| #!/bin/bash | 
 | # | 
 | # Symbolic asynchronous tasks for devstack | 
 | # | 
 | # Usage: | 
 | # | 
 | #  async_runfunc my_shell_func foo bar baz | 
 | # | 
 | #  ... do other stuff ... | 
 | # | 
 | #  async_wait my_shell_func | 
 | # | 
 |  | 
 | DEVSTACK_PARALLEL=$(trueorfalse True DEVSTACK_PARALLEL) | 
 | _ASYNC_BG_TIME=0 | 
 |  | 
 | # Keep track of how much total time was spent in background tasks | 
 | # Takes a job runtime in ms. | 
 | function _async_incr_bg_time { | 
 |     local elapsed_ms="$1" | 
 |     _ASYNC_BG_TIME=$(($_ASYNC_BG_TIME + $elapsed_ms)) | 
 | } | 
 |  | 
 | # Get the PID of a named future to wait on | 
 | function async_pidof { | 
 |     local name="$1" | 
 |     local inifile="${DEST}/async/${name}.ini" | 
 |  | 
 |     if [ -f "$inifile" ]; then | 
 |         iniget $inifile job pid | 
 |     else | 
 |         echo 'UNKNOWN' | 
 |         return 1 | 
 |     fi | 
 | } | 
 |  | 
 | # Log a message about a job. If the message contains "%command" then the | 
 | # full command line of the job will be substituted in the output | 
 | function async_log { | 
 |     local name="$1" | 
 |     shift | 
 |     local message="$*" | 
 |     local inifile=${DEST}/async/${name}.ini | 
 |     local pid | 
 |     local command | 
 |  | 
 |     pid=$(iniget $inifile job pid) | 
 |     command=$(iniget $inifile job command | tr '#' '-') | 
 |     message=$(echo "$message" | sed "s#%command#$command#g") | 
 |  | 
 |     echo "[$BASHPID Async ${name}:${pid}]: $message" | 
 | } | 
 |  | 
 | # Inner function that actually runs the requested task. We wrap it like this | 
 | # just so we can emit a finish message as soon as the work is done, to make | 
 | # it easier to find the tracking just before an error. | 
 | function async_inner { | 
 |     local name="$1" | 
 |     local rc | 
 |     local fifo="${DEST}/async/${name}.fifo" | 
 |     shift | 
 |     set -o xtrace | 
 |     if $* >${DEST}/async/${name}.log 2>&1; then | 
 |         rc=0 | 
 |         set +o xtrace | 
 |         async_log "$name" "finished successfully" | 
 |     else | 
 |         rc=$? | 
 |         set +o xtrace | 
 |         async_log "$name" "FAILED with rc $rc" | 
 |     fi | 
 |     iniset ${DEST}/async/${name}.ini job end_time $(date "+%s%3N") | 
 |     # Block on the fifo until we are signaled to exit by the main process | 
 |     cat $fifo | 
 |     return $rc | 
 | } | 
 |  | 
 | # Run something async. Takes a symbolic name and a list of arguments of | 
 | # what to run. Ideally this would be rarely used and async_runfunc() would | 
 | # be used everywhere for readability. | 
 | # | 
 | # This spawns the work in a background worker, records a "future" to be | 
 | # collected by a later call to async_wait() | 
 | function async_run { | 
 |     local xtrace | 
 |     xtrace=$(set +o | grep xtrace) | 
 |     set +o xtrace | 
 |  | 
 |     local name="$1" | 
 |     shift | 
 |     local inifile=${DEST}/async/${name}.ini | 
 |     local fifo=${DEST}/async/${name}.fifo | 
 |  | 
 |     touch $inifile | 
 |     iniset $inifile job command "$*" | 
 |     iniset $inifile job start_time $(date +%s%3N) | 
 |  | 
 |     if [[ "$DEVSTACK_PARALLEL" = "True" ]]; then | 
 |         mkfifo $fifo | 
 |         async_inner $name $* & | 
 |         iniset $inifile job pid $! | 
 |         async_log "$name" "running: %command" | 
 |         $xtrace | 
 |     else | 
 |         iniset $inifile job pid "self" | 
 |         async_log "$name" "Running synchronously: %command" | 
 |         $xtrace | 
 |         $* | 
 |         return $? | 
 |     fi | 
 | } | 
 |  | 
 | # Shortcut for running a shell function async. Uses the function name as the | 
 | # async name. | 
 | function async_runfunc { | 
 |     async_run $1 $* | 
 | } | 
 |  | 
 | # Dump some information to help debug a failed wait | 
 | function async_wait_dump { | 
 |     local failpid=$1 | 
 |  | 
 |     echo "=== Wait failure dump from $BASHPID ===" | 
 |     echo "Processes:" | 
 |     ps -f | 
 |     echo "Waiting jobs:" | 
 |     for name in $(ls ${DEST}/async/*.ini); do | 
 |         echo "Job $name :" | 
 |         cat "$name" | 
 |     done | 
 |     echo "Failed PID status:" | 
 |     sudo cat /proc/$failpid/status | 
 |     sudo cat /proc/$failpid/cmdline | 
 |     echo "=== End wait failure dump ===" | 
 | } | 
 |  | 
 | # Wait for an async future to complete. May return immediately if already | 
 | # complete, or of the future has already been waited on (avoid this). May | 
 | # block until the future completes. | 
 | function async_wait { | 
 |     local xtrace | 
