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# block until at least <barrier-size> processes of this barrier group entered the barrier
# once this happened, all latecomers will go through immediately!
# WARNING: a barrier group consists of all processes with the same barrier name *and* size!
single-use-barrier() { # <barrier-name> <barrier-size> [<timeout-in-seconds> [<sleep-cycle-time>]]
local barrier_name="$1"
local barrier_size="$2"
local timeout_in_seconds="${3:-0}"
local sleep_cycle_time="${4:-1}"
# use name and size to distinguish between invocations
# this will block inconsistent sizes on the same name!
local BARRIER_SUFFIX=${barrier_name//\//_}-$barrier_size
local BARRIER_FILE="$BATS_SUITE_TMPDIR/barrier-$BARRIER_SUFFIX"
# mark our entry for all others
# concurrent writes may interleave but should not lose their newlines
echo "in-$$" >>"$BARRIER_FILE"
local start="$SECONDS"
# wait for others to enter
while [[ $(wc -l <"$BARRIER_FILE") -lt $barrier_size ]]; do
if [[ $timeout_in_seconds -ne 0 && $((SECONDS - start)) -gt $timeout_in_seconds ]]; then
mv "$BARRIER_FILE" "$BARRIER_FILE-timeout"
printf "ERROR: single-use-barrier %s timed out\n" "$BARRIER_SUFFIX" >&2
return 1
fi
sleep "$sleep_cycle_time"
done
# mark our exit
echo "out-$$" >>"$BARRIER_FILE"
}
# block until at least <latch-size> signalling threads have passed the latch
# SINGLE_USE_LATCH_DIR must be exported!
single-use-latch::wait() { # <latch-name> <latch-size> [<timeout-in-seconds> [<sleep-cycle-time>]]
local latch_name="$1"
local latch_size="$2"
local timeout_in_seconds="${3:-0}"
local sleep_cycle_time="${4:-1}"
local LATCH_FILE
LATCH_FILE="$(single-use-latch::_filename "$latch_name")"
local start="$SECONDS"
while [[ (! -e "$LATCH_FILE") || $(wc -l <"$LATCH_FILE") -lt $latch_size ]]; do
if [[ $timeout_in_seconds -ne 0 && $((SECONDS - start)) -gt $timeout_in_seconds ]]; then
printf "ERROR: single-use-latch %s timed out\n" "$latch_name" >&2
mv "$LATCH_FILE" "$LATCH_FILE-timeout"
return 1
fi
sleep "$sleep_cycle_time"
done
}
# signal the waiting process that the latch was passed
# this does not block
# SINGLE_USE_LATCH_DIR must be exported!
single-use-latch::signal() { # <latch-name>
local latch_name="$1"
local LATCH_FILE
LATCH_FILE="$(single-use-latch::_filename "$latch_name")"
# mark our passing
# concurrent process might interleave but will still post their newline
echo "passed-$$" >>"$LATCH_FILE"
}
single-use-latch::_filename() { # <latch-name>
printf "%s\n" "${SINGLE_USE_LATCH_DIR?}/latch-${1//\//_}"
}
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