Progressively allocates all memory in a system

waste_my_ram.py

"""You probably don't want to run this.

Source: https://stackoverflow.com/a/66109163/2848528
"""
import logging
import secrets
from typing import Optional

from humanfriendly import format_size

log = logging.getLogger(__name__)


def fill_memory(
    *,
    num_unique_bytes_per_allocation: int = 1_024,
    multiplier_per_allocation: int = 1_024**2,
    max_allocations: Optional[int] = None,
) -> None:
    """Allocate available memory into a list of effectively unique bytes objects.

    This function is for diagnostic purposes.

    Args:
        num_unique_bytes_per_allocation: Each allocation is created by
            multiplying a random sequence of bytes of this length.
        multiplier_per_allocation: Each allocation is created by multiplying
            the random sequence of bytes by this number.
        max_allocations: Optional number of max allocations.
    """
    # Ref: https://stackoverflow.com/a/66109163/
    num_allocation_bytes = num_unique_bytes_per_allocation * multiplier_per_allocation
    log.info(
        "Allocating cumulative instances of %(num_allocation_bytes)s "
        "bytes (%(formatted_num_allocation_bytes)s) each. "
        "Each allocation uses %(num_unique_bytes_per_allocation)s "
        "unique bytes (%(formatted_num_unique_bytes_per_allocation)s) "
        "with a multiplier of "
        "%(multiplier_per_allocation)s (%(formatted_multiplier_per_allocation)s).",
        {
            "num_allocation_bytes": num_allocation_bytes,
            "formatted_num_allocation_bytes": format_size(num_allocation_bytes),
            "num_unique_bytes_per_allocation": num_unique_bytes_per_allocation,
            "formatted_num_unique_bytes_per_allocation": format_size(
                num_unique_bytes_per_allocation
            ),
            "multiplier_per_allocation": multiplier_per_allocation,
            "formatted_multiplier_per_allocation": format_size(
                multiplier_per_allocation
            ),
        },
    )

    # Allocate memory
    allocated = []
    num_allocation = 1
    while True:
        unique_bytes_for_allocation = secrets.token_bytes(
            num_unique_bytes_per_allocation
        )
        allocated.append(unique_bytes_for_allocation * multiplier_per_allocation)
        num_total_bytes_allocated = num_allocation * num_allocation_bytes
        log.info(
            "Used a total of %(num_total_bytes_allocated)s bytes"
            "(%(formatted_num_total_bytes_allocated)s) "
            "via %(num_allocation)s allocations.",
            {
                "num_total_bytes_allocated": num_total_bytes_allocated,
                "formatted_num_total_bytes_allocated": format_size(
                    num_total_bytes_allocated
                ),
                "num_allocation": num_allocation,
            },
        )
        if max_allocations and (max_allocations == num_allocation):
            break
        num_allocation += 1


def main():
    """Entrypoint."""
    logging.basicConfig(level=logging.INFO)
    fill_memory()


if __name__ == "__main__":
    main()