| 1 | Synchronous Programming with User-Level Threads in C∀ |
|---|
| 2 | |
|---|
| 3 | When computations cannot be satisfied immediately, programmers must use |
|---|
| 4 | one of two paradigms, Synchronous Programming and Asynchronous Programming. |
|---|
| 5 | This presentation discusses the benefits Synchronous Programming over |
|---|
| 6 | Asynchronous Programming and what requirements exist to use this paradigm. |
|---|
| 7 | It also discusses how C∀, a concurrent and backwards-compatible extension |
|---|
| 8 | of the C programming language, has powerful tools available for simple and |
|---|
| 9 | efficient Synchronous Programming. These tools include user-level threads |
|---|
| 10 | and high-level locking mechanisms which simply solve common problems. |
|---|
| 11 | Finally, the presentation shows different techniques to combine these |
|---|
| 12 | features with existing code to either uses blocking operations provided by |
|---|
| 13 | the kernel or is built according to an asynchronous paradigm. |
|---|
| 14 | |
|---|
| 15 | |
|---|
| 16 | |
|---|
| 17 | |
|---|
| 18 | |
|---|
| 19 | |
|---|
| 20 | |
|---|
| 21 | |
|---|
| 22 | |
|---|
| 23 | C∀ is a polymorphic, non-object-oriented, concurrent, backwards-compatible |
|---|
| 24 | extension of the C programming language. This paper discusses the design |
|---|
| 25 | philosophy and implementation of its advanced control-flow and concurrent/parallel |
|---|
| 26 | features, along with the supporting runtime written in C∀. These features |
|---|
| 27 | are created from scratch as ISO C has only low-level and/or unimplemented |
|---|
| 28 | concurrency, so C programmers continue to rely on library features like pthreads. |
|---|
| 29 | C∀ introduces modern language-level control-flow mechanisms, like generators, |
|---|
| 30 | coroutines, user-level threading, and monitors for mutual exclusion and |
|---|
| 31 | synchronization. The runtime provides significant programmer simplification |
|---|
| 32 | and safety by eliminating spurious wakeup and monitor barging. The runtime |
|---|
| 33 | also ensures multiple monitors can be safely acquired simultaneously (deadlock free), |
|---|
| 34 | and this feature is fully integrated with all monitor synchronization mechanisms. |
|---|
| 35 | All control-flow features integrate with the C∀ polymorphic type-system and |
|---|
| 36 | exception handling, while respecting the expectations and style of C programmers. |
|---|
| 37 | Experimental results show comparable performance of the new features with similar |
|---|
| 38 | mechanisms in other concurrent programming languages. |
|---|
| 39 | KEYWORDS |
|---|
| 40 | generator, coroutine, concurrency, parallelism, thread, monitor, runtime, C, C∀ (Cforall) |
|---|
