tembaby / memwatch Goto Github PK

/*

• Description of the modules:
• This file and its accompanying files (my_bitstring.h, m_pool.*)
• should be used as part of projects which one can suspect memory
• leaks in code.
• A new memory [de]allocator warpper routines should be defined
• which notifies mem_watcher of allocations/reallocations/deallocations
• so it can build its lists of currently allocated memory regions
• by the suspect program, which can be printed at program exit or
• at any requested time intervals.
• The program should call mem_init() early at startup so mem_watcher
• can allocate memory necessary to its internal structures and
• preform any other necessary initialization.
• Example of usage with standard C library malloc()/realloc()/free():
• At program startup: (say main.c)
• int
• main()
• {
• #if defined (WATCH_MEMORY)
• mem_init();
• #endif
• ...
• #if defined (WATCH_MEMORY)
• mem_deinit();
• #endif
• return (exit_code);
• }
• In application's header file: (say mem.h)
• void *_my_malloc(size_t siz, const char *file, int line);
• #define my_malloc(siz) _my_malloc(s, FILE, LINE)
• In module where application defines these wrappers: (say mem.c)
• void *
• _my_malloc(size_t siz, const char *file, int line)
• {
• void *p;
• p = malloc(siz);
• ... -> failure checking preformed
• #if defined (WATCH_MEMORY)
• mem_alloc_notify(siz, file, line);
• #endif
• return (p);
• }
• Same concept applies to my_realloc() and my_free() routines by calling
• mem_realloc_notify() and mem_free_notify() respectivily.
• And then at your program exit call mem_deinit() or at any other
• approperiate time call mem_stats() to print memory regions that
• the application forgot about.
• If you encounter non-zero value in ``alloc_fail'' when printing
• m_pool statistics you should increase the MAX_MEMALLOC_POOL
• as approperiate.
• The ``alloc_peek'' value can give indication about maximum number
• of allocated memory regions at any time. So a alloc_peek value
• of 1 means that every my_malloc() call is always followed by
• a corresponding my_free() call. This value also can help in
• determining the approperiate value for MAX_MEMALLOC_POOL.
• Mem_watcher will report illegal free() calls so it can be repaired
• or investigated.
• Logging is performed by MPOOL_LOG() and MLOG() macros which are
• just an aliases for printf() by default. They can by replaced
• by other printf-like logging routines (or use log.h log.c found
• on my page) or just hack this code :-).
• The use of pre-allocated memory pool and a hash table to keep
• track of allocated memory objects helps in making mem_watcher
• overhead unnoticeable.
• This code is no magic solution of memory leaks, you still need more
• effort in investigating/tracing why memory leaks happens, but it
• helps. */