debug_new.cpp File Reference

Implementation of debug versions of new and delete to check leakage. More...

#include <new>
#include <assert.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "fast_mutex.h"
#include "static_assert.h"
#include "debug_new.h"

Include dependency graph for debug_new.cpp:

Classes
struct	new_ptr_list_t
	Structure to store the position information where `new` occurs. More...
Defines
#define	_DEBUG_NEW_ALIGNMENT 16
	The alignment requirement of allocated memory blocks.
#define	_DEBUG_NEW_CALLER_ADDRESS __builtin_return_address(0)
	The expression to return the caller address.
#define	_DEBUG_NEW_ERROR_ACTION abort()
	The action to take when an error occurs.
#define	_DEBUG_NEW_FILENAME_LEN 44
	The length of file name stored if greater than zero.
#define	_DEBUG_NEW_PROGNAME NULL
	The program (executable) name to be set at compile time.
#define	_DEBUG_NEW_STD_OPER_NEW 1
	Macro to indicate whether the standard-conformant behaviour of `operator new` is wanted.
#define	_DEBUG_NEW_TAILCHECK 0
	Macro to indicate whether a writing-past-end check will be performed.
#define	_DEBUG_NEW_TAILCHECK_CHAR 0xCC
	Value of the padding bytes at the end of a memory block.
#define	_DEBUG_NEW_USE_ADDR2LINE 1
	Whether to use addr2line to convert a caller address to file/line information.
#define	_DEBUG_NEW_REDEFINE_NEW 0
	Macro to indicate whether redefinition of `new` is wanted.
#define	ALIGN(s) (((s) + _DEBUG_NEW_ALIGNMENT - 1) & ~(_DEBUG_NEW_ALIGNMENT - 1))
	Gets the aligned value of memory block size.
Functions
static bool	print_position_from_addr (const void *addr)
	Tries printing the position information from an instruction address.
static void	print_position (const void *ptr, int line)
	Prints the position information of a memory operation point.
static void *	alloc_mem (size_t size, const char *file, int line, bool is_array)
	Allocates memory and initializes control data.
static void	free_pointer (void pointer, void addr, bool is_array)
	Frees memory and adjusts pointers.
int	check_leaks ()
	Checks for memory leaks.
int	check_mem_corruption ()
	Checks for heap corruption.
void *	operator new (size_t size, const char *file, int line)
	Allocates memory with file/line information.
void *	operator new[] (size_t size, const char *file, int line)
	Allocates array memory with file/line information.
void *	operator new (size_t size) throw (std::bad_alloc)
	Allocates memory without file/line information.
void *	operator new[] (size_t size) throw (std::bad_alloc)
	Allocates array memory without file/line information.
void *	operator new (size_t size, const std::nothrow_t &) throw ()
	Allocates memory with no-throw guarantee.
void *	operator new[] (size_t size, const std::nothrow_t &) throw ()
	Allocates array memory with no-throw guarantee.
void	operator delete (void *pointer) throw ()
	Deallocates memory.
void	operator delete[] (void *pointer) throw ()
	Deallocates array memory.
void	operator delete (void pointer, const char file, int line) throw ()
	Placement deallocation function.
void	operator delete[] (void pointer, const char file, int line) throw ()
	Placement deallocation function.
void	operator delete (void *pointer, const std::nothrow_t &) throw ()
	Placement deallocation function.
void	operator delete[] (void *pointer, const std::nothrow_t &) throw ()
	Placement deallocation function.
Variables
const size_t	PLATFORM_MEM_ALIGNMENT = sizeof(size_t) * 2
	The platform memory alignment.
const unsigned	MAGIC = 0x4442474E
	Definition of the constant magic number used for error detection.
const int	ALIGNED_LIST_ITEM_SIZE = ALIGN(sizeof(new_ptr_list_t))
	The extra memory allocated by `operator new`.
static new_ptr_list_t	new_ptr_list
	List of all new'd pointers.
static fast_mutex	new_ptr_lock
	The mutex guard to protect simultaneous access to the pointer list.
static fast_mutex	new_output_lock
	The mutex guard to protect simultaneous output to new_output_fp.
static size_t	total_mem_alloc = 0
	Total memory allocated in bytes.
bool	new_autocheck_flag = true
	Flag to control whether check_leaks will be automatically called on program exit.
bool	new_verbose_flag = false
	Flag to control whether verbose messages are output.
FILE *	new_output_fp = stderr
	Pointer to the output stream.
const char *	new_progname = _DEBUG_NEW_PROGNAME
	Pointer to the program name.

Detailed Description

Implementation of debug versions of new and delete to check leakage.

Version:: 4.22, 2011/07/12

Author:: Wu Yongwei

Define Documentation

#define _DEBUG_NEW_ALIGNMENT 16

The alignment requirement of allocated memory blocks.

It must be a power of two.

#define _DEBUG_NEW_CALLER_ADDRESS __builtin_return_address(0)

The expression to return the caller address.

print_position will later on use this address to print the position information of memory operation points.

