kernel: Document signal server

2 files changed, 84 insertions, 6 deletions

diff --git a/lib/kernel/doc/src/kernel_app.xml b/lib/kernel/doc/src/kernel_app.xml
index df681a505f..c581fa9d1e 100644
--- a/lib/kernel/doc/src/kernel_app.xml
+++ b/lib/kernel/doc/src/kernel_app.xml
@@ -11,7 +11,7 @@
       Licensed under the Apache License, Version 2.0 (the "License");
       you may not use this file except in compliance with the License.
       You may obtain a copy of the License at
- 
+
           http://www.apache.org/licenses/LICENSE-2.0
 
       Unless required by applicable law or agreed to in writing, software
@@ -19,7 +19,7 @@
       WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       See the License for the specific language governing permissions and
       limitations under the License.
-    
+
     </legalnotice>
 
     <title>kernel</title>
@@ -58,6 +58,60 @@
   </section>
 
   <section>
+      <title>OS Signal Event Handler</title>
+      <p>Asynchronous OS signals may be subscribed to via the Kernel applications event manager
+          (see <seealso marker="doc/design_principles:des_princ">OTP Design Principles</seealso> and
+          <seealso marker="stdlib:gen_event"><c>gen_event(3)</c></seealso>) registered as <c>erl_signal_server</c>.
+          A default signal handler is installed which handles the following signals:</p>
+          <taglist>
+              <tag><c>sigusr1</c></tag>
+              <item><p>The default handler will halt Erlang and produce a crashdump
+                      with slogan "Received SIGUSR1".
+                      This is equivalent to calling <c>erlang:halt("Received SIGUSR1")</c>.
+              </p></item>
+
+              <tag><c>sigquit</c></tag>
+              <item><p>The default handler will halt Erlang immediately.
+                      This is equivalent to calling <c>erlang:halt()</c>.
+              </p></item>
+
+              <tag><c>sigterm</c></tag>
+              <item><p>The default handler will terminate Erlang normally.
+                      This is equivalent to calling <c>init:stop()</c>.
+              </p></item>
+          </taglist>
+
+          <section>
+              <title>Events</title>
+              <p>Any event handler added to <c>erl_signal_server</c> must handle the following events.</p>
+              <taglist>
+                  <tag><c>sighup</c></tag>
+                  <item><p>Hangup detected on controlling terminal or death of controlling process</p></item>
+                  <tag><c>sigquit</c></tag>
+                  <item><p>Quit from keyboard</p></item>
+                  <tag><c>sigabrt</c></tag>
+                  <item><p>Abort signal from abort</p></item>
+                  <tag><c>sigalrm</c></tag>
+                  <item><p>Timer signal from alarm</p></item>
+                  <tag><c>sigterm</c></tag>
+                  <item><p>Termination signal</p></item>
+                  <tag><c>sigusr1</c></tag>
+                  <item><p>User-defined signal 1</p></item>
+                  <tag><c>sigusr2</c></tag>
+                  <item><p>User-defined signal 2</p></item>
+                  <tag><c>sigchld</c></tag>
+                  <item><p>Child process stopped or terminated</p></item>
+                  <tag><c>sigstop</c></tag>
+                  <item><p>Stop process</p></item>
+                  <tag><c>sigtstp</c></tag>
+                  <item><p>Stop typed at terminal</p></item>
+              </taglist>
+
+              <p>Setting OS signals are described in <seealso marker="os#set_signal/2"><c>os:set_signal/2</c></seealso>.</p>
+          </section>
+  </section>
+
+  <section>
     <title>Configuration</title>
     <p>The following configuration parameters are defined for the Kernel
       application. For more information about configuration parameters,
@@ -405,4 +459,3 @@ MaxT = TickTime + TickTime / 4</code>
       <seealso marker="stdlib:timer"><c>timer(3)</c></seealso></p>
   </section>
 </appref>
-
diff --git a/lib/kernel/doc/src/os.xml b/lib/kernel/doc/src/os.xml
index 739ac35d2a..6ba69d12a3 100644
--- a/lib/kernel/doc/src/os.xml
+++ b/lib/kernel/doc/src/os.xml
@@ -11,7 +11,7 @@
       Licensed under the Apache License, Version 2.0 (the "License");
       you may not use this file except in compliance with the License.
       You may obtain a copy of the License at
- 
+
           http://www.apache.org/licenses/LICENSE-2.0
 
       Unless required by applicable law or agreed to in writing, software
@@ -19,7 +19,7 @@
       WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       See the License for the specific language governing permissions and
       limitations under the License.
-    
+
     </legalnotice>
 
     <title>os</title>
@@ -156,6 +156,32 @@ DirOut = os:cmd("dir"), % on Win32 platform</code>
     </func>
 
     <func>
+      <name name="set_signal" arity="2"/>
+      <fsummary>Enables or disables handling of OS signals.</fsummary>
+      <desc>
+          <p>Enables or disables OS signals.</p>
+          <p>Each signal my be set to one of the following options:</p>
+          <taglist>
+              <tag><c>ignore</c></tag>
+              <item>
+                  This signal will be ignored.
+              </item>
+
+              <tag><c>default</c></tag>
+              <item>
+                  This signal will use the default signal handler for the operating system.
+              </item>
+
+              <tag><c>handle</c></tag>
+              <item>
+                  This signal will notify <c>erl_signal_server</c> when it is received by
+                  the Erlang runtime system.
+              </item>
+          </taglist>
+      </desc>
+    </func>
+
+    <func>
       <name name="system_time" arity="0"/>
       <fsummary>Current OS system time.</fsummary>
       <desc>
@@ -296,4 +322,3 @@ calendar:now_to_universal_time(TS),
     </func>
   </funcs>
 </erlref>
-