尝试去除恶心的连接检测（TBD）

include/libipc/ipc.h

@@ -31,8 +31,6 @@ struct IPC_EXPORT chan_impl {
 
     static bool   send(ipc::handle_t h, void const * data, std::size_t size, std::uint64_t tm);
     static buff_t recv(ipc::handle_t h, std::uint64_t tm);
-
-    static bool   try_send(ipc::handle_t h, void const * data, std::size_t size, std::uint64_t tm);
     static buff_t try_recv(ipc::handle_t h);
 };
 
@@ -128,9 +126,6 @@ public:
         return chan_wrapper(name).wait_for_recv(r_count, tm);
     }
 
-    /**
-     * If timeout, this function would call 'force_push' to send the data forcibly.
-    */
     bool send(void const * data, std::size_t size, std::uint64_t tm = default_timeout) {
         return detail_t::send(h_, data, size, tm);
     }
@@ -141,23 +136,9 @@ public:
         return this->send(str.c_str(), str.size() + 1, tm);
     }
 
-    /**
-     * If timeout, this function would just return false.
-    */
-    bool try_send(void const * data, std::size_t size, std::uint64_t tm = default_timeout) {
-        return detail_t::try_send(h_, data, size, tm);
-    }
-    bool try_send(buff_t const & buff, std::uint64_t tm = default_timeout) {
-        return this->try_send(buff.data(), buff.size(), tm);
-    }
-    bool try_send(std::string const & str, std::uint64_t tm = default_timeout) {
-        return this->try_send(str.c_str(), str.size() + 1, tm);
-    }
-
     buff_t recv(std::uint64_t tm = invalid_value) {
         return detail_t::recv(h_, tm);
     }
-
     buff_t try_recv() {
         return detail_t::try_recv(h_);
     }

src/libipc/circ/elem_array.h

@@ -120,20 +120,15 @@ public:
         return head_.cursor();
     }
 
-    template <typename Q, typename F>
+    template <typename F>
-    bool push(Q* que, F&& f) {
+    bool push(F&& f) {
-        return head_.push(que, std::forward<F>(f), block_);
+        return head_.push(std::forward<F>(f), block_);
     }
 
-    template <typename Q, typename F>
+    template <typename F>
-    bool force_push(Q* que, F&& f) {
+    bool pop(cursor_t* cur, F&& f) {
-        return head_.force_push(que, std::forward<F>(f), block_);
-    }
-
-    template <typename Q, typename F, typename R>
-    bool pop(Q* que, cursor_t* cur, F&& f, R&& out) {
         if (cur == nullptr) return false;
-        return head_.pop(que, *cur, std::forward<F>(f), std::forward<R>(out), block_);
+        return head_.pop(*cur, std::forward<F>(f), block_);
     }
 };
 

src/libipc/circ/elem_def.h

@@ -50,40 +50,8 @@ public:
     }
 };
 
-template <typename P, bool = relat_trait<P>::is_broadcast>
-class conn_head;
-
 template <typename P>
-class conn_head<P, true> : public conn_head_base {
+class conn_head : public conn_head_base {
-public:
-    cc_t connect() noexcept {
-        for (unsigned k = 0;; ipc::yield(k)) {
-            cc_t curr = this->cc_.load(std::memory_order_acquire);
-            cc_t next = curr | (curr + 1); // find the first 0, and set it to 1.
-            if (next == 0) {
-                // connection-slot is full.
-                return 0;
-            }
-            if (this->cc_.compare_exchange_weak(curr, next, std::memory_order_release)) {
-                return next ^ curr; // return connected id
-            }
-        }
-    }
-
-    cc_t disconnect(cc_t cc_id) noexcept {
-        return this->cc_.fetch_and(~cc_id, std::memory_order_acq_rel) & ~cc_id;
-    }
-
-    std::size_t conn_count(std::memory_order order = std::memory_order_acquire) const noexcept {
-        cc_t cur = this->cc_.load(order);
-        cc_t cnt; // accumulates the total bits set in cc
-        for (cnt = 0; cur; ++cnt) cur &= cur - 1;
-        return cnt;
-    }
-};
-
-template <typename P>
-class conn_head<P, false> : public conn_head_base {
 public:
     cc_t connect() noexcept {
         return this->cc_.fetch_add(1, std::memory_order_relaxed) + 1;

