[PATCH] added malloc usable size and test

Joel Sherrill joel at rtems.org
Tue Mar 15 21:28:42 UTC 2022


On Tue, Mar 15, 2022 at 10:25 AM Joel Sherrill <joel at rtems.org> wrote:

>
>
> On Fri, Mar 4, 2022 at 8:58 PM zack leung <zakthertemsdev at gmail.com>
> wrote:
>
>> closes #4503
>> ---
>>  cpukit/include/rtems/libcsupport.h        |  5 +++
>>  cpukit/libcsupport/src/mallocusablesize.c | 48 +++++++++++++++++++++++
>>  spec/build/cpukit/librtemscpu.yml         |  1 +
>>  testsuites/libtests/malloctest/init.c     | 15 ++++++-
>>  4 files changed, 68 insertions(+), 1 deletion(-)
>>  create mode 100644 cpukit/libcsupport/src/mallocusablesize.c
>>
>> diff --git a/cpukit/include/rtems/libcsupport.h
>> b/cpukit/include/rtems/libcsupport.h
>> index f4be4cfc9a..5110ab0fbe 100644
>> --- a/cpukit/include/rtems/libcsupport.h
>> +++ b/cpukit/include/rtems/libcsupport.h
>> @@ -74,6 +74,11 @@ extern size_t malloc_free_space(void);
>>   */
>>  extern int malloc_info(Heap_Information_block *the_info);
>>
>> +/**
>> + * @brief Find the usable size of the block of memory .
>> + */
>> +extern size_t malloc_usable_size(void *ptr);
>> +
>>
>
> This should be in newlib's malloc.h to align with how it is done
> on Linux. This is an RTEMS specific header file.  I went ahead
> and posted the patch for this since it was small:
>
> https://sourceware.org/pipermail/newlib/2022/019430.html
>

Prototype is already in malloc.h  which is included in your tools.

Do not modify libcsupport.h and just include <malloc.h>

>
>
>
>>  /*
>>   *  Prototypes required to install newlib reentrancy user extension
>>   */
>> diff --git a/cpukit/libcsupport/src/mallocusablesize.c
>> b/cpukit/libcsupport/src/mallocusablesize.c
>> new file mode 100644
>> index 0000000000..b7e573023a
>> --- /dev/null
>> +++ b/cpukit/libcsupport/src/mallocusablesize.c
>> @@ -0,0 +1,48 @@
>> +/*
>> + * SPDX-License-Identifier: BSD-2-Clause
>> + *
>> + *  Copyright (C) 2022 zacchaeus leung
>> + *
>> + * Redistribution and use in source and binary forms, with or without
>> + * modification, are permitted provided that the following conditions
>> + * are met:
>> + * 1. Redistributions of source code must retain the above copyright
>> + *    notice, this list of conditions and the following disclaimer.
>> + * 2. Redistributions in binary form must reproduce the above copyright
>> + *    notice, this list of conditions and the following disclaimer in the
>> + *    documentation and/or other materials provided with the
>> distribution.
>> + *
>> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
>> "AS
>> IS"
>> + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
>> THE
>> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
>> PURPOSE
>> + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
>> BE
>> + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
>> + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
>> + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
>> BUSINESS
>> + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
>> IN
>> + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
>> OTHERWISE)
>> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
>> THE
>> + * POSSIBILITY OF SUCH DAMAGE.
>> + */
>> +
>> +#ifdef HAVE_CONFIG_H
>> +#include "config.h"
>> +#endif
>> +
>> +#include <rtems/libcsupport.h>
>> +#include <rtems/malloc.h>
>> +#include <rtems/score/heapimpl.h>
>> +
>> +size_t malloc_usable_size( void *ptr ) {
>> +
>> +  Heap_Control *heap_ptr ;
>> +  size_t size;
>> +  if ( ptr == NULL ) {
>>
>
> Blank line above the if. Space between ) and {
>
>
>> +    return 0;
>> +  }
>> +
>> +  heap_ptr = malloc_get_heap_pointer();
>> +  _Heap_Size_of_alloc_area( heap_ptr, ptr, &size );
>>
>>
> This should be _Protected_heap_Get_block_size() to ensure that
> locking is performed.
>
>
>> +  return size;
>> +}
>> diff --git a/spec/build/cpukit/librtemscpu.yml
>> b/spec/build/cpukit/librtemscpu.yml
>> index c224937348..2ef11e7e2d 100644
>> --- a/spec/build/cpukit/librtemscpu.yml
>> +++ b/spec/build/cpukit/librtemscpu.yml
>> @@ -670,6 +670,7 @@ source:
>>  - cpukit/libcsupport/src/lseek.c
>>  - cpukit/libcsupport/src/lstat.c
>>  - cpukit/libcsupport/src/malloc.c
>> +- cpukit/libcsupport/src/mallocusablesize.c
>>  - cpukit/libcsupport/src/malloc_deferred.c
>>  - cpukit/libcsupport/src/malloc_dirtier.c
>>  - cpukit/libcsupport/src/malloc_walk.c
>> diff --git a/testsuites/libtests/malloctest/init.c
>> b/testsuites/libtests/malloctest/init.c
>> index a33764177d..871edb540e 100644
>> --- a/testsuites/libtests/malloctest/init.c
>> +++ b/testsuites/libtests/malloctest/init.c
>> @@ -1362,6 +1362,18 @@ static void test_alloc_zero_size(void)
>>    rtems_test_assert( p == NULL );
>>    rtems_test_assert( errno == -1 );
>>  }
>> +static void test_usablesize(void)
>>
>
> Blank line above method.
>
>
>> +{
>> +  int * a = malloc(sizeof( int )*100);
>> +  int alloc_size=sizeof( int ) *100 ;
>>
>
> Spaces around =
>
> Inconsistent spaces around "*" between those two lines.
>
>
>> +  rtems_test_assert( malloc_usable_size( a ) <= alloc_size +
>> CPU_HEAP_ALIGNMENT );
>>
>
> Should also be >= alloc_size and <= alloc_size + HEAP_ALIGNMENT.
> Needs to be large enough to use.
>
>
>> +  free(a);
>> +
>> +  char * b = malloc(sizeof ( char ) 100);
>> +  int alloc_size 2= sizeof ( char ) *100 ;
>>
>
> Same
>
>> +  rtems_test_assert( malloc_usable_size ( b ) <= alloc_size2 +
>> CPU_HEAP_ALIGNMENT);
>>
>
> Same
>
>
>> +  free( b );
>> +}
>>
>>  rtems_task Init(
>>    rtems_task_argument argument
>> @@ -1405,6 +1417,7 @@ rtems_task Init(
>>    test_protected_heap_info();
>>    test_rtems_heap_allocate_aligned_with_boundary();
>>    test_rtems_malloc();
>> +  test_usablesize();
>>    test_rtems_calloc();
>>    test_greedy_allocate();
>>    test_alloc_zero_size();
>> @@ -1524,4 +1537,4 @@ RTEMS_SYSINIT_ITEM(
>>    test_early_malloc,
>>    RTEMS_SYSINIT_INITIAL_EXTENSIONS,
>>    RTEMS_SYSINIT_ORDER_FIRST
>> -);
>> +);
>> \ No newline at end of file
>>
>
> Check this one.
>
> If the test directory has a doc file explaining what it is testing,
> then testing this new method needs to be added.
>
> This is close. Mostly minor except for the malloc.h patch. For you
> locally, just manually edit the installed malloc.h file to have the
> prototype.
>
> --joel
>
> --
>> 2.35.1
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>


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