tests/browser/emmalloc_memgrowth.cpp

#include <stdio.h>
#include <stdlib.h>
#include <emscripten/heap.h>

uint64_t nextAllocationSize = 16*1024*1024;
bool allocHasFailed = false;

void grow_memory()
{
	uint8_t *ptr = (uint8_t*)malloc((size_t)nextAllocationSize);
	EM_ASM({}, ptr); // Pass ptr out to confuse LLVM that it is used, so it won't optimize it away in -O1 and higher.
	size_t heapSize = emscripten_get_heap_size();
	printf("Allocated %zu: %d. Heap size: %zu\n", (size_t)nextAllocationSize, ptr ? 1 : 0, heapSize);
	if (ptr)
	{
		if (!allocHasFailed)
		{
			nextAllocationSize *= 2;
			// Make sure we don't overflow, and also exercise malloc(-1) to gracefully return 0 in ABORTING_MALLOC=0 mode.
			if (nextAllocationSize > 0xFFFFFFFFULL)
				nextAllocationSize = 0xFFFFFFFFULL;
		}
	}
	else
	{
		nextAllocationSize /= 2;
		allocHasFailed = true;
	}
}

int main()
{
	// Exhaust all available memory.
	for(int i = 0; i < 50; ++i)
		grow_memory();
	// If we get this far without crashing on OOM, we are ok!
	printf("Test finished!\n");
#ifdef REPORT_RESULT
	REPORT_RESULT(0);
#endif
}