This project was started to explore issues regarding memory allocation by the Electron/NodeJS system.
It appears as if there is a limitation in the system regarding allocation of the ArrayBuffer object. This limitation results in the AOMAnalyzer decoder component being unable to allocate enough HEAP memory for the decode process. This failure results in the inability to analyze any video frames.
The AOMAnalyzer project utilizes the Emscripten transpiler to compile the video decoder component written in the C programming language into JavaScript. Emscripten implements the C programs HEAP using the ArrayBuffer container.
The current limitation of Electron seems to be ~2Gb. Any attempt to allocate more memory than this limit results in a RangeError: Array buffer allocation failed exception.
The problem is that our decoder (AVS2), according to profiling, appears to use at least ~5Gb of memory to decode 4Kx2K streams.
- Start the application
npm install
./node_modules/.bin/electron . - The default settings will demonstrate the limitation. The memory size is initialized to 2GB. This value can be changed or specified in Gb/Mb/Kb according to the selected option.
- Hit the 'Allocate' button.
- If the allocation succeeded the confirmation Allocated # bytes is displayed. If the allocation fails then the status Allocation of buffer failed is displayed.
Reproduced below is the code Emscripten generates to allocate the HEAP memory:
var TOTAL_STACK = Module["TOTAL_STACK"] || 5242880;
var TOTAL_MEMORY = Module["TOTAL_MEMORY"] || 2147483648;
if (TOTAL_MEMORY < TOTAL_STACK) Module.printErr("TOTAL_MEMORY should be larger than TOTAL_STACK, was " + TOTAL_MEMORY + "! (TOTAL_STACK=" + TOTAL_STACK + ")");
if (Module["buffer"]) {
buffer = Module["buffer"]
} else {
{
buffer = new ArrayBuffer(TOTAL_MEMORY)
}
}
updateGlobalBufferViews();
This code currently throws the RangeError exception. Notice TOTAL_MEMORY is equal to 2147483648 (2Gb).
This problem was verified with the following versions:
| Component | Version |
|---|---|
| nodejs | v8.5.0 |
| npm | 5.2.0 |
| electron | v1.7.8 |