1.\" $NetBSD: puffs_cc.3,v 1.14 2009/04/11 16:48:53 wiz Exp $ 2.\" 3.\" Copyright (c) 2007, 2008 Antti Kantee. All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" 26.Dd January 28, 2008 27.Dt PUFFS_CC 3 28.Os 29.Sh NAME 30.Nm puffs_cc 31.Nd puffs continuation routines 32.Sh LIBRARY 33.Lb libpuffs 34.Sh SYNOPSIS 35.In puffs.h 36.Ft void 37.Fn puffs_cc_yield "struct puffs_cc *pcc" 38.Ft void 39.Fn puffs_cc_continue "struct puffs_cc *pcc" 40.Ft void 41.Fn puffs_cc_schedule "struct puffs_cc *pcc" 42.Ft struct puffs_cc * 43.Fn puffs_cc_getcc "struct puffs_usermount *pu" 44.Sh DESCRIPTION 45These routines are used for the cooperative multitasking suite present 46in puffs. 47.Pp 48.Bl -tag -width xxxx 49.It Fn puffs_cc_yield "pcc" 50Suspend and save the current execution context and return control 51to the previous point. 52In practice, from the file system author perspective, control returns 53back to where either the mainloop or where 54.Fn puffs_dispatch_exec 55was called from. 56.It Fn puffs_cc_continue pcc 57Will suspend current execution and return control to where it was 58before before calling 59.Fn puffs_cc_yield . 60This is rarely called directly but rather through 61.Fn puffs_dispatch_exec . 62.It Fn puffs_cc_schedule "pcc" 63Schedule a continuation. 64As opposed to 65.Fn puffs_cc_continue 66this call returns immediately. 67.Fa pcc 68will be scheduled sometime in the future. 69.It Fn puffs_cc_getcc "pu" 70Returns the current pcc or 71.Dv NULL 72if this is the main thread. 73.Em NOTE : 74The argument 75.Ar pu 76will most likely disappear at some point. 77.El 78.Pp 79Before calling 80.Fn puffs_cc_yield 81a file system will typically want to record some cookie value into its 82own internal bookkeeping. 83This cookie should be hooked to the 84.Va pcc 85so that the correct continuation can be continued when the event it 86was waiting for triggers. 87Alternatively, the 88.Xr puffs_framebuf 3 89framework and 90.Fn puffs_mainloop 91can be used for handling this automatically. 92.Sh SEE ALSO 93.Xr puffs 3 , 94.Xr puffs_framebuf 3 95