From 7ecd6323ffedbfef92c87c02b2a8680dd53b772c Mon Sep 17 00:00:00 2001
From: lichao <lichao@aiotlink.com>
Date: 星期四, 06 五月 2021 19:37:50 +0800
Subject: [PATCH] rename atomic queue io function.
---
src/robust.h | 196 +++++++++++++++++++++++++++++++++++++------------
1 files changed, 148 insertions(+), 48 deletions(-)
diff --git a/src/robust.h b/src/robust.h
index 19e9bda..3334bc0 100644
--- a/src/robust.h
+++ b/src/robust.h
@@ -19,6 +19,7 @@
#ifndef ROBUST_Q31RCWYU
#define ROBUST_Q31RCWYU
+#include "log.h"
#include <atomic>
#include <chrono>
#include <memory>
@@ -32,6 +33,7 @@
using namespace std::chrono;
using namespace std::chrono_literals;
+constexpr uint64_t MaskBits(int nbits) { return (uint64_t(1) << nbits) - 1; }
void QuickSleep();
@@ -102,20 +104,60 @@
char buf[4];
};
-template <bool isRobust = false>
-class CasMutex
+class PidLocker
{
- static pid_t pid()
+public:
+ typedef int locker_t;
+ enum { eLockerBits = sizeof(locker_t) * 8 };
+ static locker_t this_locker()
{
- static pid_t val = getpid();
+ static locker_t val = getpid();
return val;
}
- static bool Killed(pid_t pid)
+ static bool is_alive(locker_t locker) { return true; }
+};
+
+class RobustPidLocker
+{
+public:
+ typedef int locker_t;
+ enum { eLockerBits = sizeof(locker_t) * 8 };
+ static locker_t this_locker()
+ {
+ static locker_t val = getpid();
+ return val;
+ }
+ static bool is_alive(locker_t locker)
{
char buf[64] = {0};
- snprintf(buf, sizeof(buf) - 1, "/proc/%d/stat", pid);
- return access(buf, F_OK) != 0;
+ snprintf(buf, sizeof(buf) - 1, "/proc/%d/stat", locker);
+ return access(buf, F_OK) == 0;
}
+};
+
+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() :
@@ -126,11 +168,11 @@
auto old = meta_.load();
int r = 0;
if (!Locked(old)) {
- r = MetaCas(old, Meta(1, pid()));
- } else if (isRobust && Killed(Pid(old))) {
- r = static_cast<int>(MetaCas(old, Meta(1, pid()))) << 1;
+ r = MetaCas(old, Meta(1, this_locker()));
+ } 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", Pid(old), pid(), r);
+ LOG_DEBUG() << "captured locker " << int64_t(Locker(old)) << " -> " << int64_t(this_locker()) << ", locker = " << r;
}
}
return r;
@@ -146,19 +188,20 @@
void unlock()
{
auto old = meta_.load();
- if (Locked(old) && Pid(old) == pid()) {
- MetaCas(old, Meta(0, pid()));
+ if (Locked(old) && Locker(old) == this_locker()) {
+ MetaCas(old, Meta(0, this_locker()));
}
}
private:
std::atomic<uint64_t> meta_;
- bool Locked(uint64_t meta) { return (meta >> 63) != 0; }
- pid_t Pid(uint64_t meta) { return meta & ~(uint64_t(1) << 63); }
- uint64_t Meta(uint64_t lk, pid_t pid) { return (lk << 63) | pid; }
+ 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); }
- static_assert(sizeof(pid_t) < sizeof(uint64_t));
};
+
+typedef CasMutex<RobustPidLocker> Mutex;
template <class Lock>
class Guard
@@ -182,7 +225,7 @@
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;
@@ -190,66 +233,123 @@
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("error allocate buffer: out of mem!");
- }
- }
- ~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)
- {
- Guard<MutexT> guard(mutex_);
- if (!full()) {
- auto old = mtail();
- buf[Pos(old)] = d;
- return mtail_.compare_exchange_strong(old, next(old));
+ throw("robust CircularBuffer allocate error: alloc buffer failed, out of mem!");
} else {
- return false;
+ memset(&buf[0], 0, sizeof(D) * capacity_);
}
+ }
+ ~CircularBuffer() { al_.deallocate(buf, capacity_); }
+
+ bool push_back(const Data d)
+ {
+ Guard<Mutex> guard(mutex_);
+ 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));
+ }
+ return false;
}
bool pop_front(Data &d)
{
- Guard<MutexT> guard(mutex_);
- if (!empty()) {
- auto old = mhead();
- d = buf[Pos(old)];
+ Guard<Mutex> guard(mutex_);
+ 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 &);
CircularBuffer(CircularBuffer &&);
CircularBuffer &operator=(const CircularBuffer &) = delete;
CircularBuffer &operator=(CircularBuffer &&) = delete;
- typedef CasMutex<true> MutexT;
- // static_assert(sizeof(MutexT) == 16);
+
meta_type next(meta_type meta) const { return Meta(Count(meta) + 1, (Pos(meta) + 1) % capacity_); }
size_type head() const { return Pos(mhead()); }
size_type tail() const { return Pos(mtail()); }
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_;
- MutexT mutex_;
+ Mutex mutex_;
std::atomic<meta_type> mhead_;
std::atomic<meta_type> mtail_;
Alloc al_;
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(const Data d, bool try_more = false)
+ {
+ bool r = false;
+ size_type i = 0;
+ do {
+ auto pos = tail();
+ if (tail_.compare_exchange_strong(pos, Next(pos))) {
+ auto cur = buf[pos].load();
+ r = Empty(cur) && buf[pos].compare_exchange_strong(cur, Enc(d));
+ }
+ } while (try_more && !r && ++i < capacity);
+ return r;
+ }
+ bool pop(Data &d, bool try_more = false)
+ {
+ bool r = false;
+ Data cur;
+ size_type i = 0;
+ do {
+ auto pos = head();
+ if (head_.compare_exchange_strong(pos, Next(pos))) {
+ cur = buf[pos].load();
+ r = !Empty(cur) && buf[pos].compare_exchange_strong(cur, 0);
+ }
+ } 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
--
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