Tag Archives: os x

Setting up Perforce Helix Core Service on OS X High Sierra

Here is a guide about how to start Perforce Helix Core as a global daemon on OS X High Sierra, running under a separate user called perforce. By the nature of this guide, some of it applies directly to my own system; readers are expected to identify those instances and change appropriately.

First, we download the p4d and p4 executable files. Some people may prefer the visual client, but this guide is focused on the command line.

Then we install the binaries into /usr/local/sbin and /usr/local/bin, respectively.

Install the server binary.

  sudo mkdir -p /usr/local/sbin
  sudo cp p4d /usr/local/sbin
  sudo chown root:wheel /usr/local/sbin/p4d
  sudo chmod 555 /usr/local/sbin/p4d

And install the client binary.

  sudo mkdir -p /usrl/local/bin
  sudo cp p4 /usr/local/bin/
  sudo chown root:wheel /usr/local/bin/p4
  sudo chmod 555 /usr/local/bin/p4

We’ll create a group and user called perforce, and store the version control database in /usr/local/var/perforce with the log in /usr/local/var/log/p4d.log.

Here I’ve carefully chosen the unique id 268 for both the group and user because it’s free on my system. To see all group ids in use on a system, this one liner can be used,

  for f in `dscl . -list /Groups`; do dscl . -read /Groups/$f; \
      done | grep PrimaryGroupID | sort -k2 -n

and to see all the user ids, this one liner can be used.

  for f in `dscl . -list /Users`; do dscl . -read /Users/$f; \
      done | grep UniqueID | sort -k2 -n

We create the group with

  sudo dscl . -create /Groups/perforce
  sudo dscl . -create /Groups/perforce PrimaryGroupID 268
  sudo dscl . -create /Groups/perforce Password '*'

and then we create the user with

  sudo dscl . -create /Users/perforce      
  sudo dscl . -create /Users/perforce UniqueID 268
  sudo dscl . -create /Users/perforce UserShell /usr/bin/false
  sudo dscl . -create /Users/perforce RealName 'Perforce Server'
  sudo dscl . -create /Users/perforce NFSHomeDirectory /usr/local/var/perforce
  sudo dscl . -create /Users/perforce PrimaryGroupID 268
  sudo dscl . -create /Users/perforce Password '*'

Then we create the log file and database directory

  sudo mkdir -p /usr/local/var/log
  sudo touch    /usr/local/var/log/p4d.log
  sudo mkdir -p /usr/local/var/perforce

and set the ownership to the new user and group.

  sudo chown perforce:perforce /usr/local/var/perforce
  sudo chown perforce:perforce /usr/local/var/log/p4d.log 

Then we create the launch daemon description file.

  sudo nano /Library/LaunchDaemons/com.perforce.plist

and add the following.

  <?xml version="1.0" encoding="UTF-8"?>
  <!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
  <plist version="1.0">
        <string>Myrkraverk's Perforce</string> 
      <string>Launches Perforce Server</string>

And finally, start the Helix Core service with

  sudo launchctl load /Library/LaunchDaemons/com.perforce.plist

we then issue

   p4 set P4PORT=localhost:1666

and we test it with

  p4 help

which outputs at the end

  Server 2018.1/1637071.

so we know it's all working.

The steps to properly set up Helix Core with p4 protect and so forth are left out of this guide; please see the administration guide from Perforce.

To use SSL for the connection, the P4PORT should start with ssl:.

Compiling Sysbench on OS X Yosemite or Later

These instructions are applicable after cloning the git repository and generating the autoconfigure scripts.

git clone 'https://github.com/akopytov/sysbench.git' sysbench
cd sysbench

In order to build Sysbench1 with PostgreSQL and MariaDB support, you need to make sure both mysql_config and pg_config are in your path.

