C Portable Runtime Evaluation

C++ Portable Runtime Evaluation

On November 1, 2007,in Code Monkey,by Tom

I recently (June 2007) did an evaluation of C++ portableruntimes for my employer (a large video security company) for use in oursystem level code. We were looking for a set of libraries that wouldabstract the operating system (threads, IPC, File I/O, etc) and allowour code to be portable across many architectures and environments. I’vedecided to publish the results of my evaluation here for anyoneinterested in portable runtimes.
Spoiler: We chose to go with the ACE version 5.4.1.
I initially considered the following runtimes for evaluation:

• Adaptive Communication Environment (ACE)
• Portable Components (POCO)
• Portable Types (PTypes)
• Boost
• Platinum
• VR Juggler Portable Runtime (VPR)

After considering the criteria we were using for evaluation (see below), I narrowed the field down to 3 candidates:

• ACE
• POCO
• PTypes

I’ve included the selection criteria and evaluation results below. Happy reading.

UPDATE 11/14/2008: Read my post about problems with ACE and debugging memory leaks in Windows.

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CANDIDATE SELECTION

Required Features

1. Must be written in C++
2. Must run on Linux (x86 and PPC) and Windows
3. Must have a modular architecture
4. Must abstract threading and synchronization
5. Must abstract sockets
6. Must abstract file I/O
7. Must abstract IPC
8. Must abstract memory management

Areas That Will Be Evaluated
Listed in order of importance:

1. Number of supported platforms
2. How actively is it maintained
3. Performance
4. Total compiled library size
5. Future potential
6. Ease of use
7. Number of relevant features
8. Breadth of acceptance
9. Documentation
10. Level of support

Reasons for Candidate Selection

ACE

Category Implementation Threads ACE_Thread, ACE_Singleton, ACE_Barrier, ACE_Condition, ACE_Guard, ACE_Mutex, ACE_Recursive_Thread_Mutex Sockets ACE_SOCK_Connector/Acceptor, ACE_SOCK_Stream, ACE_SOCK_Dgram, ACE_ICMP_Socket File I/O ACE_File, ACE_File_IO, ACE_File_Connector, ACE_OS (C runtime functions… fopen, fseek, etc) IPC ACE_MEM_Connector/Acceptor, ACE_SPIPE_Connector/Acceptor Memory Mgmt ACE_Allocator, ACE_Cached_Mem_Pool, ACE_Auto_Ptr

POCO

Category Implementation Threads Thread, ThreadPool, FastMutex, RWLock, Condition, Event, ScopedLock, ScopedRWLock, Notifications, SingletonHolder Sockets RawSocket, MulticastSocket, StreamSocket, DatagramSocket File I/O File, FileInputStream, FileOutputStream IPC NamedEvent, NamedMutex, Pipe, PipeInputStream, PipeOutputStream, SharedMemory Memory Mgmt DynamicFactory, MemoryPool, AutoPtr

PTypes

Category Implementation Threads thread, semaphore, timed semaphore, mutex, rwlock, trigger (condition/event), msgqueue, jobqueue, atomic ops (inc,dec,exchange) Sockets ipstream, ipstmserver, ipmessage, ipmsgserver, utilities (hostname, iptostring, etc) File I/O instm, outstm, infile, outfile, logfile (all stream based – defines static pin, pout, perr, pnull for access to stdin, stdout, etc) IPC namedpipe, npserver, inmemory, outmemory (all stream based) Memory Mgmt tobjlist (object list – dynamic creation/destruction)

