From 4486b2ededeecb595a3f51e40b94b302af02e65c Mon Sep 17 00:00:00 2001
From: Max Kellermann <max.kellermann@gmail.com>
Date: Thu, 11 Jul 2024 21:26:47 +0200
Subject: [PATCH] lib/alsa/NonBlock: add common base class
---
src/lib/alsa/NonBlock.cxx | 59 +++++++++++++++++++--------------------
src/lib/alsa/NonBlock.hxx | 18 ++++++++++--
2 files changed, 45 insertions(+), 32 deletions(-)
diff --git a/src/lib/alsa/NonBlock.cxx b/src/lib/alsa/NonBlock.cxx
index 800bc4886..a20255bcc 100644
--- a/src/lib/alsa/NonBlock.cxx
+++ b/src/lib/alsa/NonBlock.cxx
@@ -7,6 +7,25 @@
namespace Alsa {
+std::span<pollfd>
+NonBlock::CopyReturnedEvents(MultiSocketMonitor &m, std::size_t n) noexcept
+{
+ const auto pfds = buffer.Get(n), end = pfds + n;
+
+ auto *i = pfds;
+ m.ForEachReturnedEvent([&i, end](SocketDescriptor s, unsigned events){
+ if (i >= end)
+ return;
+
+ i->fd = s.Get();
+ i->events = i->revents = events;
+ ++i;
+ });
+
+ return {pfds, static_cast<std::size_t>(i - pfds)};
+
+}
+
Event::Duration
NonBlockPcm::PrepareSockets(MultiSocketMonitor &m, snd_pcm_t *pcm)
{
@@ -18,9 +37,9 @@ NonBlockPcm::PrepareSockets(MultiSocketMonitor &m, snd_pcm_t *pcm)
throw Alsa::MakeError(count, "snd_pcm_poll_descriptors_count() failed");
}
- struct pollfd *pfds = pfd_buffer.Get(count);
+ const auto pfds = base.Allocate(count);
- count = snd_pcm_poll_descriptors(pcm, pfds, count);
+ count = snd_pcm_poll_descriptors(pcm, pfds.data(), count);
if (count <= 0) {
if (count == 0)
throw std::runtime_error("snd_pcm_poll_descriptors() failed");
@@ -28,7 +47,7 @@ NonBlockPcm::PrepareSockets(MultiSocketMonitor &m, snd_pcm_t *pcm)
throw Alsa::MakeError(count, "snd_pcm_poll_descriptors() failed");
}
- m.ReplaceSocketList({pfds, static_cast<std::size_t>(count)});
+ m.ReplaceSocketList(pfds.first(count));
return Event::Duration(-1);
}
@@ -39,20 +58,10 @@ NonBlockPcm::DispatchSockets(MultiSocketMonitor &m, snd_pcm_t *pcm)
if (count <= 0)
return;
- const auto pfds = pfd_buffer.Get(count), end = pfds + count;
-
- auto *i = pfds;
- m.ForEachReturnedEvent([&i, end](SocketDescriptor s, unsigned events){
- if (i >= end)
- return;
-
- i->fd = s.Get();
- i->events = i->revents = events;
- ++i;
- });
+ const auto pfds = base.CopyReturnedEvents(m, count);
unsigned short dummy;
- int err = snd_pcm_poll_descriptors_revents(pcm, pfds, i - pfds, &dummy);
+ int err = snd_pcm_poll_descriptors_revents(pcm, pfds.data(), pfds.size(), &dummy);
if (err < 0)
throw Alsa::MakeError(err, "snd_pcm_poll_descriptors_revents() failed");
}
@@ -66,13 +75,13 @@ NonBlockMixer::PrepareSockets(MultiSocketMonitor &m, snd_mixer_t *mixer) noexcep
return Event::Duration(-1);
}
- struct pollfd *pfds = pfd_buffer.Get(count);
+ const auto pfds = base.Allocate(count);
- count = snd_mixer_poll_descriptors(mixer, pfds, count);
+ count = snd_mixer_poll_descriptors(mixer, pfds.data(), count);
if (count < 0)
count = 0;
- m.ReplaceSocketList({pfds, static_cast<std::size_t>(count)});
+ m.ReplaceSocketList(pfds.first(count));
return Event::Duration(-1);
}
@@ -83,20 +92,10 @@ NonBlockMixer::DispatchSockets(MultiSocketMonitor &m, snd_mixer_t *mixer) noexce
if (count <= 0)
return;
- const auto pfds = pfd_buffer.Get(count), end = pfds + count;
-
- auto *i = pfds;
- m.ForEachReturnedEvent([&i, end](SocketDescriptor s, unsigned events){
- if (i >= end)
- return;
-
- i->fd = s.Get();
- i->events = i->revents = events;
- ++i;
- });
+ const auto pfds = base.CopyReturnedEvents(m, count);
unsigned short dummy;
- snd_mixer_poll_descriptors_revents(mixer, pfds, i - pfds, &dummy);
+ snd_mixer_poll_descriptors_revents(mixer, pfds.data(), pfds.size(), &dummy);
}
} // namespace Alsa
diff --git a/src/lib/alsa/NonBlock.hxx b/src/lib/alsa/NonBlock.hxx
index aae992f50..16cfb3102 100644
--- a/src/lib/alsa/NonBlock.hxx
+++ b/src/lib/alsa/NonBlock.hxx
@@ -8,16 +8,30 @@
#include <alsa/asoundlib.h>
+#include <span>
+
class MultiSocketMonitor;
namespace Alsa {
+class NonBlock {
+ ReusableArray<pollfd> buffer;
+
+public:
+ std::span<pollfd> Allocate(std::size_t n) noexcept {
+ return {buffer.Get(n), n};
+ }
+
+ std::span<pollfd> CopyReturnedEvents(MultiSocketMonitor &m,
+ std::size_t n) noexcept;
+};
+
/**
* Helper class for #MultiSocketMonitor's virtual methods which
* manages the file descriptors for a #snd_pcm_t.
*/
class NonBlockPcm {
- ReusableArray<pollfd> pfd_buffer;
+ NonBlock base;
public:
/**
@@ -40,7 +54,7 @@ public:
* manages the file descriptors for a #snd_mixer_t.
*/
class NonBlockMixer {
- ReusableArray<pollfd> pfd_buffer;
+ NonBlock base;
public:
Event::Duration PrepareSockets(MultiSocketMonitor &m,