0002533: Feature wish: Unix.fsync, etc.

(0005252)
mottl (reporter)
2010-02-25 19:24

This has been around for a really long time. I think at least the following POSIX system calls concerning syncing should be supported: sync and fsync. They are available on virtually every Unix system and indispensable for applications that need persistence guarantees.

Note that fdatasync is not supported on FreeBSD and Mac OS X.

(0005270)
avsm (reporter)
2010-03-20 21:19

fsync(2) is also more relaxed on MacOS X; it needs the F_FULLFSYNC fcntl to ensure it actually hits the disk in-order.

(0005277)
shinwell (developer)
2010-03-30 13:01

Markus, do you have a pre-existing patch for this (or could you construct one) which could be looked at?

(0005281)
mottl (reporter)
2010-03-30 16:21

Yes, just take a look at our Core-library, file "unix_ext_stubs.c". It contains a function "unix_fsync" that can surely be taken verbatim.

There are several other functions there that could probably be added to the OCaml distribution immediately, because they are well-standardized in POSIX and do not require elaborate API additions (types, etc.). E.g. pselect, abort, sync.

Some of the others are also well-standardized, but would need extra types, etc. I'm not sure what the OCaml team's preferred procedure for adding those would be.

Issue History
Date Modified	Username	Field	Change
2005-11-18 10:13	administrator	New Issue
2010-02-25 19:24	mottl	Note Added: 0005252
2010-03-20 21:19	avsm	Note Added: 0005270
2010-03-30 13:01	shinwell	Note Added: 0005277
2010-03-30 13:02	shinwell	Status	acknowledged => assigned
2010-03-30 13:02	shinwell	Assigned To	=> shinwell
2010-03-30 16:21	mottl	Note Added: 0005281

Notes
(0005252) mottl (reporter) 2010-02-25 19:24	This has been around for a really long time. I think at least the following POSIX system calls concerning syncing should be supported: sync and fsync. They are available on virtually every Unix system and indispensable for applications that need persistence guarantees. Note that fdatasync is not supported on FreeBSD and Mac OS X.

(0005270) avsm (reporter) 2010-03-20 21:19	fsync(2) is also more relaxed on MacOS X; it needs the F_FULLFSYNC fcntl to ensure it actually hits the disk in-order.

(0005277) shinwell (developer) 2010-03-30 13:01	Markus, do you have a pre-existing patch for this (or could you construct one) which could be looked at?

(0005281) mottl (reporter) 2010-03-30 16:21	Yes, just take a look at our Core-library, file "unix_ext_stubs.c". It contains a function "unix_fsync" that can surely be taken verbatim. There are several other functions there that could probably be added to the OCaml distribution immediately, because they are well-standardized in POSIX and do not require elaborate API additions (types, etc.). E.g. pselect, abort, sync. Some of the others are also well-standardized, but would need extra types, etc. I'm not sure what the OCaml team's preferred procedure for adding those would be.

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