Coroutines are a nice concept, but at the moment there are barely any production-ready C libraries as they suffer from various shortcomings. This is a small proof-of-concept library to avoid the more common problems:
- Extensive multi-platform functionality
- To not change stack location (unlike for example pypy stacklet)
- To not allocate any memory
The heavy lifting in libkorutin is done by different backends, mainly PyPy stacklet and Boost Context. However the libraries are not used as is, but instead their assembly-coded stack switch is implemented. Thanks to their devoted developers this project can be realised (supporting all ABI's/compilers is difficult).
TODO:
- Extensive built-in self check suite
- Basic scheduler
- Channels
- Ability to run a coroutine from another coroutine
- More fallback stack switching solution in case if asm fails
- PyPy is used as an ASM based stack pointer switch. This backend is very fast, but do not support arm64
- Boost Context is used as an ASM based stack pointer switch. This backend is also very fast, and supports arm64
- Threads offer low scalability (~50 coroutines is ok), is quite slow, and uses malloc. However if no other work, this is a last resort.
- Emscripten based coroutines, the only way to run it in the browsers, has two flavours
ASYNCIFYandEMTERPRETIFY. - ucontext, TODO.
- setjmp, TODO.
| OS | ABI | Switch | Context | Threads | Emscripten |
|---|---|---|---|---|---|
| Windows | x86 | ✓ | ✓ | ✓ | ✗ |
| Windows | x64 | ✓ | ✓ | ✓ | ✗ |
| Linux | x32 | ? | ? | ? | ✗ |
| Linux | x86 | ? | ? | ? | ✗ |
| Linux | x64 | ✓ | ✓ | ✓ | ✗ |
| Linux | armv7 | ✓ | ✓ | ✓ | ✗ |
| Linux | arm64 | ? | ? | ? | ✗ |
| FreeBSD | x86 | ? | ? | ? | ✗ |
| FreeBSD | x64 | ✓ | ✓ | ✓ | ✗ |
| MacOS | x86 | ✓ | ✓ | ✓ | ✗ |
| MacOS | x64 | ✓ | ✓ | ✓ | ✗ |
| iOS | sim64 | ✓ | ✓ | ✓ | ✗ |
| iOS | armv7 | ✗ | ✓ | ✓ | ✗ |
| iOS | arm64 | ✗ | ✓ | ✓ | ✗ |
| Android | x86 | ? | ? | ? | ✗ |
| Android | x64 | ? | ? | ? | ✗ |
| Android | armv7 | ? | ✓ | ? | ✗ |
| Android | arm64 | ? | ? | ? | ✗ |
| Emscripten | asm.js | ✗ | ✗ | ✗ | ✓ |
| Emscripten | wasm | ✗ | ✗ | ✗ | ? |
- Value means switches per second.
- (X) means amount of coroutines yielded/scheduled.
- iOS test app apparently was in debug.
| OS | CPU | ABI | Switch(1024) | Switch(16384) | Context(1024) | Context(16384) | Threads(32) | Threads(64) | Threads(128) |
|---|---|---|---|---|---|---|---|---|---|
| Windows 10 x64 | i3770 | x86 | 12337349 | 10625162 | 18056174 | 12268213 | 176795 | 94395 | 45812 |
| Windows 10 x64 | i3770 | x64 | 20897959 | 9875828 | 17231499 | 8445864 | 205128 | 87551 | 47513 |
| MacOS 10.13.2 | i4980hq | x86 | 11292405 | 8162099 | 16765164 | 12252028 | 46093 | 16470 | 7181 |
| MacOS 10.13.2 | i4980hq | x64 | 22218395 | 15899470 | 17349371 | 12899821 | 46947 | 16641 | 7334 |
| iOS 9.2 (deb) | A7 | armv7 | - | - | 3497542 | 2543724 | 9604 | 2890 | 806 |
| iOS 11.2.2 (deb) | A9 | arm64 | - | - | 6145022 | 4814864 | 17764 | 6353 | 1930 |
| Android 6.0.1 | MSM8974-AC | armv7 | - | - | 2633119 | 2018506 | ? | ? | ? |
| FreeBSD 11.1 | E5-2630L v2 | x64 | 16254737 | 9077585 | 11294780 | 6821553 | 29798 | 9772 | 4436 |
| Ubuntu 17.10 | E5-2650L v3 | x64 | 14368457 | 11775094 | 13073079 | 10392292 | 49764 | 15540 | 5341 |
| Raspbian | BCM2836 | armv7 | 1019024 | ? | 428089 | ? | 31461 | ? | ? |
And some results for Emscripten:
| Browser | Flavour | Emscripten(1024) | Emscripten(16384) |
|---|---|---|---|
| Chrome 63 | ASYNCIFY | 9170502 | 6879678 |