mJS memory capacity

General
1

  1. My goal is:
    Determine whether I can install a large number (> 80) of RPC Handlers in mJS.

  2. My actions are:
    Incremental development adding RPC Handlers in init.js

  3. The result I see is:
    On startup I get error messages like this after C initialization. I know that the E:M message indicates that I am running out of memory. So as a test, I remove some of my RPC Handlers, and I can get the system to start without error or E:M message. As I re-introduce RPC Handlers in init.js (as in the indicated log), execution starts and proceeds apparently normally. As I re-introduce all of them, a similar E:M message appears and the system crashes .

[Apr 29 13:46:59.945] ◄Init Start
[Apr 29 13:47:06.583] Saving configuration: no error
[Apr 29 13:47:06.583] minheap: 201976 freeheap: 203512 freefile: 1518550
[Apr 29 13:47:06.680] C Init Done
[Apr 29 13:47:07.942] E:M 37905
[Apr 29 13:47:07.942] Heap summary for capabilities 0x00001800:
[Apr 29 13:47:07.942] At 0x3ffae6e0 len 6432 free 0 allocated 6276 min_free 0
[Apr 29 13:47:07.942] largest_free_block 0 alloc_blocks 31 free_blocks 0 total_blocks 31
[Apr 29 13:47:07.942] At 0x3ffbefa0 len 135264 free 36784 allocated 97060 min_free 3488
[Apr 29 13:47:07.942] largest_free_block 33156 alloc_blocks 341 free_blocks 6 total_blocks 347
[Apr 29 13:47:07.942] At 0x3ffe0440 len 15072 free 15036 allocated 0 min_free 15036
[Apr 29 13:47:07.942] largest_free_block 15036 alloc_blocks 0 free_blocks 1 total_blocks 1
[Apr 29 13:47:07.942] At 0x3ffe4350 len 113840 free 36912 allocated 76888 min_free 36912
[Apr 29 13:47:07.942] largest_free_block 36912 alloc_blocks 1 free_blocks 1 total_blocks 2
[Apr 29 13:47:07.942] Totals:
[Apr 29 13:47:07.942] free 88512 allocated 180440 min_free 55436 largest_free_block 36912
[Apr 29 13:47:07.942] E:M 37777
[Apr 29 13:47:07.942] Heap summary for capabilities 0x00001800:
[Apr 29 13:47:07.942] At 0x3ffae6e0 len 6432 free 0 allocated 6276 min_free 0
[Apr 29 13:47:07.942] largest_free_block 0 alloc_blocks 31 free_blocks 0 total_blocks 31
[Apr 29 13:47:07.942] At 0x3ffbefa0 len 135264 free 36784 allocated 97060 min_free 3488
[Apr 29 13:47:07.942] largest_free_block 33156 alloc_blocks 341 free_blocks 6 total_blocks 347
[Apr 29 13:47:07.942] At 0x3ffe0440 len 15072 free 15036 allocated 0 min_free 15036
[Apr 29 13:47:07.942] largest_free_block 15036 alloc_blocks 0 free_blocks 1 total_blocks 1
[Apr 29 13:47:07.942] At 0x3ffe4350 len 113840 free 36912 allocated 76888 min_free 36912
[Apr 29 13:47:07.942] largest_free_block 36912 alloc_blocks 1 free_blocks 1 total_blocks 2
[Apr 29 13:47:07.942] Totals:
[Apr 29 13:47:07.942] free 88512 allocated 180440 min_free 55436 largest_free_block 36912
[Apr 29 13:47:08.395] js start before anything else
[Apr 29 13:47:09.735] js functions done
[Apr 29 13:47:10.163] js RPCs done
[Apr 29 13:47:10.278] ←[0;32mI (61547) esp_image: segment 0: paddr=0x00010020 vaddr=0x3f400020 size=0x2def4 (188148) map←[0m
[Apr 29 13:47:10.397] ←[0;32mI (61647) esp_image: segment 1: paddr=0x0003df1c vaddr=0x3ffb0000 size=0x020fc ( 8444) ←[0m
[Apr 29 13:47:10.397] ←[0;32mI (61657) esp_image: segment 2: paddr=0x00040020 vaddr=0x400d0020 size=0xc3d78 (802168) map←[0m
[Apr 29 13:47:10.796] ←[0;32mI (62047) esp_image: segment 3: paddr=0x00103da0 vaddr=0x3ffb20fc size=0x01844 ( 6212) ←[0m
[Apr 29 13:47:10.796] ←[0;32mI (62067) esp_image: segment 4: paddr=0x001055ec vaddr=0x40080000 size=0x1ad04 (109828) ←[0m
[Apr 29 13:47:10.867] ←[0;32mI (62127) esp_image: segment 5: paddr=0x001202f8 vaddr=0x400c0000 size=0x00034 ( 52) ←[0m
[Apr 29 13:47:10.867] ←[0;32mI (62137) esp_ota_ops: New OTA data 1: seq 0x00000053, st 0x10, CRC 0xe4240fdc←[0m
[Apr 29 13:47:11.146] tUp: 61 now: 5887 mDP: 675 Peak: 0.10 Up: 100 DD: 3 dK: 25000.0 FPM: 825 ASet: 0.00 ASpeed: 0.00 SPnt: 0 TPnt: 0.00 ZPnt: 0.00 Angle: 0.00 Turbs: 333 SN: RS7017 V: 516

  1. My expectation & question is:
    What are the memory limitations in mJS?
    What can I do to optimize memory usage in mJS?
    Is there an example of an RPC Handler installation in C?

Thanks for your help?

JSW

2

There are no intrinsic memory limits in the interpreter, you alloc until you exhaust the heap and you push until you get a stack error. All that depends on how you write code and the amount of libraries you load and keep running.

That looks a bit small to keep a system like this running stable, and you seem to be using OTA

3

Here

4

Thanks for the direction. I moved about half of the js RPCs into main.c With no other logic change, the heap space now looks like this:

[May 10 13:05:22.211] tUp: 7216 now: 1683749121 MinHeap: 49048 FreeHeap: 119028

which is probably good enough. The large difference leads me to believe that for certain operations (RPC installation as a perfect example), mJS is less memory efficient than C. Are there other operations that are better off coded in C?

Thanks,

JSW

5

Can’t help with this, I only use C/C++, no mJS…

6

“There is no such thing as a free lunch”
If you want to have a higher level interpreted script language you will have to sacrifice memory footprint, execution speed, or both. If you want a cheap micro with low memory capacity you’ll have to work extra to make your application fit.
Do your analysis, architect your design, choose your tools, do your work