Reasons for Candidate Dismisal

Boost

1. Shared memory support not currently released
2. Complex file I/O abstraction
3. Only IPC is a pipe file

VPR

1. No IPC
2. Minimal features
3. Geared toward 3D graphics and virtual reality applications

Platinum

1. Still in beta

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EVALUATION RESULTS

Supported Platforms

ACE PTypes POCO Linux (Debian, RedHat, SuSE, Timesys) Linux Linux Windows (NT, Embedded NT, 2000, XP, WinCE) Windows (NT, 2000, XP) Windows (NT, 2000, XP) Mac OS X Mac OS X Mac OS X BSD (FreeBSD, NetBSD, OpenBSD) BSD (FreeBSD) BSD UNIX (Solaris, IRIX, HP-UX, Tru64UNIX, AIX, UnixWare, SCO) UNIX (Solaris) UNIX (Solaris) OpenVMS - OpenVMS QnX Neutrino - QnX LynxOS, VxWorks, ChorusOS, RTEMS, OS9, PSoS, MVS OpenEdition, CRAY UNICOS) Any POSIX-based Any POSIX-based

Project Activity

Type of Activity ACE PTypes POCO Number of developers “officially” listed 7 3 5 Number of contributers 2000+ 7 10 Year project started 1993 2002 2005 Last stable release Apr 2006 May 2007 May 2007 Last release (alpha, beta, or stable) Apr 2007 May 2007 May 2007 Number of downloads per month ~35000 130 (May 2007) 1494 (May 2007) Number of open bugs (May 2007) 266 4 10 Number of bugs fixed (May 2007) 6 0 5 Number of forum posts (May 2007) - 5 18 Number of forum posts w/ replies (May 2007) - 4 18 Number of news group/mailing list posts (May 31st-June 7th) 76 - 8

Performance

Code Review: The information in this table is here to help guage the quality of the implementation details below.

Metric ACE PTypes POCO Overall quality Good Ok Good Comments Good Ok Ok Returns values checked Good Poor Good Use of try/catch Good Poor Good Code readability Poor Good Good

Implementation Details: All of the implementationsseem to be fairly compact and efficient. However, ACE has a complex“connector” design model for file I/O that has a lot of indirection.This is probably not much of a performance issue, but it may lead us touse the C-style ACE OS methods (ACE_OS::fopen, ACE_OS::fclose, etc).

Item Platform ACE PTypes POCO Mutex Win32 Native mutex/critical section depending of scope (process/thread) Critical section (semaphore for process scope) Critical section (NamedMutex for process scope) POSIX pthread mutex pthread mutex pthread mutex Thread Win32 CreateThread (or CWinThread if using MFC) _beginthreadex CreateThread (can’t set stack size) POSIX pthread pthread pthread Socket Win32 WinSock 2 (WSA methods) WinSock 2 (Berkley interface) WinSock 2 (Berkley interface) Other Berkley sockets Berkley sockets Berkley sockets File I/O Win32 Native API (CreateFile, etc) Native API (CreateFile, etc) Native API (CreateFile, etc) Other ::open_f and ::open ::open ::open Condition Win32 Native events Native events mutexes w/ waitqueue Other mutexes/semaphores (thread/process scope) pthread conditions mutexes w/ waitqueue Auto pointer Uses ‘delete’ to remove object N/A Uses ref counts via custom interface

Total Library Size

ACE:

NOTE: ACE has a tool called soreduce that will analyize anapplication (or set of applications) for it dependencies to ACE, andgenerate a makefile that builds a custom version of ACE without unusedobjects.

Platform File Name Release (x86) Debug (x86) Release (PPC) Debug (PPC) Linux libACE.so 1.7 MB 8.1 MB 2.0 MB 8.4 MB Windows ACE.dll 1.1 MB 2.3 MB - - Windows ACE.lib 1.9 MB 2.9 MB - -

PTypes:

Platform File Name Release (x86) Debug (x86) Release (PPC) Debug (PPC) Linux libptypes.so 0.20 MB 0.20 MB 0.23 MB 0.22 MB Windows ptypes21.dll 0.16 MB 0.23 MB - - Windows ptypes21.lib 0.27 MB 0.27 MB - -

POCO:

