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提交 adf12bd3 创建 作者: Nickolai Zeldovich's avatar Nickolai Zeldovich
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c++ wrapper for marked pointers

上级 5fd96933
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正在显示 包含 132 行增加 和 56 行删除
cpprt.cc
浏览文件 @ adf12bd3
......@@ -17,6 +17,12 @@ operator new(unsigned long nbytes, void *buf)
return buf;
}
void *
operator new[](unsigned long nbytes)
{
return kmalloc(nbytes);
}
void
operator delete(void *p)
{
......
crange.cc
浏览文件 @ adf12bd3
......@@ -50,10 +50,6 @@ extern "C" {
// maybe many epochs later.
//
#define MARKED(x) (((uptr) (x)) & 0x1)
#define MARK(x) ((struct range *) (((uptr) (x)) | 0x1))
#define WOMARK(x) ((struct range *) (((uptr) (x)) & ~0x1))
enum { crange_debug = 0 };
enum { crange_checking = 0 };
......@@ -84,9 +80,9 @@ range_draw_nlevel(int nlevel)
void range::print(int l)
{
cprintf ("0x%lx-0x%lx(%lu) 0x%lx, c %d, t %d, n 0x%lx m 0x%lx\n",
cprintf ("0x%lx-0x%lx(%lu) 0x%lx, c %d, t %d, n 0x%lx m %d\n",
key, key+size, size, (long) value, curlevel.load(), nlevel,
(long) next, MARKED(next[l]));
(long) next, (bool) next[l].mark());
}
range::~range()
......@@ -96,7 +92,7 @@ range::~range()
this->cr->check(this);
// assert(this->curlevel == -1);
for (int l = 0; l < this->nlevel; l++) {
this->next[l] = (struct range *) 0xDEADBEEF;
next[l] = (struct range *) 0xDEADBEEF;
}
kmalignfree(this->lock);
kmfree(this->next);
......@@ -119,7 +115,7 @@ void range::dec_ref(void)
}
}
range::range(crange *cr, u64 k, u64 sz, void *v, struct range *n, int nlevel = 0)
range::range(crange *cr, u64 k, u64 sz, void *v, markptr<range> n, int nlevel)
: rcu_freed("range_delayed")
{
if (crange_debug)
......@@ -132,7 +128,7 @@ range::range(crange *cr, u64 k, u64 sz, void *v, struct range *n, int nlevel = 0
this->curlevel = 0;
if (nlevel == 0) this->nlevel = range_draw_nlevel(cr->nlevel);
else this->nlevel = nlevel;
this->next = (struct range**) kmalloc(sizeof(sizeof(this->next[0])) * this->nlevel); // cache align?
this->next = new markptr<range>[this->nlevel]; // cache align?
assert(this->next);
this->next[0] = n;
for (int l = 1; l < this->nlevel; l++) this->next[l] = 0;
......@@ -147,10 +143,10 @@ range::range(crange *cr, u64 k, u64 sz, void *v, struct range *n, int nlevel = 0
static range *insert(struct range *head, struct range *r)
{
struct range *n, *p;
markptr<range> n, p;
p = nullptr;
for (n = head; n != 0; p = n, n = n->next[0]) {
assert(!MARKED(n));
assert(!n.mark());
if (r->key < n->key) {
break;
}
......@@ -166,9 +162,9 @@ static range *insert(struct range *head, struct range *r)
}
// lock p if this->next == e and p isn't marked for deletion. if not, return failure.
