diff options
Diffstat (limited to 'lib/libc/sys/fcntl.2')
| -rw-r--r-- | lib/libc/sys/fcntl.2 | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/lib/libc/sys/fcntl.2 b/lib/libc/sys/fcntl.2 index f53c02f..eb752fe 100644 --- a/lib/libc/sys/fcntl.2 +++ b/lib/libc/sys/fcntl.2 @@ -330,6 +330,29 @@ This implementation detects that sleeping until a locked region is unlocked would cause a deadlock and fails with an .Er EDEADLK error. +.Sh IMPLEMENTATION NOTES +.Pp +In the non-threaded library +.Fn fcntl +is implemented as the +.Va fcntl +syscall. +.Pp +In the threaded library, the +.Va fcntl +syscall is assembled to +.Fn _thread_sys_fcntl +and +.Fn fcntl +is implemented as a function which disables thread resheduling, locks +.Va fd +for read and write, then calls +.Fn _thread_sys_fcntl . +Before returning, +.Fn fcntl +unlocks +.Va fd +and enables thread resheduling. .Sh RETURN VALUES Upon successful completion, the value returned depends on .Fa cmd |
