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| author | Zandra Norman <[email protected]> | 2017-01-23 11:49:32 +0100 |
|---|---|---|
| committer | Zandra Norman <[email protected]> | 2017-04-21 14:52:48 +0200 |
| commit | 8ca53b0f993ffbf2991e3068b76ec15b8f5eca51 (patch) | |
| tree | 3799fa1b4a6820aff34e66f6b99f72329d4d0771 /lib/stdlib/doc/src/gen_server.xml | |
| parent | b468fb90b447bbd99d351449d90f2775e84ed4f2 (diff) | |
| download | otp-8ca53b0f993ffbf2991e3068b76ec15b8f5eca51.tar.gz otp-8ca53b0f993ffbf2991e3068b76ec15b8f5eca51.tar.bz2 otp-8ca53b0f993ffbf2991e3068b76ec15b8f5eca51.zip | |
stdlib: Make gen_server callbacks optional
Diffstat (limited to 'lib/stdlib/doc/src/gen_server.xml')
| -rw-r--r-- | lib/stdlib/doc/src/gen_server.xml | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/lib/stdlib/doc/src/gen_server.xml b/lib/stdlib/doc/src/gen_server.xml index 662076b5f0..4540449792 100644 --- a/lib/stdlib/doc/src/gen_server.xml +++ b/lib/stdlib/doc/src/gen_server.xml @@ -504,6 +504,13 @@ gen_server:abcast -----> Module:handle_cast/2 <v>Reason = term()</v> </type> <desc> + <note> + <p>This callback is optional, so callback modules need not export it. + If a release upgrade/downgrade with <c>Change={advanced,Extra}</c> + specified in the <c>appup</c> file is made when <c>code_change/3</c> + isn't implemented the process will crash with an <c>undef</c> exit + reason.</p> + </note> <p>This function is called by a <c>gen_server</c> process when it is to update its internal state during a release upgrade/downgrade, that is, when the instruction <c>{update,Module,Change,...}</c>, @@ -690,6 +697,12 @@ gen_server:abcast -----> Module:handle_cast/2 <v> Reason = normal | term()</v> </type> <desc> + <note> + <p>This callback is optional, so callback modules need not + export it. The <c>gen_server</c> module provides a default + implementation of this function that logs about the unexpected + <c>Info</c> message, drops it and returns <c>{noreply, State}</c>.</p> + </note> <p>This function is called by a <c>gen_server</c> process when a time-out occurs or when it receives any other message than a synchronous or asynchronous request (or a system message).</p> @@ -750,6 +763,11 @@ gen_server:abcast -----> Module:handle_cast/2 <v>State = term()</v> </type> <desc> + <note> + <p>This callback is optional, so callback modules need not + export it. The <c>gen_server</c> module provides a default + implementation without cleanup.</p> + </note> <p>This function is called by a <c>gen_server</c> process when it is about to terminate. It is to be the opposite of <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso> |