src/libipc/ipc.cpp

@@ -484,27 +484,6 @@ static bool send(F&& gen_push, ipc::handle_t h, void const * data, std::size_t s
 }
 
 static bool send(ipc::handle_t h, void const * data, std::size_t size, std::uint64_t tm) {
-    return send([tm](auto info, auto que, auto msg_id) {
-        return [tm, info, que, msg_id](std::int32_t remain, void const * data, std::size_t size) {
-            if (!wait_for(info->wt_waiter_, [&] {
-                    return !que->push(
-                        [](void*) { return true; },
-                        info->cc_id_, msg_id, remain, data, size);
-                }, tm)) {
-                ipc::log("force_push: msg_id = %zd, remain = %d, size = %zd\n", msg_id, remain, size);
-                if (!que->force_push(
-                        clear_message<typename queue_t::value_t>,
-                        info->cc_id_, msg_id, remain, data, size)) {
-                    return false;
-                }
-            }
-            info->rd_waiter_.broadcast();
-            return true;
-        };
-    }, h, data, size);
-}
-
-static bool try_send(ipc::handle_t h, void const * data, std::size_t size, std::uint64_t tm) {
     return send([tm](auto info, auto que, auto msg_id) {
         return [tm, info, que, msg_id](std::int32_t remain, void const * data, std::size_t size) {
             if (!wait_for(info->wt_waiter_, [&] {
@@ -676,11 +655,6 @@ buff_t chan_impl<Flag>::recv(ipc::handle_t h, std::uint64_t tm) {
     return detail_impl<policy_t<Flag>>::recv(h, tm);
 }
 
-template <typename Flag>
-bool chan_impl<Flag>::try_send(ipc::handle_t h, void const * data, std::size_t size, std::uint64_t tm) {
-    return detail_impl<policy_t<Flag>>::try_send(h, data, size, tm);
-}
-
 template <typename Flag>
 buff_t chan_impl<Flag>::try_recv(ipc::handle_t h) {
     return detail_impl<policy_t<Flag>>::try_recv(h);

src/libipc/prod_cons.h

@@ -37,8 +37,8 @@ struct prod_cons_impl<wr<relat::single, relat::single, trans::unicast>> {
         return 0;
     }
 
-    template <typename W, typename F, typename E>
+    template <typename F, typename E>
-    bool push(W* /*wrapper*/, F&& f, E* elems) {
+    bool push(F&& f, E* elems) {
         auto cur_wt = circ::index_of(wt_.load(std::memory_order_relaxed));
         if (cur_wt == circ::index_of(rd_.load(std::memory_order_acquire) - 1)) {
             return false; // full
@@ -48,24 +48,13 @@ struct prod_cons_impl<wr<relat::single, relat::single, trans::unicast>> {
         return true;
     }
 
-    /**
+    template <typename F, typename E>
-     * In single-single-unicast, 'force_push' means 'no reader' or 'the only one reader is dead'.
+    bool pop(circ::u2_t& /*cur*/, F&& f, E* elems) {
-     * So we could just disconnect all connections of receiver, and return false.
-    */
-    template <typename W, typename F, typename E>
-    bool force_push(W* wrapper, F&&, E*) {
-        wrapper->elems()->disconnect_receiver(~static_cast<circ::cc_t>(0u));
-        return false;
-    }
-
-    template <typename W, typename F, typename R, typename E>
-    bool pop(W* /*wrapper*/, circ::u2_t& /*cur*/, F&& f, R&& out, E* elems) {
         auto cur_rd = circ::index_of(rd_.load(std::memory_order_relaxed));
         if (cur_rd == circ::index_of(wt_.load(std::memory_order_acquire))) {
             return false; // empty
         }
         std::forward<F>(f)(&(elems[cur_rd].data_));
-        std::forward<R>(out)(true);
         rd_.fetch_add(1, std::memory_order_release);
         return true;
     }
@@ -75,26 +64,17 @@ template <>
 struct prod_cons_impl<wr<relat::single, relat::multi , trans::unicast>>
      : prod_cons_impl<wr<relat::single, relat::single, trans::unicast>> {
 
