This patch does not change the ring_spsc template in any significant way
but merely makes the counter type (of _begin and _end) a parameter. This
allows us to use smaller type - unsigned short (2 bytes) - in the unit test
tst-ring-spsc-wraparound.cc to make it execute more rapidly.
Before this change this unit test would run for almost 3 minutes on
aarch64 and almost 10 seconds on x64. Now it executes way under a second
and still verifies the same edge condition (see
1ba76eb03cba4431b557183d1001b16991cd1fa4).
Signed-off-by: Waldemar Kozaczuk <jwkozac...@gmail.com>
---
include/lockfree/ring.hh | 22 +++++++++++-----------
include/lockfree/unordered-queue-spsc.hh | 2 +-
include/lockfree/unordered_ring_mpsc.hh | 2 +-
include/osv/net_channel.hh | 2 +-
include/osv/percpu_xmit.hh | 2 +-
tests/misc-free-perf.cc | 2 +-
tests/misc-lfring.cc | 2 +-
tests/tst-nway-merger.cc | 2 +-
tests/tst-ring-spsc-wraparound.cc | 4 ++--
9 files changed, 20 insertions(+), 20 deletions(-)
diff --git a/include/lockfree/ring.hh b/include/lockfree/ring.hh
index c9fefccc..434a14b7 100644
--- a/include/lockfree/ring.hh
+++ b/include/lockfree/ring.hh
@@ -20,7 +20,7 @@
//
// spsc ring of fixed size
//
-template<class T, unsigned MaxSize, unsigned MaxSizeMask = MaxSize - 1>
+template<class T, typename COUNTER_TYPE, COUNTER_TYPE MaxSize, COUNTER_TYPE
MaxSizeMask = MaxSize - 1>
class ring_spsc {
public:
ring_spsc(): _begin(0), _end(0)
@@ -31,7 +31,7 @@ public:
template<typename... Args>
inline bool emplace(Args&&... args)
{
- unsigned end = _end.load(std::memory_order_relaxed);
+ COUNTER_TYPE end = _end.load(std::memory_order_relaxed);
//
// It's ok to load _begin with relaxed ordering (in the size()) since
@@ -56,7 +56,7 @@ public:
bool pop(T& element)
{
- unsigned beg = _begin.load(std::memory_order_relaxed);
+ COUNTER_TYPE beg = _begin.load(std::memory_order_relaxed);
if (empty()) {
return false;
@@ -83,15 +83,15 @@ public:
* @return TRUE if there are no elements
*/
bool empty() const {
- unsigned beg = _begin.load(std::memory_order_relaxed);
- unsigned end = _end.load(std::memory_order_acquire);
+ COUNTER_TYPE beg = _begin.load(std::memory_order_relaxed);
+ COUNTER_TYPE end = _end.load(std::memory_order_acquire);
return beg == end;
}
const T& front() const {
DEBUG_ASSERT(!empty(), "calling front() on an empty queue!");
- unsigned beg = _begin.load(std::memory_order_relaxed);
+ COUNTER_TYPE beg = _begin.load(std::memory_order_relaxed);
return _ring[beg & MaxSizeMask];
}
@@ -102,16 +102,16 @@ public:
*
* @return the current number of the elements.
