v2.2.0

2026-06-04T10:26:20Z

Runtime version query API: coco_version(), coco_version_major(), coco_version_minor(), coco_version_patch().
ENSURE_IN_CORO / ENSURE_IN_CORO_RET / ENSURE_IN_CORO_VOID guard macros for coroutine-only APIs, preventing crashes when called outside a coroutine context.
POSIX signal block/unblock (coco_preempt_block_signal() / coco_preempt_unblock_signal()) with reference-counted nesting counter for critical section protection.
P binding detection for coco_go(): when called from a worker thread, the new coroutine binds to the current P instead of scanning all processors.
Periodic load balancing integrated into the worker loop (triggered every 100 coroutines processed).
Linux netpoller wakeup uses eventfd instead of pipe for lower overhead.
New examples: hot_stack, dynamic_stack, context_api.
New benchmarks: bench_mt_sched, bench_hot_cold_switch; bench_io rewritten to measure actual coroutine I/O throughput.
New tests: stress_mt_scaling, stress_channel_mt_burst, test_ctx_x86_64, test_preempt_block, test_preempt_channel, test_preempt_sched, test_coro_guard, test_sched_reinit, test_sched_balanced.
Doxygen configuration for API reference generation.
GitHub Actions CI workflow with sanitizer matrix (ASan, UBSan).
Automated release workflow triggered on version tag push.

coco_yield() return type changed from void to int (returns COCO_ERROR_INVALID when called outside a coroutine). ABI note: existing compiled objects must be recompiled.
coro->state type changed from int (non-atomic) to _Atomic int for thread-safety. ABI note: existing compiled objects must be recompiled.
Global runq wake strategy: targeted pthread_cond_signal replaces broadcast to fix thundering herd.

Multi-threaded scheduler data races and leaks:
- coro->state is now _Atomic (acquire/release ordering).
- stack_pool_multi protected by per-pool mutex.
- Wrong-pool-free on work-stealing fixed via coro->stack_pool tracking.
Channel wait_queue_lock and scheduler global_runq_lock / local_runq_lock critical sections protected from preemption.
Scheduler reinitialization: coco_global_sched_stop() now fully cleans up state (queues, counters, locks).
schedule_balanced() now actually redistributes coroutines from overloaded P's and releases hot-stack slots before migration.
Worker thread H2 path now performs load balancing (extracted shared handle_coro_done helper).
Windows APC preemption delivery: added alertable SleepEx in idle paths.
Windows worker idle sleep capped to 1ms to prevent lost pthread_cond_signal wakeups.
Windows I/O function linker conflicts between POSIX and Winsock implementations resolved.
UBSan null-pointer in stress_channel_burst: hot-stack backup/restore now rewrites stack pointers in callee-saved registers.
GCC 16 rbp clobber in sanitizer builds (-fomit-frame-pointer for register integrity test).
Signal blocking nesting counter underflow guard in coco_preempt_unblock_signal().
Munmap fallback in coco_global_sched_stop() queue cleanup when coro->stack_pool is NULL.

v2.1.0

2026-06-03T16:01:57Z

Memory leak when coroutine IDs exceed coro_table capacity (dynamic realloc expansion)
Memory leak in MT worker: dead coroutines not freed after execution
Memory leak in stress_channel_burst test: channels not destroyed on teardown
Memory leak in coco_sched_destroy: select state and non-pool stacks not cleaned up
io_uring test crash under AddressSanitizer (skipped due to mmap ring buffer incompatibility with ASAN)

2026-05-09T03:44:15Z

Release v2.0.0: multi-threaded scheduler, dynamic stack growth, preem…

2026-04-28T05:53:44Z

Release v1.0.0 - Initial release with stackful coroutines, channels, …