Tests: rework tracefile_count test to meet the tracefile count limit

The original test simply fires a test application and checks that file
count limits are not exceeded.

The test is reworked to produce events until the total stream size
stabilizes. Then the number of files is checked against the expected
limit.

Some shellcheck warnings are fixed as part of this change.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Id9ca3e16c05898c4009b4fb8fcf7882fdcb9dcf1

diff --git a/tests/regression/tools/tracefile-limits/test_tracefile_count b/tests/regression/tools/tracefile-limits/test_tracefile_count
index b44de63c003b7d74e14184154e740dc931555318..eb5d1a5f13c146aa78771414112d139f2c141bc9 100755 (executable)
--- a/tests/regression/tools/tracefile-limits/test_tracefile_count
+++ b/tests/regression/tools/tracefile-limits/test_tracefile_count
@@ -1,12 +1,13 @@
 #!/bin/bash
 #
 # Copyright (C) 2013 Christian Babeux <christian.babeux@efficios.com>
+# Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com>
 #
 # SPDX-License-Identifier: LGPL-2.1-only
 
 TEST_DESC="Tracefile count limits"
 
-CURDIR=$(dirname $0)/
+CURDIR=$(dirname "$0")/
 TESTDIR=$CURDIR/../../..
 
 TESTAPP_PATH="$TESTDIR/utils/testapp"
@@ -16,10 +17,11 @@ TESTAPP_BIN="$TESTAPP_PATH/$TESTAPP_NAME/$TESTAPP_NAME"
 STATS_BIN="$TESTDIR/utils/babelstats.pl"
 NUM_TESTS=74
 
-NUM_CPUS=`nproc`
+NUM_CPUS=$(nproc)
 PAGE_SIZE=$(getconf PAGE_SIZE)
+TRACEFILE_SIZE=$PAGE_SIZE
 
-source $TESTDIR/utils/utils.sh
+source "$TESTDIR"/utils/utils.sh
 
 if [ ! -x "$TESTAPP_BIN" ]; then
        BAIL_OUT "No UST events binary detected."
@@ -31,35 +33,20 @@ function enable_lttng_channel_count_limit ()
        channel_name="$2"
        tracefile_count_limit="$3"
 
-       test_name="Enable channel $channel_name "
-       test_name+="for session $sess_name: "
+       test_name="Enable channel \`$channel_name\` "
+       test_name+="for session \`$sess_name\`: "
        test_name+="$tracefile_count_limit tracefiles"
 
-       $TESTDIR/../src/bin/lttng/$LTTNG_BIN enable-channel \
-           -u $channel_name -s $sess_name \
-           -C $(($PAGE_SIZE*3)) -W $tracefile_count_limit \
-           --overwrite >/dev/null 2>&1
+       "$TESTDIR"/../src/bin/lttng/"$LTTNG_BIN" enable-channel \
+           -u "$channel_name" -s "$sess_name" \
+           --subbuf-size "$PAGE_SIZE" \
+           --tracefile-size "$TRACEFILE_SIZE" \
+           --tracefile-count "$tracefile_count_limit" >/dev/null 2>&1
 
        ok $? "$test_name"
 }
 
-function enable_ust_lttng_event_per_channel ()
-{
-       sess_name="$1"
-       event_name="$2"
-       channel_name="$3"
-
-       test_name="Enable event $event_name "
-       test_name+="for session $sess_name "
-       test_name+="in channel $channel_name"
-
-       $TESTDIR/../src/bin/lttng/$LTTNG_BIN enable-event "$event_name" \
-           -s $sess_name -u -c $channel_name >/dev/null 2>&1
-
-       ok $? "$test_name"
-}
-
-function validate_min_max
+function validate_min_max ()
 {
        stats="$1"
        field="$2"
@@ -70,59 +57,83 @@ function validate_min_max
        return $?
 }
 
-function validate_file_count
+function get_total_stream_file_size ()
 {
-       path="$1"
-       file_pattern="$2"
-       expected_max_count="$3"
-
-       count=`find $path -name "$file_pattern" -type f \( ! -iname "*.idx" \) | wc -l`
-
-       if [ "$count" -gt "$expected_max_count" ]; then
-           fail "Validate file count: $file_pattern"
-           diag "File count: $count expected: $expected_max_count"
-       else
-           pass "Validate file count: $file_pattern"
-       fi
+       local trace_path="$1"
+       local stream_name_pattern="$2"
+       local size
+
+       size=$(find "$trace_path" -type f -regex "$stream_name_pattern" -exec du -b -c {} + | tail -n1 | cut -f 1)
+       echo "$size"
 }
 
