diff --git a/build_assert.h b/build_assert.h new file mode 100644 index 0000000..a04d1d4 --- /dev/null +++ b/build_assert.h @@ -0,0 +1,40 @@ +/* CC0 (Public domain) - see ccan/licenses/CC0 file for details */ +#ifndef CCAN_BUILD_ASSERT_H +#define CCAN_BUILD_ASSERT_H + +/** + * BUILD_ASSERT - assert a build-time dependency. + * @cond: the compile-time condition which must be true. + * + * Your compile will fail if the condition isn't true, or can't be evaluated + * by the compiler. This can only be used within a function. + * + * Example: + * #include + * ... + * static char *foo_to_char(struct foo *foo) + * { + * // This code needs string to be at start of foo. + * BUILD_ASSERT(offsetof(struct foo, string) == 0); + * return (char *)foo; + * } + */ +#define BUILD_ASSERT(cond) \ + do { (void) sizeof(char [1 - 2*!(cond)]); } while(0) + +/** + * BUILD_ASSERT_OR_ZERO - assert a build-time dependency, as an expression. + * @cond: the compile-time condition which must be true. + * + * Your compile will fail if the condition isn't true, or can't be evaluated + * by the compiler. This can be used in an expression: its value is "0". + * + * Example: + * #define foo_to_char(foo) \ + * ((char *)(foo) \ + * + BUILD_ASSERT_OR_ZERO(offsetof(struct foo, string) == 0)) + */ +#define BUILD_ASSERT_OR_ZERO(cond) \ + (sizeof(char [1 - 2*!(cond)]) - 1) + +#endif /* CCAN_BUILD_ASSERT_H */ diff --git a/check_type.h b/check_type.h new file mode 100644 index 0000000..b675375 --- /dev/null +++ b/check_type.h @@ -0,0 +1,63 @@ +/* CC0 (Public domain) - see ccan/licenses/CC0 file for details */ +#ifndef CCAN_CHECK_TYPE_H +#define CCAN_CHECK_TYPE_H + +/** + * check_type - issue a warning or build failure if type is not correct. + * @expr: the expression whose type we should check (not evaluated). + * @type: the exact type we expect the expression to be. + * + * This macro is usually used within other macros to try to ensure that a macro + * argument is of the expected type. No type promotion of the expression is + * done: an unsigned int is not the same as an int! + * + * check_type() always evaluates to 0. + * + * If your compiler does not support typeof, then the best we can do is fail + * to compile if the sizes of the types are unequal (a less complete check). + * + * Example: + * // They should always pass a 64-bit value to _set_some_value! + * #define set_some_value(expr) \ + * _set_some_value((check_type((expr), uint64_t), (expr))) + */ + +/** + * check_types_match - issue a warning or build failure if types are not same. + * @expr1: the first expression (not evaluated). + * @expr2: the second expression (not evaluated). + * + * This macro is usually used within other macros to try to ensure that + * arguments are of identical types. No type promotion of the expressions is + * done: an unsigned int is not the same as an int! + * + * check_types_match() always evaluates to 0. + * + * If your compiler does not support typeof, then the best we can do is fail + * to compile if the sizes of the types are unequal (a less complete check). + * + * Example: + * // Do subtraction to get to enclosing type, but make sure that + * // pointer is of correct type for that member. + * #define container_of(mbr_ptr, encl_type, mbr) \ + * (check_types_match((mbr_ptr), &((encl_type *)0)->mbr), \ + * ((encl_type *) \ + * ((char *)(mbr_ptr) - offsetof(enclosing_type, mbr)))) + */ +#if HAVE_TYPEOF +#define check_type(expr, type) \ + ((typeof(expr) *)0 != (type *)0) + +#define check_types_match(expr1, expr2) \ + ((typeof(expr1) *)0 != (typeof(expr2) *)0) +#else +#include "build_assert.h" +/* Without typeof, we can only test the sizes. */ +#define check_type(expr, type) \ + BUILD_ASSERT_OR_ZERO(sizeof(expr) == sizeof(type)) + +#define check_types_match(expr1, expr2) \ + BUILD_ASSERT_OR_ZERO(sizeof(expr1) == sizeof(expr2)) +#endif /* HAVE_TYPEOF */ + +#endif /* CCAN_CHECK_TYPE_H */ diff --git a/container_of.h b/container_of.h new file mode 100644 index 0000000..ab5ac5f --- /dev/null +++ b/container_of.h @@ -0,0 +1,142 @@ +/* CC0 (Public domain) - see ccan/licenses/CC0 file for details */ +#ifndef CCAN_CONTAINER_OF_H +#define CCAN_CONTAINER_OF_H +#include "check_type.h" + +/** + * container_of - get pointer to enclosing structure + * @member_ptr: pointer to the structure member + * @containing_type: the type this member is within + * @member: the name of this member within the structure. + * + * Given a pointer to a member of a structure, this macro does pointer + * subtraction to return the pointer to the enclosing type. + * + * Example: + * struct foo { + * int fielda, fieldb; + * // ... + * }; + * struct info { + * int some_other_field; + * struct foo my_foo; + * }; + * + * static struct info *foo_to_info(struct foo *foo) + * { + * return container_of(foo, struct info, my_foo); + * } + */ +#define container_of(member_ptr, containing_type, member) \ + ((containing_type *) \ + ((char *)(member_ptr) \ + - container_off(containing_type, member)) \ + + check_types_match(*(member_ptr), ((containing_type *)0)->member)) + + +/** + * container_of_or_null - get pointer to enclosing structure, or NULL + * @member_ptr: pointer to the structure member + * @containing_type: the type this member is within + * @member: the name of this member within the structure. + * + * Given a pointer to a member of a structure, this macro does pointer + * subtraction to return the pointer to the enclosing type, unless it + * is given NULL, in which case it also returns NULL. + * + * Example: + * struct foo { + * int fielda, fieldb; + * // ... + * }; + * struct info { + * int some_other_field; + * struct foo my_foo; + * }; + * + * static struct info *foo_to_info_allowing_null(struct foo *foo) + * { + * return container_of_or_null(foo, struct info, my_foo); + * } + */ +static inline char *container_of_or_null_(void *member_ptr, size_t offset) +{ + return member_ptr ? (char *)member_ptr - offset : NULL; +} +#define container_of_or_null(member_ptr, containing_type, member) \ + ((containing_type *) \ + container_of_or_null_(member_ptr, \ + container_off(containing_type, member)) \ + + check_types_match(*(member_ptr), ((containing_type *)0)->member)) + +/** + * container_off - get offset to enclosing structure + * @containing_type: the type this member is within + * @member: the name of this member within the structure. + * + * Given a pointer to a member of a structure, this macro does + * typechecking and figures out the offset to the enclosing type. + * + * Example: + * struct foo { + * int fielda, fieldb; + * // ... + * }; + * struct info { + * int some_other_field; + * struct foo my_foo; + * }; + * + * static struct info *foo_to_info(struct foo *foo) + * { + * size_t off = container_off(struct info, my_foo); + * return (void *)((char *)foo - off); + * } + */ +#define container_off(containing_type, member) \ + offsetof(containing_type, member) + +/** + * container_of_var - get pointer to enclosing structure using a variable + * @member_ptr: pointer to the structure member + * @container_var: a pointer of same type as this member's container + * @member: the name of this member within the structure. + * + * Given a pointer to a member of a structure, this macro does pointer + * subtraction to return the pointer to the enclosing type. + * + * Example: + * static struct info *foo_to_i(struct foo *foo) + * { + * struct info *i = container_of_var(foo, i, my_foo); + * return i; + * } + */ +#if HAVE_TYPEOF +#define container_of_var(member_ptr, container_var, member) \ + container_of(member_ptr, typeof(*container_var), member) +#else +#define container_of_var(member_ptr, container_var, member) \ + ((void *)((char *)(member_ptr) - \ + container_off_var(container_var, member))) +#endif + +/** + * container_off_var - get offset of a field in enclosing structure + * @container_var: a pointer to a container structure + * @member: the name of a member within the structure. + * + * Given (any) pointer to a structure and a its member name, this + * macro does pointer subtraction to return offset of member in a + * structure memory layout. + * + */ +#if HAVE_TYPEOF +#define container_off_var(var, member) \ + container_off(typeof(*var), member) +#else +#define container_off_var(var, member) \ + ((const char *)&(var)->member - (const char *)(var)) +#endif + +#endif /* CCAN_CONTAINER_OF_H */ diff --git a/list.h b/list.h new file mode 100644 index 0000000..da21b33 --- /dev/null +++ b/list.h @@ -0,0 +1,773 @@ +/* Licensed under BSD-MIT - see ccan/licenses/BSD-MIT file for details */ +#ifndef CCAN_LIST_H +#define CCAN_LIST_H +#include +#include "str.h" +#include "container_of.h" +#include "check_type.h" + +/** + * struct list_node - an entry in a doubly-linked list + * @next: next entry (self if empty) + * @prev: previous entry (self if empty) + * + * This is used as an entry in a linked list. + * Example: + * struct child { + * const char *name; + * // Linked list of all us children. + * struct list_node list; + * }; + */ +struct list_node +{ + struct list_node *next, *prev; +}; + +/** + * struct list_head - the head of a doubly-linked list + * @h: the list_head (containing next and prev pointers) + * + * This is used as the head of a linked list. + * Example: + * struct parent { + * const char *name; + * struct list_head children; + * unsigned int num_children; + * }; + */ +struct list_head +{ + struct list_node n; +}; + +#define LIST_LOC __FILE__ ":" stringify(__LINE__) +#define list_debug(h, loc) ((void)loc, h) +#define list_debug_node(n, loc) ((void)loc, n) + +/** + * LIST_HEAD_INIT - initializer for an empty list_head + * @name: the name of the list. + * + * Explicit initializer for an empty list. + * + * See also: + * LIST_HEAD, list_head_init() + * + * Example: + * static struct list_head my_list = LIST_HEAD_INIT(my_list); + */ +#define LIST_HEAD_INIT(name) { { &name.n, &name.n } } + +/** + * LIST_HEAD - define and initialize an empty list_head + * @name: the name of the list. + * + * The LIST_HEAD macro defines a list_head and initializes it to an empty + * list. It can be prepended by "static" to define a static list_head. + * + * See also: + * LIST_HEAD_INIT, list_head_init() + * + * Example: + * static LIST_HEAD(my_global_list); + */ +#define LIST_HEAD(name) \ + struct list_head name = LIST_HEAD_INIT(name) + +/** + * list_head_init - initialize a list_head + * @h: the list_head to set to the empty list + * + * Example: + * ... + * struct parent *parent = malloc(sizeof(*parent)); + * + * list_head_init(&parent->children); + * parent->num_children = 0; + */ +static inline void list_head_init(struct list_head *h) +{ + h->n.next = h->n.prev = &h->n; +} + +/** + * list_node_init - initialize a list_node + * @n: the list_node to link to itself. + * + * You don't need to use this normally! But it lets you list_del(@n) + * safely. + */ +static inline void list_node_init(struct list_node *n) +{ + n->next = n->prev = n; +} + +/** + * list_add_after - add an entry after an existing node in a linked list + * @h: the list_head to add the node to (for debugging) + * @p: the existing list_node to add the node after + * @n: the new list_node to add to the list. + * + * The existing list_node must already be a member of the list. + * The new list_node does not need to be initialized; it will be overwritten. + * + * Example: + * struct child c1, c2, c3; + * LIST_HEAD(h); + * + * list_add_tail(&h, &c1.list); + * list_add_tail(&h, &c3.list); + * list_add_after(&h, &c1.list, &c2.list); + */ +#define list_add_after(h, p, n) list_add_after_(h, p, n, LIST_LOC) +static inline void list_add_after_(struct list_head *h, + struct list_node *p, + struct list_node *n, + const char *abortstr) +{ + n->next = p->next; + n->prev = p; + p->next->prev = n; + p->next = n; + (void)list_debug(h, abortstr); +} + +/** + * list_add - add an entry at the start of a linked list. + * @h: the list_head to add the node to + * @n: the list_node to add to the list. + * + * The list_node does not need to be initialized; it will be overwritten. + * Example: + * struct child *child = malloc(sizeof(*child)); + * + * child->name = "marvin"; + * list_add(&parent->children, &child->list); + * parent->num_children++; + */ +#define list_add(h, n) list_add_(h, n, LIST_LOC) +static inline void list_add_(struct list_head *h, + struct list_node *n, + const char *abortstr) +{ + list_add_after_(h, &h->n, n, abortstr); +} + +/** + * list_add_before - add an entry before an existing node in a linked list + * @h: the list_head to add the node to (for debugging) + * @p: the existing list_node to add the node before + * @n: the new list_node to add to the list. + * + * The existing list_node must already be a member of the list. + * The new list_node does not need to be initialized; it will be overwritten. + * + * Example: + * list_head_init(&h); + * list_add_tail(&h, &c1.list); + * list_add_tail(&h, &c3.list); + * list_add_before(&h, &c3.list, &c2.list); + */ +#define list_add_before(h, p, n) list_add_before_(h, p, n, LIST_LOC) +static inline void list_add_before_(struct list_head *h, + struct list_node *p, + struct list_node *n, + const char *abortstr) +{ + n->next = p; + n->prev = p->prev; + p->prev->next = n; + p->prev = n; + (void)list_debug(h, abortstr); +} + +/** + * list_add_tail - add an entry at the end of a linked list. + * @h: the list_head to add the node to + * @n: the list_node to add to the list. + * + * The list_node does not need to be initialized; it will be overwritten. + * Example: + * list_add_tail(&parent->children, &child->list); + * parent->num_children++; + */ +#define list_add_tail(h, n) list_add_tail_(h, n, LIST_LOC) +static inline void list_add_tail_(struct list_head *h, + struct list_node *n, + const char *abortstr) +{ + list_add_before_(h, &h->n, n, abortstr); +} + +/** + * list_empty - is a list empty? + * @h: the list_head + * + * If the list is empty, returns true. + * + * Example: + * assert(list_empty(&parent->children) == (parent->num_children == 0)); + */ +#define list_empty(h) list_empty_(h, LIST_LOC) +static inline int list_empty_(const struct list_head *h, const char* abortstr) +{ + (void)list_debug(h, abortstr); + return h->n.next == &h->n; +} + +/** + * list_empty_nodebug - is a list empty (and don't perform debug checks)? + * @h: the list_head + * + * If the list is empty, returns true. + * This differs from list_empty() in that if CCAN_LIST_DEBUG is set it + * will NOT perform debug checks. Only use this function if you REALLY + * know what you're doing. + * + * Example: + * assert(list_empty_nodebug(&parent->children) == (parent->num_children == 0)); + */ +#ifndef CCAN_LIST_DEBUG +#define list_empty_nodebug(h) list_empty(h) +#else +static inline int list_empty_nodebug(const struct list_head *h) +{ + return h->n.next == &h->n; +} +#endif + +/** + * list_del - delete an entry from an (unknown) linked list. + * @n: the list_node to delete from the list. + * + * Note that this leaves @n in an undefined state; it can be added to + * another list, but not deleted again. + * + * See also: + * list_del_from(), list_del_init() + * + * Example: + * list_del(&child->list); + * parent->num_children--; + */ +#define list_del(n) list_del_(n, LIST_LOC) +static