Free thread error software for linux

RT-Thread is a real-time operating system. It is designed specifically for small memory footprint platforms. The kernel supports the tranditional RTOS services, such as multiple threads, semaphores, mutexes, event flags, mailboxes, etc.
RT-Thread project also provides a C-expression interpreter shell, from which a programmer can access kernel variables and invoke system functions.
Main features:
Kernel Object System
- There is a kernel object system, which can access and manage all of the kernel objects. Kernel objects include most of the facilities in the kernel, for example, thread, semaphore etc. Kernel objects can be static objects, whose memory is allocated in compiling. It can be dynamic objects as well, whose memory is allocated from system heaps in runtime. Through the kernel object system, RT-Thread operating system can be independent from the memory management system and greatly enhance the scalability of the system.
Multi-Task/Thread Scheduling
- RT-Thread operating system supports multi-task systems, which are based on thread scheduling. The scheduling algorithm used in RT-Thread operating system is a full preemptive priority-based scheduling algorithm. It supports 256 priority levels, in which 0 is the highest and 255 the lowest. The 255th priority is used for idle thread. The scheduling algorithm also supports threads running at same priority level. The shared time-slice round-robin scheduling is used for this case. The time of scheduler to determine the next highest ready thread is determinant. The number of threads in the system is unlimited, only related with RAM.
Synchronization Mechanisms
- RT-Thread operating system supports the traditional semaphore and mutex. Mutex objects use inherited priority to prevent priority reversion. The semaphore release action is safe for interrupt service routine. Moreover, the block queue for thread to obtain semaphore or mutex can be sorted by priority or FIFO.
Inter-Thread Communication
- RT-Thread operating systems supports event/fast event, mail box and message queue. The event mechanism is used to awake a thead by setting one or more corresponding bit of a binary number when an event ocurs. The fast event supports event thread queue. Once a one bit event occurs, the corresponding blocked thread can be found out timing accurately, then will be waked up. In mailbox, a mail length is fixed to 4 byte, which is more effective than message queue. The send action for communication facilities is also safe for interrupt service routine.
Clock and Timer
- In default, the system uses clock tick to implement shared time-slice scheduling. The timing sensitivity of thread is implemented by timers. The timer can be set as one-shot or periodic timeout.
Memory Management
- RT-Thread operating system supports two types memory management: static memory pool management and dynamic memory heap management. The time to allocate a memory block from the memory pool is determinant and when the memory pool is empty, the allocated thread can be blocked (or immediately return, or waiting for sometime to return, which are determined by a timeout parameter). When other thread releases memory blocks to this memory pool, the blocked thread is wake up.
Enhancements:
- More porting was done to Samsung S3C44b0 CPU, AMTEL AT91SAM7S64, Nintendo DS, and Intel i386.

DM1 Thread Library is part of the DM1 project. This library was born out of my need to have a portable C++ Thread library that would be simple to use, and would provide all the necessary Threads functionality I required for the DM1 project.
Initially, this library was in C, but when I decided to re-write DM1 in C++, I ported the library to C++. During the port, I enhanced the functionality of the Threads library.
The DM1 Threads library aims to be small. It does not try to provide a comprehensive set of functionality, but only what is absolutely essential for a project like DM1. I had the simplicity of the Java Threads package in mind when creating this library.
The constructs provided by the DM1 Thread library are:
- Thread objects that represent Operating System threads.
- A Mutex is provided as a mechanism for Mutual Exclusion . Mutexes are used to ensure that a piece of code is executed by only one thread at any point in time.
- Events are provided as low-level mechanisms for thread synchronisation. Events can be waited for, and signalled to.
- A higher level object, that combines the functionality of an Event and a Mutex, is provided. This is the Monitor object. A Monitor can be locked exclusively, just like a Mutex, but it can also be made the object of a Wait operation. The signalling mechanism supports notification of one or more waiting threads.
- To enable more efficient locking when both shared and exclusive access to data is required, Latches are provided.
- Apart from the Thread synchronisation primitives described above, the library also provides a ThreadPool for the situation when it is inefficient to create a thread exclusively for a particular task, and it is desirable to share a pool of threads for executing multiple tasks.
Design Principles
The DM1 Threads library was designed with the following principles in mind:
1. Implement the bare minimum that is required. This Threads library does not aim to be a comprehensive threads package.
2. Avoid complex algorithms. If a particular construct is hard to implement correctly on all platforms, avoid it.
3. Document the library.
4. Avoid low level code, such as assembler code to implement Spin locks. Rely on the libraries provided by the Operating System.
5. Avoid holding Mutexes beyond function calls. A DM1 Thread library function will not hold any Mutex locks when it returns.
6. Avoid using clever C++ techniques wherever possible. (Unfortunately, some cleverness is required to implement the Thread class correctly).
7. Avoid dependency on external libraries. The DM1 library only requires the standard C library, apart from native Threads functionality.
8. Always report an error as soon as it is discovered.
9. Insert debug messages that can be switched on at run-time.
10. Do not throw exceptions from destructors because these might be executing as a result of an uncaught exception.
11. Never let an error go unreported.

