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Ballin' outta control.

Caleb Fenton CalebFenton

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Ballin' outta control.
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@juneoh
juneoh / sample.py
Created October 27, 2018 01:29
PyTorch AlexNet for grayscale images
import torch.nn as nn
from torchvision.models import alexnet
model = alexnet(pretrained=True, num_classes=10)
model.features[0] = nn.Conv2d(1, 64, kernel_size=(11, 11), stride=(4, 4), padding=(2, 2))

Quick Tips for Fast Code on the JVM

I was talking to a coworker recently about general techniques that almost always form the core of any effort to write very fast, down-to-the-metal hot path code on the JVM, and they pointed out that there really isn't a particularly good place to go for this information. It occurred to me that, really, I had more or less picked up all of it by word of mouth and experience, and there just aren't any good reference sources on the topic. So… here's my word of mouth.

This is by no means a comprehensive gist. It's also important to understand that the techniques that I outline in here are not 100% absolute either. Performance on the JVM is an incredibly complicated subject, and while there are rules that almost always hold true, the "almost" remains very salient. Also, for many or even most applications, there will be other techniques that I'm not mentioning which will have a greater impact. JMH, Java Flight Recorder, and a good profiler are your very best friend! Mea

#include <android/log.h>
#include <jni.h>
#include <binder/Binder.h>
#include <binder/Parcel.h>
#include <binder/IServiceManager.h>
#include <dlfcn.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
@strazzere
strazzere / gist:506a592b44c9d228d697
Last active May 9, 2023 16:13
Attaching to fast loading JNI/native code from an Android app without debugging the Dalvik code
The original issue was that some applications (ex. packers) launch the JNI/native code too fast for a person
to attach an IDA Pro instance to the process. The original solution was wrapping the jni code with your own
"surrogate" application so you could load it slower.
New process is to launch the Android/Dalvik activity with the debugger flag;
# adb shell am start -D com.play.goo_w/com.android.netservice.MainActivity
Which will cause the "Waiting for debugger..." mode to start. This starts the process, allowing you to
attach IDA Pro to the process for the native code.
@isciurus
isciurus / MainActivity.java
Last active January 14, 2021 11:57
PoC for Android GoogleAuthUtil.getToken() bug
package com.isciurus.oauth_poc;
import java.io.IOException;
import java.text.DateFormat;
import java.util.Date;
import com.google.android.gms.auth.GoogleAuthException;
import com.google.android.gms.auth.GoogleAuthUtil;
import com.google.android.gms.auth.UserRecoverableAuthException;
import android.accounts.AccountManager;
import android.app.Activity;
@jakevdp
jakevdp / discrete_cmap.py
Last active March 8, 2024 14:54
Small utility to create a discrete matplotlib colormap
# By Jake VanderPlas
# License: BSD-style
import matplotlib.pyplot as plt
import numpy as np
def discrete_cmap(N, base_cmap=None):
"""Create an N-bin discrete colormap from the specified input map"""
@gavinandresen
gavinandresen / BlockPropagation.md
Last active March 14, 2023 09:45
O(1) block propagation

O(1) Block Propagation

The problem

Bitcoin miners want their newly-found blocks to propagate across the network as quickly as possible, because every millisecond of delay increases the chances that another block, found at about the same time, wins the "block race."

@endolith
endolith / frequency_estimator.py
Last active October 30, 2023 18:08
Frequency estimation methods in Python
from __future__ import division
from numpy.fft import rfft
from numpy import argmax, mean, diff, log, nonzero
from scipy.signal import blackmanharris, correlate
from time import time
import sys
try:
import soundfile as sf
except ImportError:
from scikits.audiolab import flacread