jamel

# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 10
#
# Samples: 8K of event 'cycles:ppp'
# Event count (approx.): 23242659568
#
# Children      Self        Period  Command     Shared Object       Symbol                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
# ........  ........  ............  ..........  ..................  .............................................................

jamel

package com.mongodb.async.client;

import java.util.concurrent.CompletableFuture;

import com.mongodb.async.SingleResultCallback;
import com.mongodb.client.model.Filters;
import com.mongodb.connection.netty.NettyStreamFactoryFactory;
import com.mongodb.event.CommandFailedEvent;
import com.mongodb.event.CommandListener;
import com.mongodb.event.CommandStartedEvent;

jamel

SSH agent forwarding and screen

When connecting to a remote server via SSH it is often convenient to use SSH agent forwarding so that you don't need a separate keypair on that server for connecting to further servers.

This is enabled by adding the

ForwardAgent yes

option to any of your Host entries in ~/.ssh/config (or alternatively with the -A option). Don't set this option in a wildcard Host * section since any user on the remote server that can bypass file permissions can now als use keys loaded in your SSH agent. So only use this with hosts you trust.

jamel

import java.util.Collection;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

import org.bson.BsonDocument;
import org.bson.BsonDocumentWriter;
import org.bson.codecs.Codec;
import org.bson.codecs.Encoder;
import org.bson.codecs.EncoderContext;

jamel

#include <cstdint>
#include <limits>

template<size_t R>
class ChaCha {
public:
    typedef uint32_t result_type;

    explicit ChaCha(uint64_t seedval, uint64_t stream = 0);
    template<class Sseq> explicit ChaCha(Sseq& seq);

jamel

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

jamel

$ ls -la /private/tmp/gcc48-KEjk/gcc-4.8.2/
total 21248
drwxr-xr-x   74 jamel  wheel   2.5K Nov 22 00:51 ./
drwx------    3 jamel  wheel   102B Nov 22 00:50 ../
-rw-r--r--    1 jamel  wheel   317B Jan 10  2013 .gitignore
-rw-r--r--    1 jamel  wheel    38K Jul  4  2003 ABOUT-NLS
-rw-r--r--    1 jamel  wheel    18K Jul 14  2005 COPYING
-rw-r--r--    1 jamel  wheel    26K Jul 14  2005 COPYING.LIB
-rw-r--r--    1 jamel  wheel   3.2K Apr  9  2009 COPYING.RUNTIME
-rw-r--r--    1 jamel  wheel    34K Jul 17  2007 COPYING3

jamel

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 566aa71..e55238d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -87,7 +87,7 @@ if( UNIX )
         message( FATAL_ERROR "Unknown architecture '${ARCH}'!" )
     endif()
     if( DEFINED ENV{WPKG_COVERAGE} )
-        set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -g -O0 -Werror -Wall -Wextra -pedantic -std=gnu++0x -Wcast-align -Wcast-qual -Wctor-dtor-privacy -Wdisabled-optimization -Winit-self -Wlogical-op -Wmissing-include-dirs -Woverloaded-virtual -Wredundant-decls -Wshadow -Wsign-promo -Wstrict-null-sentinel -Wstrict-overflow=1 -Wundef -Wno-unused -Wunused-variable -Wno-variadic-macros -Wno-parentheses -Wno-unknown-pragmas -Wwrite-strings -Wswitch -fdiagnostics-show-option -fprofile-arcs -ftest-coverage" )
+      set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -g -O0 -Werror -Wall -Wextra -pedantic -std=gnu++0x -Wcast-align -Wcast-qual -Wctor-dtor-privacy -Wdisabled-optimization -Winit-self -Wlogical-op -Wmissing-include-dirs -Woverloaded-virtual -Wredundant-decls