From b5a2e7c634b438c3681b8c40c3fd8e9ab7d3e442 Mon Sep 17 00:00:00 2001 From: Quincey Koziol Date: Wed, 3 Jan 2007 10:04:55 -0500 Subject: [svn-r13101] Description: Change to more complicated method of re-adding an attribute whose name changes size, in order to get memory accesses correct. Tested on: Linux/32 2.6 (chicago) Linux/64 2.6 (chicago2) --- src/H5Oattribute.c | 58 +++++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 42 insertions(+), 16 deletions(-) diff --git a/src/H5Oattribute.c b/src/H5Oattribute.c index 423ffc3..576ce29 100644 --- a/src/H5Oattribute.c +++ b/src/H5Oattribute.c @@ -853,29 +853,55 @@ HGOTO_ERROR(H5E_ATTR, H5E_UNSUPPORTED, H5_ITER_ERROR, "renaming a shared attribu /* Mark message as dirty */ mesg->dirty = TRUE; - /* Check for attribute name getting longer */ - if(HDstrlen(udata->new_name) > HDstrlen(udata->old_name)) { - /* Increment attribute count */ - /* (must be incremented before call to H5O_msg_append_real(), in order for - * sanity checks to pass - QAK) - */ - if(oh->version > H5O_VERSION_1) - oh->nattrs++; + /* Check for attribute message changing size */ + if(HDstrlen(udata->new_name) != HDstrlen(udata->old_name)) { + H5A_t *attr; /* Attribute to re-add */ - /* Append attribute to object header */ - if(H5O_msg_append_real(udata->f, udata->dxpl_id, oh, H5O_MSG_ATTR, 0, 0, mesg->native, oh_flags_ptr) < 0) - HGOTO_ERROR(H5E_ATTR, H5E_CANTINSERT, H5_ITER_ERROR, "unable to relocate attribute in header") + /* Take ownership of the message's native info (the attribute) + * so any shared objects in the file aren't adjusted (and + * possibly deleted) when the message is released. + */ + /* (We do this more complicated sequence of actions because the + * simpler solution of adding the modified attribute first + * and then deleting the old message can re-allocate the + * list of messages during the "add the modified attribute" + * step, invalidating the message pointer we have here - QAK) + */ + attr = mesg->native; + mesg->native = NULL; /* If the later version of the object header format, decrement attribute */ - /* (must be decremented before call to H5O_release_mesg(), in order for - * sanity checks to pass - QAK) + /* (must be decremented before call to H5O_release_mesg(), + * so that the sanity checks pass - QAK) */ if(oh->version > H5O_VERSION_1) oh->nattrs--; - /* Convert message into a null message (i.e. delete it) */ - if(H5O_release_mesg(udata->f, udata->dxpl_id, oh, mesg, TRUE, TRUE) < 0) - HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, H5_ITER_ERROR, "unable to convert into null message") + /* Delete old attribute */ + /* (doesn't decrement the link count on shared components becuase + * the "native" pointer has been reset) + */ + if(H5O_release_mesg(udata->f, udata->dxpl_id, oh, mesg, FALSE, FALSE) < 0) + HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, H5_ITER_ERROR, "unable to release previous attribute") + + /* Increment attribute count */ + /* (must be incremented before call to H5O_msg_append_real(), + * so that the sanity checks pass - QAK) + */ + if(oh->version > H5O_VERSION_1) + oh->nattrs++; + + /* Append renamed attribute to object header */ + /* (increments the link count on shared components) */ + if(H5O_msg_append_real(udata->f, udata->dxpl_id, oh, H5O_MSG_ATTR, 0, 0, attr, oh_flags_ptr) < 0) + HGOTO_ERROR(H5E_ATTR, H5E_CANTINSERT, H5_ITER_ERROR, "unable to relocate renamed attribute in header") + + /* Decrement the link count on shared components */ + if(H5O_attr_delete(udata->f, udata->dxpl_id, attr, TRUE) < 0) + HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, H5_ITER_ERROR, "unable to delete attribute") + + /* Release the local copy of the attribute */ + H5O_msg_free_real(H5O_MSG_ATTR, attr); } /* end if */ /* Indicate that we found an existing attribute with the old name */ -- cgit v0.12