diff options
-rw-r--r-- | include/ruby/debug.h | 41 |
1 files changed, 23 insertions, 18 deletions
@@ -625,25 +625,29 @@ VALUE rb_tracearg_object(rb_trace_arg_t *trace_arg); * signal handler, deferring a job to collect a Ruby backtrace when it is next safe * to do so. * * Historically, this API provided two functions `rb_postponed_job_register` and * `rb_postponed_job_register_one`, which claimed to be fully async-signal-safe and * would call back the provided `func` and `data` at an appropriate time. However, * these functions were subject to race conditions which could cause crashes when - * racing with Ruby's internal use of them. - * - * Therefore, this API has now been changed, and now requires that jobs scheduled - * from a signal handler context are pre-registered in advance into a fixed-size - * table. This table is quite small (it only has 32 entries on most systems) - * and so gems should generally only preregister one or two funcs. This process is - * managed by the `rb_postponed_job_preregister` and `rb_postponed_job_trigger` - * functions. * - * We also provide the old `rb_postponed_job_register` and - * `rb_postponed_job_register_one` functions for backwards compatability, but with - * changed semantics; `rb_postponed_job_register` now behaves the same as - * `rb_postponed_job_register_once`. These changes should remain compatible with all - * of the observed in-the-wild usages of the postponed job APIs, which almost all - * use the _one API and pass `0` for data anyway. */ @@ -670,7 +674,7 @@ typedef unsigned int rb_postponed_job_handle_t; * cause Ruby to call back into the registered `func` with `data` at a later time, in * a context where the GVL is held and it is safe to perform Ruby allocations. * - * If the given func was already pre-registered, this method will overwrite the * stored data with the newly passed data, and return the same handle instance as * was previously returned. * @@ -681,7 +685,7 @@ typedef unsigned int rb_postponed_job_handle_t; * `rb_postponed_job_trigger` on the same handle, it's undefined whether `func` will * be called with the old data or the new data. * - * Although the current implementation of this method is in fact async-signal-safe and * has defined semantics when called concurrently on the same `func`, a future Ruby * version might require that this method be called under the GVL; thus, programs which * aim to be forward-compatible should call this method whilst holding the GVL. @@ -730,8 +734,9 @@ void rb_postponed_job_trigger(rb_postponed_job_handle_t h); * @note Prevoius versions of Ruby promised that the (`func`, `data`) pairs would * be executed as many times as they were registered with this function; in * reality this was always subject to race conditions and this function no - * longer provides this guarantee. Instead, we only promise that `func` will - * be called once. * * @deprecated This interface implies that arbitrarily many `func`'s can be enqueued * over the lifetime of the program, whilst in reality the registration |