ruby--ruby/include/ruby/ractor.h

265 lines
8.7 KiB
C++

#ifndef RUBY_RACTOR_H /*-*-C++-*-vi:se ft=cpp:*/
#define RUBY_RACTOR_H 1
/**
* @file
* @author Koichi Sasada
* @date Tue Nov 17 16:39:15 2020
* @copyright Copyright (C) 2020 Yukihiro Matsumoto
* @copyright This file is a part of the programming language Ruby.
* Permission is hereby granted, to either redistribute and/or
* modify this file, provided that the conditions mentioned in the
* file COPYING are met. Consult the file for details.
*/
#include "internal/dllexport.h" /* RUBY_EXTERN is here */
#include "internal/fl_type.h" /* FL_TEST_RAW is here */
#include "internal/special_consts.h" /* RB_SPECIAL_CONSTS_P is here */
#include "internal/stdbool.h" /* bool is here */
#include "internal/value.h" /* VALUE is here */
/** Type that defines a ractor-local storage. */
struct rb_ractor_local_storage_type {
/**
* A function to mark a ractor-local storage.
*
* @param[out] ptr A ractor-local storage.
* @post Ruby objects inside of `ptr` are marked.
*/
void (*mark)(void *ptr);
/**
* A function to destruct a ractor-local storage.
*
* @param[out] ptr A ractor-local storage.
* @post `ptr` is not a valid pointer.
*/
void (*free)(void *ptr);
// TODO: update
};
/** (Opaque) struct that holds a ractor-local storage key. */
typedef struct rb_ractor_local_key_struct *rb_ractor_local_key_t;
RBIMPL_SYMBOL_EXPORT_BEGIN()
/**
* `Ractor` class.
*
* @ingroup object
*/
RUBY_EXTERN VALUE rb_cRactor;
/**
* Queries the standard input of the current Ractor that is calling this
* function.
*
* @return An IO.
* @note This can be different from the process-global one.
*/
VALUE rb_ractor_stdin(void);
/**
* Queries the standard output of the current Ractor that is calling this
* function.
*
* @return An IO.
* @note This can be different from the process-global one.
*/
VALUE rb_ractor_stdout(void);
/**
* Queries the standard error of the current Ractor that is calling this
* function.
*
* @return An IO.
* @note This can be different from the process-global one.
*/
VALUE rb_ractor_stderr(void);
/**
* Assigns an IO to the standard input of the Ractor that is calling this
* function.
*
* @param[in] io An IO.
* @post `io` is the standard input of the current ractor.
* @post In case the calling Ractor is the main Ractor, it also updates
* the process global ::rb_stdin.
*/
void rb_ractor_stdin_set(VALUE io);
/**
* Assigns an IO to the standard output of the Ractor that is calling this
* function.
*
* @param[in] io An IO.
* @post `io` is the standard input of the current ractor.
* @post In case the calling Ractor is the main Ractor, it also updates
* the process global ::rb_stdout.
*/
void rb_ractor_stdout_set(VALUE io);
/**
* Assigns an IO to the standard error of the Ractor that is calling this
* function.
*
* @param[in] io An IO.
* @post `io` is the standard input of the current ractor.
* @post In case the calling Ractor is the main Ractor, it also updates
* the process global ::rb_stderr.
*/
void rb_ractor_stderr_set(VALUE io);
/**
* Issues a new key.
*
* @return A newly issued ractor-local storage key. Keys issued using this
* key can be associated to a Ruby object per Ractor.
*/
rb_ractor_local_key_t rb_ractor_local_storage_value_newkey(void);
/**
* Queries the key.
*
* @param[in] key A ractor-local storage key to lookup.
* @retval RUBY_Qnil No such key.
* @retval otherwise A value corresponds to `key` in the current Ractor.
* @note This cannot distinguish between a nonexistent key and a key
* exists and corresponds to ::RUBY_Qnil.
*/
VALUE rb_ractor_local_storage_value(rb_ractor_local_key_t key);
/**
* Queries the key.
*
* @param[in] key A ractor-local storage key to lookup.
* @param[out] val Return value buffer.
* @retval false `key` not found.
* @retval true `key` found.
* @post `val` is updated so that it has the value corresponds to `key`
* in the current Ractor.
*/
bool rb_ractor_local_storage_value_lookup(rb_ractor_local_key_t key, VALUE *val);
/**
* Associates the passed value to the passed key.
*
* @param[in] key A ractor-local storage key.
