From d33a69463f1a75134d01191be0b9e1bdd757dd4b Mon Sep 17 00:00:00 2001
From: lichao <lichao@aiotlink.com>
Date: 星期五, 30 四月 2021 15:27:59 +0800
Subject: [PATCH] add atomic queue, no lock, unorder.
---
src/robust.h | 120 +++++++++++++++++++++++++++++++++++++++++++++++++-----------
1 files changed, 98 insertions(+), 22 deletions(-)
diff --git a/src/robust.h b/src/robust.h
index 983567f..b7459ad 100644
--- a/src/robust.h
+++ b/src/robust.h
@@ -107,6 +107,7 @@
{
public:
typedef int locker_t;
+ enum { eLockerBits = sizeof(locker_t) * 8 };
static locker_t this_locker()
{
static locker_t val = getpid();
@@ -119,6 +120,7 @@
{
public:
typedef int locker_t;
+ enum { eLockerBits = sizeof(locker_t) * 8 };
static locker_t this_locker()
{
static locker_t val = getpid();
@@ -132,12 +134,29 @@
}
};
+class ExpiredLocker
+{
+public:
+ typedef int64_t locker_t;
+ enum { eLockerBits = 63 };
+ static locker_t this_locker() { return Now(); }
+ static bool is_alive(locker_t locker)
+ {
+ return Now() < locker + steady_clock::duration(10s).count();
+ }
+
+private:
+ static locker_t Now() { return steady_clock::now().time_since_epoch().count(); }
+};
+
template <class LockerT>
class CasMutex
{
typedef typename LockerT::locker_t locker_t;
static inline locker_t this_locker() { return LockerT::this_locker(); }
static inline bool is_alive(locker_t locker) { return LockerT::is_alive(locker); }
+ static const uint64_t kLockerMask = MaskBits(LockerT::eLockerBits);
+ static_assert(LockerT::eLockerBits < 64, "locker size must be smaller than 64 bit!");
public:
CasMutex() :
@@ -152,7 +171,7 @@
} else if (!is_alive(Locker(old))) {
r = static_cast<int>(MetaCas(old, Meta(1, this_locker()))) << 1;
if (r) {
- printf("captured pid %d -> %d, r = %d\n", Locker(old), this_locker(), r);
+ printf("captured locker %ld -> %ld, locker = %d\n", int64_t(Locker(old)), int64_t(this_locker()), r);
}
}
return r;
@@ -174,10 +193,9 @@
}
private:
- static_assert(sizeof(locker_t) < sizeof(uint64_t), "locker size must be smaller than 64 bit!");
std::atomic<uint64_t> meta_;
- bool Locked(uint64_t meta) { return (meta >> 63) != 0; }
- locker_t Locker(uint64_t meta) { return meta & MaskBits(sizeof(locker_t) * 8); }
+ bool Locked(uint64_t meta) { return (meta >> 63) == 1; }
+ locker_t Locker(uint64_t meta) { return meta & kLockerMask; }
uint64_t Meta(uint64_t lk, locker_t lid) { return (lk << 63) | lid; }
bool MetaCas(uint64_t exp, uint64_t val) { return meta_.compare_exchange_strong(exp, val); }
};
@@ -206,7 +224,7 @@
typedef uint64_t meta_type;
static size_type Pos(meta_type meta) { return meta & 0xFFFFFFFF; }
static count_type Count(meta_type meta) { return meta >> 32; }
- static size_type Meta(meta_type count, size_type pos) { return (count << 32) | pos; }
+ static meta_type Meta(meta_type count, size_type pos) { return (count << 32) | pos; }
public:
typedef D Data;
@@ -214,41 +232,40 @@
CircularBuffer(const size_type cap) :
CircularBuffer(cap, Alloc()) {}
CircularBuffer(const size_type cap, Alloc const &al) :
- state_(0), capacity_(cap), mhead_(0), mtail_(0), al_(al), buf(al_.allocate(cap))
+ capacity_(cap + 1), mhead_(0), mtail_(0), al_(al), buf(al_.allocate(capacity_))
{
if (!buf) {
throw("robust CircularBuffer allocate error: alloc buffer failed, out of mem!");
+ } else {
+ memset(&buf[0], 0, sizeof(D) * capacity_);
}
}
~CircularBuffer() { al_.deallocate(buf, capacity_); }