-    template <typename W, typename F, typename E>
+    template <typename F, 
-    bool force_push(W* wrapper, F&&, E*) {
-        wrapper->elems()->disconnect_receiver(1);
-        return false;
-    }
-
-    template <typename W, typename F, typename R, 
               template <std::size_t, std::size_t> class E, std::size_t DS, std::size_t AS>
-    bool pop(W* /*wrapper*/, circ::u2_t& /*cur*/, F&& f, R&& out, E<DS, AS>* elems) {
+    bool pop(circ::u2_t& /*cur*/, F&& f, E<DS, AS>* elems) {
-        byte_t buff[DS];
         for (unsigned k = 0;;) {
             auto cur_rd = rd_.load(std::memory_order_relaxed);
             if (circ::index_of(cur_rd) ==
                 circ::index_of(wt_.load(std::memory_order_acquire))) {
                 return false; // empty
             }
-            std::memcpy(buff, &(elems[circ::index_of(cur_rd)].data_), sizeof(buff));
             if (rd_.compare_exchange_weak(cur_rd, cur_rd + 1, std::memory_order_release)) {
-                std::forward<F>(f)(buff);
+                std::forward<F>(f)(&(elems[circ::index_of(cur_rd)].data_));
-                std::forward<R>(out)(true);
                 return true;
             }
             ipc::yield(k);
@@ -116,8 +96,8 @@ struct prod_cons_impl<wr<relat::multi , relat::multi, trans::unicast>>
 
     alignas(cache_line_size) std::atomic<circ::u2_t> ct_; // commit index
 
-    template <typename W, typename F, typename E>
+    template <typename F, typename E>
-    bool push(W* /*wrapper*/, F&& f, E* elems) {
+    bool push(F&& f, E* elems) {
         circ::u2_t cur_ct, nxt_ct;
         for (unsigned k = 0;;) {
             cur_ct = ct_.load(std::memory_order_relaxed);
@@ -153,16 +133,9 @@ struct prod_cons_impl<wr<relat::multi , relat::multi, trans::unicast>>
         return true;
     }
 
-    template <typename W, typename F, typename E>
+    template <typename F, 
-    bool force_push(W* wrapper, F&&, E*) {
-        wrapper->elems()->disconnect_receiver(1);
-        return false;
-    }
-
-    template <typename W, typename F, typename R, 
               template <std::size_t, std::size_t> class E, std::size_t DS, std::size_t AS>
-    bool pop(W* /*wrapper*/, circ::u2_t& /*cur*/, F&& f, R&& out, E<DS, AS>* elems) {
+    bool pop(circ::u2_t& /*cur*/, F&& f, E<DS, AS>* elems) {
-        byte_t buff[DS];
         for (unsigned k = 0;;) {
             auto cur_rd = rd_.load(std::memory_order_relaxed);
             auto cur_wt = wt_.load(std::memory_order_acquire);
@@ -179,250 +152,159 @@ struct prod_cons_impl<wr<relat::multi , relat::multi, trans::unicast>>
                 }
                 k = 0;
             }
-            else {
+            else if (rd_.compare_exchange_weak(cur_rd, cur_rd + 1, std::memory_order_release)) {
-                std::memcpy(buff, &(elems[circ::index_of(cur_rd)].data_), sizeof(buff));
+                std::forward<F>(f)(&(elems[id_rd].data_));
-                if (rd_.compare_exchange_weak(cur_rd, cur_rd + 1, std::memory_order_release)) {
-                    std::forward<F>(f)(buff);
-                    std::forward<R>(out)(true);
                 return true;
             }
             ipc::yield(k);
         }
     }
-    }
 };
 
 template <>
 struct prod_cons_impl<wr<relat::single, relat::multi, trans::broadcast>> {
 
