Shut down the ALSA probe retry threads cleanly on exit.

diff --git a/alsa_pool.cpp b/alsa_pool.cpp
index 22a61af88d27e982a229bf8f8eccbe593c8c9612..5983446e37ab4f687cfaa7a9e4db11d497eff711 100644 (file)
--- a/alsa_pool.cpp
+++ b/alsa_pool.cpp
@@ -29,6 +29,10 @@ ALSAPool::~ALSAPool()
        }
        should_quit = true;
        inotify_thread.join();
+
+       while (retry_threads_running > 0) {
+               this_thread::sleep_for(std::chrono::milliseconds(100));
+       }
 }
 
 std::vector<ALSAPool::Device> ALSAPool::get_devices()
@@ -104,6 +108,7 @@ void ALSAPool::probe_device_with_retry(unsigned card_index, unsigned dev_index)
        // then start it ourselves.
        fprintf(stderr, "Trying %s again in one second...\n", address);
        add_device_tries_left[address] = num_retries;
+       ++retry_threads_running;
        thread(&ALSAPool::probe_device_retry_thread_func, this, card_index, dev_index).detach();
 }
 
@@ -117,11 +122,12 @@ void ALSAPool::probe_device_retry_thread_func(unsigned card_index, unsigned dev_
 
                // See if there are any retries left.
                lock_guard<mutex> lock(add_device_mutex);
-               if (!add_device_tries_left.count(address) ||
+               if (should_quit ||
+                   !add_device_tries_left.count(address) ||
                    add_device_tries_left[address] == 0) {
                        add_device_tries_left.erase(address);
                        fprintf(stderr, "Giving up probe of %s.\n", address);
-                       return;
+                       break;
                }
 
                // Seemingly there were. Give it a try (we still hold the mutex).
@@ -129,11 +135,11 @@ void ALSAPool::probe_device_retry_thread_func(unsigned card_index, unsigned dev_
                if (result == ProbeResult::SUCCESS) {
                        add_device_tries_left.erase(address);
                        fprintf(stderr, "Probe of %s succeeded.\n", address);
-                       return;
+                       break;
                } else if (result == ProbeResult::FAILURE || --add_device_tries_left[address] == 0) {
                        add_device_tries_left.erase(address);
                        fprintf(stderr, "Giving up probe of %s.\n", address);
-                       return;
+                       break;
                }
 
                // Failed again.
@@ -141,6 +147,8 @@ void ALSAPool::probe_device_retry_thread_func(unsigned card_index, unsigned dev_
                fprintf(stderr, "Trying %s again in one second (%d tries left)...\n",
                        address, add_device_tries_left[address]);
        }
+
+       --retry_threads_running;
 }
 
 ALSAPool::ProbeResult ALSAPool::probe_device_once(unsigned card_index, unsigned dev_index)

diff --git a/alsa_pool.h b/alsa_pool.h
index b5d4cd542742b6dfbfdbf4c862a56961335aab99..c9cd61abda1e8ecbbbaa575bf6021b5ecae141bd 100644 (file)
--- a/alsa_pool.h
+++ b/alsa_pool.h
@@ -149,8 +149,8 @@ private:
                                        const std::string &address);
 
        std::atomic<bool> should_quit{false};
-
        std::thread inotify_thread;
+       std::atomic<int> retry_threads_running{0};
 
        friend class ALSAInput;
 };