Malloc

Offers an interface to check for system memory allocated with malloc and co.

Summary

Malloc	Offers an interface to check for system memory allocated with malloc and co.
Copyright	This program is free software.
Files
C-kern/api/platform/malloc.h	Header file of Malloc.
C-kern/platform/Linux/malloc.c	Implementation file of Malloc impl.
Functions
init
prepare_malloc	Inits test of system-malloc.
manage
trimmemory_malloc	Frees preallocated memory which is not in use.
query
allocatedsize_malloc	Returns allocated number of bytes which are not freed.
sizeusable_malloc	Returns number of usable bytes in the allocated memory block addr.
test
unittest_platform_malloc	Unittest for query usage of malloc resources.
inline implementation
Macros
sizeusable_malloc	Implements sizeusable_malloc.

Copyright

This program is free software. You can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

Author

Files

C-kern/api/platform/malloc.h

Header file of Malloc.

C-kern/platform/Linux/malloc.c

Implementation file of Malloc impl.

Functions

Summary

init
prepare_malloc	Inits test of system-malloc.
manage
trimmemory_malloc	Frees preallocated memory which is not in use.
query
allocatedsize_malloc	Returns allocated number of bytes which are not freed.
sizeusable_malloc	Returns number of usable bytes in the allocated memory block addr.
test
unittest_platform_malloc	Unittest for query usage of malloc resources.

init

prepare_malloc

int prepare_malloc( void )

Inits test of system-malloc. The GNU C library offers a query function for information about malloced memory so it is not necessary to wrap the malloc function with a test implementation. For that reason this function does only two steps: 1. Call system functions which allocate internal memory (strerror) which is never freed. 2. Free all allocated but unused memory. Same as trimmemory_malloc.

manage

trimmemory_malloc

int trimmemory_malloc( void )

Frees preallocated memory which is not in use. Therefore unused heap memory pages are unmapped from virtual memory. This function is useful if you want to compare the layout of all virtual mapped memory pages at the beginning of the test with the layout at the end of the test. If a lot of memory is allocated and freed during the execution of your test it is possible that additional system pages will be mapped into the heap address space. The call to trimmemory_malloc unmaps them and makes therefore the layouts comparable.

query

allocatedsize_malloc

int allocatedsize_malloc( /*out*/size_t * number_of_allocated_bytes )

Returns allocated number of bytes which are not freed. It is not necessary to call trimmemory_malloc before calling this function. If you do not call prepare_malloc before this function then it is called for you if this is necessary. At the start of your test save the number of allocated bytes of system memory returned from allocatedsize_malloc. At the end of your test call it a second time and compare the result with the value received from the first call to make sure no system memory is wasted.

sizeusable_malloc

size_t sizeusable_malloc( void * addr )

Returns number of usable bytes in the allocated memory block addr. The parameter addr must the value returned by a call to malloc. The returned value is equal or greater than parameter size in malloc(size). The value 0 is returned in case addr is 0.

test

unittest_platform_malloc

int unittest_platform_malloc( void )

Unittest for query usage of malloc resources.

inline implementation

Summary

Macros
sizeusable_malloc	Implements sizeusable_malloc.

Macros

sizeusable_malloc

#define sizeusable_malloc( addr ) (malloc_usable_size(addr))

Implements sizeusable_malloc.