-    using rc_t = std::uint64_t;
+    using flag_t = std::uint64_t;
-
-    enum : rc_t {
-        ep_mask = 0x00000000ffffffffull,
-        ep_incr = 0x0000000100000000ull
-    };
 
     template <std::size_t DataSize, std::size_t AlignSize>
     struct elem_t {
         std::aligned_storage_t<DataSize, AlignSize> data_ {};
-        std::atomic<rc_t> rc_ { 0 }; // read-counter
+        std::atomic<flag_t> f_rc_ { 0 }; // read-flag
     };
 
     alignas(cache_line_size) std::atomic<circ::u2_t> wt_;   // write index
-    alignas(cache_line_size) rc_t epoch_ { 0 };             // only one writer
 
     circ::u2_t cursor() const noexcept {
         return wt_.load(std::memory_order_acquire);
     }
 
-    template <typename W, typename F, typename E>
+    template <typename F, typename E>
-    bool push(W* wrapper, F&& f, E* elems) {
+    bool push(F&& f, E* elems) {
-        E* el;
+        E* el = elems + circ::index_of(wt_.load(std::memory_order_relaxed));
-        for (unsigned k = 0;;) {
+        auto cur_rc = el->f_rc_.exchange(~0ull, std::memory_order_acq_rel);
-            circ::cc_t cc = wrapper->elems()->connections(std::memory_order_relaxed);
+        // check for consumers to read this element
-            if (cc == 0) return false; // no reader
+        if (cur_rc != 0) {
-            el = elems + circ::index_of(wt_.load(std::memory_order_relaxed));
+            return false; // full
-            // check all consumers have finished reading this element
-            auto cur_rc = el->rc_.load(std::memory_order_acquire);
-            circ::cc_t rem_cc = cur_rc & ep_mask;
-            if ((cc & rem_cc) && ((cur_rc & ~ep_mask) == epoch_)) {
-                return false; // has not finished yet
-            }
-            // consider rem_cc to be 0 here
-            if (el->rc_.compare_exchange_weak(
-                        cur_rc, epoch_ | static_cast<rc_t>(cc), std::memory_order_release)) {
-                break;
-            }
-            ipc::yield(k);
         }
         std::forward<F>(f)(&(el->data_));
         wt_.fetch_add(1, std::memory_order_release);
         return true;
     }
 
-    template <typename W, typename F, typename E>
+    template <typename F, typename E>
-    bool force_push(W* wrapper, F&& f, E* elems) {
+    bool pop(circ::u2_t& cur, F&& f, E* elems) {
-        E* el;
+        if (cur == cursor()) return false; // empty
-        epoch_ += ep_incr;
+        E* el = elems + circ::index_of(cur++);
-        for (unsigned k = 0;;) {
-            circ::cc_t cc = wrapper->elems()->connections(std::memory_order_relaxed);
-            if (cc == 0) return false; // no reader
-            el = elems + circ::index_of(wt_.load(std::memory_order_relaxed));
-            // check all consumers have finished reading this element
-            auto cur_rc = el->rc_.load(std::memory_order_acquire);
-            circ::cc_t rem_cc = cur_rc & ep_mask;
-            if (cc & rem_cc) {
-                ipc::log("force_push: k = %u, cc = %u, rem_cc = %u\n", k, cc, rem_cc);
-                cc = wrapper->elems()->disconnect_receiver(rem_cc); // disconnect all invalid readers
-                if (cc == 0) return false; // no reader
-            }
-            // just compare & exchange
-            if (el->rc_.compare_exchange_weak(
-                        cur_rc, epoch_ | static_cast<rc_t>(cc), std::memory_order_release)) {
-                break;
-            }
-            ipc::yield(k);
-        }
         std::forward<F>(f)(&(el->data_));
-        wt_.fetch_add(1, std::memory_order_release);
+        el->f_rc_.store(0, std::memory_order_release);
         return true;
     }
-
-    template <typename W, typename F, typename R, typename E>
-    bool pop(W* wrapper, circ::u2_t& cur, F&& f, R&& out, E* elems) {
-        if (cur == cursor()) return false; // acquire
-        auto* el = elems + circ::index_of(cur++);
-        std::forward<F>(f)(&(el->data_));
-        for (unsigned k = 0;;) {
-            auto cur_rc = el->rc_.load(std::memory_order_acquire);
-            if ((cur_rc & ep_mask) == 0) {
-                std::forward<R>(out)(true);
-                return true;
-            }
-            auto nxt_rc = cur_rc & ~static_cast<rc_t>(wrapper->connected_id());
-            if (el->rc_.compare_exchange_weak(cur_rc, nxt_rc, std::memory_order_release)) {
-                std::forward<R>(out)((nxt_rc & ep_mask) == 0);
-                return true;
-            }
-            ipc::yield(k);
-        }
-    }
 };
 
