rclc_example: memory leak

[Zard-C]

A memory leak occurs when running the rclc_example

• Hardware description: x86_64 GNU/Linux
• RTOS:
• Installation type:
• Version or commit hash: humble

Steps to reproduce the issue

source install/setup.zsh 
valgrind --tool=memcheck --leak-check=full ./install/rclc_examples/lib/rclc_examples/example_sub_context 

Expected behavior

no memory leaking

Actual behavior

==115904== Memcheck, a memory error detector
==115904== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==115904== Using Valgrind-3.15.0 and LibVEX; rerun with -h for copyright info
==115904== Command: ./install/rclc_examples/lib/rclc_examples/example_sub_context
==115904== 
Created subscriber topic_foo:
Created subscriber topic_bar:
Created subscriber topic_baz:
Debug: number of DDS handles: 3

Published message Hello World! on topic_foo
Callback: I heard: Hello World! on topic_foo
Callback: context contains: foo counting from zero
Callback: context also contains: 0

Published message Hello World! on topic_bar
Callback: I heard: Hello World! on topic_bar
Callback: context contains: bar counting from 100
Callback: context also contains: 100

Published message Hello World! on topic_baz
Callback: I heard: Hello World! on topic_baz
Callback: context contains: baz counting from 300
Callback: context also contains: 300

Published message Hello World! on topic_foo
Callback: I heard: Hello World! on topic_foo
Callback: context contains: foo counting from zero
Callback: context also contains: 1

Published message Hello World! on topic_bar
Callback: I heard: Hello World! on topic_bar
Callback: context contains: bar counting from 100
Callback: context also contains: 101

Published message Hello World! on topic_baz
Callback: I heard: Hello World! on topic_baz
Callback: context contains: baz counting from 300
Callback: context also contains: 301

Published message Hello World! on topic_foo
Callback: I heard: Hello World! on topic_foo
Callback: context contains: foo counting from zero
Callback: context also contains: 2

Published message Hello World! on topic_bar
Callback: I heard: Hello World! on topic_bar
Callback: context contains: bar counting from 100
Callback: context also contains: 102

Published message Hello World! on topic_baz
Callback: I heard: Hello World! on topic_baz
Callback: context contains: baz counting from 300
Callback: context also contains: 302

Published message Hello World! on topic_foo
Callback: I heard: Hello World! on topic_foo
Callback: context contains: foo counting from zero
Callback: context also contains: 3

Published message Hello World! on topic_bar
Callback: I heard: Hello World! on topic_bar
Callback: context contains: bar counting from 100
Callback: context also contains: 103

Published message Hello World! on topic_baz
Callback: I heard: Hello World! on topic_baz
Callback: context contains: baz counting from 300
Callback: context also contains: 303

Published message Hello World! on topic_foo
Callback: I heard: Hello World! on topic_foo
Callback: context contains: foo counting from zero
Callback: context also contains: 4

Published message Hello World! on topic_bar
Callback: I heard: Hello World! on topic_bar
Callback: context contains: bar counting from 100
Callback: context also contains: 104

Published message Hello World! on topic_baz
Callback: I heard: Hello World! on topic_baz
Callback: context contains: baz counting from 300
Callback: context also contains: 304

Published message Hello World! on topic_foo
Callback: I heard: Hello World! on topic_foo
Callback: context contains: foo counting from zero
Callback: context also contains: 5

Published message Hello World! on topic_bar
Callback: I heard: Hello World! on topic_bar
Callback: context contains: bar counting from 100
Callback: context also contains: 105

Published message Hello World! on topic_baz
Callback: I heard: Hello World! on topic_baz
Callback: context contains: baz counting from 300
Callback: context also contains: 305

Published message Hello World! on topic_foo
Callback: I heard: Hello World! on topic_foo
Callback: context contains: foo counting from zero
Callback: context also contains: 6

Published message Hello World! on topic_bar
Callback: I heard: Hello World! on topic_bar
Callback: context contains: bar counting from 100
Callback: context also contains: 106

Published message Hello World! on topic_baz
Callback: I heard: Hello World! on topic_baz
Callback: context contains: baz counting from 300
Callback: context also contains: 306

Published message Hello World! on topic_foo
Callback: I heard: Hello World! on topic_foo
Callback: context contains: foo counting from zero
Callback: context also contains: 7