#define _DEBUG_NEW_ERROR_ACTION abort()

The action to take when an error occurs.

The default behaviour is to call abort, unless _DEBUG_NEW_ERROR_CRASH is defined, in which case a segmentation fault will be triggered instead (which can be useful on platforms like Windows that do not generate a core dump when abort is called).

#define _DEBUG_NEW_FILENAME_LEN 44

The length of file name stored if greater than zero.

If it is zero, only a const char pointer will be stored. Currently the default value is non-zero (thus to copy the file name) on non-Windows platforms, because I once found that the exit leakage check could not access the address of the file name on Linux (in my case, a core dump occurred when check_leaks tried to access the file name in a shared library after a SIGINT). This value makes the size of new_ptr_list_t 64 on non-Windows 32-bit platforms.

#define _DEBUG_NEW_PROGNAME NULL

The program (executable) name to be set at compile time.

It is better to assign the full program path to new_progname in main (at run time) than to use this (compile-time) macro, but this macro serves well as a quick hack. Note also that double quotation marks need to be used around the program name, i.e., one should specify a command-line option like -D_DEBUG_NEW_PROGNAME="a.out" in bash, or -D_DEBUG_NEW_PROGNAME="a.exe" in the Windows command prompt.

#define _DEBUG_NEW_REDEFINE_NEW 0

Macro to indicate whether redefinition of new is wanted.

Here it is defined to 0 to disable the redefinition of new.

#define _DEBUG_NEW_STD_OPER_NEW 1

Macro to indicate whether the standard-conformant behaviour of operator new is wanted.

It is on by default now, but the user may set it to 0 to revert to the old behaviour.

#define _DEBUG_NEW_TAILCHECK 0

Macro to indicate whether a writing-past-end check will be performed.

Define it to a positive integer as the number of padding bytes at the end of a memory block for checking.

#define _DEBUG_NEW_TAILCHECK_CHAR 0xCC

Value of the padding bytes at the end of a memory block.

#define _DEBUG_NEW_USE_ADDR2LINE 1

Whether to use addr2line to convert a caller address to file/line information.

Defining it to a non-zero value will enable the conversion (automatically done if GCC is detected). Defining it to zero will disable the conversion.

#define ALIGN ( s ) (((s) + _DEBUG_NEW_ALIGNMENT - 1) & ~(_DEBUG_NEW_ALIGNMENT - 1))

Gets the aligned value of memory block size.

Function Documentation

static void* alloc_mem	(	size_t	size,
		const char *	file,
		int	line,
		bool	is_array
	)			`[static]`

Allocates memory and initializes control data.

Parameters:

	size	size of the required memory block
	file	null-terminated string of the file name
	line	line number
	is_array	boolean value whether this is an array operation

Returns:: pointer to the user-requested memory area; NULL if memory allocation is not successful

int check_leaks ( )

Checks for memory leaks.

Returns:: zero if no leakage is found; the number of leaks otherwise

int check_mem_corruption ( )

Checks for heap corruption.

Returns:: zero if no problem is found; the number of found memory corruptions otherwise

static void free_pointer	(	void *	pointer,
		void *	addr,
		bool	is_array
	)			`[static]`

Frees memory and adjusts pointers.

Parameters:

	pointer	pointer to the previously allocated memory
	addr	pointer to the caller
	is_array	flag indicating whether it is invoked by a `delete[]` call

void operator delete	(	void *	pointer,
		const std::nothrow_t &
	)			throw ()

Placement deallocation function.

For details, please check Section 5.3.4 of the C++ 1998 Standard.

Parameters:

pointer

pointer to the previously allocated memory

void operator delete	(	void *	pointer,
		const char *	file,
		int	line
	)			throw ()

Placement deallocation function.

For details, please check Section 5.3.4 of the C++ 1998 Standard.

Parameters:

	pointer	pointer to the previously allocated memory
	file	null-terminated string of the file name
	line	line number

See also:: http://www.csci.csusb.edu/dick/c++std/cd2/expr.html#expr.new; http://wyw.dcweb.cn/leakage.htm

void operator delete ( void * pointer ) throw ()

Deallocates memory.

Parameters:

pointer

pointer to the previously allocated memory

void operator delete[]	(	void *	pointer,
		const std::nothrow_t &
	)			throw ()

Placement deallocation function.

For details, please check Section 5.3.4 of the C++ 1998 Standard.

Parameters:

pointer

pointer to the previously allocated memory

void operator delete[]	(	void *	pointer,
		const char *	file,
		int	line
	)			throw ()

Placement deallocation function.

For details, please check Section 5.3.4 of the C++ 1998 Standard.

Parameters:

	pointer	pointer to the previously allocated memory
	file	null-terminated string of the file name
	line	line number

void operator delete[] ( void * pointer ) throw ()

Deallocates array memory.

