Ctrl+K

Linux* OS C/C++ Dynamic Memory Interface Replacement

Linux* OS C/C++ Dynamic Memory Interface Replacement#

Release version of the proxy library is libtbbmalloc_proxy.so, debug version is libtbbmalloc_proxy_debug.so.

The following dynamic memory functions are replaced:

  • Standard C library functions: malloc, calloc, realloc, free, (added in C11) aligned_alloc

  • Standard POSIX* function: posix_memalign

  • Obsolete functions: valloc, memalign, pvalloc, mallopt

  • Replaceable global C++ operators new and delete

  • GNU C library (glibc) specific functions: malloc_usable_size, __libc_malloc, __libc_calloc, __libc_memalign, __libc_free, __libc_realloc, __libc_pvalloc, __libc_valloc

You can do the replacement either by loading the proxy library at program load time using the LD_PRELOAD environment variable (without changing the executable file), or by linking the main executable file with the proxy library.

The OS program loader must be able to find the proxy library and the scalable memory allocator library at program load time. For that you may include the directory containing the libraries in the LD_LIBRARY_PATH environment variable or add it to /etc/ld.so.conf.

There are limitations for dynamic memory replacement:

  • glibc memory allocation hooks, such as __malloc_hook, are not supported.

  • Mono is not supported.

Examples

These examples show how to set LD_PRELOAD and how to link a program to use the memory allocation replacements.

# Set LD_PRELOAD to load the release version of the proxy library
LD_PRELOAD=libtbbmalloc_proxy.so
# Link with the release version of the proxy library
g++ foo.o bar.o -ltbbmalloc_proxy -o a.out

To use the debug version of the library, replace tbbmalloc_proxy with tbbmalloc_proxy_debug in the above examples.