* @param[in] val Arbitrary ruby object.
* @post `val` corresponds to `key` in the current Ractor.
*/
void rb_ractor_local_storage_value_set(rb_ractor_local_key_t key, VALUE val);
/**
* A type of ractor-local storage that destructs itself using ::ruby_xfree.
*
* @internal
*
* Why it is visible from 3rd party extension libraries is not obvious to
* @shyouhei.
*/
RUBY_EXTERN const struct rb_ractor_local_storage_type rb_ractor_local_storage_type_free;
/** @alias{rb_ractor_local_storage_type_free} */
#define RB_RACTOR_LOCAL_STORAGE_TYPE_FREE (&rb_ractor_local_storage_type_free)
/**
* Extended version of rb_ractor_local_storage_value_newkey(). It additionally
* takes the type of the issuing key.
*
* @param[in] type How the value associated with the issuing key should
* behave.
* @return A newly issued ractor-local storage key, of type `type`.
*/
rb_ractor_local_key_t rb_ractor_local_storage_ptr_newkey(const struct rb_ractor_local_storage_type *type);
/**
* Identical to rb_ractor_local_storage_value() except the return type.
*
* @param[in] key A ractor-local storage key to lookup.
* @retval NULL No such key.
* @retval otherwise A value corresponds to `key` in the current Ractor.
*/
void *rb_ractor_local_storage_ptr(rb_ractor_local_key_t key);
/**
* Identical to rb_ractor_local_storage_value_set() except the parameter type.
*
* @param[in] key A ractor-local storage key.
* @param[in] ptr A pointer that conforms `key`'s type.
* @post `ptr` corresponds to `key` in the current Ractor.
*/
void rb_ractor_local_storage_ptr_set(rb_ractor_local_key_t key, void *ptr);
/**
* Destructively transforms the passed object so that multiple Ractors can
* share it. What is a shareable object and what is not is a nuanced concept,
* and @ko1 says the definition can still change. However extension library
* authors might interest to learn how to use #RUBY_TYPED_FROZEN_SHAREABLE.
*
* @param[out] obj Arbitrary ruby object to modify.
* @exception rb_eRactorError Ractors cannot share `obj` by nature.
* @return Passed `obj`.
* @post Multiple Ractors can share `obj`.
*
* @internal
*
* In case an exception is raised, `obj` remains in an intermediate state where
* some of its part is frozen and others are not. @shyouhei is not sure if it
* is either an intended behaviour, current implementation limitation, or
* simply a bug. Note also that there is no way to "melt" a frozen object.
*/
VALUE rb_ractor_make_shareable(VALUE obj);
/**
* Identical to rb_ractor_make_shareable(), except it returns a (deep) copy of
* the passed one instead of modifying it in-place.
*
* @param[in] obj Arbitrary ruby object to duplicate.
* @exception rb_eRactorError Ractors cannot share `obj` by nature.
* @return A deep copy of `obj` which is sharable among Ractors.
*/
VALUE rb_ractor_make_shareable_copy(VALUE obj);
RBIMPL_SYMBOL_EXPORT_END()
/**
* Queries if the passed object has previously classified as shareable or not.
* This doesn't mean anything in practice... Objects can be shared later.
* Always use rb_ractor_shareable_p() instead.
*
* @param[in] obj Object in question.
* @retval RUBY_FL_SHAREABLE It once was shareable before.
* @retval 0 Otherwise.
*/
#define RB_OBJ_SHAREABLE_P(obj) FL_TEST_RAW((obj), RUBY_FL_SHAREABLE)
/**
* Queries if multiple Ractors can share the passed object or not. Ractors run
* without protecting each other. Sharing an object among them is basically
* dangerous, disabled by default. However there are objects that are
* extremely carefully implemented to be Ractor-safe; for instance integers
* have such property. This function can classify that.
*
* @param[in] obj Arbitrary ruby object.
* @retval true `obj` is capable of shared across ractors.
* @retval false `obj` cannot travel across ractor boundaries.
*/
static inline bool
rb_ractor_shareable_p(VALUE obj)
{
bool rb_ractor_shareable_p_continue(VALUE obj);
if (RB_SPECIAL_CONST_P(obj)) {
return true;
}
else if (RB_OBJ_SHAREABLE_P(obj)) {
return true;
}
else {
return rb_ractor_shareable_p_continue(obj);
}
}
#endif /* RUBY_RACTOR_H */