<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="color: rgb(0, 0, 0); font-size: 14px; font-family: Calibri, sans-serif; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>Hi All,</div><div><br></div><div>I'm trying to get a little clarification on exactly how concurrency works with MOAB. When one process is reading a mesh (or more likely, data on a mesh) from a file and another process attempts to write to that file, what happens? Does the writer get blocked until the reader is through? Can the file be modified by the writer while a reader has an in-memory representation of the file? Is there a mechanism for the reader to know if the underlying file has changed (is this what <a class="el" href="https://redmine.scorec.rpi.edu/anonsvn/itaps/software/tags/1.3/tools/doxygen/html/group__MeshModification.html#ga392c572f006e88ebe62bffade3be8b9"></a><a href="https://redmine.scorec.rpi.edu/anonsvn/itaps/software/tags/1.3/tools/doxygen/html/group__MeshModification.html">iMesh_areEHValid</a> does)?</div><div><br></div><div>Does the same answer apply (with roles reversed) if the reader process starts after the writer process?</div><div><br></div><div>Are there strategies in place for dealing with these situations?</div><div><br></div><div>Thanks in advance,</div><div>Chris</div></body></html>