From c507c19eeaec88abfe875e82a971c31364e93c0f Mon Sep 17 00:00:00 2001
From: Philipp Spilger <philipp.spilger@kip.uni-heidelberg.de>
Date: Thu, 22 Feb 2024 11:20:09 +0100
Subject: [PATCH] feat: Use atomic move for updating build cache
* removes need to lock build cache when updating
Change-Id: I0374ba4df9709f97a1eda6f27f0215de445d4e03
---
lib/yashchiki/commons.sh | 63 -------------------
.../update_build_cache_in_container.sh | 26 ++++----
2 files changed, 15 insertions(+), 74 deletions(-)
diff --git a/lib/yashchiki/commons.sh b/lib/yashchiki/commons.sh
index 6529a50a..532c3d72 100755
--- a/lib/yashchiki/commons.sh
+++ b/lib/yashchiki/commons.sh
@@ -25,8 +25,6 @@ export MY_SPACK_BIN=/opt/spack/bin/spack
export MY_SPACK_CMD="${MY_SPACK_BIN} --config-scope ${YASHCHIKI_SPACK_CONFIG}"
export MY_SPACK_VIEW_PREFIX="/opt/spack_views"
-export LOCK_FILENAME=lock
-
# NOTE: build caches contain relavite symlinks to preserved_packages, so the
# relation that build_caches and preserved_packages are in the same folder
# should be maintained inside the container!
@@ -41,10 +39,8 @@ export BUILD_CACHE_OUTSIDE
BASE_BUILD_CACHE_INSIDE="/opt/build_cache"
BUILD_CACHE_INSIDE="${BASE_BUILD_CACHE_INSIDE}/${YASHCHIKI_BUILD_CACHE_NAME}"
-BUILD_CACHE_LOCK="${BUILD_CACHE_INSIDE}/${LOCK_FILENAME}"
export BASE_BUILD_CACHE_INSIDE
export BUILD_CACHE_INSIDE
-export BUILD_CACHE_LOCK
SOURCE_CACHE_DIR="${YASHCHIKI_CACHES_ROOT}/download_cache"
export SOURCE_CACHE_DIR
@@ -204,63 +200,6 @@ populate_views() {
-#################################
-# HELPER FUNCTIONS NEEDED BELOW #
-#################################
-
-# Usage:
-# lock_file [-e] [-w <sec>] <file>
-#
-# Lock the given file, the file will be unlocked once the process exits. Make
-# sure to only use it in subshells to automatically unlock afterwards.
-#
-# Args:
-# -e Lock exculsively (otherwise shared)
-# -w <secs> How long to wait for lock until retrying. [default: 10]
-#
-lock_file() {
- local OPTIND
- local opt
- local args_flock=()
- local exclusive=0
- local info_exclusive=""
- local wait_secs=10
- local opts OPTIND OPTARG
-
- while getopts ":ew:" opt
- do
- case "${opt}" in
- e) exclusive=1 ;;
- w) wait_secs="${OPTARG}" ;;
- *) echo -e "Invalid option to lock_file(): $OPTARG\n" >&2; exit 1 ;;
- esac
- done
- shift $(( OPTIND - 1 ))
-
- local fd_lock
- local filename_lock="$1"
- # ensure that we can always access lockfile
- if [ ! -f "${filename_lock}" ]; then
- touch "${filename_lock}"
- chmod 777 "${filename_lock}"
- fi
- exec {fd_lock}>"${filename_lock}"
-
- if (( exclusive == 1 )); then
- args_flock+=( "-e" )
- info_exclusive="(exclusively) "
- else
- args_flock+=( "-s" )
- info_exclusive="(shared) "
- fi
-
- while /bin/true; do
- echo "Obtaining build_cache lock ${info_exclusive}from ${filename_lock}." 1>&2
- flock ${args_flock[*]} -w "${wait_secs}" ${fd_lock} && break \
- || echo "Could not lock ${filename_lock}, retrying in ${wait_secs} seconds.." 1>&2
- done
-}
-
###################################
# HELPER FUNCTIONS FOR BUILDCACHE #
###################################
@@ -382,9 +321,7 @@ get_specfiles() {
# Install the given set of packages from yashchiki's buildcache.
install_from_buildcache() {
local install_failed=0
- # don't forget to unlock builcache in case of error, but then propagate
(
- lock_file "${BUILD_CACHE_LOCK}"
_install_from_buildcache "${@}"
) || install_failed=1
diff --git a/lib/yashchiki/update_build_cache_in_container.sh b/lib/yashchiki/update_build_cache_in_container.sh
index c16ee96f..9615bdbf 100755
--- a/lib/yashchiki/update_build_cache_in_container.sh
+++ b/lib/yashchiki/update_build_cache_in_container.sh
@@ -3,7 +3,6 @@
# General plan of action:
#
# Create a hard-linked copy, update that copy and only copy new additions back.
-# This ensure minimum locking time.
#
set -euo pipefail
@@ -69,14 +68,6 @@ get_hashes_to_store() {
comm -13 <(get_hashes_in_buildcache "${base_buildcache}") <(get_hashes_in_spack)
}
-if [ "${destination_folder}" = "${base_buildcache}" ]; then
- # if the destination folder is the same as the base buildcache, we need to
- # lock exclusively since we put things into the buildcache
- lock_file -e "${base_buildcache}/${LOCK_FILENAME}"
-else
- lock_file "${base_buildcache}/${LOCK_FILENAME}"
-fi
-
args_progress="--eta"
if (( quiet == 1 )); then
args_progress=""
@@ -85,10 +76,23 @@ fi
# find requires current working directory to be readable by spack user
cd ${MY_SPACK_FOLDER}
+# Create tmpdir in destination folder to compress into,
+# atomically move compressed files into the destination folder afterwards
+tmpdir_in_destination_folder="$(mktemp -d --tmpdir=${destination_folder})"
+
+rm_tmpdir() {
+ rm -r $tmpdir_in_destination_folder
+}
+trap rm_tmpdir EXIT
+
get_hashes_to_store \
| parallel -r ${args_progress} -j${YASHCHIKI_JOBS} \
- tar Pcfz "${destination_folder}/{}.tar.gz" \"\$\(spack location -i /{}\)\"
+ tar Pcfz "${tmpdir_in_destination_folder}/{}.tar.gz" \"\$\(spack location -i /{}\)\"
# verify integrity (of actual files, not possible symlinks)
-find "${destination_folder}" -type f -name "*.tar.gz" -print0 \
+find "${tmpdir_in_destination_folder}" -type f -name "*.tar.gz" -print0 \
| parallel -r -0 -j${YASHCHIKI_JOBS} "tar Ptf '{}' 1>/dev/null"
+
+# atomically move files into destination folder
+find "${tmpdir_in_destination_folder}" -type f -name "*.tar.gz" -print0 \
+ | parallel -r -0 -j${YASHCHIKI_JOBS} "mv '{}' ${destination_folder} 1>/dev/null"
--
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