18462SApril.Chin@Sun.COM#!/usr/bin/ksh93 28462SApril.Chin@Sun.COM 38462SApril.Chin@Sun.COM# 48462SApril.Chin@Sun.COM# CDDL HEADER START 58462SApril.Chin@Sun.COM# 68462SApril.Chin@Sun.COM# The contents of this file are subject to the terms of the 78462SApril.Chin@Sun.COM# Common Development and Distribution License (the "License"). 88462SApril.Chin@Sun.COM# You may not use this file except in compliance with the License. 98462SApril.Chin@Sun.COM# 108462SApril.Chin@Sun.COM# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 118462SApril.Chin@Sun.COM# or http://www.opensolaris.org/os/licensing. 128462SApril.Chin@Sun.COM# See the License for the specific language governing permissions 138462SApril.Chin@Sun.COM# and limitations under the License. 148462SApril.Chin@Sun.COM# 158462SApril.Chin@Sun.COM# When distributing Covered Code, include this CDDL HEADER in each 168462SApril.Chin@Sun.COM# file and include the License file at usr/src/OPENSOLARIS.LICENSE. 178462SApril.Chin@Sun.COM# If applicable, add the following below this CDDL HEADER, with the 188462SApril.Chin@Sun.COM# fields enclosed by brackets "[]" replaced with your own identifying 198462SApril.Chin@Sun.COM# information: Portions Copyright [yyyy] [name of copyright owner] 208462SApril.Chin@Sun.COM# 218462SApril.Chin@Sun.COM# CDDL HEADER END 228462SApril.Chin@Sun.COM# 238462SApril.Chin@Sun.COM 248462SApril.Chin@Sun.COM# 25*12068SRoger.Faulkner@Oracle.COM# Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved. 268462SApril.Chin@Sun.COM# 278462SApril.Chin@Sun.COM 288462SApril.Chin@Sun.COM# 298462SApril.Chin@Sun.COM# filemutexdemo1 - a simple locking demo which supports read/write 308462SApril.Chin@Sun.COM# locks and critical sections (like JAVA's "syncronized" keyword) 318462SApril.Chin@Sun.COM# 328462SApril.Chin@Sun.COM 338462SApril.Chin@Sun.COM# Solaris needs /usr/xpg6/bin:/usr/xpg4/bin because the tools in /usr/bin are not POSIX-conformant 348462SApril.Chin@Sun.COMexport PATH=/usr/xpg6/bin:/usr/xpg4/bin:/bin:/usr/bin 358462SApril.Chin@Sun.COM 368462SApril.Chin@Sun.COM# Make sure all math stuff runs in the "C" locale to avoid problems 378462SApril.Chin@Sun.COM# with alternative # radix point representations (e.g. ',' instead of 388462SApril.Chin@Sun.COM# '.' in de_DE.*-locales). This needs to be set _before_ any 398462SApril.Chin@Sun.COM# floating-point constants are defined in this script). 408462SApril.Chin@Sun.COMif [[ "${LC_ALL}" != "" ]] ; then 418462SApril.Chin@Sun.COM export \ 428462SApril.Chin@Sun.COM LC_MONETARY="${LC_ALL}" \ 438462SApril.Chin@Sun.COM LC_MESSAGES="${LC_ALL}" \ 448462SApril.Chin@Sun.COM LC_COLLATE="${LC_ALL}" \ 458462SApril.Chin@Sun.COM LC_CTYPE="${LC_ALL}" 468462SApril.Chin@Sun.COM unset LC_ALL 478462SApril.Chin@Sun.COMfi 488462SApril.Chin@Sun.COMexport LC_NUMERIC=C 498462SApril.Chin@Sun.COM 508462SApril.Chin@Sun.COM# Definition for a mutex which uses the filesystem for locking 518462SApril.Chin@Sun.COMtypeset -T filemutex_t=( 528462SApril.Chin@Sun.COM typeset name 538462SApril.Chin@Sun.COM 548462SApril.Chin@Sun.COM typeset lock_dirname 558462SApril.Chin@Sun.COM 568462SApril.Chin@Sun.COM typeset locked_exclusive="false" 578462SApril.Chin@Sun.COM