Functions
enum Dwarf_Sec_Alloc_Pref	dwarf_set_load_preference (enum Dwarf_Sec_Alloc_Pref dw_load_preference)
	Set/Retrieve section allocation preference.

int	dwarf_get_mmap_count (Dwarf_Debug dw_dbg, Dwarf_Unsigned dw_mmap_count, Dwarf_Unsigned dw_mmap_size, Dwarf_Unsigned dw_malloc_count, Dwarf_Unsigned dw_malloc_size)
	Retrieve count of mmap/malloc sections.

Detailed Description

Functions related to the choice of malloc/read or mmap for object section memory allocation.

The default allocation preference is mmap.

The environment variable DWARF_WHICH_ALLOC is also involved at runtime. If the value is 'malloc' then use of read/malloc is preferred. If the value is 'mmap' then use of mmap is preferred.

If present and valid this environment variable takes precedence over dwarf_set_load_preference().

Function Documentation

◆ dwarf_set_load_preference()

enum Dwarf_Sec_Alloc_Pref dwarf_set_load_preference ( enum Dwarf_Sec_Alloc_Pref dw_load_preference )

Since: {0.12.0}

By default object file sections are loaded using malloc and read (Dwarf_Alloc_Malloc). This works everywhere and works well on all but gigantic object files.

The preference of Dwarf_Alloc_Mmap does not guarantee mmap will be used for object section data, but does cause mmap() to be used when possible.

dw_load_preference is one of Dwarf_Alloc_Malloc (1) Dwarf_Alloc_Mmap (2)

Must be called before calling a dwarf_init*() to be effective in a dwarf_init*(). The value is remembered for subsequent dwarf_init*() in the library runtime being executed.

Parameters

dw_load_preference If passed in Dwarf_Alloc_Mmap then future calls to any dwarf_init*() function will use mmap to load object sections if possible. If passed in Dwarf_Alloc_Malloc then future calls to any dwarf_init*() function will use mmap to load sections. Any other value passed in dw_load_preference is ignored.

Returns: Always returns the value before dw_load_preference applied, of this runtime global preference.

◆ dwarf_get_mmap_count()

int dwarf_get_mmap_count	(	Dwarf_Debug	dw_dbg,
		Dwarf_Unsigned *	dw_mmap_count,
		Dwarf_Unsigned *	dw_mmap_size,
		Dwarf_Unsigned *	dw_malloc_count,
		Dwarf_Unsigned *	dw_malloc_size
	)

Since: {0.12.0}

Note that compressed section contents will be expanded into a malloc/read section in all cases.

Parameters

dw_dbg	A valid open Dwarf_Debug.
dw_mmap_count	On success the number of sections allocated with mmap is returned. If null passed in the argument is ignored.
dw_mmap_size	On success the size total in bytes of sections allocated with mmap is returned. If null passed in the argument is ignored.
dw_malloc_count	On success the number of sections read/allocated with read/malloc is returned. If null passed in the argument is ignored. On success the number of sections allocated with malloc/read is returned.
dw_malloc_size	On success the total size in bytes of sections with malloc/read is returned. If null passed in the argument is ignored. On success the number of sections read/allocated with read/malloc is returned.

Returns: On success returns DW_DLV_OK and sets the counts and total size through the respective non-null pointer arguments. If dw_dbg is invalid or NULL the function returns DW_DLV_ERROR. Never returns DW_DLV_NO_ENTRY.