Hi,
I'm still working on my firmware for Pinetime! Thanks to your help a
couple of weeks ago, BLE connectivity is now much more reliable.
As a remainder, I work on a firmware based on FreeRTOS and running on
the NRF52 MCU. It uses NimBLE as BLE stack. I use the FreeRTOS port
available in the source tree
(https://github.com/apache/mynewt-nimble/tree/master/porting/npl).
However, I noticed that my code would crash after a certain number of
connections/disconnections. I noticed that use of the heap memory
allocated to FreeRTOS would grow by ~100 bytes each time a new
connection is established and this memory is never released.
I discovered that this memory is used by 2 timers (mynewt "callouts")
that are created in npl_freertos_callout_init(). This function calls
xTimerCreate() which allocates the memory necessary for the timer. This
memory is taken from the heap allocated for FreeRTOS.
When the connection is closed, xTimerDelete() is never called meaning
that the memory is not freed.
When a new device connects, 2 new timers are created, allocating ~100B
from the heap. This continues until the heap is full and refuses to give
any more memory.
Note that I use heap_4.c, which allows memory to be allocated and freed.
To my surprise, there is NO function npl_freertos_callout_uninit() or
npl_freertos_callout_delete() or anything else. It looks like timers
(callouts) are not intended to be removed once they are created. Should
they be reused/recycled?
Anyway, I modified the function npl_freertos_callout_init() so that it
does nothing if the handle is not NULL and... it looks like it works
(even if I don't think this is a valid fix):
void npl_freertos_callout_init(struct ble_npl_callout *co, struct
ble_npl_eventq *evq,
ble_npl_event_fn *ev_cb, void *ev_arg)
{
if(co->handle != NULL) return; // <---- I added this line.
memset(co, 0, sizeof(*co));
co->handle = xTimerCreate("co", 1, pdFALSE, co,
os_callout_timer_cb);
co->evq = evq;
ble_npl_event_init(&co->ev, ev_cb, ev_arg);
}
Is this a bug that must be fixed in the source code or am I missing
something about the creation and deletion of timers?
Thanks for your help,
JF
