I am working on an application that allocate data dynamically at initialization, and my malloc/calloc returns NULL a lot earlier than I expected.
Using a debug macro, I determined that:
- The last memory successfully allocated is 8 bytes at 0x200021A8.
- I allocated 238 bytes for my data. Counting in overheads, the total should be +- 320 bytes.
I checked the memory map file and the heap is 2048B. I should not run out of memory yet.
HEAP 0x20002058 Section 2048 arm_startup_nrf51.o(HEAP)
What is going on?
I am using a nRF51 Dongle without SoftDevice. But this code is intended to be brought over to nRF51 running S110 v8 and nRF52 running the most up-to-date SoftDevice. I am a little worried about whether working with a SoftDevice will limit me even further.
Here is the macro I used for debugging:
#define DEBUG_ALLOC_MACRO(POINTER, NUM_ELEMENTS, TYPE) \
do \
{ \
POINTER = (TYPE*) calloc(NUM_ELEMENTS, sizeof(TYPE)); \
if (POINTER != NULL) \
{ \
mem_counter += \
((NUM_ELEMENTS * sizeof(TYPE))); \
} \
printf("%s(%d) Allocated %d x %s(%d) = %d B at 0x%p - Total %d B\n", \
__FILE__, \
__LINE__, \
NUM_ELEMENTS, \
#TYPE, \
sizeof(TYPE), \
(NUM_ELEMENTS * sizeof(TYPE)), \
POINTER, \
mem_counter \
); \
} \
while (0)
And here is the log it generated.
file1.c(17) Allocated 1 x struct1(36) = 36 B at 0x20002060 - Total 36 B
file2.c(87) Allocated 8 x struct2(12) = 96 B at 0x20002088 - Total 132 B
parse_util.c(126) Allocated 4 x int16_t(2) = 8 B at 0x200020f0 - Total 140 B
parse_util.c(126) Allocated 5 x int16_t(2) = 10 B at 0x20002100 - Total 150 B
parse_util.c(126) Allocated 5 x int16_t(2) = 10 B at 0x20002110 - Total 160 B
parse_util.c(126) Allocated 1 x int16_t(2) = 2 B at 0x20002120 - Total 162 B
file2.c(100) Allocated 4 x struct3(28) = 112 B at 0x20002128 - Total 274 B
parse_util.c(90) Allocated 1 x uint8_t(1) = 1 B at 0x200021a0 - Total 275 B
parse_util.c(90) Allocated 8 x uint8_t(1) = 8 B at 0x200021a8 - Total 283 B
parse_util.c(90) Allocated 8 x uint8_t(1) = 8 B at 0x00000000 - Total 283 B