I use Zsh, so this is my way of doing it, when both Postgres and MariaDB have been installed with MacPorts.

path=( /opt/local/lib/mariadb-10.1/bin /opt/local/lib/postgresql96/bin $path )

Then run

./configure --with-pgsql --with-mysql --prefix=/path/of/your/choice

You are likely to get an error like

ld: library not found for -lgcc_s.10.4

if you do not also


before running make, while building the bundled LuaJit. This is documented in their installation instructions.

Of course, this isn’t taken care of by the wrapper Autotools, nor is there a configure flag to set this.

An alternative might be --with-system-luajit but that depends on your situation.

Then you finish it off with make install. Happy benchmarking.

1 I hope I’m linking to the right git repository.

The Case of the Apparent NSS Memory Corruption

This is a story of my encounter with an apparent memory corruption issue in the Netscape Security Services library.

The source I’m discussing can be found on Github.

© Alzay | Dreamstime.com – Computer test

Usually, when I try to get acquainted with a new API, I start to write simple program, one API call by call, which I compile and run after each step.

Imagine my surprise, when after adding the following function call (the only thing I added)

  PK11_FindKeyByAnyCert( certificate, passwd );

I got this memory corruption error.

  dblfree(56630,0x7fff73f61300) malloc: *** error for object 0x7fd39250ce70: pointer being freed was not allocated
  *** set a breakpoint in malloc_error_break to debug
  zsh: abort      ./dblfree

The above error is taken from my minimal example of the problem, not the actual program I was working on at the time. The only difference is the name of the binary and the hex numbers.

So what is happening here? I didn’t know. And to find out, it’s really important to use the right tool for the job.

So the first thing I did was to instrument my code with the built-in OS X tools, instruments(1). That didn’t tell me much; either because it doesn’t help in this particular instance, or that I just don’t know how to use it.

I will make a note that some people suggested Valgrind. I didn’t go that way because the problem seems to be adequately described with the Clang Address Sanitizer.

Continue reading The Case of the Apparent NSS Memory Corruption

When Dtrace Fails – Spectacularly

So, I’ve been spending some time looking at Dtrace today. At first, I created a proof of concept on OS X, and then went on to try it in production on FreeBSD.

No such luck. After several hours of trying to figure out what the heck was going wrong, I tried the following experiment, on OS X.

% uname -a
Darwin foo 14.5.0 Darwin Kernel Version 14.5.0: Tue Sep  1 21:23:09 PDT 2015; root:xnu-2782.50.1~1/RELEASE_X86_64 x86_64
% cat hello.c
#include <stdio.h>

int main(int argc, char *argv[]) {
printf( "Hello\n" );
return 0;
% dtrace -n 'pid$target::main:entry{printf("%#p\n",uregs[R_RBP]);}' -c ./hello
dtrace: description 'pid$target::main:entry' matched 1 probe
dtrace: pid 9224 has exited
CPU     ID                    FUNCTION:NAME
0    67470                       main:entry 0x7fff583c1c20

And then again on FreeBSD.

% uname -a
FreeBSD bar 10.2-RELEASE FreeBSD 10.2-RELEASE #0 r286666: Wed Aug 12 15:26:37 UTC 2015     root@releng1.nyi.freebsd.org:/usr/obj/usr/src/sys/GENERIC  amd64
% cat hello.c
#include <stdio.h>

int main(int argc, char *argv[]) {
    printf( "Hello\n" );
    return 0;
% dtrace -n 'pid$target::main:entry{printf("%#p\n",uregs[R_RBP]);}' -c ./hello
dtrace: description 'pid$target::main:entry' matched 1 probe
dtrace: pid 84313 has exited
CPU     ID                    FUNCTION:NAME
  2  54008                       main:entry 0

As you can see, the printed value of the %rbp register is zero on FreeBSD. In my experiments, trying to read that register always yields zero. Similarly, I do not trust it for other registers.

This seems to be a bug in FreeBSD’s Dtrace. At the time of this writing, I have not tried it on recent Illumos.