Cheap Threads: Change Log

Change Log

2002/01/13 -- Corrected a silly typo that had caused the ct_clear function to be accidentally commented out.

2002/06/30 -- Implemented a facility to broadcast a message to all threads.
Also: corrected some bugs connected with messages. These bugs occurred when either of the following occurred:
- A thread sent a message to itself.
- Two or more input messages were enqueued to the same thread at the same time.
2002/08/11 -- Provided an alternative version of Cheap Threads designed for use in embedded systems. By using different combinations of modules, the application can avoid the use of file IO, dynamically allocated memory, or both.

2002/09/08 -- Fixed a bug whereby the sender of a broadcast message was not itself receiving the message.
Also: Introduced functions (ct_enqueue(), ct_distribute_enq() and ct_broadcast_enq()) for awakening sleeping threads without sending a message. As a result the recipients do not have to examine and discard an empty message. So far these functions are neither documented nor fully tested.

2002/09/21 -- Fixed a bug. If a thread called ct_exit(), its destructor function (if there was one) would be called twice. Thanks to Mauro Condarelli for the bug report.

2002/09/26 -- Added a new function ct_create_sleeping_thread(). It is exactly like ct_create_thread() except that it does not not enqueue the new thread for execution. Instead, the thread will sleep until it receives an event.

2002/09/30 -- Added a new function ct_self_data() to return a pointer to the current thread's data.
Also: changed the scheduling algorithm. If a thread returns without removing all messages from its input queue, it will be enqueued for execution at the highest priority, even if it has tried to put itself to sleep. In theory, but probably not in practice, this change could break existing code. See the discussion elsewhere for details.

2002/11/16 -- Corrected a misplaced #endif in ctutil.h, which had caused compile errors when debugging was turned off. Thanks to Jeff Tomich for the bug report.

2003/05/19 -- Provided a timeout facility. A thread can now put itself to sleep to be awakened after a specified interval, if no other event awakens it first.
Also: started a Cheap Threads mailing list, hosted by Yahoo.

2003/06/08 -- Used a reference counting scheme to streamline the machinery for passing messages. Messaging now uses less memory, especially for long messages sent to multiple recipients. Thanks to Mauro Condarelli for the suggestion.

2003/07/27 -- Fixed a memory leak introduced by the previous release (v2.5). The leak occurred when an enqueue was sent to a thread. The fix is confined to ctsched.c and to its embedded counterpart ectsched.c.

2003/08/31 -- Added demo1, a simple demo program. No changes to the Cheap Threads routines themselves.

2003/09/06 -- Tweaked header file ct.h so that, within a C++ program, the prototyped functions will all be declared as extern "C". C++ programs can now call the Cheap Threads functions directly.