int range::lockif(range *e)
int range::lockif(markptr<range> e)
{
assert(!MARKED(e));
assert(!e.mark());
acquire(this->lock);
if (this->next[0] == e) {
return 1;
......@@ -187,11 +183,10 @@ int range::lockif(range *e)
static void mark(range *f, range *s)
{
struct range *e;
for (e = f; e && e != s; e = WOMARK(e->next[0])) {
for (e = f; e && e != s; e = e->next[0].ptr()) {
assert(e);
for (int l = e->nlevel-1; l >= 0; l--) {
(void) __sync_fetch_and_or(&(e->next[l]), (struct range *)0x1);
}
for (int l = e->nlevel-1; l >= 0; l--)
e->next[l].mark() = 1;
}
}
......@@ -199,7 +194,7 @@ static void mark(range *f, range *s)
static void unlockn(range *f, range *l)
{
struct range *e;
for (e = f; e != l; e = WOMARK(e->next[0])) {
for (e = f; e != l; e = e->next[0].ptr()) {
assert(e);
release(e->lock);
}
......@@ -210,7 +205,7 @@ static void unlockn(range *f, range *l)
static void freen(struct range *f, struct range *l)
{
struct range *e;
for (e = f; e != l; e = WOMARK(e->next[0])) {
for (e = f; e != l; e = e->next[0].ptr()) {
assert(e);
assert(e->curlevel >= 0);
e->dec_ref();
......@@ -276,11 +271,10 @@ static range *replace(u64 k, u64 sz, void *v, range *f, range *l, range *s)
void
crange::print(int full)
{
struct range *e;
for (int l = 0; l < this->nlevel; l++) {
int c = 0;
cprintf("crange %d: ", l);
for (e = this->crange_head->next[l]; e; e = WOMARK(e->next[l])) {
for (range *e = crange_head->next[l].ptr(); e != 0; e = e->next[l].ptr()) {
c++;
if (full) e->print(l);
}
......@@ -300,8 +294,8 @@ crange::~crange()
{
if (crange_debug) cprintf("crange_free: 0x%lx\n", (u64) this);
range *e, *n;
for (e = WOMARK(this->crange_head->next[0]); e; e = n) {
n = WOMARK(e->next[0]);
for (e = this->crange_head->next[0].ptr(); e; e = n) {
n = e->next[0].ptr();
delete e;
}
delete this->crange_head;
......@@ -315,30 +309,30 @@ void crange::check(struct range *absent)
int t = mycpu()->id;
struct range *e, *s;
for (int l = 0; l < this->nlevel; l++) {
for (e = this->crange_head->next[l]; e; e = s) {
for (e = this->crange_head->next[l].ptr(); e; e = s) {
assert(e->curlevel < this->nlevel);
if (absent == e) {
cprintf("%d: check level failed; 0x%lx is present\n", l, (u64) absent);
assert(0);
}
// look for e level down, but only for non-marked nodes.
if (l > 0 && e->next[l] != 0 && !MARKED(e->next[l])) {
if (l > 0 && e->next[l] != 0 && !e->next[l].mark()) {
struct range *n;
for (n = WOMARK(this->crange_head->next[l-1]); n && n != e; n = WOMARK(n->next[l-1]))
for (n = crange_head->next[l-1].ptr(); n && n != e; n = n->next[l-1].ptr())
;
__sync_synchronize();
// if e is marked now, skip the check (the memory barrier ensures that we reread it
// from memory (and not from a register)
if (!MARKED(e->next[l]) && n != e) {
cprintf("%d: check level %d failed 0x%lx-0x%lx(%lu) m %lu c %d t %d; in high level but not low\n", t, l, e->key, e->key+e->size, e->size, MARKED(e->next[l]), e->curlevel.load(), e->nlevel);
if (!e->next[l].mark() && n != e) {
cprintf("%d: check level %d failed 0x%lx-0x%lx(%lu) m %d c %d t %d; in high level but not low\n", t, l, e->key, e->key+e->size, e->size, (bool)e->next[l].mark(), e->curlevel.load(), e->nlevel);
this->print(1);
assert(0);
}
}
// check if succ range is after n
s = WOMARK(e->next[l]);
s = e->next[l].ptr();
assert(s != e);
if (!MARKED(e->next[l]) && s && (e->key + e->size > s->key)) {
if (!e->next[l].mark() && s && (e->key + e->size > s->key)) {
if (crange_debug) cprintf("%d: e(%lu,%lu) overlaps with s(%lu,%lu)\n", t, e->key, e->size, s->key, e->size);
this->print(1);
assert(0);
......@@ -354,11 +348,11 @@ int crange::del_index(range *p0, range **e, int l)
{
int r = 1;
assert(l < (*e)->nlevel);
if (!MARKED((*e)->next[l])) // don't remove unmarked ranges from index
if (!(*e)->next[l].mark()) // don't remove unmarked ranges from index
return r;
if (l == 0) return 0; // but not on level 0; they are locked when removed
// crange_check(cr, NULL);
while (*e && MARKED((*e)->next[l])) {
while (*e && (*e)->next[l].mark()) {
#if 0
if (l != (*e)->curlevel) {
// range is still in the index one level up, back out. we want to remove it first
......@@ -368,11 +362,11 @@ int crange::del_index(range *p0, range **e, int l)
goto done;
}
#endif
int cas = __sync_bool_compare_and_swap(&(p0->next[l]), *e, WOMARK((*e)->next[l]));
bool cas = p0->next[l].cmpxch(*e, (*e)->next[l].ptr().load());
if (cas) {
assert((*e)->curlevel >= 0);
(*e)->dec_ref();
*e = WOMARK((*e)->next[l]);
*e = (*e)->next[l].ptr();
} else {
// cprintf("%d: crange_del_index: retry del %u(%u)\n", mycpu()->id, (*e)->key, (*e)->key + (*e)->size);
r = -1;
......@@ -387,18 +381,18 @@ int crange::del_index(range *p0, range **e, int l)
// Insert e into index one level up, between p and s, if e hasn't been inserted
// yet on that level.