Published message Hello World! on topic_bar
Callback: I heard: Hello World! on topic_bar
Callback: context contains: bar counting from 100
Callback: context also contains: 107

Published message Hello World! on topic_baz
Callback: I heard: Hello World! on topic_baz
Callback: context contains: baz counting from 300
Callback: context also contains: 307

Published message Hello World! on topic_foo
Callback: I heard: Hello World! on topic_foo
Callback: context contains: foo counting from zero
Callback: context also contains: 8

Published message Hello World! on topic_bar
Callback: I heard: Hello World! on topic_bar
Callback: context contains: bar counting from 100
Callback: context also contains: 108

Published message Hello World! on topic_baz
Callback: I heard: Hello World! on topic_baz
Callback: context contains: baz counting from 300
Callback: context also contains: 308

Published message Hello World! on topic_foo
Callback: I heard: Hello World! on topic_foo
Callback: context contains: foo counting from zero
Callback: context also contains: 9

Published message Hello World! on topic_bar
Callback: I heard: Hello World! on topic_bar
Callback: context contains: bar counting from 100
Callback: context also contains: 109

Published message Hello World! on topic_baz
Callback: I heard: Hello World! on topic_baz
Callback: context contains: baz counting from 300
Callback: context also contains: 309
==115904== 
==115904== HEAP SUMMARY:
==115904==     in use at exit: 42,654 bytes in 97 blocks
==115904==   total heap usage: 12,916 allocs, 12,819 frees, 3,748,842 bytes allocated
==115904== 
==115904== 3 bytes in 3 blocks are definitely lost in loss record 1 of 23
==115904==    at 0x483B7F3: malloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)
==115904==    by 0x48E9006: __default_allocate (allocator.c:37)
==115904==    by 0x4BCEF61: rosidl_runtime_c__String__init (string_functions.c:34)
==115904==    by 0x48D6030: std_msgs__msg__String__init (string__functions.c:25)
==115904==    by 0x109B61: main (example_sub_context.c:112)
==115904== 
==115904== LEAK SUMMARY:
==115904==    definitely lost: 3 bytes in 3 blocks
==115904==    indirectly lost: 0 bytes in 0 blocks
==115904==      possibly lost: 0 bytes in 0 blocks
==115904==    still reachable: 42,651 bytes in 94 blocks
==115904==         suppressed: 0 bytes in 0 blocks
==115904== Reachable blocks (those to which a pointer was found) are not shown.
==115904== To see them, rerun with: --leak-check=full --show-leak-kinds=all
==115904== 
==115904== For lists of detected and suppressed errors, rerun with: -s
==115904== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)

Additional information

[JanStaschulat]

@Zard-C thanks for this issue and the fix. Could you run valgrind with the fixed version and, thereby, document that the memory leak was resolved?

[Zard-C]

@Zard-C thanks for this issue and the fix. Could you run valgrind with the fixed version and, thereby, document that the memory leak was resolved? Hi, here is the valgrind report of the fixed version,

==143265== Memcheck, a memory error detector
==143265== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==143265== Using Valgrind-3.15.0 and LibVEX; rerun with -h for copyright info
==143265== Command: ./install/rclc_examples/lib/rclc_examples/example_sub_context
==143265== 
Created subscriber topic_foo:
Created subscriber topic_bar:
Created subscriber topic_baz:
Debug: number of DDS handles: 3

Published message Hello World! on topic_foo Callback: I heard: Hello World! on topic_foo Callback: context contains: foo counting from zero Callback: context also contains: 0

Published message Hello World! on topic_bar Callback: I heard: Hello World! on topic_bar Callback: context contains: bar counting from 100 Callback: context also contains: 100

Published message Hello World! on topic_baz Callback: I heard: Hello World! on topic_baz Callback: context contains: baz counting from 300 Callback: context also contains: 300

Published message Hello World! on topic_foo Callback: I heard: Hello World! on topic_foo Callback: context contains: foo counting from zero Callback: context also contains: 1

Published message Hello World! on topic_bar Callback: I heard: Hello World! on topic_bar Callback: context contains: bar counting from 100 Callback: context also contains: 101

Published message Hello World! on topic_baz Callback: I heard: Hello World! on topic_baz Callback: context contains: baz counting from 300 Callback: context also contains: 301

Published message Hello World! on topic_foo Callback: I heard: Hello World! on topic_foo Callback: context contains: foo counting from zero Callback: context also contains: 2