 |     xtrace=$(set +o | grep xtrace) | 
 |     set +o xtrace | 
 |  | 
 |     local pid rc running inifile runtime fifo | 
 |     rc=0 | 
 |     for name in $*; do | 
 |         running=$(ls ${DEST}/async/*.ini 2>/dev/null | wc -l) | 
 |         inifile="${DEST}/async/${name}.ini" | 
 |         fifo="${DEST}/async/${name}.fifo" | 
 |  | 
 |         if pid=$(async_pidof "$name"); then | 
 |             async_log "$name" "Waiting for completion of %command" \ | 
 |                       "running on PID $pid ($running other jobs running)" | 
 |             time_start async_wait | 
 |             if [[ "$pid" != "self" ]]; then | 
 |                 # Signal the child to go ahead and exit since we are about to | 
 |                 # wait for it to collect its status. | 
 |                 async_log "$name" "Signaling child to exit" | 
 |                 echo WAKEUP > $fifo | 
 |                 async_log "$name" "Signaled" | 
 |                 # Do not actually call wait if we ran synchronously | 
 |                 if wait $pid; then | 
 |                     rc=0 | 
 |                 else | 
 |                     rc=$? | 
 |                 fi | 
 |                 cat ${DEST}/async/${name}.log | 
 |                 rm -f $fifo | 
 |             fi | 
 |             time_stop async_wait | 
 |             local start_time | 
 |             local end_time | 
 |             start_time=$(iniget $inifile job start_time) | 
 |             end_time=$(iniget $inifile job end_time) | 
 |             _async_incr_bg_time $(($end_time - $start_time)) | 
 |             runtime=$((($end_time - $start_time) / 1000)) | 
 |             async_log "$name" "finished %command with result" \ | 
 |                       "$rc in $runtime seconds" | 
 |             rm -f $inifile | 
 |             if [ $rc -ne 0 ]; then | 
 |                 async_wait_dump $pid | 
 |                 echo Stopping async wait due to error: $* | 
 |                 break | 
 |             fi | 
 |         else | 
 |             # This could probably be removed - it is really just here | 
 |             # to help notice if you wait for something by the wrong | 
 |             # name, but it also shows up for things we didn't start | 
 |             # because they were not enabled. | 
 |             echo Not waiting for async task $name that we never started or \ | 
 |                  has already been waited for | 
 |         fi | 
 |     done | 
 |  | 
 |     $xtrace | 
 |     return $rc | 
 | } | 
 |  | 
 | # Check for uncollected futures and wait on them | 
 | function async_cleanup { | 
 |     local name | 
 |  | 
 |     if [[ "$DEVSTACK_PARALLEL" != "True" ]]; then | 
 |         return 0 | 
 |     fi | 
 |  | 
 |     for inifile in $(find ${DEST}/async -name '*.ini'); do | 
 |         name=$(basename $pidfile .ini) | 
 |         echo "WARNING: uncollected async future $name" | 
 |         async_wait $name || true | 
 |     done | 
 | } | 
 |  | 
 | # Make sure our async dir is created and clean | 
 | function async_init { | 
 |     local async_dir=${DEST}/async | 
 |  | 
 |     # Clean any residue if present from previous runs | 
 |     rm -Rf $async_dir | 
 |  | 
 |     # Make sure we have a state directory | 
 |     mkdir -p $async_dir | 
 | } | 
 |  | 
 | function async_print_timing { | 
 |     local bg_time_minus_wait | 
 |     local elapsed_time | 
 |     local serial_time | 
 |     local speedup | 
 |  | 
 |     if [[ "$DEVSTACK_PARALLEL" != "True" ]]; then | 
 |         return 0 | 
 |     fi | 
 |  | 
 |     # The logic here is: All the background task time would be | 
 |     # serialized if we did not do them in the background. So we can | 
 |     # add that to the elapsed time for the whole run. However, time we | 
 |     # spend waiting for async things to finish adds to the elapsed | 
 |     # time, but is time where we're not doing anything useful. Thus, | 
 |     # we substract that from the would-be-serialized time. | 
 |  | 
 |     bg_time_minus_wait=$((\ | 
 |             ($_ASYNC_BG_TIME - ${_TIME_TOTAL[async_wait]}) / 1000)) | 
 |     elapsed_time=$(($(date "+%s") - $_TIME_BEGIN)) | 
 |     serial_time=$(($elapsed_time + $bg_time_minus_wait)) | 
 |  | 
 |     echo | 
 |     echo "=================" | 
 |     echo " Async summary" | 
 |     echo "=================" | 
 |     echo " Time spent in the background minus waits: $bg_time_minus_wait sec" | 
 |     echo " Elapsed time: $elapsed_time sec" | 
 |     echo " Time if we did everything serially: $serial_time sec" | 
 |     echo " Speedup: " $(echo | awk "{print $serial_time / $elapsed_time}") | 
 | } |