Merged in sandervrijders/ouroboros/be-flow-down (pull request #596)

ipcpd, lib: Add flow down events

1 files changed, 36 insertions, 16 deletions

diff --git a/src/lib/shm_rbuff_pthr.c b/src/lib/shm_rbuff_pthr.c
index 9567762f..fb183d8f 100644
--- a/src/lib/shm_rbuff_pthr.c
+++ b/src/lib/shm_rbuff_pthr.c
@@ -26,6 +26,7 @@
 #include <ouroboros/lockfile.h>
 #include <ouroboros/time_utils.h>
 #include <ouroboros/errno.h>
+#include <ouroboros/fccntl.h>
 
 #include <pthread.h>
 #include <sys/mman.h>
@@ -41,8 +42,6 @@
 #include <stdbool.h>
 
 #define FN_MAX_CHARS 255
-#define RB_OPEN 0
-#define RB_CLOSED 1
 
 #define SHM_RBUFF_FILE_SIZE ((SHM_BUFFER_SIZE) * sizeof(ssize_t)          \
                              + 3 * sizeof(size_t)                         \
@@ -138,7 +137,7 @@ struct shm_rbuff * shm_rbuff_create(pid_t api, int port_id)
         pthread_cond_init(rb->add, &cattr);
         pthread_cond_init(rb->del, &cattr);
 
-        *rb->acl = RB_OPEN;
+        *rb->acl  = ACL_RDWR;
         *rb->head = 0;
         *rb->tail = 0;
 
@@ -226,8 +225,11 @@ void shm_rbuff_destroy(struct shm_rbuff * rb)
         free(rb);
 }
 
-int shm_rbuff_write(struct shm_rbuff * rb, size_t idx)
+int shm_rbuff_write(struct shm_rbuff * rb,
+                    size_t             idx)
 {
+        int ret = 0;
+
         assert(rb);
         assert(idx < SHM_BUFFER_SIZE);
 
@@ -237,14 +239,18 @@ int shm_rbuff_write(struct shm_rbuff * rb, size_t idx)
         if (pthread_mutex_lock(rb->lock) == EOWNERDEAD)
                 pthread_mutex_consistent(rb->lock);
 #endif
-        if (*rb->acl == RB_CLOSED) {
-                pthread_mutex_unlock(rb->lock);
-                return -ENOTALLOC;
+
+        if (*rb->acl != ACL_RDWR) {
+                if (*rb->acl & ACL_FLOWDOWN)
+                        ret = -EFLOWDOWN;
+                else if (*rb->acl & ACL_RDONLY)
+                        ret = -ENOTALLOC;
+                goto err;
         }
 
         if (!shm_rbuff_free(rb)) {
-                pthread_mutex_unlock(rb->lock);
-                return -EAGAIN;
+                ret = -EAGAIN;
+                goto err;
         }
 
         if (shm_rbuff_empty(rb))
@@ -256,6 +262,9 @@ int shm_rbuff_write(struct shm_rbuff * rb, size_t idx)
         pthread_mutex_unlock(rb->lock);
 
         return 0;
+ err:
+        pthread_mutex_unlock(rb->lock);
+        return ret;
 }
 
 ssize_t shm_rbuff_read(struct shm_rbuff * rb)
@@ -270,9 +279,11 @@ ssize_t shm_rbuff_read(struct shm_rbuff * rb)
         if (pthread_mutex_lock(rb->lock) == EOWNERDEAD)
                 pthread_mutex_consistent(rb->lock);
 #endif
+
         if (shm_rbuff_empty(rb)) {
+                ret = *rb->acl & ACL_FLOWDOWN ? -EFLOWDOWN : -EAGAIN;
                 pthread_mutex_unlock(rb->lock);
-                return -EAGAIN;
+                return ret;
         }
 
         ret = *tail_el_ptr(rb);
@@ -297,6 +308,12 @@ ssize_t shm_rbuff_read_b(struct shm_rbuff *      rb,
         if (pthread_mutex_lock(rb->lock) == EOWNERDEAD)
                 pthread_mutex_consistent(rb->lock);
 #endif
+
+        if (shm_rbuff_empty(rb) && (*rb->acl & ACL_FLOWDOWN)) {
+                pthread_mutex_unlock(rb->lock);
+                return -EFLOWDOWN;
+        }
+
         pthread_cleanup_push((void(*)(void *))pthread_mutex_unlock,
                              (void *) rb->lock);
 
@@ -324,7 +341,8 @@ ssize_t shm_rbuff_read_b(struct shm_rbuff *      rb,
         return idx;
 }
 
-void shm_rbuff_block(struct shm_rbuff * rb)
+void shm_rbuff_set_acl(struct shm_rbuff * rb,
+                       uint32_t           flags)
 {
         assert(rb);
 
@@ -334,13 +352,15 @@ void shm_rbuff_block(struct shm_rbuff * rb)
         if (pthread_mutex_lock(rb->lock) == EOWNERDEAD)
                 pthread_mutex_consistent(rb->lock);
 #endif
-        *rb->acl = RB_CLOSED;
+        *rb->acl = (size_t) flags;
 
         pthread_mutex_unlock(rb->lock);
 }
 
-void shm_rbuff_unblock(struct shm_rbuff * rb)
+uint32_t shm_rbuff_get_acl(struct shm_rbuff * rb)
 {
+        uint32_t flags;
+
         assert(rb);
 
 #ifndef HAVE_ROBUST_MUTEX
@@ -349,9 +369,11 @@ void shm_rbuff_unblock(struct shm_rbuff * rb)
         if (pthread_mutex_lock(rb->lock) == EOWNERDEAD)
                 pthread_mutex_consistent(rb->lock);
 #endif
-        *rb->acl = RB_OPEN;
+        flags = (uint32_t) *rb->acl;
 
         pthread_mutex_unlock(rb->lock);
+
+        return flags;
 }
 
 void shm_rbuff_fini(struct shm_rbuff * rb)
@@ -364,8 +386,6 @@ void shm_rbuff_fini(struct shm_rbuff * rb)
         if (pthread_mutex_lock(rb->lock) == EOWNERDEAD)
                 pthread_mutex_consistent(rb->lock);
 #endif
-        assert(*rb->acl == RB_CLOSED);
-
         pthread_cleanup_push((void(*)(void *))pthread_mutex_unlock,
                              (void *) rb->lock);