State Threads project is a small library for designing scalable Internet applications.
The State Threads is a small application library which provides a foundation for writing fast and highly scalable Internet applications (such as Web servers, proxy servers, mail transfer agents, etc.) on UNIX-like platforms.
It offers a threading API for structuring a network application as an event-driven state machine.
The State Threads library is a derivative of the Netscape Portable Runtime library (NSPR) and therefore is distributed under the Mozilla Public License (MPL) version 1.1 or the GNU General Public License (GPL) version 2 or later.
Enhancements:
- Added support for kqueue and epoll on platforms that support them.
- Added ability to choose the event notification system at program startup.
- Long-overdue public definitions of ST_UTIME_NO_TIMEOUT (-1ULL) and ST_UTIME_NO_WAIT (0) [bug 1514436].
- Documentation patch for st_utime() [bug 1514484].
- Documentation patch for st_timecache_set() [bug 1514486].
- Documentation patch for st_netfd_serialize_accept() [bug 1514494].
- Added st_writev_resid() [rfe 1538344].
- Added st_readv_resid() [rfe 1538768] and, for symmetry, st_readv().

Thread Safe Template Library (TSTL) is a C++ library that provides thread-safe storage data structures without global locking. The library includes classes for maps based on a non-binary extensible hashing tree for very fast access, a pipe, a timercache, and a fast writer multiple reader guard without global locking (which uses the interlocked Intel instruction set).
Enhancements:
- Porting for x64 AMD, Intel, and MSVC 8.0.
- A new cache template with policy by element number.
- Access to elements has been implemented via a map template.
- The adding policy in the timer cache template has been changed.
- The string hash routine has been optimized.
- The timings in the nbmap.h template have changed.

Thread::Apartment is an apartment threading wrapper for Perl objects.

SYNOPSIS

package MyClass;

use Thread::Apartment::Server;
use base qw(Thread::Apartment::Server);

sub new {
#
# the usual constructor
#
}
#
# mark some methods as simplex
#
sub get_simplex_methods {
return { bar => 1 };
}
#
# mark some methods as urgent
#
sub get_urgent_methods {
return { bingo => 1 };
}

sub foo {
#
# do something
#
}

sub bar {
#
# do something else
#
}

sub bingo {
print "BINGO!n";
}

1;

#
# create pool of 20 apartment threads
#
Thread::Apartment->create_pool(AptPoolSize => 20);

my $apt = Thread::Apartment->new(
AptClass => MyClass, # class to install in apartment
AptTimeout => 10, # timeout secs for TQD responses
AptRequire => { # classes to require into the thread
This::Class => 1.234,
That::Class => 0.02
},
AptParams => @params_for_MyClass) || die $@;

my $result = $apt->foo(@params);
die $@ unless $result;
#
# bar is simplex
#
$apt->bar(@params);

Thread::Apartment provides an apartment threading wrapper for Perl classes. "Apartment threading" is a method for isolating an object (or object hierarchy) in its own thread, and providing external interfaces via lightweight client proxy objects. This approach is especially valuable in the Perl threads environment, which doesnt provide a direct means of passing complex, nested structure objects between threads, and for non-threadsafe legacy object architectures, e.g., Perl/Tk.

By using lightweight client proxy objects that implement the Thread::Queue::Queueable interface, with Thread::Queue::Duplex objects as the communication channel between client proxies and apartment threads (or between threads in general), a more thread-friendly OO environment is provided, ala Java, i.e., the ability to pass arbitrary objects between arbitrary threads.

Plone Error Reporting is a project which facilitates the submission of useful bug reports to Plone.
PloneErrorReporting replaces default_error_message and prefs_error_log_showEntry with pages that facilitate the submission of useful bug reports to Plone.
It is designed with the goal of improving the information provided by bug reporters.
To see PloneErrorReporting in action, first install the product, then create a python script called imabug in the ZMI that contains the single line
raise AttributeError, bad attribute
Now, while still authenticated, load the page http://mysite/imabug. You should see a step-by-step procedure for reporting bugs at the bottom of the error page as long as you are logged in as a Manager. Similarly, when you view bugs in the Plone error log, you will see the bug submitting procedure.
Enhancements:
- Moved the product to use its own translation domain. This fixes an issue were half-translated sentences showed up in the templates.

Inter-Thread Communication (ITC) aims to make it exceedingly easy to call functions in other threads.
The lexer does all the work, so just run the lexer on your headers, then call the stub functions.
In addition, it also provides a complete threading API, with the four threading primitives and a high speed threadsafe FIFO class.
Enhancements:
- It add support for GCC 4.x, and the build system is fixed.