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author | yar <yar@FreeBSD.org> | 2004-05-17 23:09:10 +0000 |
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committer | yar <yar@FreeBSD.org> | 2004-05-17 23:09:10 +0000 |
commit | 75331fe5be2c94da9c5ef4db51ded9f039f78410 (patch) | |
tree | c91b8ed3b77526e170afd00035d74d30b0184dd5 /lib/libc/sys/fcntl.2 | |
parent | 7730ed4e269438738132eddf46a10fcec2e1a0f4 (diff) | |
download | FreeBSD-src-75331fe5be2c94da9c5ef4db51ded9f039f78410.zip FreeBSD-src-75331fe5be2c94da9c5ef4db51ded9f039f78410.tar.gz |
Clarify and extend paragraphs on interoperation
of fcntl(2), flock(2), and lockf(3) advisory locks.
Add such a paragraph to the flock(2) manpage for the
sake of consistency.
Reviewed by: Cyrille Lefevre and Kirk McKusick on -arch
MFC after: 2 weeks
Diffstat (limited to 'lib/libc/sys/fcntl.2')
-rw-r--r-- | lib/libc/sys/fcntl.2 | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/lib/libc/sys/fcntl.2 b/lib/libc/sys/fcntl.2 index c888890..92b7440 100644 --- a/lib/libc/sys/fcntl.2 +++ b/lib/libc/sys/fcntl.2 @@ -341,11 +341,26 @@ The system call is recommended for applications that want to ensure the integrity of their locks when using library routines or wish to pass locks to their children. -Note that -.Xr flock 2 +.Pp +The +.Fn fcntl , +.Xr flock 2 , and +.Xr lockf 3 +locks are compatible. +Processes using different locking interfaces can cooperate +over the same file safely. +However, only one of such interfaces should be used within +the same process. +If a file is locked by a process through +.Xr flock 2 , +any record within the file will be seen as locked +from the viewpoint of another process using .Fn fcntl -locks may be safely used concurrently but +or +.Xr lockf 3 , +and vice versa. +Note that .Fn fcntl F_GETLK returns \-1 in .Fa l_pid @@ -558,6 +573,7 @@ for the reasons as stated in .Xr getdtablesize 2 , .Xr open 2 , .Xr sigvec 2 , +.Xr lockf 3 , .Xr tcgetpgrp 3 , .Xr tcsetpgrp 3 .Sh HISTORY |