> I would like to build a rich "process api" that can fork, merge, pause, yield, yield until, drop while, synchronize, wait (latch), react according to events.

> I would like to build a rich "process api" that can fork, merge, pause, yield, yield until, drop while, synchronize, wait (latch), react according to events. I feel every distributed systems builds this again and again. Years ago I attempted to build an experimental language with first-class resumable functions. Every function can be invoked by the caller through a special reference type called "quaint". The caller can resume or stop the execution of the function either after reaching a timeout, or after passing a "wait label": https://github.com/bbu/quaint-lang https://github.com/bbu/quaint-lang A typical CPU-intensive example where preemption is done by the caller after a certain timeout: entry { fibq: quaint(u32) = ~fibonacci(32 as u32); ps("At start: "), pu8(fibq@start), pnl(); iter: u32 = 0:u32; do { wait fibq for 1000 msec; ps("Iteration "), pu32(iter++), pnl(); } while !fibq@end; ps("At end: "), pu8(fibq@end), pnl(); const value: u32 = *fibq; ps("Reaped value: "), pu32(value), pnl(); } fibonacci(number: u32): u32 { if number == 0:u32 || number == 1:u32 { return number; } else { return fibonacci(number - 1:u32) + fibonacci(number - 2:u32); } } An example that uses "wait labels" to suspend execution of the callee at certain points: entry { q: quaint(u64) = ~pointless_function(); wait q until pointless_function::label_a; ps("At label_a: "), pu8(q@pointless_function::label_a), pnl(); wait q until pointless_function::label_b; ps("At label_b: "), pu8(q@pointless_function::label_b), pnl(); wait q until pointless_function::label_c; ps("At label_c: "), pu8(q@pointless_function::label_c), pnl(); wait q; ps("At end: "), pu8(q@end), pnl(); ps("Result: "), pu64(*q), pnl(); } pointless_function: u64 { i: u64 = 0 as u64; while ++i < 1000000:u64 { x: vptr = malloc(1024:usize); free(x); if i == 300000:u64 { [label_a] } elif i == 600000:u64 { [label_b] } elif i == 900000:u64 { [label_c] } } return i; }