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#!/usr/bin/env python
# @lint-avoid-python-3-compatibility-imports
#
# uobjnew Summarize object allocations in high-level languages.
# For Linux, uses BCC, eBPF.
#
# USAGE: uobjnew [-h] [-T TOP] [-v] {c,java,ruby,tcl} pid [interval]
#
# Copyright 2016 Sasha Goldshtein
# Licensed under the Apache License, Version 2.0 (the "License")
#
# 25-Oct-2016 Sasha Goldshtein Created this.
from __future__ import print_function
import argparse
from bcc import BPF, USDT, utils
from time import sleep
import os
# C needs to be the last language.
languages = ["c", "java", "ruby", "tcl"]
examples = """examples:
./uobjnew -l java 145 # summarize Java allocations in process 145
./uobjnew -l c 2020 1 # grab malloc() sizes and print every second
./uobjnew -l ruby 6712 -C 10 # top 10 Ruby types by number of allocations
./uobjnew -l ruby 6712 -S 10 # top 10 Ruby types by total size
"""
parser = argparse.ArgumentParser(
description="Summarize object allocations in high-level languages.",
formatter_class=argparse.RawDescriptionHelpFormatter,
epilog=examples)
parser.add_argument("-l", "--language", choices=languages,
help="language to trace")
parser.add_argument("pid", type=int, help="process id to attach to")
parser.add_argument("interval", type=int, nargs='?',
help="print every specified number of seconds")
parser.add_argument("-C", "--top-count", type=int,
help="number of most frequently allocated types to print")
parser.add_argument("-S", "--top-size", type=int,
help="number of largest types by allocated bytes to print")
parser.add_argument("-v", "--verbose", action="store_true",
help="verbose mode: print the BPF program (for debugging purposes)")
parser.add_argument("--ebpf", action="store_true",
help=argparse.SUPPRESS)
args = parser.parse_args()
language = args.language
if not language:
language = utils.detect_language(languages, args.pid)
program = """
#include <linux/ptrace.h>
struct key_t {
#if MALLOC_TRACING
u64 size;
#else
char name[50];
#endif
};
struct val_t {
u64 total_size;
u64 num_allocs;
};
BPF_HASH(allocs, struct key_t, struct val_t);
""".replace("MALLOC_TRACING", "1" if language == "c" else "0")
usdt = USDT(pid=args.pid)
#
# C
#
if language == "c":
program += """
int alloc_entry(struct pt_regs *ctx, size_t size) {
struct key_t key = {};
struct val_t *valp, zero = {};
key.size = size;
valp = allocs.lookup_or_init(&key, &zero);
valp->total_size += size;
valp->num_allocs += 1;
return 0;
}
"""
#
# Java
#
elif language == "java":
program += """
int alloc_entry(struct pt_regs *ctx) {
struct key_t key = {};
struct val_t *valp, zero = {};
u64 classptr = 0, size = 0;
bpf_usdt_readarg(2, ctx, &classptr);
bpf_usdt_readarg(4, ctx, &size);
bpf_probe_read(&key.name, sizeof(key.name), (void *)classptr);
valp = allocs.lookup_or_init(&key, &zero);
valp->total_size += size;
valp->num_allocs += 1;
return 0;
}
"""
usdt.enable_probe_or_bail("object__alloc", "alloc_entry")
#
# Ruby
#
elif language == "ruby":
create_template = """
int THETHING_alloc_entry(struct pt_regs *ctx) {
struct key_t key = { .name = "THETHING" };
struct val_t *valp, zero = {};
u64 size = 0;
bpf_usdt_readarg(1, ctx, &size);
valp = allocs.lookup_or_init(&key, &zero);
valp->total_size += size;
valp->num_allocs += 1;
return 0;
}
"""
program += """
int object_alloc_entry(struct pt_regs *ctx) {
struct key_t key = {};
struct val_t *valp, zero = {};
u64 classptr = 0;
bpf_usdt_readarg(1, ctx, &classptr);
bpf_probe_read(&key.name, sizeof(key.name), (void *)classptr);
valp = allocs.lookup_or_init(&key, &zero);
valp->num_allocs += 1; // We don't know the size, unfortunately
return 0;
}
"""
usdt.enable_probe_or_bail("object__create", "object_alloc_entry")
for thing in ["string", "hash", "array"]:
program += create_template.replace("THETHING", thing)
usdt.enable_probe_or_bail("%s__create" % thing,
"%s_alloc_entry" % thing)
#
# Tcl
#
elif language == "tcl":
program += """
int alloc_entry(struct pt_regs *ctx) {
struct key_t key = { .name = "<ALL>" };
struct val_t *valp, zero = {};
valp = allocs.lookup_or_init(&key, &zero);
valp->num_allocs += 1;
return 0;
}
"""
usdt.enable_probe_or_bail("obj__create", "alloc_entry")
else:
print("No language detected; use -l to trace a language.")
exit(1)
if args.ebpf or args.verbose:
if args.verbose:
print(usdt.get_text())
print(program)
if args.ebpf:
exit()
bpf = BPF(text=program, usdt_contexts=[usdt])
if language == "c":
bpf.attach_uprobe(name="c", sym="malloc", fn_name="alloc_entry",
pid=args.pid)
exit_signaled = False
print("Tracing allocations in process %d (language: %s)... Ctrl-C to quit." %
(args.pid, language or "none"))
while True:
try:
sleep(args.interval or 99999999)
except KeyboardInterrupt:
exit_signaled = True
print()
data = bpf["allocs"]
if args.top_count:
data = sorted(data.items(), key=lambda kv: kv[1].num_allocs)
data = data[-args.top_count:]
elif args.top_size:
data = sorted(data.items(), key=lambda kv: kv[1].total_size)
data = data[-args.top_size:]
else:
data = sorted(data.items(), key=lambda kv: kv[1].total_size)
print("%-30s %8s %12s" % ("NAME/TYPE", "# ALLOCS", "# BYTES"))
for key, value in data:
if language == "c":
obj_type = "block size %d" % key.size
else:
obj_type = key.name
print("%-30s %8d %12d" %
(obj_type, value.num_allocs, value.total_size))
if args.interval and not exit_signaled:
bpf["allocs"].clear()
else:
exit()