 template <>
 struct prod_cons_impl<wr<relat::multi, relat::multi, trans::broadcast>> {
 
-    using rc_t   = std::uint64_t;
     using flag_t = std::uint64_t;
 
-    enum : rc_t {
+    enum : flag_t {
-        rc_mask = 0x00000000ffffffffull,
+        pushing = 1ull,
-        ep_mask = 0x00ffffffffffffffull,
+        pushed  = ~0ull,
-        ep_incr = 0x0100000000000000ull,
+        popped  = 0ull,
-        ic_mask = 0xff000000ffffffffull,
-        ic_incr = 0x0000000100000000ull
     };
 
     template <std::size_t DataSize, std::size_t AlignSize>
     struct elem_t {
         std::aligned_storage_t<DataSize, AlignSize> data_ {};
-        std::atomic<rc_t  > rc_   { 0 }; // read-counter
+        std::atomic<flag_t> f_rc_ { 0 }; // read-flag
-        std::atomic<flag_t> f_ct_ { 0 }; // commit flag
+        std::atomic<flag_t> f_ct_ { 0 }; // commit-flag
     };
 
     alignas(cache_line_size) std::atomic<circ::u2_t> ct_;   // commit index
-    alignas(cache_line_size) std::atomic<rc_t> epoch_ { 0 };
+    alignas(cache_line_size) std::atomic<circ::u2_t> wt_;   // write index
 
     circ::u2_t cursor() const noexcept {
-        return ct_.load(std::memory_order_acquire);
+        return wt_.load(std::memory_order_acquire);
     }
 
