From 550abd2a78c593d6a8ed587a5c9f028931b4d494 Mon Sep 17 00:00:00 2001
From: rillig <rillig>
Date: Fri, 4 Aug 2006 20:52:27 +0000
Subject: Fixed the locking, as suggested by Johnny on the tech-pkg mailing
 list.

Added two targets acquire-localbase-lock and release-localbase-lock,
which mark the complete LOCALBASE directory as locked, so that multiple
packages cannot run the install, deinstall or bin-install targets at the
same time.

The install target aquires locks in both WRKSRC and LOCALBASE, the other
two targets only need the LOCALBASE lock, since they may be run without
WRKSRC being present on the system.

locking.mk must be included before tools.mk and the PKG_FAIL_REASON
check.
---
 mk/internal/locking.mk | 131 ++++++++++++++++++++++++++++++++++---------------
 1 file changed, 91 insertions(+), 40 deletions(-)

(limited to 'mk/internal')

diff --git a/mk/internal/locking.mk b/mk/internal/locking.mk
index 7a0bed0c484..4943835212e 100644
--- a/mk/internal/locking.mk
+++ b/mk/internal/locking.mk
@@ -1,39 +1,62 @@
-# $NetBSD: locking.mk,v 1.1 2006/08/04 05:55:18 rillig Exp $
+# $NetBSD: locking.mk,v 1.2 2006/08/04 20:52:27 rillig Exp $
 #
 
-# acquire-lock and release-lock are two .USE macro targets that aquire
-# and release coarse-grained locks. There are two areas of pkgsrc that
-# can be locked: The WRKDIR of a specific package or the LOCALBASE.
-# Which of those is locked depends on the name of the target where the
-# {acquire,release}-lock macro is used. If it contains -install-, as for
-# example acquire-install-lock, LOCALBASE is locked. Otherwise, WRKDIR
-# is locked.
+# 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_LOCKFILE=	${WRKDIR}/.lockfile
-_PREFIX_LOCKFILE=	${PKG_DBDIR}/.lockfile
-_GET_LOCKFILE_CMD= \
-	case ${.TARGET} in						\
-	*-install-*)	lockfile=${_PREFIX_LOCKFILE};;			\
-	*)		lockfile=${_WRKDIR_LOCKFILE};;			\
-	esac
+_LOCALBASE_LOCKFILE=	${LOCALBASE}/.lockfile
+
+#
+# Sanity checks.
+#
 
-acquire-lock: .USE
 .if ${PKGSRC_LOCKTYPE} == "none"
-	@${DO_NADA}
-.else
-	@if ${TEST} ! -x ${SHLOCK:Q}""; then				\
-		${ERROR_MSG} "The ${SHLOCK:Q} utility does not exist, and is necessary for locking."; \
-		${ERROR_MSG} "Please \""${MAKE:Q}" install\" in ../../pkgtools/shlock."; \
-		exit 1;							\
-	fi
+# No further checks.
+.elif ${PKGSRC_LOCKTYPE} == "once" || ${PKGSRC_LOCKTYPE} == "sleep"
 .  if !defined(OBJHOSTNAME)
-	@${ERROR_MSG} "PKGSRC_LOCKTYPE needs OBJHOSTNAME defined.";	\
-	exit 1
+PKG_FAIL_REASON+=	"[locking.mk] PKGSRC_LOCKTYPE needs OBJHOSTNAME defined."
 .  endif
-	${_PKG_SILENT}${_PKG_DEBUG}set -e;				\
-	${_GET_LOCKFILE_CMD};						\
+.else
+PKG_FAIL_REASON+=	"[locking.mk] PKGSRC_LOCKTYPE must be one of {none,once,sleep}, not ${PKGSRC_LOCKTYPE}."
+.endif
+
+#
+# Needed tools.
+#
+
+.if ${PKGSRC_LOCKTYPE} != "none"
+USE_TOOLS+=		shlock
+.endif
+.if ${PKGSRC_LOCKTYPE} == "sleep"
+USE_TOOLS+=		sleep
+.endif
+
+#
+# The commands.
+#
+
+_CHECK_IF_SHLOCK_IS_AVAILABLE_CMD= \
+	${TEST} -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 ${TEST} -z "$$ppid"; then					\
 		${ERROR_MSG} "No parent process ID found.";		\
@@ -49,7 +72,7 @@ acquire-lock: .USE
 		fi;							\
 		lockdir=`echo "$$lockfile" | sed "s,/[^/]*\$$,,"`;	\
 		${MKDIR} "$$lockdir";					\
-		if ${SHLOCK} -f "$$lockfile" -p $$ppid; then		\
+		if ${SHLOCK} -f "$$lockfile" -p "$$ppid"; then		\
 			break;						\
 		fi;							\
 		lockpid=`${CAT} "$$lockfile"`;				\
@@ -61,22 +84,50 @@ acquire-lock: .USE
 			${SLEEP} ${PKGSRC_SLEEPSECS};			\
 			;;						\
 		esac;							\
-	done;								\
-	if ${PKG_VERBOSE:D${TRUE}:U${FALSE}}; then			\
-		lockpid=`${CAT} "$$lockfile"`;				\
-		${STEP_MSG} "Lock acquired for \`\`${.TARGET:S/^acquire-//:S/-lock$//}'' on behalf of process $$lockpid"; \
-	fi
+	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: .USE
+_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 ${PKGSRC_LOCKTYPE} == "none"
+acquire-lock release-lock acquire-localbase-lock release-localbase-lock: .USE
 	@${DO_NADA}
 .else
+acquire-lock: .USE
 	${_PKG_SILENT}${_PKG_DEBUG} set -e;				\
-	${_GET_LOCKFILE_CMD};						\
-	if ${PKG_VERBOSE:D${TRUE}:U${FALSE}}; then			\
-		lockpid=`${CAT} "$$lockfile"`;				\
-		${STEP_MSG} "Lock released for \`\`${.TARGET:S/^release-//:S/-lock$//}'' on behalf of process $$lockpid"; \
-	fi;								\
-	${RM} -f "$$lockfile"
+	lockfile=${_WRKDIR_LOCKFILE};					\
+	${_ACQUIRE_LOCK_CMD}
+
+release-lock: .USE
+	${_PKG_SILENT}${_PKG_DEBUG} set -e;				\
+	lockfile=${_WRKDIR_LOCKFILE};					\
+	${_RELEASE_LOCK_CMD}
+
+acquire-localbase-lock: .USE
+	${_PKG_SILENT}${_PKG_DEBUG} set -e;				\
+	lockfile=${_LOCALBASE_LOCKFILE};				\
+	${_ACQUIRE_LOCK_CMD}
+
+release-localbase-lock: .USE
+	${_PKG_SILENT}${_PKG_DEBUG} set -e;				\
+	lockfile=${_LOCALBASE_LOCKFILE};				\
+	${_RELEASE_LOCK_CMD}
 .endif
-- 
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