diff options
Diffstat (limited to 'mk/misc/locking.mk')
| -rw-r--r-- | mk/misc/locking.mk | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/mk/misc/locking.mk b/mk/misc/locking.mk new file mode 100644 index 00000000000..201683e1835 --- /dev/null +++ b/mk/misc/locking.mk @@ -0,0 +1,168 @@ +# $NetBSD: locking.mk,v 1.1 2020/05/10 06:52:50 rillig Exp $ +# +# User-settable variables: +# +# WRKDIR_LOCKTYPE +# The type of locking used for WRKDIR. +# +# Possible values: none once sleep +# Default value: none +# Recommended: once +# +# LOCALBASE_LOCKTYPE +# The type of locking used for LOCALBASE. +# +# Possible values: none once sleep +# Default value: none +# Recommended: sleep +# +# See also: PKGSRC_LOCKTYPE. +# Keywords: lock locking parallel + +# This file provides the following .USE targets: +# +# acquire-lock +# Acquires a coarse-grained lock in WRKDIR. +# +# release-lock +# Releases the lock in WRKDIR. +# +# acquire-localbase-lock +# Acquires a coarse-grained lock in LOCALBASE. +# +# release-localbase-lock +# Releases the lock in LOCALBASE. +# + +WRKDIR_LOCKTYPE?= ${PKGSRC_LOCKTYPE} +LOCALBASE_LOCKTYPE?= ${PKGSRC_LOCKTYPE} + +_WRKDIR_LOCKFILE= ${WRKDIR}/.lockfile +_LOCALBASE_LOCKFILE= ${LOCALBASE}/.lockfile +_LOCKVARS= WRKDIR_LOCKTYPE LOCALBASE_LOCKTYPE + +# +# Sanity checks. +# + +.for v in ${_LOCKVARS} +_OK= no +. for t in none once sleep +. if ${${v}} == "${t}" +_OK= yes +. endif +. endfor +. if ${_OK} != "yes" +PKG_FAIL_REASON+= "[locking.mk] ${v} must be one of { none once sleep }, not ${${v}}." +. endif +.endfor + +# +# Needed tools. +# + +.for v in ${_LOCKVARS} +. if ${${v}} != "none" +USE_TOOLS+= shlock +. endif +. if ${${v}} == "sleep" +USE_TOOLS+= sleep +. endif +.endfor + +# +# The commands. +# + +_CHECK_IF_SHLOCK_IS_AVAILABLE_CMD= \ + [ "${PKGPATH}" != "pkgtools/shlock" ] || exit 0; \ + [ -x ${SHLOCK:Q}"" ] || { \ + ${ERROR_MSG} "[locking.mk] shlock is not installed."; \ + ${ERROR_MSG} "[locking.mk] Please \"(cd ../../pkgtools/shlock && ${MAKE} install)\"."; \ + exit 1; \ + } + +_ACQUIRE_LOCK_CMD= \ + ${_CHECK_IF_SHLOCK_IS_AVAILABLE_CMD}; \ + ppid=`${PS} -p $$$$ -o ppid | ${AWK} 'NR == 2 { print $$1 }'`; \ + if [ -z "$$ppid" ]; then \ + ${ERROR_MSG} "No parent process ID found."; \ + exit 1; \ + fi; \ + while :; do \ + if [ -f /var/run/dmesg.boot -a -f "$$lockfile" ]; then \ + rebooted=`${FIND} /var/run/dmesg.boot -newer "$$lockfile" -print`; \ + if [ "$$rebooted" ]; then \ + ${STEP_MSG} "Removing stale $$lockfile"; \ + ${RM} -f "$$lockfile"; \ + fi; \ + fi; \ + lockdir=`echo "$$lockfile" | sed "s,/[^/]*\$$,,"`; \ + ${MKDIR} "$$lockdir"; \ + if ${SHLOCK} -f "$$lockfile" -p "$$ppid"; then \ + break; \ + fi; \ + lockpid=`${CAT} "$$lockfile"`; \ + case "$$locktype" in \ + once) ${FAIL_MSG} "Lock ${.TARGET} is held by pid $$lockpid" ;; \ + sleep) ${STEP_MSG} "Lock ${.TARGET} is held by pid $$lockpid"; \ + ${SLEEP} ${PKGSRC_SLEEPSECS}; \ + ;; \ + esac; \ + done; +.if defined(PKG_VERBOSE) +_ACQUIRE_LOCK_CMD+= \ + lockpid=`${CAT} "$$lockfile"`; \ + ${STEP_MSG} "Lock $$lockfile acquired for \`\`${.TARGET:S/^acquire-//:S/-lock$//}'' on behalf of process $$lockpid"; +.endif + +_RELEASE_LOCK_CMD= # nothing +.if defined(PKG_VERBOSE) +_RELEASE_LOCK_CMD+= \ + lockpid=`${CAT} "$$lockfile"`; \ + ${STEP_MSG} "Lock $$lockfile released for \`\`${.TARGET:S/^release-//:S/-lock$//}'' on behalf of process $$lockpid"; +.endif +_RELEASE_LOCK_CMD+= \ + ${RM} -f "$$lockfile" + +# +# The targets. +# + +.PHONY: acquire-lock release-lock +.PHONY: acquire-localbase-lock release-localbase-lock + +.if ${LOCALBASE_LOCKTYPE} == "none" +acquire-localbase-lock release-localbase-lock: .USE + @${DO_NADA} +.else +acquire-localbase-lock: .USE + ${RUN} \ + lockfile=${_LOCALBASE_LOCKFILE}; \ + locktype=${LOCALBASE_LOCKTYPE}; \ + ${_ACQUIRE_LOCK_CMD} + +release-localbase-lock: .USE + ${RUN} \ + lockfile=${_LOCALBASE_LOCKFILE}; \ + locktype=${LOCALBASE_LOCKTYPE}; \ + ${_RELEASE_LOCK_CMD} +.endif + +.if ${WRKDIR_LOCKTYPE} == "none" +acquire-lock release-lock: .USE + @${DO_NADA} +.else +acquire-lock: .USE + ${RUN} \ + lockfile=${_WRKDIR_LOCKFILE}; \ + locktype=${WRKDIR_LOCKTYPE}; \ + ${_ACQUIRE_LOCK_CMD} + +release-lock: .USE + ${RUN} \ + lockfile=${_WRKDIR_LOCKFILE}; \ + locktype=${WRKDIR_LOCKTYPE}; \ + ${_RELEASE_LOCK_CMD} + +.endif |