From 7fcad1fa03c21b9a9916a12b816ec886a5b68920 Mon Sep 17 00:00:00 2001 From: Samuel Williams Date: Sat, 15 Oct 2022 21:43:45 +1300 Subject: Update `Fiber::Scheduler` documentation. (#6562) --- cont.c | 340 +---------------------------------------------------------------- 1 file changed, 1 insertion(+), 339 deletions(-) (limited to 'cont.c') diff --git a/cont.c b/cont.c index 39f0fc8171..b6d26d716e 100644 --- a/cont.c +++ b/cont.c @@ -1991,7 +1991,7 @@ rb_fiber_s_schedule_kw(int argc, VALUE* argv, int kw_splat) VALUE fiber = Qnil; if (scheduler != Qnil) { - fiber = rb_funcall_passing_block_kw(scheduler, rb_intern("fiber"), argc, argv, kw_splat); + fiber = rb_fiber_scheduler_fiber(scheduler, argc, argv, kw_splat); } else { rb_raise(rb_eRuntimeError, "No scheduler is available!"); @@ -3000,329 +3000,6 @@ rb_fiber_pool_initialize(int argc, VALUE* argv, VALUE self) * fiber.resume #=> FiberError: dead fiber called */ -/* - * Document-class: Fiber::SchedulerInterface - * - * This is not an existing class, but documentation of the interface that Scheduler - * object should comply to in order to be used as argument to Fiber.scheduler and handle non-blocking - * fibers. See also the "Non-blocking fibers" section in Fiber class docs for explanations - * of some concepts. - * - * Scheduler's behavior and usage are expected to be as follows: - * - * * When the execution in the non-blocking Fiber reaches some blocking operation (like - * sleep, wait for a process, or a non-ready I/O), it calls some of the scheduler's - * hook methods, listed below. - * * Scheduler somehow registers what the current fiber is waiting on, and yields control - * to other fibers with Fiber.yield (so the fiber would be suspended while expecting its - * wait to end, and other fibers in the same thread can perform) - * * At the end of the current thread execution, the scheduler's method #close is called - * * The scheduler runs into a wait loop, checking all the blocked fibers (which it has - * registered on hook calls) and resuming them when the awaited resource is ready - * (e.g. I/O ready or sleep time elapsed). - * - * A typical implementation would probably rely for this closing loop on a gem like - * EventMachine[https://github.com/eventmachine/eventmachine] or - * Async[https://github.com/socketry/async]. - * - * This way concurrent execution will be achieved transparently for every - * individual Fiber's code. - * - * Hook methods are: - * - * * #io_wait, #io_read, and #io_write - * * #process_wait - * * #kernel_sleep - * * #timeout_after - * * #address_resolve - * * #block and #unblock - * * (the list is expanded as Ruby developers make more methods having non-blocking calls) - * - * When not specified otherwise, the hook implementations are mandatory: if they are not - * implemented, the methods trying to call hook will fail. To provide backward compatibility, - * in the future hooks will be optional (if they are not implemented, due to the scheduler - * being created for the older Ruby version, the code which needs this hook will not fail, - * and will just behave in a blocking fashion). - * - * It is also strongly recommended that the scheduler implements the #fiber method, which is - * delegated to by Fiber.schedule. - * - * Sample _toy_ implementation of the scheduler can be found in Ruby's code, in - * test/fiber/scheduler.rb - * - */ - -#if 0 /* for RDoc */ -/* - * - * Document-method: Fiber::SchedulerInterface#close - * - * Called when the current thread exits. The scheduler is expected to implement this - * method in order to allow all waiting fibers to finalize their execution. - * - * The suggested pattern is to implement the main event loop in the #close method. - * - */ -static VALUE -rb_fiber_scheduler_interface_close(VALUE self) -{ -} - -/* - * Document-method: SchedulerInterface#process_wait - * call-seq: process_wait(pid, flags) - * - * Invoked by Process::Status.wait in order to wait for a specified process. - * See that method description for arguments description. - * - * Suggested minimal implementation: - * - * Thread.new do - * Process::Status.wait(pid, flags) - * end.value - * - * This hook is optional: if it is not present in the current scheduler, - * Process::Status.wait will behave as a blocking method. - * - * Expected to return a Process::Status instance. - */ -static VALUE -rb_fiber_scheduler_interface_process_wait(VALUE self) -{ -} - -/* - * Document-method: SchedulerInterface#io_wait - * call-seq: io_wait(io, events, timeout) - * - * Invoked by IO#wait, IO#wait_readable, IO#wait_writable to ask whether the - * specified