Platform File Name Release (x86) Debug (x86) Release (PPC) Debug (PPC) Linux libPocoFoundation.so 1.3 MB 8.0 MB 1.4 MB 7.6 MB Linux libPocoNet.so 0.79 MB 5.7 MB 0.85 MB 5.2 MB Linux libPocoUtil.so 0.24 MB 2.0 MB 0.26 MB 2.0 MB Linux libPocoXML.so 0.53 MB 3.5 MB 0.59 MB 3.3 MB Windows PocoFoundation.dll 1.0 MB 2.2 MB - - Windows PocoFoundation.lib 1.1 MB 1.1 MB - - Windows PocoNet.dll 0.60 MB 1.3 MB - - Windows PocoNet.lib 0.72 MB 0.72 MB - - Windows PocoUtil.dll 0.26 MB 0.62 MB - - Windows PocoUtil.lib 0.25 MB 0.25 MB - - Windows PocoXML.dll 0.50 MB 0.98 MB - - Windows PocoXML.lib 0.50 MB 0.50 MB - -

Future Potential

ACE:

• Started in 1993.
• Still under active development.
• I received 2 responses to my newsgroup post within 30 minutes.
• I emailed Douglas Schmidt (creator of ACE) directly with some questions, and received a reply within 45 minutes.
• Has very wide acceptance.
• The next stable release is scheduled for the end of summer 2007.
• Several companies commerically supporting it.

PTypes:

• Started in 2002.
• The creator took a 2 year break from working on it, but is now back.
• Has a smaller following than ACE.
• Has minimal activity on it’s forum.
• Couldn’t find any commercial support for it.

POCO:

• Started in 2005.
• Still under active development.
• Has a small but growing following.
• Light activity on the forum, but questions answered quickly.
• Commerical support provided by the same company that created it.

Ease of Use

NOTE: These results are very subjective, as no formal methods were used.

POCO provided that most straight-forward set of classes out of allthe candidates evaluated. The functionality of the classes andassociated methods should be obvious to any software engineer. PTypeswas a close second behind POCO regarding ease-of-use. ACE has a highlearning curve, with many architectural design concepts that may be newto some. However, once up the learning curve, ACE doesn’t seem muchharder to use than the other candidates (except for the shear volume ofclasses available).

Relevant Features

ACE is by-far the most complete feature set of all the candidates.However, it is unlikely we will utilize many of the features of ACE, butit does provide us the option to so if we need. PTypes seems a littlelight on some of the core features, so we might have to still createsome classes to fully meet our needs. POCO is complete, providing aclean implementation and architecture. The nice thing about POCO is it’sfeature set can easily be limited to only an OS abstraction layer. ACEhas so many other features, that it might have the tendency to creapoutside the domain of simple OS abstraction.

I’ve avoided listing all the relevant features here, because the documentation for all candidates is freely available online.

Breadth of Acceptance

ACE PTypes POCO ATD, Airforce Research Lab, BAE Systems, BBN, Boeing, CDI/GDIS, Cisco, Comverse, DARPA, Ericsson, Experian, Global MAINTECH, Hughes Network Systems, IBM, Kodak, Krones, Lockheed Martin, Lucent, Microsoft, Mitre, Motorola CGISS, Motorola Iridium, OCI, Office of Naval Research, Oresis, OSC, OTI, Nokia, Nortel, NSF, PrismTechnologies, QNX, Qualcomm, Raytheon, Riverace, SAIC, Siemens, Sprint, Telcordia, USENIX, Veritas - TAC AB, RF-iT

Documentation

Category ACE PTypes POCO Documentation quality Good Good Good Tutorials and Examples/Quality Yes (good) Yes (minimal) Yes (good) Books on the project Yes (3) No No

Level of Support

Category ACE PTypes POCO Forum No Yes Yes Mailing list/Newsgroup yes No Yes Level of forum/newsgroup/list activity High Minimal Some Companies providing commercial support Riverace, Remedy IT, Terabit, OCI - Applied Informatics (POCO creators)