Merge branch 'dev' into major

* dev:
  Move init of smp rw mutex from init to sys_args to make sure that it is initialized before the first erts_sys_getenv call
  Move erts_sys_env_init() to erts_sys_pre_init()
  Remove _DEBUG from start_erl.c
  Spelling correction in erlsrv doc
  Convert windows start_erl to take rootdir on command line
  Add command start_disabled to erlsrv
  Add global lock for erlsrv to avoid races
  Change start order so that service_event gets initialized before it's used

Conflicts:
	erts/emulator/sys/win32/sys.c

2 files changed, 39 insertions, 7 deletions

diff --git a/erts/doc/src/erlsrv.xml b/erts/doc/src/erlsrv.xml
index 0dfad2a112..919caa9542 100644
--- a/erts/doc/src/erlsrv.xml
+++ b/erts/doc/src/erlsrv.xml
@@ -273,7 +273,7 @@
       </desc>
     </func>
     <func>
-      <name>erlsrv {start | stop | disable | enable} &lt;service-name></name>
+      <name>erlsrv {start | start_disabled | stop | disable | enable} &lt;service-name></name>
       <fsummary>Manipulate the current service status.</fsummary>
       <desc>
         <p>These commands are only added for convenience, the normal
@@ -287,6 +287,21 @@
           service actually is stopped. Enabling a service sets it in
           automatic mode, that is started at boot. This command cannot
           set the service to manual.  </p>
+
+	<p>The <c>start_disabled</c> command operates on a service
+	regardless of if it's enabled/disabled or started/stopped.  It
+	does this by first enabling it (regardless of if it's enabled
+	or not), then starting it (if it's not already started) and
+	then disabling it. The result will be a disabled but started
+	service, regardless of its earlier state. This is useful for
+	starting services temporarily during a release upgrade. The
+	difference between using <c>start_disabled</c> and the
+	sequence <c>enable</c>, <c>start</c> and <c>disable</c> is
+	that all other <c>erlsrv</c> commands are locked out during
+	the sequence of operations in <c>start_disable</c>, making the
+	operation atomic from an <c>erlsrv</c> user's point of
+	view.</p>
+
       </desc>
     </func>
     <func>
diff --git a/erts/doc/src/start_erl.xml b/erts/doc/src/start_erl.xml
index 21cc901f52..6f6930af7e 100644
--- a/erts/doc/src/start_erl.xml
+++ b/erts/doc/src/start_erl.xml
@@ -69,12 +69,29 @@
           <c><![CDATA[erl]]></c> program. Everything <em>after</em><c><![CDATA[++]]></c> is
            interpreted as options to <c><![CDATA[start_erl]]></c> itself.</item>
           <tag>-reldir &lt;release root&gt;</tag>
-          <item>Mandatory if the environment variable <c><![CDATA[RELDIR]]></c> is not
-           specified. Tells start_erl where the root of the
-           release tree is placed in the file-system 
-           (like &lt;Erlang root&gt;\\releases). The
-          <c><![CDATA[start_erl.data]]></c> file is expected to be placed in
-           this directory (if not otherwise specified).</item>
+
+          <item>Mandatory if the environment variable
+          <c><![CDATA[RELDIR]]></c> is not specified and no
+          <c>-rootdir</c> option is given. Tells start_erl where the
+          root of the release tree is placed in the file-system (typically
+          &lt;Erlang root&gt;\\releases). The
+          <c><![CDATA[start_erl.data]]></c> file is expected to be
+          placed in this directory (if not otherwise specified). If
+          only the <c>-rootdir</c> option is given, the directory is
+          assumed to be &lt;Erlang root&gt;\\releases.</item>
+
+	  <tag>-rootdir &lt;Erlang root directory&gt;</tag> 
+
+	  <item>Mandatory if <c>-reldir</c> is not given and there is
+	  no <c><![CDATA[RELDIR]]></c> in the environment. This
+	  specifies the Erlang installation root directory (under
+	  which the <c>lib</c>, <c>releases</c> and
+	  <c>erts-&lt;Version&gt;</c> directories are placed). If only
+	  <c>-reldir</c> (or the environment variable
+	  <c><![CDATA[RELDIR]]></c>) is given, the Erlang root is assumed to
+	  be the directory exactly one level above the release
+	  directory.</item>
+
           <tag>-data &lt;data file name&gt;</tag>
           <item>Optional, specifies another data file than start_erl.data
            in the &lt;release root&gt;. It is specified relative to the