implement flame graph generation

1 files changed, 113 insertions, 0 deletions

diff --git a/scripts/flame_graph.sh b/scripts/flame_graph.sh
new file mode 100755
index 0000000..ae9129c
--- /dev/null
+++ b/scripts/flame_graph.sh
@@ -0,0 +1,113 @@
+#!/usr/bin/env bash
+
+# Copyright (c) 2023 Egor Tensin <Egor.Tensin@gmail.com>
+# This file is part of the "cimple" project.
+# For details, see https://github.com/egor-tensin/cimple.
+# Distributed under the MIT License.
+
+# This script attaches to a set of processes and makes a flame graph using
+# flamegraph.pl.
+
+set -o errexit -o nounset -o pipefail
+shopt -s inherit_errexit lastpipe
+
+script_name="$( basename -- "${BASH_SOURCE[0]}" )"
+readonly script_name
+
+script_usage() {
+    local msg
+    for msg; do
+        echo "$script_name: $msg"
+    done
+
+    echo "usage: $script_name OUTPUT_PATH PID [PID...]"
+}
+
+join_pids() {
+    local result=''
+    while [ "$#" -gt 0 ]; do
+        if [ -n "$result" ]; then
+            result="$result,"
+        fi
+        result="$result$1"
+        shift
+    done
+    echo "$result"
+}
+
+output_dir=''
+
+cleanup() {
+    if [ -n "$output_dir" ]; then
+        echo "Removing temporary directory: $output_dir"
+        rm -rf -- "$output_dir"
+    fi
+}
+
+make_graph() {
+    wait "$record_pid" || true
+    perf script -i "$output_dir/perf.data" > "$output_dir/perf.out"
+    stackcollapse-perf.pl "$output_dir/perf.out" > "$output_dir/perf.folded"
+    flamegraph.pl --width 2400 "$output_dir/perf.folded" > "$output_path"
+}
+
+record_pid=''
+
+stop_record() {
+    echo "Stopping 'perf record' process $record_pid"
+    kill -SIGINT "$record_pid"
+    make_graph
+}
+
+check_tools() {
+    local tool
+    for tool in perf stackcollapse-perf.pl flamegraph.pl; do
+        if ! command -v "$tool" &> /dev/null; then
+            echo "$script_name: $tool is missing" >&2
+            exit 1
+        fi
+    done
+}
+
+main() {
+    trap cleanup EXIT
+    check_tools
+
+    if [ "$#" -lt 1 ]; then
+        script_usage "output path is required" >&2
+        exit 1
+    fi
+    local output_path="$1"
+    output_path="$( realpath -- "$output_path" )"
+    shift
+
+    if [ "$#" -lt 1 ]; then
+        script_usage "at least one process ID is required" >&2
+        exit 1
+    fi
+    local pids
+    pids="$( join_pids "$@" )"
+    shift
+
+    echo "Output path: $output_path"
+    echo "PIDs: $pids"
+
+    output_dir="$( dirname -- "$output_path" )"
+    output_dir="$( mktemp -d --tmpdir="$output_dir" )"
+    readonly output_dir
+
+    perf record \
+        -o "$output_dir/perf.data" \
+        --freq=99 \
+        --call-graph dwarf,65528 \
+        --pid="$pids" \
+        --no-inherit &
+
+    record_pid="$!"
+    echo "Started 'perf record' process $record_pid"
+    trap stop_record SIGINT SIGTERM
+
+    make_graph
+}
+
+main "$@"