diff options
Diffstat (limited to 'lib/libc/gen/lockf.3')
| -rw-r--r-- | lib/libc/gen/lockf.3 | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/lib/libc/gen/lockf.3 b/lib/libc/gen/lockf.3 index 1cfc40a..fe877bd 100644 --- a/lib/libc/gen/lockf.3 +++ b/lib/libc/gen/lockf.3 @@ -96,7 +96,8 @@ detects if a lock by another process is present on the specified section. The .Fa size argument is the number of contiguous bytes to be locked or -unlocked. The section to be locked or unlocked starts at the current +unlocked. +The section to be locked or unlocked starts at the current offset in the file and extends forward for a positive size or backward for a negative size (the preceding bytes up to but not including the current offset). However, it is not permitted to lock a section that @@ -112,9 +113,11 @@ The sections locked with or .Dv F_TLOCK may, in whole or in part, contain or be contained by a previously -locked section for the same process. When this occurs, or if adjacent +locked section for the same process. +When this occurs, or if adjacent locked sections would occur, the sections are combined into a single -locked section. If the request would cause the number of locks to +locked section. +If the request would cause the number of locks to exceed a system-imposed limit, the request will fail. .Pp .Dv F_LOCK @@ -133,15 +136,18 @@ file descriptor for the file. .Pp .Dv F_ULOCK requests release (wholly or in part) one or more locked sections -controlled by the process. Locked sections will be unlocked starting +controlled by the process. +Locked sections will be unlocked starting at the current file offset through .Fa size bytes or to the end of file if size is 0. When all of a locked section is not released (that is, when the beginning or end of the area to be unlocked falls within a locked section), the remaining portions of -that section are still locked by the process. Releasing the center +that section are still locked by the process. +Releasing the center portion of a locked section will cause the remaining locked beginning -and end portions to become two separate locked sections. If the +and end portions to become two separate locked sections. +If the request would cause the number of locks in the system to exceed a system-imposed limit, the request will fail. .Pp |
