From 23d2007c5ed2e42426f951b7fba65ab3624c43b5 Mon Sep 17 00:00:00 2001
From: mutouyun <orz@orzz.org>
Date: Sun, 3 Jan 2021 14:03:16 +0800
Subject: [PATCH] =?UTF-8?q?=E5=AF=B9mmb=E6=9D=A5=E8=AF=B4=EF=BC=8Cincr?=
 =?UTF-8?q?=E4=B8=8A=E9=99=9065535=E4=B8=8D=E5=A4=9F=E5=A4=A7=EF=BC=8C?=
 =?UTF-8?q?=E8=B0=83=E6=95=B4=E8=87=B316,777,215?=
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---
 src/libipc/prod_cons.h | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/src/libipc/prod_cons.h b/src/libipc/prod_cons.h
index c573aca..735abbc 100755
--- a/src/libipc/prod_cons.h
+++ b/src/libipc/prod_cons.h
@@ -285,16 +285,17 @@ struct prod_cons_impl<wr<relat::single, relat::multi, trans::broadcast>> {
 };
 
 template <>
-struct prod_cons_impl<wr<relat::multi , relat::multi, trans::broadcast>> {
+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 {
         rc_mask = 0x00000000ffffffffull,
-        ep_mask = 0x0000ffffffffffffull,
-        ep_incr = 0x0001000000000000ull,
-        ic_mask = 0xffff0000ffffffffull
+        ep_mask = 0x00ffffffffffffffull,
+        ep_incr = 0x0100000000000000ull,
+        ic_mask = 0xff000000ffffffffull,
+        ic_incr = 0x0000000100000000ull
     };
 
     template <std::size_t DataSize, std::size_t AlignSize>
@@ -312,8 +313,7 @@ struct prod_cons_impl<wr<relat::multi , relat::multi, trans::broadcast>> {
     }
 
     constexpr static rc_t inc_rc(rc_t rc) noexcept {
-        auto ic = static_cast<std::uint16_t>((rc & ~ic_mask) >> 32);
-        return (rc & ic_mask) | (static_cast<rc_t>(ic + 1) << 32);
+        return (rc & ic_mask) | ((rc + ic_incr) & ~ic_mask);
     }
 
     constexpr static rc_t inc_mask(rc_t rc) noexcept {
@@ -324,6 +324,7 @@ struct prod_cons_impl<wr<relat::multi , relat::multi, trans::broadcast>> {
     bool push(W* wrapper, F&& f, E* elems) {
         E* el;
         circ::u2_t cur_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);
             if (cc == 0) return false; // no reader
@@ -331,7 +332,6 @@ struct prod_cons_impl<wr<relat::multi , relat::multi, trans::broadcast>> {
             // check all consumers have finished reading this element
             auto cur_rc = el->rc_.load(std::memory_order_relaxed);
             circ::cc_t rem_cc = cur_rc & rc_mask;
-            rc_t epoch = epoch_.load(std::memory_order_acquire);
             if ((cc & rem_cc) && ((cur_rc & ~ep_mask) == epoch)) {
                 return false; // has not finished yet
             }
@@ -343,7 +343,8 @@ struct prod_cons_impl<wr<relat::multi , relat::multi, trans::broadcast>> {
             }
             // 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_release)) {
+                        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);
@@ -375,7 +376,8 @@ struct prod_cons_impl<wr<relat::multi , relat::multi, trans::broadcast>> {
             }
             // 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_release)) {
+                        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);