PRE-2016 Valgrind: Memory still reachable with trivial program using

by

It’s Valgrind’s fault. First, -fsanitize=leak does not show anything. Second, Valgrind itself states that:

First of all: relax, it’s probably not a bug, but a feature. Many
implementations of the C++ standard libraries use their own memory
pool allocators. Memory for quite a number of destructed objects is
not immediately freed and given back to the OS, but kept in the
pool(s) for later re-use. The fact that the pools are not freed at the
exit of the program cause Valgrind to report this memory as still
reachable. The behaviour not to free pools at the exit could be called
a bug of the library though.

Using GCC, you can force the STL to use malloc and to free memory as
soon as possible by globally disabling memory caching. Beware! Doing
so will probably slow down your program, sometimes drastically.

With GCC 2.91, 2.95, 3.0 and 3.1, compile all source using the STL
with -D__USE_MALLOC. Beware! This was removed from GCC starting with
version 3.3.

With GCC 3.2.2 and later, you should export the environment variable
GLIBCPP_FORCE_NEW before running your program.

With GCC 3.4 and later, that variable has changed name to
GLIBCXX_FORCE_NEW.

[…]

I guess those alleged memory pools are freed after program’s termination, in the so-called start-up code that calls main, among the other settings. Internal functions defined outside user’s code should be treated as if they didn’t exist, that’s why Valgrind can’t (and shouldn’t) see further frees.

More Related Contents:

  1. pinpointing “conditional jump or move depends on uninitialized value(s)” valgrind message
  2. cpp – valgrind – Invalid read of size 8
  3. How to profile memory usage?
  4. How can I use valgrind with Python C++ extensions?
  5. valgrind memory leak errors when using pthread_create
  6. Why does valgrind say basic SDL program is leaking memory?
  7. Valgrind errors when linked with -static — Why?
  8. Does boost::bind() copy parameters by reference or by value?
  9. Resolve build errors due to circular dependency amongst classes
  10. Why must a short be converted to an int before arithmetic operations in C and C++?
  11. How do I iterate over cin line by line in C++?
  12. How to convert an enum type variable to a string?
  13. Testing stream.good() or !stream.eof() reads last line twice [duplicate]
  14. How do you pass a member function pointer?
  15. How to open an std::fstream (ofstream or ifstream) with a unicode filename?
  16. “\n” or ‘\n’ or std::endl to std::cout? [duplicate]
  17. Subclass/inherit standard containers?
  18. What does it mean when a numeric constant in C/C++ is prefixed with a 0?
  19. how do you insert the value in a sorted vector?
  20. Forward declare a standard container?
  21. Is there a LINQ library for C++? [closed]
  22. Child process receives parent’s SIGINT
  23. How to Convert unsigned char* to std::string in C++?
  24. Using Quaternions for OpenGL Rotations [duplicate]
  25. linking with clang++ on OS X generates lots of symbol not found errors
  26. What is the purpose of the “final” keyword in C++11 for functions?
  27. problems with Move constructor and Move overloaded assignment operator?
  28. is it possible to make function that will accept multiple data types for given argument?
  29. How to tell if a lib was compiled with /mt or /md?
  30. How do I include the string header?

Leave a Comment