typeset locked_shared="false" 588462SApril.Chin@Sun.COM 598462SApril.Chin@Sun.COM # keep track of subshell level. The problem is that we do not know a 608462SApril.Chin@Sun.COM # way to figure out whether someone calls "unlock" in a subshell and then 618462SApril.Chin@Sun.COM # leaves the subshell and calls "unlock" again 628462SApril.Chin@Sun.COM integer subshell=-1 638462SApril.Chin@Sun.COM 648462SApril.Chin@Sun.COM typeset lock_dirname 658462SApril.Chin@Sun.COM 668462SApril.Chin@Sun.COM # create a filemutex instance (including lock directory) 678462SApril.Chin@Sun.COM function create 688462SApril.Chin@Sun.COM { 698462SApril.Chin@Sun.COM # make sure we return an error if the init didn't work 708462SApril.Chin@Sun.COM set -o errexit 718462SApril.Chin@Sun.COM 728462SApril.Chin@Sun.COM [[ "$1" == "" ]] && return 1 738462SApril.Chin@Sun.COM 748462SApril.Chin@Sun.COM _.name="$1" 758462SApril.Chin@Sun.COM _.lock_dirname="/tmp/filemutex_t_${_.name}.lock" 768462SApril.Chin@Sun.COM 778462SApril.Chin@Sun.COM mkdir "${_.lock_dirname}" 788462SApril.Chin@Sun.COM 798462SApril.Chin@Sun.COM # last entry, used to mark the mutex as initalised+valid 808462SApril.Chin@Sun.COM (( _.subshell=.sh.subshell )) 818462SApril.Chin@Sun.COM return 0 828462SApril.Chin@Sun.COM } 838462SApril.Chin@Sun.COM 848462SApril.Chin@Sun.COM # use a filemutex instance (same as "create" but without creating 858462SApril.Chin@Sun.COM # the lock directory) 868462SApril.Chin@Sun.COM function create_child 878462SApril.Chin@Sun.COM { 888462SApril.Chin@Sun.COM # make sure we return an error if the init didn't work 898462SApril.Chin@Sun.COM set -o errexit 908462SApril.Chin@Sun.COM 918462SApril.Chin@Sun.COM [[ "$1" == "" ]] && return 1 928462SApril.Chin@Sun.COM 938462SApril.Chin@Sun.COM _.name="$1" 948462SApril.Chin@Sun.COM _.lock_dirname="/tmp/filemutex_t_${_.name}.lock" 958462SApril.Chin@Sun.COM 968462SApril.Chin@Sun.COM # last entry, used to mark the mutex as initalised+valid 978462SApril.Chin@Sun.COM (( _.subshell=.sh.subshell )) 988462SApril.Chin@Sun.COM return 0 998462SApril.Chin@Sun.COM } 1008462SApril.Chin@Sun.COM 1018462SApril.Chin@Sun.COM function check_subshell 1028462SApril.Chin@Sun.COM { 1038462SApril.Chin@Sun.COM (( _.subshell == .sh.subshell )) && return 0 1048462SApril.Chin@Sun.COM print -u2 -f "filemutex_t.%s(%s): Wrong subshell level\n" "$1" "${_.name}" 1058462SApril.Chin@Sun.COM return 1 1068462SApril.Chin@Sun.COM } 1078462SApril.Chin@Sun.COM 1088462SApril.Chin@Sun.COM function try_lock_shared 1098462SApril.Chin@Sun.COM { 1108462SApril.Chin@Sun.COM _.check_subshell "try_lock_shared" || return 1 1118462SApril.Chin@Sun.COM 1128462SApril.Chin@Sun.COM mkdir "${_.lock_dirname}/shared_${PPID}_$$" 2>/dev/null || return 1 1138462SApril.Chin@Sun.COM _.locked_shared="true" 1148462SApril.Chin@Sun.COM return 0 1158462SApril.Chin@Sun.COM } 1168462SApril.Chin@Sun.COM 1178462SApril.Chin@Sun.COM function lock_shared 1188462SApril.Chin@Sun.COM { 1198462SApril.Chin@Sun.COM float interval=0.2 1208462SApril.Chin@Sun.COM 1218462SApril.Chin@Sun.COM _.check_subshell "lock_shared" || return 1 1228462SApril.Chin@Sun.COM 1238462SApril.Chin@Sun.COM while ! _.try_lock_shared ; do sleep ${interval} ; (( interval+=interval/10. )) ; done 1248462SApril.Chin@Sun.COM return 0 1258462SApril.Chin@Sun.COM } 1268462SApril.Chin@Sun.COM 1278462SApril.Chin@Sun.COM function try_lock_exclusive 1288462SApril.Chin@Sun.COM { 1298462SApril.Chin@Sun.COM _.check_subshell "try_lock_exclusive" || return 1 1308462SApril.Chin@Sun.COM 1318462SApril.Chin@Sun.COM rmdir "${_.lock_dirname}" 2>/dev/null || return 1 1328462SApril.Chin@Sun.COM _.locked_exclusive="true" 1338462SApril.Chin@Sun.COM return 0 1348462SApril.Chin@Sun.COM } 1358462SApril.Chin@Sun.COM 1368462SApril.Chin@Sun.COM function lock_exclusive 1378462SApril.Chin@Sun.COM { 1388462SApril.Chin@Sun.COM float interval=0.2 1398462SApril.Chin@Sun.COM 1408462SApril.Chin@Sun.COM _.check_subshell "lock_exclusive" || return 1 1418462SApril.Chin@Sun.COM 1428462SApril.Chin@Sun.COM while ! _.try_lock_exclusive ; do sleep ${interval} ; (( interval+=interval/10. )) ; done 1438462SApril.Chin@Sun.COM return 0 1448462SApril.Chin@Sun.COM } 1458462SApril.Chin@Sun.COM 1468462SApril.Chin@Sun.COM # critical section support (like java's "synchronized" keyword) 1478462SApril.Chin@Sun.COM function synchronized 1488462SApril.Chin@Sun.COM { 1498462SApril.Chin@Sun.COM integer retcode 1508462SApril.Chin@Sun.COM 1518462SApril.Chin@Sun.COM _.check_subshell "synchronized" || return 1 1528462SApril.Chin@Sun.COM 1538462SApril.Chin@Sun.COM _.lock_exclusive 1548462SApril.Chin@Sun.COM 1558462SApril.Chin@Sun.COM "$@" 1568462SApril.Chin@Sun.COM (( retcode=$? )) 1578462SApril.Chin@Sun.COM 1588462SApril.Chin@Sun.COM _.unlock 1598462SApril.Chin@Sun.COM 1608462SApril.Chin@Sun.COM return ${retcode} 1618462SApril.Chin@Sun.COM } 1628462SApril.Chin@Sun.COM 1638462SApril.Chin@Sun.COM # critical section support with shared lock 1648462SApril.Chin@Sun.COM function synchronized_shared 1658462SApril.Chin@Sun.COM { 1668462SApril.Chin@Sun.COM integer retcode 1678462SApril.Chin@Sun.COM 1688462SApril.Chin@Sun.COM _.check_subshell "synchronized_shared" || return 1 1698462SApril.Chin@Sun.COM 1708462SApril.Chin@Sun.COM _.lock_shared 1718462SApril.Chin@Sun.COM 1728462SApril.Chin@Sun.COM "$@" 1738462SApril.Chin@Sun.COM (( retcode=$? )) 1748462SApril.Chin@Sun.COM 1758462SApril.Chin@Sun.COM _.unlock 1768462SApril.Chin@Sun.COM 1778462SApril.Chin@Sun.COM return ${retcode} 1788462SApril.Chin@Sun.COM } 1798462SApril.Chin@Sun.COM 1808462SApril.Chin@Sun.COM function unlock 1818462SApril.Chin@Sun.COM { 1828462SApril.Chin@Sun.COM # return an error if rmdir/mkdir/check_subshell fail... 1838462SApril.Chin@Sun.COM set -o errexit 1848462SApril.Chin@Sun.COM 1858462SApril.Chin@Sun.COM _.check_subshell "unlock" 1868462SApril.Chin@Sun.COM 1878462SApril.Chin@Sun.COM if ${_.locked_shared} ; then 1888462SApril.Chin@Sun.COM rmdir "${_.lock_dirname}/shared_${PPID}_$$" 1898462SApril.Chin@Sun.COM _.locked_shared="false" 1908462SApril.Chin@Sun.COM return 0 1918462SApril.Chin@Sun.COM elif ${_.locked_exclusive} ; then 1928462SApril.Chin@Sun.COM mkdir "${_.lock_dirname}" 1938462SApril.Chin@Sun.COM _.locked_exclusive="false" 1948462SApril.Chin@Sun.COM return 0 1958462SApril.Chin@Sun.COM fi 1968462SApril.Chin@Sun.COM 1978462SApril.Chin@Sun.COM print -u2 -f "filemutex_t.unlock(%s): mutex '%s' not locked." "$1" "${_.name}" 1988462SApril.Chin@Sun.COM return 1 1998462SApril.Chin@Sun.COM } 2008462SApril.Chin@Sun.COM 2018462SApril.Chin@Sun.COM # destroy mutex if noone is using it anymore (not the same as "unset" !!)) 