Limit RAM usage to python program

Question

I'm trying to limit the RAM usage from a Python program to half so it doesn't totally freezes when all the RAM is used, for this I'm using the following code which is not working and my laptop is still freezing:

import sys import resource  def memory_limit():     rsrc = resource.RLIMIT_DATA     soft, hard = resource.getrlimit(rsrc)     soft /= 2     resource.setrlimit(rsrc, (soft, hard))  if __name__ == '__main__':     memory_limit() # Limitates maximun memory usage to half     try:         main()     except MemoryError:         sys.stderr.write('MAXIMUM MEMORY EXCEEDED')         sys.exit(-1) 

I'm using other functions which I call from the main function.

What am I doing wrong?

Thanks in advance.

PD: I already searched about this and found the code I've put but it's still not working...

Answer 1

Ok so I've made some research and found a function to get the memory from Linux systems here: Determine free RAM in Python and I modified it a bit to get just the free memory available and set the maximum memory available as its half.

Code:

def memory_limit():     soft, hard = resource.getrlimit(resource.RLIMIT_AS)     resource.setrlimit(resource.RLIMIT_AS, (get_memory() * 1024 / 2, hard))  def get_memory():     with open('/proc/meminfo', 'r') as mem:         free_memory = 0         for i in mem:             sline = i.split()             if str(sline[0]) in ('MemFree:', 'Buffers:', 'Cached:'):                 free_memory += int(sline[1])     return free_memory  if __name__ == '__main__':     memory_limit() # Limitates maximun memory usage to half     try:         main()     except MemoryError:         sys.stderr.write('\n\nERROR: Memory Exception\n')         sys.exit(1) 

The line to set it to the half is resource.setrlimit(resource.RLIMIT_AS, (get_memory() * 1024 / 2, hard)) where get_memory() * 1024 / 2 sets it to the half (it's in bytes).

Hope this can help others in future with the same matter! =)

Answer 2

I modify the answer of @Ulises CT. Because I think to change too much original function is not so good, so I turn it to a decorator. I hope it helps.

import resource import platform import sys  def memory_limit(percentage: float):     """     只在linux操作系统起作用     """     if platform.system() != "Linux":         print('Only works on linux!')         return     soft, hard = resource.getrlimit(resource.RLIMIT_AS)     resource.setrlimit(resource.RLIMIT_AS, (get_memory() * 1024 * percentage, hard))  def get_memory():     with open('/proc/meminfo', 'r') as mem:         free_memory = 0         for i in mem:             sline = i.split()             if str(sline[0]) in ('MemFree:', 'Buffers:', 'Cached:'):                 free_memory += int(sline[1])     return free_memory  def memory(percentage=0.8):     def decorator(function):         def wrapper(*args, **kwargs):             memory_limit(percentage)             try:                 return function(*args, **kwargs)             except MemoryError:                 mem = get_memory() / 1024 /1024                 print('Remain: %.2f GB' % mem)                 sys.stderr.write('\n\nERROR: Memory Exception\n')                 sys.exit(1)         return wrapper     return decorator  @memory(percentage=0.8) def main():     print('My memory is limited to 80%.')