void crange::add_index(int l, range *e, range *p1, range *s1)
void crange::add_index(int l, range *e, range *p1, markptr<range> s1)
{
if (l >= e->nlevel-1) return;
if (MARKED(e->next[l+1])) return;
if (e->next[l+1].mark()) return;
// crange_check(cr, NULL);
if (cmpxch(&e->curlevel, l, l+1)) {
assert(e->curlevel < e->nlevel);
// this is the core inserting at level l+1, but some core may be deleting
struct range *s = WOMARK(s1);
struct range *s = s1.ptr();
do {
struct range *n = e->next[l+1]; // Null and perhaps marked
if (MARKED(n)) {
markptr<range> n = e->next[l+1]; // Null and perhaps marked
if (n.mark()) {
// this range has been deleted, don't insert into index.
// undo increment of cur->level.
e->curlevel--;
......@@ -406,9 +400,9 @@ void crange::add_index(int l, range *e, range *p1, range *s1)
goto done;
}
assert (n == 0);
} while (!__sync_bool_compare_and_swap(&(e->next[l+1]), 0, s));
if (!__sync_bool_compare_and_swap(&(p1->next[l+1]), s, e)) { // insert in list l+1
(void) __sync_fetch_and_and(&(e->next[l+1]), (struct range *)0x1); // failed, keep mark bit
} while (!e->next[l+1].cmpxch(0, s));
if (!p1->next[l+1].cmpxch(s, e)) { // insert in list l+1
e->next[l+1].ptr() = 0; // failed, keep mark bit
e->curlevel--;
// cprintf("%d: crange_add_index: retry add level %d %u(%u)\n", mycpu()->id, l+1, e->key, e->key+e->size);
//INCRETRY;
......@@ -439,7 +433,7 @@ int crange::lock_range(u64 k, u64 sz, int l, range **er, range **pr, range **fr,
if (l == 0) {
acquire(e->lock); // lock all ranges in the sequence
}
e = WOMARK(e->next[l]);
e = e->next[l].ptr();
}
*sr = e;
*er = e;
......@@ -463,7 +457,7 @@ int crange::find_and_lock(u64 k, u64 sz, range **p0, range **f0, range **l0, ran
p1 = *p0; // remember last previous (p0) as the previous one level up (p1)
*p0 = (l == this->nlevel-1) ? this->crange_head : p1; // set current previous
s1 = *s0;
for (e = WOMARK((*p0)->next[l]); e; *p0 = e, e = WOMARK(e->next[l])) {
for (e = (*p0)->next[l].ptr(); e; *p0 = e, e = e->next[l].ptr()) {
assert(l < e->nlevel);
int r = this->del_index(*p0, &e, l);
if (r == -1) goto retry; // deletion failed because some other core did it; try again
......@@ -512,13 +506,13 @@ range* crange::search(u64 k, u64 sz, int mod)
r = nullptr;
p = this->crange_head;
for (int l = this->nlevel-1; l >= 0; l--) {
for (e = WOMARK(p->next[l]); e; p = e, e = WOMARK(e->next[l])) {
for (e = p->next[l].ptr(); e; p = e, e = e->next[l].ptr()) {
if (crange_debug)
cprintf("level %d: 0x%lx 0x%lx-%lx(%lu) 0x%lx-0x%lx(%lu)\n", l, (u64) p, p->key, p->key+p->size, p->size, e->key, e->key+e->size, e->size);
// skip all marked ranges, but don't update p because
// we don't want to descend on a marked range down.
while (e && MARKED(e->next[l])) {
e = WOMARK(e->next[l]);
while (e && e->next[l].mark()) {
e = e->next[l].ptr();
}
if (!e) break;
if (mod && l < n && l > 0) {
......@@ -565,7 +559,7 @@ void crange::del(u64 k, u64 sz)
while (1) {
// hook new list into bottom list; if del resulted in a new list, use that (repl), otherwise
// set predecessor to successor.