-    constexpr static rc_t inc_rc(rc_t rc) noexcept {
+    template <typename F, typename E>
-        return (rc & ic_mask) | ((rc + ic_incr) & ~ic_mask);
+    bool push(F&& f, E* elems) {
-    }
-
-    constexpr static rc_t inc_mask(rc_t rc) noexcept {
-        return inc_rc(rc) & ~rc_mask;
-    }
-
-    template <typename W, typename F, typename E>
-    bool push(W* wrapper, F&& f, E* elems) {
         E* el;
-        circ::u2_t cur_ct;
+        circ::u2_t cur_ct, nxt_ct;
-        rc_t epoch = epoch_.load(std::memory_order_acquire);
         for (unsigned k = 0;;) {
-            circ::cc_t cc = wrapper->elems()->connections(std::memory_order_relaxed);
+            auto cac_ct = ct_.load(std::memory_order_relaxed);
-            if (cc == 0) return false; // no reader
+            cur_ct = cac_ct;
-            el = elems + circ::index_of(cur_ct = ct_.load(std::memory_order_relaxed));
+            nxt_ct = cur_ct + 1;
-            // check all consumers have finished reading this element
+            el = elems + circ::index_of(cac_ct);
-            auto cur_rc = el->rc_.load(std::memory_order_relaxed);
+            for (unsigned k = 0;;) {
-            circ::cc_t rem_cc = cur_rc & rc_mask;
+                auto cur_rc = el->f_rc_.load(std::memory_order_acquire);
-            if ((cc & rem_cc) && ((cur_rc & ~ep_mask) == epoch)) {
+                switch (cur_rc) {
-                return false; // has not finished yet
+                // helper
+                case pushing:
+                    ct_.compare_exchange_strong(cac_ct, nxt_ct, std::memory_order_release);
+                    goto try_next;
+                // full
+                case pushed:
+                    return false;
+                // writable
+                default:
+                    break;
                 }
-            else if (!rem_cc) {
+                if (el->f_rc_.compare_exchange_weak(cur_rc, pushing, std::memory_order_release)) {
-                auto cur_fl = el->f_ct_.load(std::memory_order_acquire);
-                if ((cur_fl != cur_ct) && cur_fl) {
-                    return false; // full
-                }
-            }
-            // consider rem_cc to be 0 here
-            if (el->rc_.compare_exchange_weak(
-                        cur_rc, inc_mask(epoch | (cur_rc & ep_mask)) | static_cast<rc_t>(cc), std::memory_order_relaxed) &&
-                epoch_.compare_exchange_weak(epoch, epoch, std::memory_order_acq_rel)) {
                     break;
                 }
                 ipc::yield(k);
             }
-        // only one thread/process would touch here at one time
+            ct_.compare_exchange_strong(cac_ct, nxt_ct, std::memory_order_relaxed);
-        ct_.store(cur_ct + 1, std::memory_order_release);
+            el->f_rc_.store(pushed, std::memory_order_relaxed);
-        std::forward<F>(f)(&(el->data_));
+            std::atomic_thread_fence(std::memory_order_release);
-        // set flag & try update wt
-        el->f_ct_.store(~static_cast<flag_t>(cur_ct), std::memory_order_release);
-        return true;
-    }
-
-    template <typename W, typename F, typename E>
-    bool force_push(W* wrapper, F&& f, E* elems) {
-        E* el;
-        circ::u2_t cur_ct;
-        rc_t epoch = epoch_.fetch_add(ep_incr, std::memory_order_release) + ep_incr;
-        for (unsigned k = 0;;) {
-            circ::cc_t cc = wrapper->elems()->connections(std::memory_order_relaxed);
-            if (cc == 0) return false; // no reader
-            el = elems + circ::index_of(cur_ct = ct_.load(std::memory_order_relaxed));
-            // check all consumers have finished reading this element
-            auto cur_rc = el->rc_.load(std::memory_order_acquire);
-            circ::cc_t rem_cc = cur_rc & rc_mask;
-            if (cc & rem_cc) {
-                ipc::log("force_push: k = %u, cc = %u, rem_cc = %u\n", k, cc, rem_cc);
-                cc = wrapper->elems()->disconnect_receiver(rem_cc); // disconnect all invalid readers
-                if (cc == 0) return false; // no reader
-            }
-            // just compare & exchange
-            if (el->rc_.compare_exchange_weak(
-                        cur_rc, inc_mask(epoch | (cur_rc & ep_mask)) | static_cast<rc_t>(cc), std::memory_order_relaxed)) {
-                if (epoch == epoch_.load(std::memory_order_acquire)) {
             break;
-                }
+        try_next:
-                else if (push(wrapper, std::forward<F>(f), elems)) {
-                    return true;
-                }
-                epoch = epoch_.fetch_add(ep_incr, std::memory_order_release) + ep_incr;
-            }
             ipc::yield(k);
         }
-        // only one thread/process would touch here at one time
-        ct_.store(cur_ct + 1, std::memory_order_release);
         std::forward<F>(f)(&(el->data_));
         // set flag & try update wt
         el->f_ct_.store(~static_cast<flag_t>(cur_ct), std::memory_order_release);
+        while (1) {
+            auto cac_ct = el->f_ct_.load(std::memory_order_acquire);
+            if (cur_ct != wt_.load(std::memory_order_relaxed)) {
+                return true;
+            }
+            if ((~cac_ct) != cur_ct) {
+                return true;
+            }
+            if (!el->f_ct_.compare_exchange_strong(cac_ct, 0, std::memory_order_relaxed)) {
+                return true;
+            }
+            wt_.store(nxt_ct, std::memory_order_release);
+            cur_ct = nxt_ct;
+            nxt_ct = cur_ct + 1;
+            el = elems + circ::index_of(cur_ct);
+        }
         return true;
     }
 
