[alsa] Add a configurable poll interval, fix #111

celtera · Aug 2, 2024 · b0a4cf1 · b0a4cf1
1 parent 9cda570
commit b0a4cf1
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Showing 8 changed files with 22 additions and 4 deletions.
diff --git a/include/libremidi/backends/alsa_raw/config.hpp b/include/libremidi/backends/alsa_raw/config.hpp
@@ -61,6 +61,7 @@ struct manual_poll_parameters
 struct alsa_raw_input_configuration
 {
   std::function<bool(const manual_poll_parameters&)> manual_poll;
+  std::chrono::milliseconds poll_period{2};
 };
 
 struct alsa_raw_output_configuration

diff --git a/include/libremidi/backends/alsa_raw/midi_in.hpp b/include/libremidi/backends/alsa_raw/midi_in.hpp
@@ -219,11 +219,14 @@ class midi_in_alsa_raw_threaded : public midi_in_impl
   void run_thread(auto parse_func)
   {
     fds_.push_back(this->termination_event);
+    const auto period
+        = std::chrono::duration_cast<std::chrono::milliseconds>(this->configuration.poll_period)
+              .count();
 
     for (;;)
     {
       // Poll
-      ssize_t err = poll(fds_.data(), fds_.size(), -1);
+      ssize_t err = poll(fds_.data(), fds_.size(), period);
       if (err == -EAGAIN)
         continue;
       else if (err < 0)

diff --git a/include/libremidi/backends/alsa_raw_ump/config.hpp b/include/libremidi/backends/alsa_raw_ump/config.hpp
@@ -6,6 +6,7 @@ namespace libremidi::alsa_raw_ump
 struct input_configuration
 {
   std::function<bool(const manual_poll_parameters&)> manual_poll;
+  std::chrono::milliseconds poll_period{2};
 };
 
 struct output_configuration

diff --git a/include/libremidi/backends/alsa_raw_ump/midi_in.hpp b/include/libremidi/backends/alsa_raw_ump/midi_in.hpp
@@ -214,11 +214,14 @@ class midi_in_impl_threaded : public midi_in_impl
   void run_thread(auto parse_func)
   {
     fds_.push_back(this->termination_event);
+    const auto period
+        = std::chrono::duration_cast<std::chrono::milliseconds>(this->configuration.poll_period)
+              .count();
 
     for (;;)
     {
       // Poll
-      ssize_t err = poll(fds_.data(), fds_.size(), -1);
+      ssize_t err = poll(fds_.data(), fds_.size(), period);
       if (err == -EAGAIN)
         continue;
       else if (err < 0)

diff --git a/include/libremidi/backends/alsa_seq/config.hpp b/include/libremidi/backends/alsa_seq/config.hpp
@@ -38,6 +38,7 @@ struct input_configuration
   snd_seq_t* context{};
   std::function<bool(const poll_parameters&)> manual_poll;
   std::function<bool(snd_seq_addr_t)> stop_poll;
+  std::chrono::milliseconds poll_period{2};
 
   static constexpr int midi_version = 1;
 };
@@ -56,6 +57,7 @@ struct observer_configuration
   snd_seq_t* context{};
   std::function<bool(const poll_parameters&)> manual_poll;
   std::function<bool(snd_seq_addr_t)> stop_poll;
+  std::chrono::milliseconds poll_period{100};
 
   static constexpr int midi_version = 1;
 };

diff --git a/include/libremidi/backends/alsa_seq/midi_in.hpp b/include/libremidi/backends/alsa_seq/midi_in.hpp
@@ -425,12 +425,15 @@ class midi_in_alsa_threaded : public midi_in_impl<ConfigurationBase, Configurati
     poll_fds[0] = this->termination_event;
     alsa_data::snd.seq.poll_descriptors(this->seq, poll_fds + 1, poll_fd_count - 1, POLLIN);
 
+    const auto period
+        = std::chrono::duration_cast<std::chrono::milliseconds>(this->configuration.poll_period)
+              .count();
     for (;;)
     {
       if (alsa_data::snd.seq.event_input_pending(this->seq, 1) == 0)
       {
         // No data pending
-        if (poll(poll_fds, poll_fd_count, 0) >= 0)
+        if (poll(poll_fds, poll_fd_count, period) >= 0)
         {
           // We got our stop-thread signal
           if (termination_event.ready(poll_fds[0]))

diff --git a/include/libremidi/backends/alsa_seq/observer.hpp b/include/libremidi/backends/alsa_seq/observer.hpp
@@ -279,9 +279,12 @@ class observer_threaded : public observer_impl<ConfigurationImpl>
     // Start the listening thread
     thread = std::thread{[this] {
       auto& snd = alsa_data::snd;
+      const auto period
+          = std::chrono::duration_cast<std::chrono::milliseconds>(this->configuration.poll_period)
+                .count();
       for (;;)
       {
-        int err = poll(descriptors_.data(), descriptors_.size(), -1);
+        int err = poll(descriptors_.data(), descriptors_.size(), period);
         if (err >= 0)
         {
           // We got our stop-thread signal

diff --git a/include/libremidi/backends/alsa_seq_ump/config.hpp b/include/libremidi/backends/alsa_seq_ump/config.hpp
@@ -28,6 +28,7 @@ struct input_configuration
   snd_seq_t* context{};
   std::function<bool(const poll_parameters&)> manual_poll;
   std::function<bool(snd_seq_addr_t)> stop_poll;
+  std::chrono::milliseconds poll_period{2};
 
   static constexpr int midi_version = 2;
 };
@@ -46,6 +47,7 @@ struct observer_configuration
   snd_seq_t* context{};
   std::function<bool(const libremidi::alsa_seq::poll_parameters&)> manual_poll;
   std::function<bool(snd_seq_addr_t)> stop_poll;
+  std::chrono::milliseconds poll_period{100};
 
   static constexpr int midi_version = 2;
 };