb->lock, &mattr))
+                goto fail_mutex;
+
+        if (pthread_condattr_init(&cattr))
+                goto fail_cattr;
+
+        pthread_condattr_setpshared(&cattr, PTHREAD_PROCESS_SHARED);
+#ifndef __APPLE__
+        pthread_condattr_setclock(&cattr, PTHREAD_COND_CLOCK);
+#endif
+        if (pthread_cond_init(rb->add, &cattr))
+                goto fail_add;
+
+        if (pthread_cond_init(rb->del, &cattr))
+                goto fail_del;
+
+        *rb->acl  = ACL_RDWR;
+        *rb->head = 0;
+        *rb->tail = 0;
+
+        rb->api = api;
+        rb->port_id = port_id;
+
+        pthread_mutexattr_destroy(&mattr);
+        pthread_condattr_destroy(&cattr);
+
+        return rb;
+
+ fail_del:
+        pthread_cond_destroy(rb->add);
+ fail_add:
+        pthread_condattr_destroy(&cattr);
+ fail_cattr:
+        pthread_mutex_destroy(rb->lock);
+ fail_mutex:
+        pthread_mutexattr_destroy(&mattr);
+ fail_mattr:
+        shm_rbuff_destroy(rb);
+ fail_rb:
+        return NULL;
+}
+
+struct shm_rbuff * shm_rbuff_open(pid_t api, int port_id)
+{
+        return rbuff_create(api, port_id, O_RDWR);
+}
+
 #if (defined(SHM_RBUFF_LOCKLESS) &&                            \
      (defined(__GNUC__) || defined (__clang__)))
 #include "shm_rbuff_ll.c"