-    template <typename W, typename F, typename R, typename E, std::size_t N>
+    template <typename F, typename E, std::size_t N>
-    bool pop(W* wrapper, circ::u2_t& cur, F&& f, R&& out, E(& elems)[N]) {
+    bool pop(circ::u2_t& cur, F&& f, E(& elems)[N]) {
-        auto* el = elems + circ::index_of(cur);
+        for (unsigned k = 0;;) {
-        auto cur_fl = el->f_ct_.load(std::memory_order_acquire);
+            auto cur_wt = wt_.load(std::memory_order_acquire);
-        if (cur_fl != ~static_cast<flag_t>(cur)) {
+            auto id_rd  = circ::index_of(cur);
+            auto id_wt  = circ::index_of(cur_wt);
+            if (id_rd == id_wt) {
+                auto* el = elems + id_wt;
+                auto cac_ct = el->f_ct_.load(std::memory_order_acquire);
+                if ((~cac_ct) != cur_wt) {
                     return false; // empty
                 }
+                if (el->f_ct_.compare_exchange_weak(cac_ct, 0, std::memory_order_relaxed)) {
+                    wt_.store(cur_wt + 1, std::memory_order_release);
+                }
+                k = 0;
+            }
+            else {
                 ++cur;
+                auto* el = elems + id_rd;
                 std::forward<F>(f)(&(el->data_));
-        for (unsigned k = 0;;) {
+                el->f_rc_.store(popped, std::memory_order_release);
-            auto cur_rc = el->rc_.load(std::memory_order_acquire);
-            if ((cur_rc & rc_mask) == 0) {
-                std::forward<R>(out)(true);
-                el->f_ct_.store(cur + N - 1, std::memory_order_release);
-                return true;
-            }
-            auto nxt_rc = inc_rc(cur_rc) & ~static_cast<rc_t>(wrapper->connected_id());
-            bool last_one = false;
-            if ((last_one = (nxt_rc & rc_mask) == 0)) {
-                el->f_ct_.store(cur + N - 1, std::memory_order_release);
-            }
-            if (el->rc_.compare_exchange_weak(cur_rc, nxt_rc, std::memory_order_release)) {
-                std::forward<R>(out)(last_one);
                 return true;
             }
             ipc::yield(k);

src/libipc/queue.h

@@ -158,27 +158,19 @@ public:
     template <typename T, typename F, typename... P>
     bool push(F&& prep, P&&... params) {
         if (elems_ == nullptr) return false;
-        return elems_->push(this, [&](void* p) {
+        return elems_->push([&](void* p) {
             if (prep(p)) ::new (p) T(std::forward<P>(params)...);
         });
     }
 
-    template <typename T, typename F, typename... P>
+    template <typename T>
-    bool force_push(F&& prep, P&&... params) {
+    bool pop(T& item) {
-        if (elems_ == nullptr) return false;
-        return elems_->force_push(this, [&](void* p) {
-            if (prep(p)) ::new (p) T(std::forward<P>(params)...);
-        });
-    }
-
-    template <typename T, typename F>
-    bool pop(T& item, F&& out) {
         if (elems_ == nullptr) {
             return false;
         }
-        return elems_->pop(this, &(this->cursor_), [&item](void* p) {
+        return elems_->pop(&(this->cursor_), [&item](void* p) {
             ::new (&item) T(std::move(*static_cast<T*>(p)));
-        }, std::forward<F>(out));
+        });
     }
 };
 
@@ -198,18 +190,8 @@ public:
         return base_t::template push<T>(std::forward<P>(params)...);
     }
 