descriptor is ready for specified events within - * the specified +timeout+. - * - * +events+ is a bit mask of IO::READABLE, IO::WRITABLE, and - * IO::PRIORITY. - * - * Suggested implementation should register which Fiber is waiting for which - * resources and immediately calling Fiber.yield to pass control to other - * fibers. Then, in the #close method, the scheduler might dispatch all the - * I/O resources to fibers waiting for it. - * - * Expected to return the subset of events that are ready immediately. - * - */ -static VALUE -rb_fiber_scheduler_interface_io_wait(VALUE self) -{ -} - -/* - * Document-method: SchedulerInterface#io_read - * call-seq: io_read(io, buffer, length) -> read length or -errno - * - * Invoked by IO#read to read +length+ bytes from +io+ into a specified - * +buffer+ (see IO::Buffer). - * - * The +length+ argument is the "minimum length to be read". - * If the IO buffer size is 8KiB, but the +length+ is +1024+ (1KiB), up to - * 8KiB might be read, but at least 1KiB will be. - * Generally, the only case where less data than +length+ will be read is if - * there is an error reading the data. - * - * Specifying a +length+ of 0 is valid and means try reading at least once - * and return any available data. - * - * Suggested implementation should try to read from +io+ in a non-blocking - * manner and call #io_wait if the +io+ is not ready (which will yield control - * to other fibers). - * - * See IO::Buffer for an interface available to return data. - * - * Expected to return number of bytes read, or, in case of an error, -errno - * (negated number corresponding to system's error code). - * - * The method should be considered _experimental_. - */ -static VALUE -rb_fiber_scheduler_interface_io_read(VALUE self) -{ -} - -/* - * Document-method: SchedulerInterface#io_write - * call-seq: io_write(io, buffer, length) -> written length or -errno - * - * Invoked by IO#write to write +length+ bytes to +io+ from - * from a specified +buffer+ (see IO::Buffer). - * - * The +length+ argument is the "(minimum) length to be written". - * If the IO buffer size is 8KiB, but the +length+ specified is 1024 (1KiB), - * at most 8KiB will be written, but at least 1KiB will be. - * Generally, the only case where less data than +length+ will be written is if - * there is an error writing the data. - * - * Specifying a +length+ of 0 is valid and means try writing at least once, - * as much data as possible. - * - * Suggested implementation should try to write to +io+ in a non-blocking - * manner and call #io_wait if the +io+ is not ready (which will yield control - * to other fibers). - * - * See IO::Buffer for an interface available to get data from buffer efficiently. - * - * Expected to return number of bytes written, or, in case of an error, -errno - * (negated number corresponding to system's error code). - * - * The method should be considered _experimental_. - */ -static VALUE -rb_fiber_scheduler_interface_io_write(VALUE self) -{ -} - -/* - * Document-method: SchedulerInterface#kernel_sleep - * call-seq: kernel_sleep(duration = nil) - * - * Invoked by Kernel#sleep and Mutex#sleep and is expected to provide - * an implementation of sleeping in a non-blocking way. Implementation might - * register the current fiber in some list of "which fiber wait until what - * moment", call Fiber.yield to pass control, and then in #close resume - * the fibers whose wait period has elapsed. - * - */ -static VALUE -rb_fiber_scheduler_interface_kernel_sleep(VALUE self) -{ -} - -/* - * Document-method: SchedulerInterface#address_resolve - * call-seq: address_resolve(hostname) -> array_of_strings or nil - * - * Invoked by any method that performs a non-reverse DNS lookup. The most - * notable method is Addrinfo.getaddrinfo, but there are many other. - * - * The method is expected to return an array of strings corresponding to ip - * addresses the +hostname+ is resolved to, or +nil+ if it can not be resolved. - * - * Fairly exhaustive list of all possible call-sites: - * - * - Addrinfo.getaddrinfo - * - Addrinfo.tcp - * - Addrinfo.udp - * - Addrinfo.ip - * - Addrinfo.new - * - Addrinfo.marshal_load - * - SOCKSSocket.new - * - TCPServer.new - * - TCPSocket.new - * - IPSocket.getaddress - * - TCPSocket.gethostbyname - * - UDPSocket#connect - * - UDPSocket#bind - * - UDPSocket#send - * - Socket.getaddrinfo - * - Socket.gethostbyname - * - Socket.pack_sockaddr_in - * - Socket.sockaddr_in - * - Socket.unpack_sockaddr_in - */ -static VALUE -rb_fiber_scheduler_interface_address_resolve(VALUE self) -{ -} - -/* - * Document-method: SchedulerInterface#timeout_after - * call-seq: timeout_after(duration, exception_class, *exception_arguments, &block) -> result of block - * - * Invoked by Timeout.timeout to execute the given +block+ within the given - * +duration+. It can also be invoked directly by the scheduler or user code. - * - * Attempt to limit the execution time of a given +block+ to the given - * +duration+ if possible. When a non-blocking operation causes the +block+'s - * execution time to exceed the specified +duration+, that non-blocking - * operation should be interrupted by raising the specified +exception_class+ - * constructed with the given +exception_arguments+. - * - * General execution timeouts are often considered risky. This implementation - * will only interrupt non-blocking operations. This is by design because it's - * expected that non-blocking operations can fail for a variety of - * unpredictable reasons, so applications should already be robust in handling - * these conditions and by implication timeouts. - * - * However, as a result of this design, if the +block+ does not invoke any - * non-blocking operations, it will be impossible to interrupt it. If you - * desire to provide predictable points for timeouts, consider adding - * +sleep(0)+. - * - * If the block is executed successfully, its result will be returned. - * - * The exception will typically be raised using Fiber#raise. - */ -static VALUE -rb_fiber_scheduler_interface_timeout_after(VALUE self) -{ -} - -/* - * Document-method: SchedulerInterface#block - * call-seq: block(blocker, timeout = nil) - * - * Invoked by methods like Thread.join, and by Mutex, to signify that current - * Fiber is blocked until further notice (e.g. #unblock) or until +timeout+ has - * elapsed. - * - * +blocker+ is what we are waiting on, informational only (for debugging and - * logging). There are no guarantee about its value. - * - * Expected to return boolean, specifying whether the blocking operation was - * successful or not. - */ -static VALUE -rb_fiber_scheduler_interface_block(VALUE self) -{ -} - -/* - * Document-method: SchedulerInterface#unblock - * call-seq: unblock(blocker, fiber) - * - * Invoked to wake up Fiber previously blocked with #block (for example, Mutex#lock - * calls #block and Mutex#unlock calls #unblock). The scheduler should use - * the +fiber+ parameter to understand which fiber is unblocked. - * - * +blocker+ is what was awaited for, but it is informational only (for debugging - * and logging), and it is not guaranteed to be the same value as the +blocker+ for - * #block. - * - */ -static VALUE -rb_fiber_scheduler_interface_unblock(VALUE self) -{ -} - -/* - * Document-method: SchedulerInterface#fiber - * call-seq: fiber(&block) - * - * Implementation of the Fiber.schedule. The method is expected to immediately - * run the given block of code in a separate non-blocking fiber, and to return that Fiber. - * - * Minimal suggested implementation is: - * - * def fiber(&block) - * fiber = Fiber.new(blocking: false, &block) - * fiber.resume - * fiber - * end - */ -static VALUE -rb_fiber_scheduler_interface_fiber(VALUE self) -{ -} -#endif - void Init_Cont(void) { @@ -3374,21 +3051,6 @@ Init_Cont(void) rb_define_singleton_method(rb_cFiber, "schedule", rb_fiber_s_schedule, -1); -#if 0 /* for RDoc */ - rb_cFiberScheduler = rb_define_class_under(rb_cFiber, "SchedulerInterface", rb_cObject); - rb_define_method(rb_cFiberScheduler, "close", rb_fiber_scheduler_interface_close, 0); - rb_define_method(rb_cFiberScheduler, "process_wait", rb_fiber_scheduler_interface_process_wait, 0); - rb_define_method(rb_cFiberScheduler, "io_wait", rb_fiber_scheduler_interface_io_wait, 0); - rb_define_method(rb_cFiberScheduler, "io_read", rb_fiber_scheduler_interface_io_read, 0); - rb_define_method(rb_cFiberScheduler, "io_write", rb_fiber_scheduler_interface_io_write, 0); - rb_define_method(rb_cFiberScheduler, "kernel_sleep", rb_fiber_scheduler_interface_kernel_sleep, 0); - rb_define_method(rb_cFiberScheduler, "address_resolve", rb_fiber_scheduler_interface_address_resolve, 0); - rb_define_method(rb_cFiberScheduler, "timeout_after", rb_fiber_scheduler_interface_timeout_after, 0); - rb_define_method(rb_cFiberScheduler, "block", rb_fiber_scheduler_interface_block, 0); - rb_define_method(rb_cFiberScheduler, "unblock", rb_fiber_scheduler_interface_unblock, 0); - rb_define_method(rb_cFiberScheduler, "fiber", rb_fiber_scheduler_interface_fiber, 0); -#endif - #ifdef RB_EXPERIMENTAL_FIBER_POOL rb_cFiberPool = rb_define_class_under(rb_cFiber, "Pool", rb_cObject); rb_define_alloc_func(rb_cFiberPool, fiber_pool_alloc); -- cgit v1.2.1