inline void list_del_(struct list_node *n, const char* abortstr) +{ + (void)list_debug_node(n, abortstr); + n->next->prev = n->prev; + n->prev->next = n->next; +#ifdef CCAN_LIST_DEBUG + /* Catch use-after-del. */ + n->next = n->prev = NULL; +#endif +} + +/** + * list_del_init - delete a node, and reset it so it can be deleted again. + * @n: the list_node to be deleted. + * + * list_del(@n) or list_del_init() again after this will be safe, + * which can be useful in some cases. + * + * See also: + * list_del_from(), list_del() + * + * Example: + * list_del_init(&child->list); + * parent->num_children--; + */ +#define list_del_init(n) list_del_init_(n, LIST_LOC) +static inline void list_del_init_(struct list_node *n, const char *abortstr) +{ + list_del_(n, abortstr); + list_node_init(n); +} + +/** + * list_del_from - delete an entry from a known linked list. + * @h: the list_head the node is in. + * @n: the list_node to delete from the list. + * + * This explicitly indicates which list a node is expected to be in, + * which is better documentation and can catch more bugs. + * + * See also: list_del() + * + * Example: + * list_del_from(&parent->children, &child->list); + * parent->num_children--; + */ +static inline void list_del_from(struct list_head *h, struct list_node *n) +{ +#ifdef CCAN_LIST_DEBUG + { + /* Thorough check: make sure it was in list! */ + struct list_node *i; + for (i = h->n.next; i != n; i = i->next) + assert(i != &h->n); + } +#endif /* CCAN_LIST_DEBUG */ + + /* Quick test that catches a surprising number of bugs. */ + assert(!list_empty(h)); + list_del(n); +} + +/** + * list_swap - swap out an entry from an (unknown) linked list for a new one. + * @o: the list_node to replace from the list. + * @n: the list_node to insert in place of the old one. + * + * Note that this leaves @o in an undefined state; it can be added to + * another list, but not deleted/swapped again. + * + * See also: + * list_del() + * + * Example: + * struct child x1, x2; + * LIST_HEAD(xh); + * + * list_add(&xh, &x1.list); + * list_swap(&x1.list, &x2.list); + */ +#define list_swap(o, n) list_swap_(o, n, LIST_LOC) +static inline void list_swap_(struct list_node *o, + struct list_node *n, + const char* abortstr) +{ + (void)list_debug_node(o, abortstr); + *n = *o; + n->next->prev = n; + n->prev->next = n; +#ifdef CCAN_LIST_DEBUG + /* Catch use-after-del. */ + o->next = o->prev = NULL; +#endif +} + +/** + * list_entry - convert a list_node back into the structure containing it. + * @n: the list_node + * @type: the type of the entry + * @member: the list_node member of the type + * + * Example: + * // First list entry is children.next; convert back to child. + * child = list_entry(parent->children.n.next, struct child, list); + * + * See Also: + * list_top(), list_for_each() + */ +#define list_entry(n, type, member) container_of(n, type, member) + +/** + * list_top - get the first entry in a list + * @h: the list_head + * @type: the type of the entry + * @member: the list_node member of the type + * + * If the list is empty, returns NULL. + * + * Example: + * struct child *first; + * first = list_top(&parent->children, struct child, list); + * if (!first) + * printf("Empty list!\n"); + */ +#define list_top(h, type, member) \ + ((type *)list_top_((h), list_off_(type, member))) + +static inline const void *list_top_(const struct list_head *h, size_t off) +{ + if (list_empty(h)) + return NULL; + return (const char *)h->n.next - off; +} + +/** + * list_pop - remove the first entry in a list + * @h: the list_head + * @type: the type of the entry + * @member: the list_node member of the type + * + * If the list is empty, returns NULL. + * + * Example: + * struct child *one; + * one = list_pop(&parent->children, struct child, list); + * if (!one) + * printf("Empty list!\n"); + */ +#define list_pop(h, type, member) \ + ((type *)list_pop_((h), list_off_(type, member))) + +static inline const void *list_pop_(const struct list_head *h, size_t off) +{ + struct list_node *n; + + if (list_empty(h)) + return NULL; + n = h->n.next; + list_del(n); + return (const char *)n - off; +} + +/** + * list_tail - get the last entry in a list + * @h: the list_head + * @type: the type of the entry + * @member: the list_node member of the type + * + * If the list is empty, returns NULL. + * + * Example: + * struct child *last; + * last = list_tail(&parent->children, struct child, list); + * if (!last) + * printf("Empty list!