-    template <typename... P>
-    bool force_push(P&&... params) {
-        return base_t::template force_push<T>(std::forward<P>(params)...);
-    }
-
     bool pop(T& item) {
-        return base_t::pop(item, [](bool) {});
+        return base_t::pop(item);
-    }
-
-    template <typename F>
-    bool pop(T& item, F&& out) {
-        return base_t::pop(item, std::forward<F>(out));
     }
 };
 

test/test_ipc.cpp

@@ -73,11 +73,9 @@ void test_basic(char const * name) {
 
     que_t que1 { name };
     EXPECT_FALSE(que1.send(test1));
-    EXPECT_FALSE(que1.try_send(test2));
 
     que_t que2 { que1.name(), ipc::receiver };
     ASSERT_TRUE(que1.send(test1));
-    ASSERT_TRUE(que1.try_send(test2));
 
     EXPECT_EQ(que2.recv(), test1);
     EXPECT_EQ(que2.recv(), test2);

test/test_queue.cpp

@@ -5,7 +5,6 @@
 #include <new>
 #include <vector>
 #include <unordered_map>
-#include <climits>  // CHAR_BIT
 
 #include "libipc/prod_cons.h"
 #include "libipc/policy.h"
@@ -143,6 +142,8 @@ TEST(Queue, el_connection) {
         for (std::size_t i = 0; i < 10000; ++i) {
             ASSERT_TRUE(el.connect_sender());
         }
+        el.disconnect_sender();
+        EXPECT_TRUE(el.connect_sender());
     }
     {
         elems_t<ipc::relat::single, ipc::relat::single, ipc::trans::unicast> el;
@@ -156,12 +157,13 @@ TEST(Queue, el_connection) {
     }
     {
         elems_t<ipc::relat::single, ipc::relat::multi, ipc::trans::broadcast> el;
-        for (std::size_t i = 0; i < (sizeof(ipc::circ::cc_t) * CHAR_BIT); ++i) {
+        auto cc = el.connect_receiver();
+        EXPECT_EQ(cc, 1);
+        for (std::size_t i = 0; i < 10000; ++i) {
             ASSERT_NE(el.connect_receiver(), 0);
         }
-        for (std::size_t i = 0; i < 10000; ++i) {
+        EXPECT_EQ(el.disconnect_receiver(cc), 10000);
-            ASSERT_EQ(el.connect_receiver(), 0);
+        EXPECT_EQ(el.connect_receiver(), 10000 + cc);
-        }
     }
 }
 
@@ -227,25 +229,18 @@ TEST(Queue, connection) {
         for (std::size_t i = 0; i < 10000; ++i) {
             ASSERT_TRUE(que.connect());
         }
-        for (std::size_t i = 1; i < (sizeof(ipc::circ::cc_t) * CHAR_BIT); ++i) {
-            queue_t<ipc::relat::multi, ipc::relat::multi, ipc::trans::broadcast> que{&el};
-            ASSERT_TRUE(que.connect());
-        }
         for (std::size_t i = 0; i < 10000; ++i) {
             queue_t<ipc::relat::multi, ipc::relat::multi, ipc::trans::broadcast> que{&el};
-            ASSERT_FALSE(que.connect());
+            ASSERT_TRUE(que.connect());
         }
         ASSERT_TRUE(que.disconnect());
         for (std::size_t i = 0; i < 10000; ++i) {
             ASSERT_FALSE(que.disconnect());
         }
-        {
-            queue_t<ipc::relat::multi, ipc::relat::multi, ipc::trans::broadcast> que{&el};
-            ASSERT_TRUE(que.connect());
-        }
         for (std::size_t i = 0; i < 10000; ++i) {
             queue_t<ipc::relat::multi, ipc::relat::multi, ipc::trans::broadcast> que{&el};
-            ASSERT_FALSE(que.connect());
+            ASSERT_TRUE(que.connect());
+            ASSERT_TRUE(que.disconnect());
         }
     }
 }