config/functions: add multi-threaded helpers

config/functions

@@ -1197,6 +1197,148 @@ enable_service () {
   done
 }
 
+
+### MULTI-THREADED FUNCTION HELPERS ###
+# Prevent concurrent modifications to a package (unpack) or
+# package:target (install/build).
+#
+# If a package is already locked and the owner is ourselves
+# then assume we already have the required lock.
+pkg_lock() {
+  [ "${MTWITHLOCKS}" != "yes" ] && return 0
+
+  local pkg="$1" task="$2" parent_pkg="$3"
+  local this_job="${MTJOBID}"
+  local lock_job lock_task lock_pkg
+
+  exec 98>"${THREAD_CONTROL}/locks/${pkg}.${task}"
+  if ! flock --nonblock --exclusive 98; then
+    while [ : ]; do
+      read -r lock_job lock_task lock_pkg <<<$(cat "${THREAD_CONTROL}/locks/${pkg}.${task}.owner" 2>/dev/null)
+      [ -n "${lock_job}" ] && break || sleep 1
+    done
+
+    if [ ${lock_job} != ${this_job} ]; then
+      pkg_lock_status "STALLED" "${parent_pkg}" "${task}" "$(printf "waiting on [%02d] %s %s" ${lock_job} "${lock_task}" "${lock_pkg}")"
+      flock --exclusive 98
+    fi
+  fi
+  echo "${this_job} ${task} ${pkg}" >"${THREAD_CONTROL}/locks/${pkg}.${task}.owner"
+
+  pkg_lock_status "LOCKED" "${pkg}" "${task}"
+}
+
+# Log additional information for a locked package.
+pkg_lock_status() {
+  [ "${MTWITHLOCKS}" != "yes" ] && return 0
+
+  local status="$1" pkg="$2" task="$3" msg="$4"
+  local this_job="${MTJOBID}" line
+
+  printf -v line "%s: <%05d> [%02d/%0*d] %-7s %-7s %-35s" \
+    "$(date +%Y-%m-%d\ %H:%M:%S.%N)" $$ ${this_job} ${#MTMAXJOBS} ${PARALLEL_SEQ:-0} "${status}" "${task}" "${pkg}"
+  [ -n "${msg}" ] && line+=" (${msg})"
+
+  echo "${line}" >>"${THREAD_CONTROL}/history"
+
+  [ "${DASHBOARD}" != "no" ] && update_dashboard "${status}" "${pkg}" "${task}" "${msg}"
+}
+
+update_dashboard() {
+  local status="$1" pkg="$2" task="$3" msg="$4"
+  local line sedline preamble num elapsed projdevarch
+  local boldred boldgreen boldyellow endcolor
+
+  (
+    flock --exclusive 97
+
+    [ -n "${MTJOBID}" ] && sedline=$((MTJOBID + 2)) || sedline=1
+
+    num=$(cat "${THREAD_CONTROL}/status" | wc -l)
+    while [ ${num} -lt ${sedline} ]; do echo "" >>"${THREAD_CONTROL}/status"; num=$((num + 1)); done
+
+    num=$(($(cat "${THREAD_CONTROL}/progress.prev") + 1))
+    projdevarch="${PROJECT}/"
+    [ -n "${DEVICE}" ] && projdevarch+="${DEVICE}/"
+    projdevarch+="${TARGET_ARCH}"
+    TZ=UTC0 printf -v elapsed "%(%H:%M:%S)T" $(($(date +%s) - MTBUILDSTART))
+    printf -v preamble "%s Dashboard (%s) - %d of %d jobs completed, %s elapsed" "${DISTRONAME}" "${projdevarch}" ${num} ${MTMAXJOBS} "${elapsed}"
+    printf -v preamble "%b%-105s %s" "\e[2J\e[0;0H" "${preamble//\//\\/}" "$(date "+%Y-%m-%d %H:%M:%S")"
+
+    # Only update the header when caller is not a worker thread
+    if [ -z "${MTJOBID}" ]; then
+      sed -e "1s/.*/${preamble}/" -i "${THREAD_CONTROL}/status"
+    else
+      if [ "${DISABLE_COLORS}" != "yes" ]; then
+        boldred="\e[1;31m"
+        boldgreen="\e[1;32m"
+        boldyellow="\e[1;33m"
+        white="\e[0;37m"
+        endcolor="\e[0m"
+
+        case "${status}" in
+          IDLE)    color="${white}";;
+          STALLED) color="${boldyellow}";;
+          MUTEX/W) color="${boldyellow}";;
+          FAILED ) color="${boldred}";;
+          *)       color="${boldgreen}";;
+        esac
+      fi
+
+      printf -v line "[%02d\/%0*d] %b%-7s%b %-7s %-35s" ${MTJOBID} ${#MTMAXJOBS} ${PARALLEL_SEQ:-0} "${color}" "${status//\//\\/}" "${endcolor}" "${task}" "${pkg}"
+      [ -n "${msg}" ] && line+=" ${msg//\//\\/}"
+      sed -e "1s/.*/${preamble}/;${sedline}s/.*/${line}/" -i "${THREAD_CONTROL}/status"
+    fi
+  ) 97>"${THREAD_CONTROL}/locks/.status"
+}
+
+# Thread concurrency helpers to avoid concurrency issues with some code,
+# eg. when Python installs directly into $TOOLCHAIN.
+# Test MTJOBID so that these functions are a no-op during non-multithreaded builds.
+acquire_exclusive_lock() {
+  [ "${MTWITHLOCKS}" != "yes" ] && return 0
+
+  local pkg="$1" task="$2" lockfile="${3:-.global}"
+  local this_job="${MTJOBID}"
+  local lock_job lock_task lock_pkg
+
+  exec 96>"${THREAD_CONTROL}/locks/${lockfile}"
+  if ! flock --nonblock --exclusive 96; then
+    while [ : ]; do
+      read -r lock_job lock_task lock_pkg <<<$(cat "${THREAD_CONTROL}/locks/${lockfile}.owner" 2>/dev/null)
+      [ -n "${lock_job}" ] && break || sleep 1
+    done
+
+    if [ ${lock_job} != ${this_job} ]; then
+      pkg_lock_status "MUTEX/W" "${pkg}" "${task}" "$(printf "mutex: %s; waiting on [%02d] %s %s" "${lockfile}" ${lock_job} "${lock_task}" "${lock_pkg}")"
+      flock --exclusive 96
+    fi
+  fi
+  echo "${this_job} ${task} ${pkg}" >"${THREAD_CONTROL}/locks/${lockfile}.owner"
+
+  pkg_lock_status "MUTEX" "${pkg}" "${task}" "mutex: ${lockfile}"
+}
+
+release_exclusive_lock() {
+  [ "${MTWITHLOCKS}" != "yes" ] && return 0
+
+  local pkg="$1" task="$2"
+
+  flock --unlock 96 2>/dev/null
+
+  pkg_lock_status "ACTIVE" "${pkg}" "${task}"
+}
+
+# Execute single command using mutex
+exec_thread_safe() {
+  local result
+  acquire_exclusive_lock "${PKG_NAME:exec}" "execcmd"
+  $@
+  result=$?
+  release_exclusive_lock "${PKG_NAME:exec}" "execcmd"
+  return ${result}
+}
+
 # Use distribution functions if any
 if [ -f "distributions/$DISTRO/config/functions" ]; then
   . distributions/$DISTRO/config/functions