API: More gracefully fail when opening shared memory segment fails.

[vpp.git] / src / svm / svm.c

diff --git a/src/svm/svm.c b/src/svm/svm.c
index 97add5a..663324e 100644 (file)
--- a/src/svm/svm.c
+++ b/src/svm/svm.c
@@ -458,14 +458,15 @@ svm_map_region (svm_map_region_args_t * a)
   struct stat stat;
   struct timespec ts, tsrem;
 
-  if (CLIB_DEBUG > 1)
-    clib_warning ("[%d] map region %s", getpid (), a->name);
-
   ASSERT ((a->size & ~(MMAP_PAGESIZE - 1)) == a->size);
   ASSERT (a->name);
 
   shm_name = shm_name_from_svm_map_region_args (a);
 
+  if (CLIB_DEBUG > 1)
+    clib_warning ("[%d] map region %s: shm_open (%s)",
+                 getpid (), a->name, shm_name);
+
   svm_fd = shm_open ((char *) shm_name, O_RDWR | O_CREAT | O_EXCL, 0777);
 
   if (svm_fd >= 0)
@@ -491,7 +492,7 @@ svm_map_region (svm_map_region_args_t * a)
          return (0);
        }
 
-      rp = mmap ((void *) a->baseva, a->size,
+      rp = mmap (uword_to_pointer (a->baseva, void *), a->size,
                 PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, svm_fd, 0);
 
       if (rp == (svm_region_t *) MAP_FAILED)
@@ -533,9 +534,10 @@ svm_map_region (svm_map_region_args_t * a)
       rp->virtual_size = a->size;
 
       rp->region_heap =
-       mheap_alloc_with_flags ((void *) (a->baseva + MMAP_PAGESIZE),
-                               (a->pvt_heap_size != 0) ?
-                               a->pvt_heap_size : SVM_PVT_MHEAP_SIZE,
+       mheap_alloc_with_flags (uword_to_pointer
+                               (a->baseva + MMAP_PAGESIZE, void *),
+                               (a->pvt_heap_size !=
+                                0) ? a->pvt_heap_size : SVM_PVT_MHEAP_SIZE,
                                MHEAP_FLAG_DISABLE_VM);
       oldheap = svm_push_pvt_heap (rp);
 
@@ -661,7 +663,7 @@ svm_map_region (svm_map_region_args_t * a)
       a->size = rp->virtual_size;
       munmap (rp, MMAP_PAGESIZE);
 
-      rp = (void *) mmap ((void *) a->baseva, a->size,
+      rp = (void *) mmap (uword_to_pointer (a->baseva, void *), a->size,
                          PROT_READ | PROT_WRITE,
                          MAP_SHARED | MAP_FIXED, svm_fd, 0);
       if ((uword) rp == (uword) MAP_FAILED)
@@ -731,7 +733,7 @@ svm_mutex_cleanup (void)
     }
 }
 
-static void
+static int
 svm_region_init_internal (svm_map_region_args_t * a)
 {
   svm_region_t *rp;
@@ -740,7 +742,7 @@ svm_region_init_internal (svm_map_region_args_t * a)
 
   /* guard against klutz calls */
   if (root_rp)
-    return;
+    return -1;
 
   root_rp_refcount++;
 
@@ -755,7 +757,8 @@ svm_region_init_internal (svm_map_region_args_t * a)
   a->baseva += randomize_baseva;
 
   rp = svm_map_region (a);
-  ASSERT (rp);
+  if (!rp)
+    return -1;
 
   region_lock (rp, 3);
 
@@ -776,6 +779,8 @@ svm_region_init_internal (svm_map_region_args_t * a)
     }
   region_unlock (rp);
   root_rp = rp;
+
+  return 0;
 }
 
 void
@@ -795,7 +800,7 @@ svm_region_init (void)
   svm_region_init_internal (a);
 }
 
-void
+int
 svm_region_init_chroot (const char *root_path)
 {
   svm_map_region_args_t _a, *a = &_a;
@@ -809,7 +814,7 @@ svm_region_init_chroot (const char *root_path)
   a->uid = 0;
   a->gid = 0;
 
-  svm_region_init_internal (a);
+  return svm_region_init_internal (a);
 }
 
 void
@@ -860,7 +865,8 @@ svm_region_find_or_create (svm_map_region_args_t * a)
   ASSERT (mp);
 
   /* Map the named region from the correct chroot environment */
-  a->root_path = (char *) mp->root_path;
+  if (a->root_path == NULL)
+    a->root_path = (char *) mp->root_path;
 
   /*
    * See if this region is already known. If it is, we're
@@ -946,6 +952,29 @@ svm_region_find_or_create (svm_map_region_args_t * a)
   return (rp);
 }
 
+void
+svm_region_unlink (svm_region_t * rp)
+{
+  svm_map_region_args_t _a, *a = &_a;
+  svm_main_region_t *mp;
+  u8 *shm_name;
+
+  ASSERT (root_rp);
+  ASSERT (rp);
+  ASSERT (vec_c_string_is_terminated (rp->region_name));
+
+  mp = root_rp->data_base;
+  ASSERT (mp);
+
+  a->root_path = (char *) mp->root_path;
+  a->name = rp->region_name;
+  shm_name = shm_name_from_svm_map_region_args (a);
+  if (CLIB_DEBUG > 1)
+    clib_warning ("[%d] shm_unlink (%s)", getpid (), shm_name);
+  shm_unlink ((const char *) shm_name);
+  vec_free (shm_name);
+}
+
 /*
  * svm_region_unmap
  *
@@ -1055,7 +1084,7 @@ found:
       vec_free (name);
 
       region_unlock (rp);
-      shm_unlink (rp->region_name);
+      svm_region_unlink (rp);
       munmap ((void *) virtual_base, virtual_size);
       region_unlock (root_rp);
       svm_pop_heap (oldheap);
@@ -1070,9 +1099,6 @@ found:
 
 /*
  * svm_region_exit
- * There is no clean way to unlink the
- * root region when all clients go away,
- * so remove the pid entry and call it a day.
  */
 void
 svm_region_exit ()
@@ -1115,6 +1141,9 @@ svm_region_exit ()
 
 found:
 
+  if (vec_len (root_rp->client_pids) == 0)
+    svm_region_unlink (root_rp);
+
   region_unlock (root_rp);
   svm_pop_heap (oldheap);