2028462SApril.Chin@Sun.COM function destroy 2038462SApril.Chin@Sun.COM { 2048462SApril.Chin@Sun.COM _.check_subshell "destroy" || return 1 2058462SApril.Chin@Sun.COM 2068462SApril.Chin@Sun.COM (${_.locked_exclusive} || ${_.locked_shared}) && _.unlock 2078462SApril.Chin@Sun.COM rmdir "${_.lock_dirname}" 2088462SApril.Chin@Sun.COM return 0 2098462SApril.Chin@Sun.COM } 2108462SApril.Chin@Sun.COM) 2118462SApril.Chin@Sun.COM 2128462SApril.Chin@Sun.COM# main 2138462SApril.Chin@Sun.COMbuiltin mkdir 2148462SApril.Chin@Sun.COMbuiltin rmdir 2158462SApril.Chin@Sun.COM 2168462SApril.Chin@Sun.COMprint "## Start." 2178462SApril.Chin@Sun.COM 2188462SApril.Chin@Sun.COMtypeset -r mymutexname="hello_world" 2198462SApril.Chin@Sun.COM 2208462SApril.Chin@Sun.COMfilemutex_t fs 2218462SApril.Chin@Sun.COM 2228462SApril.Chin@Sun.COMfs.create "${mymutexname}" || print -u2 "Mutex init failed." 2238462SApril.Chin@Sun.COM 2248462SApril.Chin@Sun.COMprint "# Starting child which keeps an exclusive lock for 10 seconds..." 2258462SApril.Chin@Sun.COM( 2268462SApril.Chin@Sun.COM filemutex_t child_fs 2278462SApril.Chin@Sun.COM 2288462SApril.Chin@Sun.COM child_fs.create_child "${mymutexname}" 2298462SApril.Chin@Sun.COM 2308462SApril.Chin@Sun.COM child_fs.lock_exclusive 2318462SApril.Chin@Sun.COM sleep 10 2328462SApril.Chin@Sun.COM child_fs.unlock 2338462SApril.Chin@Sun.COM) & 2348462SApril.Chin@Sun.COM 2358462SApril.Chin@Sun.COMsleep 1 2368462SApril.Chin@Sun.COM 2378462SApril.Chin@Sun.COMprintf "%T: # Waiting to obtain a shared lock...\n" 2388462SApril.Chin@Sun.COMfs.lock_shared 2398462SApril.Chin@Sun.COMprintf "%T: # Obtained shared lock\n" 2408462SApril.Chin@Sun.COM 2418462SApril.Chin@Sun.COMprintf "fs.locked_exclusive=%s, fs.locked_shared=%s\n" "${fs.locked_exclusive}" "${fs.locked_shared}" 2428462SApril.Chin@Sun.COM 2438462SApril.Chin@Sun.COMls -lad /tmp/filemutex*/* 2448462SApril.Chin@Sun.COM 2458462SApril.Chin@Sun.COMprintf "%T: # Executing child which runs printf '|%%s|\\\n' 'hello' 'world' inside a synchronized section\n" 2468462SApril.Chin@Sun.COM( 2478462SApril.Chin@Sun.COM filemutex_t child_fs 2488462SApril.Chin@Sun.COM 2498462SApril.Chin@Sun.COM child_fs.create_child "${mymutexname}" 2508462SApril.Chin@Sun.COM 2518462SApril.Chin@Sun.COM child_fs.synchronized printf '|%s|\n' 'hello' 'world' 2528462SApril.Chin@Sun.COM) & 2538462SApril.Chin@Sun.COM 2548462SApril.Chin@Sun.COMprintf "%T: # Sleeping 5 secs while holding the shared lock...\n" 2558462SApril.Chin@Sun.COMsleep 5. 2568462SApril.Chin@Sun.COM 2578462SApril.Chin@Sun.COMprintf "%T: # Releasing shared lock...\n" 2588462SApril.Chin@Sun.COMfs.unlock 2598462SApril.Chin@Sun.COM 2608462SApril.Chin@Sun.COMsleep 5. 2618462SApril.Chin@Sun.COMprint "# Destroying lock..." 2628462SApril.Chin@Sun.COMfs.destroy 2638462SApril.Chin@Sun.COM 2648462SApril.Chin@Sun.COMprint "## Done." 2658462SApril.Chin@Sun.COM 2668462SApril.Chin@Sun.COMexit 0 267