energymon 0.0.1

Python bindings to native energymon libraries

EnergyMon Python Bindings

This project provides Python bindings to energymon libraries.

If using this project for other scientific works or publications, please reference:

• Connor Imes, Lars Bergstrom, and Henry Hoffmann. "A Portable Interface for Runtime Energy Monitoring". In: FSE. 2016. DOI: https://doi.org/10.1145/2950290.2983956

Dependencies

The energymon libraries should be installed to the system and on the library search path (e.g., LD_LIBRARY_PATH).

The latest energymon C libraries can be found at https://github.com/energymon/energymon.

Building

To install from source:

pip install .

Usage

The module exposes an energymon class, which is a binding to the energymon C struct. First, users are responsible for loading an energymon library using ctypes. For example:

from ctypes import CDLL
from ctypes.util import find_library

# maybe try to find the library by name:
lib_path = find_library("energymon-default")
if lib_path is None:
    # maybe fall back on a relative or absolute path
    lib_path = "libenergymon-default.so"
lib = CDLL(lib_path, use_errno=True)

The module exposes some utilities to simplify usage, e.g., to "get" the energymon, handle pointers, convert data types, check for errors, and raise exceptions. For example:

from energymon import util

em = util.get_energymon(lib, 'energymon_get_default')
print(util.get_source(em))
util.init(em)
try:
    print(util.get_uj(em))
finally:
    util.finish(em)

Direct bindings

To directly use the energymon API, create and "get" the struct to populate its function pointers, then initialize, do work, and cleanup when finished. For example:

from ctypes import pointer, create_string_buffer, sizeof, set_errno, get_errno
from energymon import energymon

em = energymon()
pem = pointer(em)

if lib.energymon_get_default(pem) != 0:
    # handle error...
    exit(1)

name = create_string_buffer(256)
if not em.fsource(name, sizeof(name)):
    # handle error
    exit(1)

print(name.value.decode())
if em.finit(pem) != 0:
    # handle error
    exit(1)

set_errno(0)
uj = em.fread(pem)
if uj == 0 and get_errno() != 0:
    # handle error (but don't skip cleanup!)
    pass

if em.ffinish(pem) != 0:
    # handle error
    exit(1)

Project Source

Find this and related project sources at the energymon organization on GitHub.
This project originates at: https://github.com/energymon/energymon-py

Bug reports and pull requests for bug fixes and enhancements are welcome.