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| author | Zandra Norman <[email protected]> | 2017-01-23 17:06:48 +0100 |
|---|---|---|
| committer | Raimo Niskanen <[email protected]> | 2017-04-21 16:13:29 +0200 |
| commit | eff1ee5ebf1d767d610cd6bc059e5f4dea57d2af (patch) | |
| tree | 6912a1608745b8df0470e4d54552b28080af87a4 /lib/stdlib/doc/src/gen_statem.xml | |
| parent | 30cae2492d8d8e927d57c0dc656ee2dfbec0a70c (diff) | |
| download | otp-eff1ee5ebf1d767d610cd6bc059e5f4dea57d2af.tar.gz otp-eff1ee5ebf1d767d610cd6bc059e5f4dea57d2af.tar.bz2 otp-eff1ee5ebf1d767d610cd6bc059e5f4dea57d2af.zip | |
stdlib: Make gen_statem callbacks optional
Diffstat (limited to 'lib/stdlib/doc/src/gen_statem.xml')
| -rw-r--r-- | lib/stdlib/doc/src/gen_statem.xml | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/lib/stdlib/doc/src/gen_statem.xml b/lib/stdlib/doc/src/gen_statem.xml index 1b99b65e09..bc86415d28 100644 --- a/lib/stdlib/doc/src/gen_statem.xml +++ b/lib/stdlib/doc/src/gen_statem.xml @@ -1733,6 +1733,16 @@ handle_event(_, _, State, Data) -> <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/4</c> is not implemented + the process will crash with exit reason <c>undef</c>. + </p> + </note> <p> This function is called by a <c>gen_statem</c> when it is to update its internal state during a release upgrade/downgrade, |