Parameters:

pointer

pointer to the previously allocated memory

void* operator new	(	size_t	size,
		const std::nothrow_t &
	)			throw ()

Allocates memory with no-throw guarantee.

Parameters:

size

size of the required memory block

Returns:: pointer to the memory allocated; or NULL if memory is insufficient

void* operator new ( size_t size ) throw (std::bad_alloc)

Allocates memory without file/line information.

Parameters:

size

size of the required memory block

Returns:: pointer to the memory allocated; or NULL if memory is insufficient (_DEBUG_NEW_STD_OPER_NEW is 0)

Exceptions:

bad_alloc

memory is insufficient (_DEBUG_NEW_STD_OPER_NEW is 1)

void* operator new	(	size_t	size,
		const char *	file,
		int	line
	)

Allocates memory with file/line information.

Parameters:

	size	size of the required memory block
	file	null-terminated string of the file name
	line	line number

Returns:: pointer to the memory allocated; or NULL if memory is insufficient (_DEBUG_NEW_STD_OPER_NEW is 0)

Exceptions:

bad_alloc

memory is insufficient (_DEBUG_NEW_STD_OPER_NEW is 1)

void* operator new[]	(	size_t	size,
		const std::nothrow_t &
	)			throw ()

Allocates array memory with no-throw guarantee.

Parameters:

size

size of the required memory block

Returns:: pointer to the memory allocated; or NULL if memory is insufficient

void* operator new[] ( size_t size ) throw (std::bad_alloc)

Allocates array memory without file/line information.

Parameters:

size

size of the required memory block

Returns:: pointer to the memory allocated; or NULL if memory is insufficient (_DEBUG_NEW_STD_OPER_NEW is 0)

Exceptions:

bad_alloc

memory is insufficient (_DEBUG_NEW_STD_OPER_NEW is 1)

void* operator new[]	(	size_t	size,
		const char *	file,
		int	line
	)

Allocates array memory with file/line information.

Parameters:

	size	size of the required memory block
	file	null-terminated string of the file name
	line	line number

Returns:: pointer to the memory allocated; or NULL if memory is insufficient (_DEBUG_NEW_STD_OPER_NEW is 0)

Exceptions:

bad_alloc

memory is insufficient (_DEBUG_NEW_STD_OPER_NEW is 1)

static void print_position	(	const void *	ptr,
		int	line
	)			`[static]`

Prints the position information of a memory operation point.

When _DEBUG_NEW_USE_ADDR2LINE is defined to a non-zero value, this function will try to convert a given caller address to file/line information with addr2line.

Parameters:

	ptr	source file name if line is non-zero; caller address otherwise
	line	source line number if non-zero; indication that ptr is the caller address otherwise

static bool print_position_from_addr ( const void * addr ) [static]

Tries printing the position information from an instruction address.

This is the version that uses addr2line.

Parameters:

addr

the instruction address to convert and print

Returns:: true if the address is converted successfully (and the result is printed); false if no useful information is got (and nothing is printed)

Variable Documentation

const int ALIGNED_LIST_ITEM_SIZE = ALIGN(sizeof(new_ptr_list_t))

The extra memory allocated by operator new.

const unsigned MAGIC = 0x4442474E

Definition of the constant magic number used for error detection.

bool new_autocheck_flag = true

Flag to control whether check_leaks will be automatically called on program exit.

FILE* new_output_fp = stderr

Pointer to the output stream.

The default output is stderr, and one may change it to a user stream if needed (say, new_verbose_flag is true and there are a lot of (de)allocations).

fast_mutex new_output_lock [static]

The mutex guard to protect simultaneous output to new_output_fp.

const char* new_progname = _DEBUG_NEW_PROGNAME

Pointer to the program name.

Its initial value is the macro _DEBUG_NEW_PROGNAME. You should try to assign the program path to it early in your application. Assigning argv[0] to it in main is one way. If you use bash or ksh (or similar), the following statement is probably what you want: `new_progname = getenv("_");'.

new_ptr_list_t new_ptr_list [static]

Initial value:

 {
    &new_ptr_list,
    &new_ptr_list,
    0,
    {



        ""

    },
    0,
    0,
    MAGIC
}

List of all new'd pointers.

fast_mutex new_ptr_lock [static]

The mutex guard to protect simultaneous access to the pointer list.

bool new_verbose_flag = false

Flag to control whether verbose messages are output.

const size_t PLATFORM_MEM_ALIGNMENT = sizeof(size_t) * 2

The platform memory alignment.

The current value works well in platforms I have tested: Windows XP, Windows 7 x64, and Mac OS X Leopard. It may be smaller than the real alignment, but must be bigger than sizeof(size_t) for it work. __debug_new_recorder uses it to detect misaligned pointer returned by `new NonPODType[size]'.

size_t total_mem_alloc = 0 [static]

Total memory allocated in bytes.

debug_new.cpp File Reference

Classes

Defines

Functions

Variables

Detailed Description

Define Documentation

Function Documentation

Variable Documentation