From: Federico Terraneo <fede.tft@hotmail.it>
To: newlib@sourceware.org
Subject: Re: Implementing a heap watermark
Date: Mon, 9 Nov 2020 15:08:53 +0100 [thread overview]
Message-ID: <DB8PR10MB290591B4DDEE8F9BF24544EBF9EA0@DB8PR10MB2905.EURPRD10.PROD.OUTLOOK.COM> (raw)
In-Reply-To: <sig.1581dd2f6c.CWXP265MB0039727CFB485A2881FCE9ADBEEB0@CWXP265MB0039.GBRP265.PROD.OUTLOOK.COM>
Dear Rob,
functionality is available in the Miosix OS, which uses newlib. You can
have a look at the code to see how to implement such a functionality.
The functionality you are interested in is the getAbsoluteFreeHeap()
member function of the MemoryProfiling class.
https://github.com/fedetft/miosix-kernel/blob/master/miosix/util/util.h#L88
It is implemented in terms of getMaxHeap() function that tracks heap
requests directly from _sbrk_r
https://github.com/fedetft/miosix-kernel/blob/master/miosix/stdlib_integration/libc_integration.cpp#L61
Hope this helps,
Federico
On 08/11/20 18:14, Rob Meades via Newlib wrote:
> I run/test my library code on various embedded processors (STM32F4, NRF52/53, ESP32), all of which use newlib.
>
> I need to implement a "minimum heap ever available" watermark kind of function so that, after my tests are run, I can be sure that I have left sufficient room for user code to obtain heap memory.
>
> Such a facility does not seem to be available in newlib out of the box: does anyone have any recommendations on how to go about implementing such a function?
>
> For instance, is the newlib malloc()ater guaranteed to only call sbrk() when it really needs more memory, as opposed to when it might have free blocks available but it is "cheaper" to call sbrk() then to allocate from those blocks? If the former then simply monitoring sbrk() would do the job for me. If the latter then I probably have to intercept the malloc()/free() calls to track what's going on.
>
> Rob
>
> .
>
prev parent reply other threads:[~2020-11-09 14:09 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-08 17:14 Rob Meades
2020-11-09 14:08 ` Federico Terraneo [this message]
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