Merge pull request #1407 from eltex-ecss/auto_hibernate_timeout

Add option hibernate_after to gen_server, gen_statem and gen_event. 
Also added to the deprecated gen_fsm behaviour.

OTP14405

3 files changed, 39 insertions, 5 deletions

diff --git a/lib/stdlib/doc/src/gen_event.xml b/lib/stdlib/doc/src/gen_event.xml
index 09bde3e397..012737c390 100644
--- a/lib/stdlib/doc/src/gen_event.xml
+++ b/lib/stdlib/doc/src/gen_event.xml
@@ -358,7 +358,7 @@ gen_event:stop             ----->  Module:terminate/2
         <v>&nbsp;Name = atom()</v>
         <v>&nbsp;GlobalName = ViaName = term()</v>
         <v>Options = [Option]</v>
-        <v>&nbsp;Option = {debug,Dbgs} | {timeout,Time} | {spawn_opt,SOpts}</v>
+        <v>&nbsp;Option = {debug,Dbgs} | {timeout,Time} | {hibernate_after,HibernateAfterTimeout} | {spawn_opt,SOpts}</v>
         <v>&nbsp;&nbsp;Dbgs = [Dbg]</v>
         <v>&nbsp;&nbsp;&nbsp;Dbg = trace | log | statistics | {log_to_file,FileName} | {install,{Func,FuncState}}</v>
         <v>&nbsp;&nbsp;SOpts = [term()]</v>
@@ -385,7 +385,7 @@ gen_event:stop             ----->  Module:terminate/2
         <v>&nbsp;Name = atom()</v>
         <v>&nbsp;GlobalName = ViaName = term()</v>
         <v>Options = [Option]</v>
-        <v>&nbsp;Option = {debug,Dbgs} | {timeout,Time} | {spawn_opt,SOpts}</v>
+        <v>&nbsp;Option = {debug,Dbgs} | {timeout,Time} | {hibernate_after,HibernateAfterTimeout} | {spawn_opt,SOpts}</v>
         <v>&nbsp;&nbsp;Dbgs = [Dbg]</v>
         <v>&nbsp;&nbsp;&nbsp;Dbg = trace | log | statistics | {log_to_file,FileName} | {install,{Func,FuncState}}</v>
         <v>&nbsp;&nbsp;SOpts = [term()]</v>
@@ -419,6 +419,12 @@ gen_event:stop             ----->  Module:terminate/2
               <seealso marker="kernel:global"><c>global</c></seealso>.
               Thus, <c>{via,global,GlobalName}</c> is a valid reference.</p>
           </item>
+          <item>
+            <p>If option <c>{hibernate_after,HibernateAfterTimeout}</c> is present, the <c>gen_event</c>
+              process awaits any message for <c>HibernateAfterTimeout</c> milliseconds and
+              if no message is received, the process goes into hibernation automatically
+              (by calling <seealso marker="proc_lib#hibernate/3"><c>proc_lib:hibernate/3</c></seealso>).</p>
+          </item>
         </list>
         <p>If the event manager is successfully created, the function
           returns <c>{ok,Pid}</c>, where <c>Pid</c> is the pid of
diff --git a/lib/stdlib/doc/src/gen_server.xml b/lib/stdlib/doc/src/gen_server.xml
index a8006bb870..7d137fc772 100644
--- a/lib/stdlib/doc/src/gen_server.xml
+++ b/lib/stdlib/doc/src/gen_server.xml
@@ -199,7 +199,7 @@ gen_server:abcast     -----> Module:handle_cast/2
       <type>
         <v>Module = atom()</v>
         <v>Options = [Option]</v>
-        <v>&nbsp;Option = {debug,Dbgs}</v>
+        <v>&nbsp;Option = {debug,Dbgs} | {hibernate_after,HibernateAfterTimeout}</v>
         <v>&nbsp;&nbsp;Dbgs = [Dbg]</v>
         <v>&nbsp;&nbsp;&nbsp;Dbg = trace | log | statistics</v>
         <v>&nbsp;&nbsp;&nbsp;&nbsp;| {log_to_file,FileName} | {install,{Func,FuncState}}</v>
@@ -334,7 +334,7 @@ gen_server:abcast     -----> Module:handle_cast/2
         <v>Module = atom()</v>
         <v>Args = term()</v>
         <v>Options = [Option]</v>
-        <v>&nbsp;Option = {debug,Dbgs} | {timeout,Time} | {spawn_opt,SOpts}</v>