\n"); + */ +#define list_tail(h, type, member) \ + ((type *)list_tail_((h), list_off_(type, member))) + +static inline const void *list_tail_(const struct list_head *h, size_t off) +{ + if (list_empty(h)) + return NULL; + return (const char *)h->n.prev - off; +} + +/** + * list_for_each - iterate through a list. + * @h: the list_head (warning: evaluated multiple times!) + * @i: the structure containing the list_node + * @member: the list_node member of the structure + * + * This is a convenient wrapper to iterate @i over the entire list. It's + * a for loop, so you can break and continue as normal. + * + * Example: + * list_for_each(&parent->children, child, list) + * printf("Name: %s\n", child->name); + */ +#define list_for_each(h, i, member) \ + list_for_each_off(h, i, list_off_var_(i, member)) + +/** + * list_for_each_rev - iterate through a list backwards. + * @h: the list_head + * @i: the structure containing the list_node + * @member: the list_node member of the structure + * + * This is a convenient wrapper to iterate @i over the entire list. It's + * a for loop, so you can break and continue as normal. + * + * Example: + * list_for_each_rev(&parent->children, child, list) + * printf("Name: %s\n", child->name); + */ +#define list_for_each_rev(h, i, member) \ + list_for_each_rev_off(h, i, list_off_var_(i, member)) + +/** + * list_for_each_rev_safe - iterate through a list backwards, + * maybe during deletion + * @h: the list_head + * @i: the structure containing the list_node + * @nxt: the structure containing the list_node + * @member: the list_node member of the structure + * + * This is a convenient wrapper to iterate @i over the entire list backwards. + * It's a for loop, so you can break and continue as normal. The extra + * variable * @nxt is used to hold the next element, so you can delete @i + * from the list. + * + * Example: + * struct child *next; + * list_for_each_rev_safe(&parent->children, child, next, list) { + * printf("Name: %s\n", child->name); + * } + */ +#define list_for_each_rev_safe(h, i, nxt, member) \ + list_for_each_rev_safe_off(h, i, nxt, list_off_var_(i, member)) + +/** + * list_for_each_safe - iterate through a list, maybe during deletion + * @h: the list_head + * @i: the structure containing the list_node + * @nxt: the structure containing the list_node + * @member: the list_node member of the structure + * + * This is a convenient wrapper to iterate @i over the entire list. It's + * a for loop, so you can break and continue as normal. The extra variable + * @nxt is used to hold the next element, so you can delete @i from the list. + * + * Example: + * list_for_each_safe(&parent->children, child, next, list) { + * list_del(&child->list); + * parent->num_children--; + * } + */ +#define list_for_each_safe(h, i, nxt, member) \ + list_for_each_safe_off(h, i, nxt, list_off_var_(i, member)) + +/** + * list_next - get the next entry in a list + * @h: the list_head + * @i: a pointer to an entry in the list. + * @member: the list_node member of the structure + * + * If @i was the last entry in the list, returns NULL. + * + * Example: + * struct child *second; + * second = list_next(&parent->children, first, list); + * if (!second) + * printf("No second child!\n"); + */ +#define list_next(h, i, member) \ + ((list_typeof(i))list_entry_or_null(list_debug(h, \ + __FILE__ ":" stringify(__LINE__)), \ + (i)->member.next, \ + list_off_var_((i), member))) + +/** + * list_prev - get the previous entry in a list + * @h: the list_head + * @i: a pointer to an entry in the list. + * @member: the list_node member of the structure + * + * If @i was the first entry in the list, returns NULL. + * + * Example: + * first = list_prev(&parent->children, second, list); + * if (!first) + * printf("Can't go back to first child?!\n"); + */ +#define list_prev(h, i, member) \ + ((list_typeof(i))list_entry_or_null(list_debug(h, \ + __FILE__ ":" stringify(__LINE__)), \ + (i)->member.prev, \ + list_off_var_((i), member))) + +/** + * list_append_list - empty one list onto the end of another. + * @to: the list to append into + * @from: the list to empty. + * + * This takes the entire contents of @from and moves it to the end of + * @to. After this @from will be empty. + * + * Example: + * struct list_head adopter; + * + * list_append_list(&adopter, &parent->children); + * assert(list_empty(&parent->children)); + * parent->num_children = 0; + */ +#define list_append_list(t, f) list_append_list_(t, f, \ + __FILE__ ":" stringify(__LINE__)) +static inline void list_append_list_(struct list_head *to, + struct list_head *from, + const char *abortstr) +{ + struct list_node *from_tail = list_debug(from, abortstr)->n.prev; + struct list_node *to_tail = list_debug(to, abortstr)->n.prev; + + /* Sew in head and entire list. */ + to->n.prev = from_tail; + from_tail->next = &to->n; + to_tail->next = &from->n; + from->n.prev = to_tail; + + /* Now remove head. */ + list_del(&from->n); + list_head_init(from); +} + +/** + * list_prepend_list - empty one list into the start of another. + * @to: the list to prepend into + * @from: the list to empty. + * + * This takes the entire contents of @from and moves it to the start + * of @to. After this @from will be empty. + * + * Example: + * list_prepend_list(&adopter, &parent->children); + * assert(list_empty(&parent->children)); + * parent->num_children = 0; + */ +#define list_prepend_list(t, f) list_prepend_list_(t, f, LIST_LOC) +static inline void list_prepend_list_(struct list_head *to, + struct list_head *from, + const char *abortstr) +{ + struct list_node *from_tail = list_debug(from, abortstr)->n.prev; + struct list_node *to_head = list_debug(to, abortstr)->n.next; + + /* Sew in head and entire list. */ + to->n.next = &from->n; + from->n.prev = &to->n; + to_head->prev = from_tail; + from_tail->next = to_head; + + /* Now remove head. */ + list_del(&from->n); + list_head_init(from); +} + +/* internal macros, do not use directly */ +#define list_for_each_off_dir_(h, i, off, dir) \ + for (i = list_node_to_off_(list_debug(h, LIST_LOC)->n.dir, \ + (off)); \ + list_node_from_off_((void *)i, (off)) != &(h)->n; \ + i = list_node_to_off_(list_node_from_off_((void *)i, (off))->dir, \ + (off))) + +#define list_for_each_safe_off_dir_(h, i, nxt, off, dir) \ + for (i = list_node_to_off_(list_debug(h, LIST_LOC)->n.dir, \ + (off)), \ + nxt = list_node_to_off_(list_node_from_off_(i, (off))->dir, \ + (off)); \ + list_node_from_off_(i, (off)) != &(h)->n; \ + i = nxt, \ + nxt = list_node_to_off_(list_node_from_off_(i, (off))->dir, \ + (off))) + +/** + * list_for_each_off - iterate through a list of memory regions. + * @h: the list_head + * @i: the pointer to a memory region wich contains list node data. + * @off: offset(relative to @i) at which list node data resides. + * + * This is a low-level wrapper to iterate @i over the entire list, used to + * implement all oher, more high-level, for-each constructs. It's a for loop, + * so you can break and continue as normal. + * + * WARNING! Being the low-level macro that it is, this wrapper doesn't know + * nor care about the type of @i. The only assumtion made is that @i points + * to a chunk of memory that at some @offset, relative to @i, contains a + * properly filled `struct node_list' which in turn contains pointers to + * memory chunks and it's turtles all the way down. Whith all that in mind + * remember that given the wrong pointer/offset couple this macro will + * happilly churn all you memory untill SEGFAULT stops it, in other words + * caveat emptor. + * + * It is worth mentioning that one of legitimate use-cases for that wrapper + * is operation on opaque types with known offset for `struct list_node' + * member(preferably 0), because it allows you not to disclose the type of + * @i. + * + * Example: + * list_for_each_off(&parent->children, child, + * offsetof(struct child, list)) + * printf("Name: %s\n", child->name); + */ +#define list_for_each_off(h, i, off) \ + list_for_each_off_dir_((h),(i),(off),next) + +/** + * list_for_each_rev_off - iterate through a list of memory regions backwards + * @h: the list_head + * @i: the pointer to a memory region wich contains list node data. + * @off: offset(relative to @i) at which list node data resides. + * + * See list_for_each_off for details + */ +#define list_for_each_rev_off(h, i, off) \ + list_for_each_off_dir_((h),(i),(off),prev) + +/** + * list_for_each_safe_off - iterate through a list of memory regions, maybe + * during deletion + * @h: the list_head + * @i: the pointer to a memory region wich contains list node data. + * @nxt: the structure containing the list_node + * @off: offset(relative to @i) at which list node data resides. + * + * For details see `list_for_each_off' and `list_for_each_safe' + * descriptions. + * + * Example: + * list_for_each_safe_off(&parent->children, child, + * next, offsetof(struct child, list)) + * printf("Name: %s\n", child->name); + */ +#define list_for_each_safe_off(h, i, nxt, off) \ + list_for_each_safe_off_dir_((h),(i),(nxt),(off),next) + +/** + * list_for_each_rev_safe_off - iterate backwards through a list of + * memory regions, maybe during deletion + * @h: the list_head + * @i: the pointer to a memory region wich contains list node data. + * @nxt: the structure containing the list_node + * @off: offset(relative to @i) at which list node data resides. + * + * For details see `list_for_each_rev_off' and `list_for_each_rev_safe' + * descriptions. + * + * Example: + * list_for_each_rev_safe_off(&parent->children, child, + * next, offsetof(struct child, list)) + * printf("Name: %s\n", child->name); + */ +#define list_for_each_rev_safe_off(h, i, nxt, off) \ + list_for_each_safe_off_dir_((h),(i),(nxt),(off),prev) + +/* Other -off variants. */ +#define list_entry_off(n, type, off) \ + ((type *)list_node_from_off_((n), (off))) + +#define list_head_off(h, type, off) \ + ((type *)list_head_off((h), (off))) + +#define list_tail_off(h, type, off) \ + ((type *)list_tail_((h), (off))) + +#define list_add_off(h, n, off) \ + list_add((h), list_node_from_off_((n), (off))) + +#define list_del_off(n, off) \ + list_del(list_node_from_off_((n), (off))) + +#define list_del_from_off(h, n, off) \ + list_del_from(h, list_node_from_off_((n), (off))) + +/* Offset helper functions so we only single-evaluate. */ +static inline void *list_node_to_off_(struct list_node *node, size_t off) +{ + return (void *)((char *)node - off); +} +static inline struct list_node *list_node_from_off_(void *ptr, size_t off) +{ + return (struct list_node *)((char *)ptr + off); +} + +/* Get the offset of the member, but make sure it's a list_node. */ +#define list_off_(type, member) \ + (container_off(type, member) + \ + check_type(((type *)0)->member, struct list_node)) + +#define list_off_var_(var, member) \ + (container_off_var(var, member) + \ + check_type(var->member, struct list_node)) + +#if HAVE_TYPEOF +#define list_typeof(var) typeof(var) +#else +#define list_typeof(var) void * +#endif + +/* Returns member, or NULL if at end of list. */ +static inline void *list_entry_or_null(const struct list_head *h, + const struct list_node *n, + size_t off) +{ + if (n == &h->n) + return NULL; + return (char *)n - off; +} +#endif /* CCAN_LIST_H */ diff --git a/st.c b/st.c index d689c81..15e6abf 100644 --- a/st.c +++ b/st.c @@ -14,6 +14,7 @@ #include #endif #include +#include "list.h" typedef struct st_table_entry st_table_entry; diff --git a/str.h b/str.h new file mode 100644 index 0000000..9a9da9c --- /dev/null +++ b/str.h @@ -0,0 +1,16 @@ +/* CC0 (Public domain) - see ccan/licenses/CC0 file for details */ +#ifndef CCAN_STR_H +#define CCAN_STR_H +/** + * stringify - Turn expression into a string literal + * @expr: any C expression + * + * Example: + * #define PRINT_COND_IF_FALSE(cond) \ + * ((cond) || printf("%s is false!", stringify(cond))) + */ +#define stringify(expr) stringify_1(expr) +/* Double-indirection required to stringify expansions */ +#define stringify_1(expr) #expr + +#endif /* CCAN_STR_H */ diff --git a/thread.c b/thread.c index 2102a26..3c85569 100644 --- a/thread.c +++ b/thread.c @@ -1224,7 +1224,7 @@ blocking_region_end(rb_thread_t *th, struct rb_blocking_region_buffer *region) gvl_acquire(th->vm, th); rb_thread_set_current(th); thread_debug("leave blocking region (%p)\n", (void *)th); - remove_signal_thread_list(th); + unregister_ubf_list(th); th->blocking_region_buffer = 0; reset_unblock_function(th, ®ion->oldubf); if (th->status == THREAD_STOPPED) { diff --git a/thread_pthread.c b/thread_pthread.c index c8a7a16..2992756 100644 --- a/thread_pthread.c +++ b/thread_pthread.c @@ -413,12 +413,8 @@ native_cond_timeout(rb_nativethread_cond_t *cond, struct timespec timeout_rel) #endif #if defined(SIGVTALRM) && !defined(__CYGWIN__) && !defined(__SYMBIAN32__) -#define USE_SIGNAL_THREAD_LIST 1 -#endif -#ifdef USE_SIGNAL_THREAD_LIST -static void add_signal_thread_list(rb_thread_t *th); -static void remove_signal_thread_list(rb_thread_t *th); -static rb_nativethread_lock_t signal_thread_list_lock; +#define USE_UBF_LIST 1 +static rb_nativethread_lock_t ubf_list_lock; #endif static pthread_key_t ruby_native_thread_key; @@ -451,8 +447,8 @@ Init_native_thread(void) pthread_key_create(&ruby_native_thread_key, NULL); th->thread_id = pthread_self(); native_thread_init(th); -#ifdef USE_SIGNAL_THREAD_LIST - native_mutex_initialize(&signal_thread_list_lock); +#ifdef USE_UBF_LIST + native_mutex_initialize(&ubf_list_lock); #endif #ifndef __native_client__ posix_signal(SIGVTALRM, null_func); @@ -462,7 +458,12 @@ Init_native_thread(void) static void native_thread_init(rb_thread_t *th) { - native_cond_initialize(&th->native_thread_data.sleep_cond, RB_CONDATTR_CLOCK_MONOTONIC); + native_thread_data_t *nd = &th->native_thread_data; + +#ifdef USE_UBF_LIST + list_node_init(&nd->ubf_list); +#endif + native_cond_initialize(&nd->sleep_cond, RB_CONDATTR_CLOCK_MONOTONIC); ruby_thread_set_native(th); } @@ -1130,144 +1131,90 @@ native_sleep(rb_thread_t *th, struct timeval *timeout_tv) thread_debug("native_sleep done\n"); } -#ifdef USE_SIGNAL_THREAD_LIST -struct signal_thread_list { - rb_thread_t *th; - struct signal_thread_list *prev; - struct signal_thread_list *next; -}; - -static struct signal_thread_list signal_thread_list_anchor = { - 0, 0, 0, -}; - -#define FGLOCK(lock, body) do { \ - native_mutex_lock(lock); \ - { \ - body; \ - } \ - native_mutex_unlock(lock); \ -} while (0) +#ifdef USE_UBF_LIST +static LIST_HEAD(ubf_list_head); -#if 0 /* for debug */ +/* The thread 'th' is registered to be trying unblock. */ static void -print_signal_list(char *str) +register_ubf_list(rb_thread_t *th) { - struct signal_thread_list *list = - signal_thread_list_anchor.next; - thread_debug("list (%s)> ", str); - while (list) { - thread_debug("%p (%p), ", list->th, list->th->thread_id); - list = list->next; - } - thread_debug("\n"); -} -#endif - -static void -add_signal_thread_list(rb_thread_t *th) -{ - if (!th->native_thread_data.signal_thread_list) { - FGLOCK(&signal_thread_list_lock, { - struct signal_thread_list *list = - malloc(sizeof(struct signal_thread_list)); - - if (list == 0) { - fprintf(stderr, "[FATAL] failed to allocate memory\n"); - exit(EXIT_FAILURE); - } - - list->th = th; - - list->prev = &signal_thread_list_anchor; - list->next = signal_thread_list_anchor.next; - if (list->next) { - list->next->prev = list; - } - signal_thread_list_anchor.next = list; - th->native_thread_data.signal_thread_list = list; - }); - } + struct list_node *node = &th->native_thread_data.ubf_list; + if (list_empty((struct list_head*)node)) { + native_mutex_lock(&ubf_list_lock); + list_add(&ubf_list_head, node); + native_mutex_unlock(&ubf_list_lock); + } } +/* The thread 'th' is unblocked. It no longer need to be registered. */ static void -remove_signal_thread_list(rb_thread_t *th) +unregister_ubf_list(rb_thread_t *th) { - if (th->native_thread_data.signal_thread_list) { - FGLOCK(&signal_thread_list_lock, { - struct signal_thread_list *list = - (struct signal_thread_list *) - th->native_thread_data.signal_thread_list; - - list->prev->next = list->next; - if (list->next) { - list->next->prev = list->prev; - } - th->native_thread_data.signal_thread_list = 0; - list->th = 0; - free(list); /* ok */ - }); - } + struct list_node *node = &th->native_thread_data.ubf_list; + + if (!list_empty((struct list_head*)node)) { + native_mutex_lock(&ubf_list_lock); + list_del_init(node); + native_mutex_unlock(&ubf_list_lock); + } } +/* + * send a signal to intent that a target thread return from blocking syscall. + * Maybe any signal is ok, but we chose SIGVTALRM. + */ static void -ubf_select_each(rb_thread_t *th) +ubf_wakeup_thread(rb_thread_t *th) { - thread_debug("ubf_select_each (%p)\n", (void *)th->thread_id); - if (th) { - pthread_kill(th->thread_id, SIGVTALRM); - } + if (th) + pthread_kill(th->thread_id, SIGVTALRM); } static void ubf_select(void *ptr) { rb_thread_t *th = (rb_thread_t *)ptr; - add_signal_thread_list(th); + register_ubf_list(th); /* - * ubf_select_each() doesn't guarantee to wake up the target thread. - * Therefore, we need to activate timer thread when called from - * Thread#kill etc. + * ubf_wakeup_thread() doesn't guarantee to wake up a target thread. + * Therefore, we repeatedly call ubf_wakeup_thread() until a target thread + * exit from ubf function. * In the other hands, we shouldn't call rb_thread_wakeup_timer_thread() * if running on timer thread because it may make endless wakeups. */ if (pthread_self() != timer_thread_id) rb_thread_wakeup_timer_thread(); - ubf_select_each(th); + ubf_wakeup_thread(th); } -static void -ping_signal_thread_list(void) +static int +ubf_threads_empty(void) { - if (signal_thread_list_anchor.next) { - FGLOCK(&signal_thread_list_lock, { - struct signal_thread_list *list; - - list = signal_thread_list_anchor.next; - while (list) { - ubf_select_each(list->th); - list = list->next; - } - }); - } + return list_empty(&ubf_list_head); } -static int -check_signal_thread_list(void) +static void +ubf_wakeup_all_threads(void) { - if (signal_thread_list_anchor.next) - return 1; - else - return 0; + rb_thread_t *th; + + if (!ubf_threads_empty()) { + native_mutex_lock(&ubf_list_lock); + list_for_each(&ubf_list_head, th, native_thread_data.ubf_list) { + ubf_wakeup_thread(th); + } + native_mutex_unlock(&ubf_list_lock); + } } -#else /* USE_SIGNAL_THREAD_LIST */ -#define add_signal_thread_list(th) (void)(th) -#define remove_signal_thread_list(th) (void)(th) + +#else /* USE_UBF_LIST */ +#define register_ubf_list(th) (void)(th) +#define unregister_ubf_list(th) (void)(th) #define ubf_select 0 -static void ping_signal_thread_list(void) { return; } -static int check_signal_thread_list(void) { return 0; } -#endif /* USE_SIGNAL_THREAD_LIST */ +static void ubf_wakeup_all_threads(void) { return; } +static int ubf_threads_empty(void) { return 1; } +#endif /* USE_UBF_LIST */ #define TT_DEBUG 0 #define WRITE_CONST(fd, str) (void)(write((fd),(str),sizeof(str)-1)<0) @@ -1430,7 +1377,7 @@ timer_thread_sleep(rb_global_vm_lock_t* gvl) pollfds[1].fd = timer_thread_pipe_low[0]; pollfds[1].events = POLLIN; - need_polling = check_signal_thread_list(); + need_polling = !ubf_threads_empty(); if (gvl->waiting > 0 || need_polling) { /* polling (TIME_QUANTUM_USEC usec) */ @@ -1505,7 +1452,7 @@ thread_timer(void *p) while (system_working > 0) { /* timer function */ - ping_signal_thread_list(); + ubf_wakeup_all_threads(); timer_thread_function(0); if (TT_DEBUG) WRITE_CONST(2, "tick\n"); diff --git a/thread_pthread.h b/thread_pthread.h index 5ccdaec..f71b911 100644 --- a/thread_pthread.h +++ b/thread_pthread.h @@ -15,6 +15,9 @@ #ifdef HAVE_PTHREAD_NP_H #include #endif + +#include "list.h" + typedef pthread_t rb_nativethread_id_t; typedef pthread_mutex_t rb_nativethread_lock_t; @@ -26,7 +29,7 @@ typedef struct rb_thread_cond_struct { } rb_nativethread_cond_t; typedef struct native_thread_data_struct { - void *signal_thread_list; + struct list_node ubf_list; rb_nativethread_cond_t sleep_cond; } native_thread_data_t; diff --git a/thread_win32.c b/thread_win32.c index dffe70d..1590dc1 100644 --- a/thread_win32.c +++ b/thread_win32.c @@ -19,7 +19,7 @@ #undef Sleep #define native_thread_yield() Sleep(0) -#define remove_signal_thread_list(th) +#define unregister_ubf_list(th) static volatile DWORD ruby_native_thread_key = TLS_OUT_OF_INDEXES; diff --git a/variable.c b/variable.c index f9a607f..d4f444a 100644 --- a/variable.c +++ b/variable.c @@ -19,6 +19,7 @@ #include "constant.h" #include "internal.h" #include "id.h" +#include "list.h" st_table *rb_global_tbl; static ID autoload, classpath, tmp_classpath, classid; diff --git a/vm_core.h b/vm_core.h index ee37cb6..5a6c752 100644 --- a/vm_core.h +++ b/vm_core.h @@ -23,6 +23,7 @@ #include "id.h" #include "method.h" #include "ruby_atomic.h" +#include "list.h" #include "thread_native.h"