posix: shared memory support

Add POSIX shared memory manager (Shm). Includes a hook-based
approach for the backing memory storage that defaults to the
Workspace, and a test is provided using the heap. A test is
also provided for the basic use of mmap'ing a shared memory
object. This test currently fails at the mmap stage due to
no support for mmap.

1 files changed, 28 insertions, 2 deletions

diff --git a/cpukit/posix/src/shmunlink.c b/cpukit/posix/src/shmunlink.c
index f5599227b1..ab18450dc7 100644
--- a/cpukit/posix/src/shmunlink.c
+++ b/cpukit/posix/src/shmunlink.c
@@ -18,9 +18,35 @@
 #include <errno.h>
 #include <rtems/seterr.h>
 
+#include <rtems/posix/shmimpl.h>
+
 int shm_unlink( const char *name )
 {
-  (void) name;
+  Objects_Get_by_name_error obj_err;
+  int err = 0;
+  POSIX_Shm_Control *shm;
+
+  shm = _POSIX_Shm_Get_by_name( name, 0, &obj_err );
+  switch ( obj_err ) {
+    case OBJECTS_GET_BY_NAME_INVALID_NAME:
+      err = ENOENT;
+      break;
+
+    case OBJECTS_GET_BY_NAME_NAME_TOO_LONG:
+      err = ENAMETOOLONG;
+      break;
 
-  rtems_set_errno_and_return_minus_one( ENOENT );
+    case OBJECTS_GET_BY_NAME_NO_OBJECT:
+    default:
+      _Objects_Close( &_POSIX_Shm_Information, &shm->Object );
+      if ( shm->reference_count == 0 ) {
+        /* TODO: need to make sure this counts mmaps too! */
+        /* only remove the shm object if no references exist to it. */
+        _POSIX_Shm_Free( shm );
+      }
+      break;
+  }
+  if ( err != 0 )
+    rtems_set_errno_and_return_minus_one( err );
+  return 0;
 }