[esock|doc] Add text about the abort message

If another process closes the socket, the caller will
receive an abort message instead (of the select message).

OTP-15731

1 files changed, 12 insertions, 1 deletions

diff --git a/erts/doc/src/socket_usage.xml b/erts/doc/src/socket_usage.xml
index 3d18bd1af7..fcfe9b54ec 100644
--- a/erts/doc/src/socket_usage.xml
+++ b/erts/doc/src/socket_usage.xml
@@ -56,8 +56,19 @@
       when there is actually nothing to read, it will return with
       <c>{ok, SelectInfo}</c>. When data eventually arrives a 'select message'
       will be sent to the caller:
-      <c>{'$socket', Sock, select, Info}</c>. The caller can make another
+      <list type="ordered">
+	<item><c>{'$socket', Sock, select, Info}</c></item>
+      </list>
+      The caller can then make another
       call to the recv function and now expect data.</p>
+      <p>The user must also be prepared to receive an abort message:
+      <list type="ordered">
+	<item><c>{'$socket', Sock, abort, Reason}</c></item>
+      </list>
+      If the operation is aborted
+      for whatever reason (e.g. if the socket is closed "by someone else").
+      The <c>Reason</c> part contains the abort reason (in case the socket
+      has been closed <c>Reason = {Ref, closed}</c>). </p>
       <p>Note that all other users are <em>locked out</em> until the
       'current user' has called the function (recv in this case). So either
       immediately call the function or