pkgsrc/mk/internal/locking.mk

168 lines
3.9 KiB
Makefile

# $NetBSD: locking.mk,v 1.10 2018/02/19 13:00:10 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