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author | Lennart Poettering <lennart@poettering.net> | 2015-04-20 20:56:17 +0200 |
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committer | Lennart Poettering <lennart@poettering.net> | 2015-04-21 00:58:56 +0200 |
commit | ba780c116fc919c58fad07f45f4e800a062af63e (patch) | |
tree | 6e323746e5367a95b9749869e5ea178ed12c727f /CODING_STYLE | |
parent | 81bd37a85fed090350a84db1f0741125582d160e (diff) |
CODING_STYLE: document how destructors should work
Diffstat (limited to 'CODING_STYLE')
-rw-r--r-- | CODING_STYLE | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/CODING_STYLE b/CODING_STYLE index feb1a9dd67..a295ca77f2 100644 --- a/CODING_STYLE +++ b/CODING_STYLE @@ -239,3 +239,19 @@ 2, i.e. stdin, stdout, stderr, should those fds be closed. Given the special semantics of those fds, it's probably a good idea to avoid them. F_DUPFD_CLOEXEC with "3" as parameter avoids them. + +- When you define a destructor or unref() call for an object, please + accept a NULL object and simply treat this as NOP. This is similar + to how libc free() works, which accepts NULL pointers and becomes a + NOP for them. By following this scheme a lot of if checks can be + removed before invoking your destructor, which makes the code + substantially more readable and robust. + +- Related to this: when you define a destructor or unref() call for an + object, please make it return the same type it takes and always + return NULL from it. This allows writing code like this: + + p = foobar_unref(p); + + which will always work regardless if p is initialized or not, and + guarantees that p is NULL afterwards, all in just one line. |