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| author | julian <julian@FreeBSD.org> | 1996-01-22 00:02:33 +0000 |
|---|---|---|
| committer | julian <julian@FreeBSD.org> | 1996-01-22 00:02:33 +0000 |
| commit | 619b731f5bb5e09dcf1eaf1fbd96383ca64398fd (patch) | |
| tree | a89c7f50ec371cef4418259b9dccdd31ebb2f61f /lib/libc/sys/fcntl.2 | |
| parent | 663b14fb2f3198fb0bfb62ae16b6b56c2a4dd055 (diff) | |
| download | FreeBSD-src-619b731f5bb5e09dcf1eaf1fbd96383ca64398fd.zip FreeBSD-src-619b731f5bb5e09dcf1eaf1fbd96383ca64398fd.tar.gz | |
Reviewed by: julian and (hsu?)
Submitted by: John Birrel(L?)
changes for threadsafe operations
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 |