-function test_tracefile_count_limit ()
+function get_stream_file_count ()
 {
-       count_limit="$1"
-       trace_path=$(mktemp -d)
-       session_name=$(randstring 16 0)
-       channel_name="channel"
-       event_name="tp:tptest"
-       num_iter=100000
-       expected_max=$(($num_iter - 1))
+       local trace_path="$1"
+       local stream_name_pattern="$2"
+       local count
 
-       diag "Test tracefile count limit : $count_limit tracefiles"
-
-       create_lttng_session_ok $session_name $trace_path
-
-       enable_lttng_channel_count_limit \
-           $session_name $channel_name $count_limit
+       count=$(find "$trace_path" -type f -regex "$stream_name_pattern" | wc -l)
+       echo "$count"
+}
 
-       enable_ust_lttng_event_per_channel \
-           $session_name $event_name $channel_name
+function test_tracefile_count_limit ()
+{
+       local count_limit="$1"
+
+       local channel_name="channel"
+       local cpuno=$((RANDOM % NUM_CPUS))
+       local event_name="tp:tptest"
+       local expected_size=$((count_limit * TRACEFILE_SIZE))
+       local num_iter=100000
+       local previous_stream_size=-1
+       local session_name
+       local stream_pattern=".*${channel_name}_${cpuno}_[0-9]*"
+       local stream_size=0
+       local trace_path
 
-       start_lttng_tracing_ok $session_name
+       session_name=$(randstring 16 0)
+       trace_path=$(mktemp -d)
 
-       $TESTAPP_BIN -i $num_iter >/dev/null 2>&1
+       diag "Test tracefile count limit : CPU $cpuno, $count_limit tracefiles, expecting a maximum of $expected_size bytes per CPU"
 
-       stop_lttng_tracing_ok $session_name
+       create_lttng_session_ok "$session_name" "$trace_path"
 
-       destroy_lttng_session_ok $session_name
+       enable_lttng_channel_count_limit \
+           "$session_name" "$channel_name" "$count_limit"
+
+       enable_ust_lttng_event_ok \
+           "$session_name" "$event_name" "$channel_name"
+
+       # Run the test app until the total stream size stops changing the
+       # expected size is exceeded (error).
+       #
+       # The `$stream_size` will not stabilize until the trace file count
+       # limit is reached. This is guaranteed by the use of start/produce/stop
+       # cycles forcing the consumption of buffers, preventing unwanted stall
+       # in stream size.
+       while [ "$stream_size" -ne "$previous_stream_size" ]; do
+               start_lttng_tracing_notap "$session_name"
+               taskset -c "$cpuno" "$TESTAPP_BIN" -i "$num_iter" >/dev/null 2>&1
+               stop_lttng_tracing_notap "$session_name"
+
+               previous_stream_size="$stream_size"
+               stream_size=$(get_total_stream_file_size "$trace_path" "$stream_pattern")
+               diag "Completed an iteration: previous size = $previous_stream_size bytes, new size = $stream_size bytes"
+
+               if [ "$stream_size" -gt "$expected_size" ]; then
+                       diag "Total size for CPU $cpuno exceeds expected size: stream size = $stream_size bytes, expected size = $expected_size"
+                       break
+               fi
+       done
 
-       # Validate tracing dir
+       destroy_lttng_session_ok "$session_name"
 
-       for cpuno in $(seq 0 $(($NUM_CPUS - 1)))
-       do
-               validate_file_count \
-                   $trace_path "${channel_name}_${cpuno}_*" $count_limit
-       done
+       [ "$expected_size" -eq "$stream_size" ]
+       ok $? "Total stream size of CPU $cpuno is $expected_size"
 
-       # Validate tracing data
+       [ "$(get_stream_file_count "$trace_path" "$stream_pattern")" -eq "$count_limit" ]
+       ok $? "Stream meets the trace file limit of $count_limit"
 
        stats=`babeltrace $trace_path | $STATS_BIN --tracepoint $event_name`
 
@@ -135,23 +146,20 @@ function test_tracefile_count_limit ()
        validate_min_max "$stats" "longfield" "[0-9]+" "$expected_max"
        ok $? "Trace validation - longfield"
 
-       rm -rf $trace_path
+       rm -rf "$trace_path"
 }
 
 LIMITS=("1" "2" "4" "8" "10" "16" "32" "64")
 
-# The file count validation depends on the number of streams (1 per cpu)
-TOTAL_TESTS=$(($NUM_TESTS + (${#LIMITS[@]} * $NUM_CPUS)))
-
-plan_tests $TOTAL_TESTS
+plan_tests $NUM_TESTS
 
 print_test_banner "$TEST_DESC"
 
 start_lttng_sessiond
 
-for limit in ${LIMITS[@]};
+for limit in "${LIMITS[@]}";
 do
-       test_tracefile_count_limit $limit
+       test_tracefile_count_limit "$limit"
 done
 
 stop_lttng_sessiond