Published message Hello World! on topic_bar Callback: I heard: Hello World! on topic_bar Callback: context contains: bar counting from 100 Callback: context also contains: 102

Published message Hello World! on topic_baz Callback: I heard: Hello World! on topic_baz Callback: context contains: baz counting from 300 Callback: context also contains: 302

Published message Hello World! on topic_foo Callback: I heard: Hello World! on topic_foo Callback: context contains: foo counting from zero Callback: context also contains: 3

Published message Hello World! on topic_bar Callback: I heard: Hello World! on topic_bar Callback: context contains: bar counting from 100 Callback: context also contains: 103

Published message Hello World! on topic_baz Callback: I heard: Hello World! on topic_baz Callback: context contains: baz counting from 300 Callback: context also contains: 303

Published message Hello World! on topic_foo Callback: I heard: Hello World! on topic_foo Callback: context contains: foo counting from zero Callback: context also contains: 4

Published message Hello World! on topic_bar Callback: I heard: Hello World! on topic_bar Callback: context contains: bar counting from 100 Callback: context also contains: 104

Published message Hello World! on topic_baz Callback: I heard: Hello World! on topic_baz Callback: context contains: baz counting from 300 Callback: context also contains: 304

Published message Hello World! on topic_foo Callback: I heard: Hello World! on topic_foo Callback: context contains: foo counting from zero Callback: context also contains: 5

Published message Hello World! on topic_bar Callback: I heard: Hello World! on topic_bar Callback: context contains: bar counting from 100 Callback: context also contains: 105

Published message Hello World! on topic_baz Callback: I heard: Hello World! on topic_baz Callback: context contains: baz counting from 300 Callback: context also contains: 305

Published message Hello World! on topic_foo Callback: I heard: Hello World! on topic_foo Callback: context contains: foo counting from zero Callback: context also contains: 6

Published message Hello World! on topic_bar Callback: I heard: Hello World! on topic_bar Callback: context contains: bar counting from 100 Callback: context also contains: 106

Published message Hello World! on topic_baz Callback: I heard: Hello World! on topic_baz Callback: context contains: baz counting from 300 Callback: context also contains: 306

Published message Hello World! on topic_foo Callback: I heard: Hello World! on topic_foo Callback: context contains: foo counting from zero Callback: context also contains: 7

Published message Hello World! on topic_bar Callback: I heard: Hello World! on topic_bar Callback: context contains: bar counting from 100 Callback: context also contains: 107

Published message Hello World! on topic_baz Callback: I heard: Hello World! on topic_baz Callback: context contains: baz counting from 300 Callback: context also contains: 307

Published message Hello World! on topic_foo Callback: I heard: Hello World! on topic_foo Callback: context contains: foo counting from zero Callback: context also contains: 8

Published message Hello World! on topic_bar Callback: I heard: Hello World! on topic_bar Callback: context contains: bar counting from 100 Callback: context also contains: 108

Published message Hello World! on topic_baz Callback: I heard: Hello World! on topic_baz Callback: context contains: baz counting from 300 Callback: context also contains: 308

Published message Hello World! on topic_foo Callback: I heard: Hello World! on topic_foo Callback: context contains: foo counting from zero Callback: context also contains: 9

Published message Hello World! on topic_bar Callback: I heard: Hello World! on topic_bar Callback: context contains: bar counting from 100 Callback: context also contains: 109

Published message Hello World! on topic_baz Callback: I heard: Hello World! on topic_baz Callback: context contains: baz counting from 300 Callback: context also contains: 309 ==143265== ==143265== HEAP SUMMARY: ==143265== in use at exit: 42,651 bytes in 94 blocks ==143265== total heap usage: 14,486 allocs, 14,392 frees, 3,879,879 bytes allocated ==143265== ==143265== LEAK SUMMARY: ==143265== definitely lost: 0 bytes in 0 blocks ==143265== indirectly lost: 0 bytes in 0 blocks ==143265== possibly lost: 0 bytes in 0 blocks ==143265== still reachable: 42,651 bytes in 94 blocks ==143265== suppressed: 0 bytes in 0 blocks ==143265== Reachable blocks (those to which a pointer was found) are not shown. ==143265== To see them, rerun with: --leak-check=full --show-leak-kinds=all ==143265== ==143265== For lists of detected and suppressed errors, rerun with: -s ==143265== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)

[Zard-C]

This issue is fixed by https://github.com/ros2/rclc/pull/386