diff options
| author | Tom Lane | 2025-07-01 16:40:35 +0000 |
|---|---|---|
| committer | Tom Lane | 2025-07-01 16:40:35 +0000 |
| commit | 1fd772d192909a4f0e1ce88ebc72c8c43b81b025 (patch) | |
| tree | 6e25d6c46685e430fbca15200d85214138d6932d | |
| parent | 29213636e6cddcb7b2c877bff8cb9ba470d392db (diff) | |
Make sure IOV_MAX is defined.
We stopped defining IOV_MAX on non-Windows systems in 75357ab94, on
the assumption that every non-Windows system defines it in <limits.h>
as required by X/Open. GNU Hurd, however, doesn't follow that
standard either. Put back the old logic to assume 16 if it's
not defined.
Author: Michael Banck <[email protected]>
Co-authored-by: Christoph Berg <[email protected]>
Reviewed-by: Tom Lane <[email protected]>
Discussion: https://postgr.es/m/[email protected]
Discussion: https://postgr.es/m/[email protected]
Backpatch-through: 16
| -rw-r--r-- | src/include/port/pg_iovec.h | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/src/include/port/pg_iovec.h b/src/include/port/pg_iovec.h index df40c7208be..90be3af449d 100644 --- a/src/include/port/pg_iovec.h +++ b/src/include/port/pg_iovec.h @@ -21,9 +21,6 @@ #else -/* POSIX requires at least 16 as a maximum iovcnt. */ -#define IOV_MAX 16 - /* Define our own POSIX-compatible iovec struct. */ struct iovec { @@ -34,6 +31,15 @@ struct iovec #endif /* + * If <limits.h> didn't define IOV_MAX, define our own. X/Open requires at + * least 16. (GNU Hurd apparently feel that they're not bound by X/Open, + * because they don't define this symbol at all.) + */ +#ifndef IOV_MAX +#define IOV_MAX 16 +#endif + +/* * Define a reasonable maximum that is safe to use on the stack in arrays of * struct iovec and other small types. The operating system could limit us to * a number as low as 16, but most systems have 1024. |