Author: kevans Date: Tue Nov 17 03:26:56 2020 New Revision: 367742 URL: https://svnweb.freebsd.org/changeset/base/367742
Log: _umtx_op: document UMTX_OP_SEM2_WAIT copyout behavior This clever technique to get a time remaining back was added to support sem_clockwait_np. Reviewed by: kib, vangyzen MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D27160 Modified: head/lib/libc/sys/_umtx_op.2 Modified: head/lib/libc/sys/_umtx_op.2 ============================================================================== --- head/lib/libc/sys/_umtx_op.2 Tue Nov 17 02:18:34 2020 (r367741) +++ head/lib/libc/sys/_umtx_op.2 Tue Nov 17 03:26:56 2020 (r367742) @@ -28,7 +28,7 @@ .\" .\" $FreeBSD$ .\" -.Dd November 13, 2017 +.Dd November 16, 2020 .Dt _UMTX_OP 2 .Os .Sh NAME @@ -1101,6 +1101,15 @@ The arguments to the request are: .It Fa obj Pointer to the semaphore (of type .Vt struct _usem2 ) . +.It Fa uaddr +Size of the memory passed in via the +.Fa uaddr2 +argument. +.It Fa uaddr2 +Optional pointer to a structure of type +.Vt struct _umtx_time , +which may be followed by a structure of type +.Vt struct timespec . .El .Pp Put the requesting thread onto a sleep queue if the semaphore counter @@ -1124,6 +1133,18 @@ An unblocked signal delivered during such wait results interruption and .Er EINTR error. +.Pp +If +.Dv UMTX_ABSTIME +was not set, and the operation was interrupted and the caller passed in a +.Fa uaddr2 +large enough to hold a +.Vt struct timespec +following the initial +.Vt struct _umtx_time , +then the +.Vt struct timespec +is updated to contain the unslept amount. .It Dv UMTX_OP_SEM2_WAKE Wake up waiters on semaphore lock. The arguments to the request are: _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