+        <v>&nbsp;Option = {debug,Dbgs} | {timeout,Time} | {hibernate_after,HibernateAfterTimeout} | {spawn_opt,SOpts}</v>
         <v>&nbsp;&nbsp;Dbgs = [Dbg]</v>
         <v>&nbsp;&nbsp;&nbsp;Dbg = trace | log | statistics | {log_to_file,FileName} | {install,{Func,FuncState}}</v>
         <v>&nbsp;&nbsp;SOpts = [term()]</v>
@@ -364,7 +364,7 @@ gen_server:abcast     -----> Module:handle_cast/2
         <v>Module = atom()</v>
         <v>Args = term()</v>
         <v>Options = [Option]</v>
-        <v>&nbsp;Option = {debug,Dbgs} | {timeout,Time} | {spawn_opt,SOpts}</v>
+        <v>&nbsp;Option = {debug,Dbgs} | {timeout,Time} | {hibernate_after,HibernateAfterTimeout} | {spawn_opt,SOpts}</v>
         <v>&nbsp;&nbsp;Dbgs = [Dbg]</v>
         <v>&nbsp;&nbsp;&nbsp;Dbg = trace | log | statistics | {log_to_file,FileName} | {install,{Func,FuncState}}</v>
         <v>&nbsp;&nbsp;SOpts = [term()]</v>
@@ -417,6 +417,12 @@ gen_server:abcast     -----> Module:handle_cast/2
               returns <c>{error,timeout}</c>.</p>
           </item>
           <item>
+            <p>If option <c>{hibernate_after,HibernateAfterTimeout}</c> is present, the <c>gen_server</c>
+              process awaits any message for <c>HibernateAfterTimeout</c> milliseconds and
+              if no message is received, the process goes into hibernation automatically
+              (by calling <seealso marker="proc_lib#hibernate/3"><c>proc_lib:hibernate/3</c></seealso>).</p>
+          </item>
+          <item>
             <p>If option <c>{debug,Dbgs}</c> is present,
               the corresponding <c>sys</c> function is called for each
               item in <c>Dbgs</c>; see
diff --git a/lib/stdlib/doc/src/gen_statem.xml b/lib/stdlib/doc/src/gen_statem.xml
index 17a3a3c83c..1aac88c308 100644
--- a/lib/stdlib/doc/src/gen_statem.xml
+++ b/lib/stdlib/doc/src/gen_statem.xml
@@ -453,6 +453,21 @@ handle_event(_, _, State, Data) ->
       </desc>
     </datatype>
     <datatype>
+      <name name="hibernate_after_opt"/>
+      <desc>
+	<p>
+          hibernate_after option that can be used when starting
+	  a <c>gen_statem</c> server through,
+	  <seealso marker="#enter_loop/4"><c>enter_loop/4-6</c></seealso>.
+	</p>
+    <p>If option<seealso marker="#type-hibernate_after_opt"><c>{hibernate_after,HibernateAfterTimeout}</c></seealso> is present, the <c>gen_statem</c>
+        process awaits any message for <c>HibernateAfterTimeout</c> milliseconds and
+        if no message is received, the process goes into hibernation automatically
+        (by calling <seealso marker="proc_lib#hibernate/3"><c>proc_lib:hibernate/3</c></seealso>).
+    </p>
+      </desc>
+    </datatype>
+    <datatype>
       <name name="start_opt"/>
       <desc>
 	<p>
@@ -1551,6 +1566,13 @@ handle_event(_, _, State, Data) ->
             </p>
           </item>
           <item>
+            <p>If option<seealso marker="#type-hibernate_after_opt"><c>{hibernate_after,HibernateAfterTimeout}</c></seealso> is present, the <c>gen_statem</c>
+              process awaits any message for <c>HibernateAfterTimeout</c> milliseconds and
+              if no message is received, the process goes into hibernation automatically
+              (by calling <seealso marker="proc_lib#hibernate/3"><c>proc_lib:hibernate/3</c></seealso>).
+            </p>
+          </item>
+          <item>
             <p>
               If option
               <seealso marker="#type-debug_opt"><c>{debug,Dbgs}</c></seealso>