- size_type size() const { return (capacity_ + tail() - head()) % capacity_; }
- bool full() const { return (capacity_ + tail() + 1 - head()) % capacity_ == 0; }
- bool empty() const { return head() == tail(); }
- bool push_back(Data d)
+ bool push_back(const Data d)
{
Guard<Mutex> guard(mutex_);
- if (!full()) {
- auto old = mtail();
- buf[Pos(old)] = d;
+ auto old = mtail();
+ auto pos = Pos(old);
+ auto full = ((capacity_ + pos + 1 - head()) % capacity_ == 0);
+ if (!full) {
+ buf[pos] = d;
return mtail_.compare_exchange_strong(old, next(old));
- } else {
- return false;
}
+ return false;
}
bool pop_front(Data &d)
{
Guard<Mutex> guard(mutex_);
- if (!empty()) {
- auto old = mhead();
- d = buf[Pos(old)];
+ auto old = mhead();
+ auto pos = Pos(old);
+ if (!(pos == tail())) {
+ d = buf[pos];
return mhead_.compare_exchange_strong(old, next(old));
} else {
return false;
}
}
- bool Ready() const { return state_.load() == eStateReady; }
- void PutReady() { state_.store(eStateReady); }
private:
CircularBuffer(const CircularBuffer &);
@@ -262,8 +279,6 @@
meta_type mhead() const { return mhead_.load(); }
meta_type mtail() const { return mtail_.load(); }
// data
- enum { eStateReady = 0x19833891 };
- std::atomic<uint32_t> state_;
const size_type capacity_;
Mutex mutex_;
std::atomic<meta_type> mhead_;
@@ -272,5 +287,66 @@
typename Alloc::pointer buf = nullptr;
};
+template <unsigned PowerSize = 4, class Int = int64_t>
+class AtomicQueue
+{
+public:
+ typedef uint32_t size_type;
+ typedef Int Data;
+ typedef std::atomic<Data> AData;
+ static_assert(sizeof(Data) == sizeof(AData));
+ enum {
+ power = PowerSize,
+ capacity = (1 << power),
+ mask = capacity - 1,
+ };
+
+ AtomicQueue() { memset(this, 0, sizeof(*this)); }
+ size_type head() const { return head_.load(); }
+ size_type tail() const { return tail_.load(); }
+ bool like_empty() const { return head() == tail() && Empty(buf[head()]); }
+ bool like_full() const { return head() == tail() && !Empty(buf[head()]); }
+ bool push_back(const Data d, bool try_more = false)
+ {
+ bool r = false;
+ size_type i = 0;
+ do {
+ auto pos = tail();
+ auto cur = buf[pos].load();
+ r = Empty(cur) && buf[pos].compare_exchange_strong(cur, Enc(d));
+ tail_.compare_exchange_strong(pos, Next(pos));
+ } while (try_more && !r && ++i < capacity);
+ return r;
+ }
+ bool pop_front(Data &d, bool try_more = false)
+ {
+ bool r = false;
+ Data cur;
+ size_type i = 0;
+ do {
+ auto pos = head();
+ cur = buf[pos].load();
+ r = !Empty(cur) && buf[pos].compare_exchange_strong(cur, 0);
+ head_.compare_exchange_strong(pos, Next(pos));
+ } while (try_more && !r && ++i < capacity);
+ if (r) { d = Dec(cur); }
+ return r;
+ }
+
+private:
+ static_assert(std::is_integral<Data>::value, "Data must be integral type!");
+ static_assert(std::is_signed<Data>::value, "Data must be signed type!");
+ static_assert(PowerSize < 10, "RobustQ63 max size is 2^10!");
+
+ static inline bool Empty(const Data d) { return (d & 1) == 0; } // lowest bit 1 means data ok.
+ static inline Data Enc(const Data d) { return (d << 1) | 1; } // lowest bit 1 means data ok.
+ static inline Data Dec(const Data d) { return d >> 1; } // lowest bit 1 means data ok.
+ static size_type Next(const size_type index) { return (index + 1) & mask; }
+
+ std::atomic<size_type> head_;
+ std::atomic<size_type> tail_;
+ AData buf[capacity];
+};
+
} // namespace robust
#endif // end of include guard: ROBUST_Q31RCWYU
--
Gitblit v1.8.0