*/
- unsigned size() const {
- unsigned end = _end.load(std::memory_order_relaxed);
- unsigned beg = _begin.load(std::memory_order_relaxed);
+ COUNTER_TYPE size() const {
+ COUNTER_TYPE end = _end.load(std::memory_order_relaxed);
+ COUNTER_TYPE beg = _begin.load(std::memory_order_relaxed);
return (end - beg);
}
private:
- std::atomic<unsigned> _begin CACHELINE_ALIGNED;
- std::atomic<unsigned> _end CACHELINE_ALIGNED;
+ std::atomic<COUNTER_TYPE> _begin CACHELINE_ALIGNED;
+ std::atomic<COUNTER_TYPE> _end CACHELINE_ALIGNED;
T _ring[MaxSize];
};
diff --git a/include/lockfree/unordered-queue-spsc.hh
b/include/lockfree/unordered-queue-spsc.hh
index 72f77790..702da681 100644
--- a/include/lockfree/unordered-queue-spsc.hh
+++ b/include/lockfree/unordered-queue-spsc.hh
@@ -26,7 +26,7 @@ namespace lockfree {
template <typename LT, unsigned RingSize>
class unordered_queue_spsc {
private:
- ring_spsc<LT*,RingSize> _ring;
+ ring_spsc<LT*,unsigned,RingSize> _ring;
unordered_queue_mpsc<LT> _queue;
public:
diff --git a/include/lockfree/unordered_ring_mpsc.hh
b/include/lockfree/unordered_ring_mpsc.hh
index 72599bae..6c6d1165 100644
--- a/include/lockfree/unordered_ring_mpsc.hh
+++ b/include/lockfree/unordered_ring_mpsc.hh
@@ -26,7 +26,7 @@ template<class T, unsigned MaxSizePerCpu>
class unordered_ring_mpsc
{
private:
- std::vector<ring_spsc<T,MaxSizePerCpu>> rings;
+ std::vector<ring_spsc<T,unsigned,MaxSizePerCpu>> rings;
public:
using ring_mpsc_t = unordered_ring_mpsc<T,MaxSizePerCpu>;
diff --git a/include/osv/net_channel.hh b/include/osv/net_channel.hh
index 2784e9e7..11cc09cb 100644
--- a/include/osv/net_channel.hh
+++ b/include/osv/net_channel.hh
@@ -33,7 +33,7 @@ extern void* memory::alloc_page();
class net_channel {
private:
std::function<void (mbuf*)> _process_packet;
- ring_spsc<mbuf*, 256> _queue;
+ ring_spsc<mbuf*, unsigned, 256> _queue;
sched::thread_handle _waiting_thread CACHELINE_ALIGNED;
// extra list of threads to wake
osv::rcu_ptr<std::vector<pollreq*>> _pollers;
diff --git a/include/osv/percpu_xmit.hh b/include/osv/percpu_xmit.hh
index 7ec6f1be..4b44bf6a 100644
--- a/include/osv/percpu_xmit.hh
+++ b/include/osv/percpu_xmit.hh
@@ -151,7 +151,7 @@ public:
private:
lockfree::queue_mpsc<wait_record> _waitq;
- ring_spsc<value_type, CpuTxqSize> _r;
+ ring_spsc<value_type, unsigned, CpuTxqSize> _r;
//
// We don't want to wake the waiters when the Tx worker is going to sleep.
diff --git a/tests/misc-free-perf.cc b/tests/misc-free-perf.cc
index b9dc24b2..c7478adf 100644
--- a/tests/misc-free-perf.cc
+++ b/tests/misc-free-perf.cc
@@ -21,7 +21,7 @@ struct linked_object {
};
using _clock = std::chrono::high_resolution_clock;
-using queue_t = ring_spsc<void*,64*1024*1024>;
+using queue_t = ring_spsc<void*,unsigned,64*1024*1024>;
// Manages threads, allocates each thread on a different CPU
class thread_allocator
diff --git a/tests/misc-lfring.cc b/tests/misc-lfring.cc
index 83e3de84..ade201f1 100644
--- a/tests/misc-lfring.cc
+++ b/tests/misc-lfring.cc
@@ -64,7 +64,7 @@ public:
private:
- ring_spsc<int, 4096> _ring;
+ ring_spsc<int,unsigned,4096> _ring;
int _stats[2][max_random] = {};
diff --git a/tests/tst-nway-merger.cc b/tests/tst-nway-merger.cc
index 5f37a16a..83a0cc7d 100644
--- a/tests/tst-nway-merger.cc
+++ b/tests/tst-nway-merger.cc
@@ -69,7 +69,7 @@ public:
bool empty() const { return _r.empty(); }
private:
- ring_spsc<T, MaxSize> _r;
+ ring_spsc<T,unsigned,MaxSize> _r;
};
typedef my_spsc_ring<my_struct, 8> my_spsc_queue;
diff --git a/tests/tst-ring-spsc-wraparound.cc
b/tests/tst-ring-spsc-wraparound.cc
index 2490755d..64953aed 100644
--- a/tests/tst-ring-spsc-wraparound.cc
+++ b/tests/tst-ring-spsc-wraparound.cc
@@ -17,8 +17,8 @@ using namespace std;
int main(int argc, char *argv[])
{
- ring_spsc<int, 256> test_ring;
- unsigned count;
+ ring_spsc<int, unsigned short, 256> test_ring;
+ unsigned short count;
int val;
for (count = 1; count != 0; count++) {
--
2.27.0
--
You received this message because you are subscribed to the Google Groups "OSv
Development" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to osv-dev+unsubscr...@googlegroups.com.
To view this discussion on the web visit
https://groups.google.com/d/msgid/osv-dev/20220503203505.41452-1-jwkozaczuk%40gmail.com.