if (__sync_bool_compare_and_swap(&(prev->next[0]), first, repl ? repl : succ)) {
if (prev->next[0].cmpxch(first, repl ? repl : succ)) {
release(prev->lock);
freen(first, last); // put on delayed list before unlocking
unlockn(first, last);
......@@ -605,8 +599,8 @@ void crange::add(u64 k, u64 sz, void *v)
repl = insert(repl, r);
mark(first, succ);
if (prev)
assert(!MARKED(prev->next[0]));
if (__sync_bool_compare_and_swap(&(prev->next[0]), first ? first : succ, repl)) {
assert(!prev->next[0].mark());
if (prev->next[0].cmpxch(first ? first : succ, repl)) {
release(prev->lock);
freen(first, last); // put on delayed list before unlocking
unlockn(first, last);
......@@ -621,7 +615,7 @@ void crange::add(u64 k, u64 sz, void *v)
int crange::foreach(int (*cb)(range *r, void *), void *st)
{
struct range *e;
for (e = WOMARK(this->crange_head->next[0]); e; e = WOMARK(e->next[0])) {
for (e = crange_head->next[0].ptr(); e; e = e->next[0].ptr()) {
if (!cb(e, st))
return 0;
}
......
crange.hh
浏览文件 @ adf12bd3
......@@ -5,6 +5,82 @@
using std::atomic;
struct crange;
struct range;
template<class T>
class markptr_ptr;
template<class T>
class markptr_mark;
template<class T>
class markptr {
protected:
atomic<uptr> _p;
public:
markptr() : _p(0) {}
markptr(T* v) : _p((uptr) v) {}
markptr(const markptr<T> &v) : _p(v._p.load()) {}
void operator=(T* v) { _p = (uptr) v; }
void operator=(const markptr<T> &v) { _p = v._p.load(); }
bool operator!=(const markptr<T> &v) const { return _p != v._p; }
bool operator==(const markptr<T> &v) const { return _p == v._p; }
markptr_ptr<T>& ptr() {
return *(markptr_ptr<T>*) this;
}
markptr_mark<T>& mark() {
return *(markptr_mark<T>*) this;
}
// Convenience operator to avoid having to write out xx.ptr()->...
T* operator->() { return ptr(); }
bool cmpxch(markptr<T> expected, markptr<T> desired) {
uptr ee = expected._p.load();
return _p.compare_exchange_weak(ee, desired._p.load());
}
};
template<class T>
class markptr_ptr : private markptr<T> {
public:
void operator=(T *ptr) {
uptr p0, p1;
do {
p0 = markptr<T>::_p.load();
p1 = (p0 & 1) | (uptr) ptr;
} while (!markptr<T>::_p.compare_exchange_weak(p0, p1));
}
T* load() const {
return (T*) (markptr<T>::_p.load() & ~1);
}
operator T*() const { return load(); }
};
template<class T>
class markptr_mark : public markptr<T> {
public:
void operator=(bool mark) {
uptr p0, p1;
do {
p0 = markptr<T>::_p.load();
p1 = (p0 & ~1) | !!mark;
} while (!markptr<T>::_p.compare_exchange_weak(p0, p1));
}
bool load() const {
return markptr<T>::_p.load() & 1;
}
operator bool() const { return load(); }
};
struct range : public rcu_freed {
public:
......@@ -14,9 +90,9 @@ public:
atomic<int> curlevel; // the current levels it appears on
int nlevel; // the number of levels this range should appear
crange *cr; // the crange this range is part of
struct range** next; // one next pointer per level
struct spinlock *lock; // on separate cache line?
range(crange *cr, u64 k, u64 sz, void *v, struct range *n, int nlevel);
markptr<range>* next; // one next pointer per level
spinlock *lock; // on separate cache line?
range(crange *cr, u64 k, u64 sz, void *v, markptr<range> n, int nlevel = 0);
~range();
virtual void do_gc() {
delete this;
......@@ -24,7 +100,7 @@ public:
void print(int l);
void free_delayed();
void dec_ref(void);
int lockif(range *e);
int lockif(markptr<range> e);
} __mpalign__;
struct crange {
......@@ -41,7 +117,7 @@ public:
void print(int);
void check(struct range *absent);
int del_index(range *p0, range **e, int l);
void add_index(int l, range *e, range *p1, range *s1);
void add_index(int l, range *e, range *p1, markptr<range> s1);
int lock_range(u64 k, u64 sz, int l, range **er, range **pr, range **fr, range **lr, range **sr);
int find_and_lock(u64 k, u64 sz, range **p0, range **f0, range **l0, range **s0);
};
......
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