add a test for underflow handling and expose os API

CMakeLists.txt

@@ -68,6 +68,7 @@ set(LIBSOUNDIO_SOURCES
 set(CONFIGURE_OUT_FILE "${CMAKE_BINARY_DIR}/config.h")
 set(LIBSOUNDIO_HEADERS
     "${CMAKE_SOURCE_DIR}/src/soundio.h"
+    "${CMAKE_SOURCE_DIR}/src/os.h"
     ${CONFIGURE_OUT_FILE}
 )
 
@@ -214,6 +215,14 @@ set_target_properties(unit_tests PROPERTIES
 include_directories(${TEST_INCLUDES})
 add_test(UnitTests unit_tests)
 
+add_executable(underflow test/underflow.c)
+set_target_properties(underflow PROPERTIES
+    LINKER_LANGUAGE C
+    COMPILE_FLAGS ${EXAMPLE_CFLAGS})
+include_directories(${EXAMPLE_INCLUDES})
+target_link_libraries(underflow libsoundio_shared)
+
+
 
 add_custom_target(coverage
     DEPENDS unit_tests

README.md

@@ -249,10 +249,6 @@ view `coverage/index.html` in a browser.
  0. Verify that JACK xrun callback context is the same as process callback.
     If not, might need to hav xrun callback set a flag and have process callback
     call the underflow callback.
- 0. Detect PulseAudio server going offline and emit `on_backend_disconnect`.
- 0. Instead fo open(), start(), pause(), open() starts it and it starts paused.
- 0. Create a test for underflow handling. It just makes a sine wave for 5
-    seconds, then on next audio callback, sleep for 2 seconds.
  0. Create a test for pausing and resuming input and output streams.
  0. Create a test for the latency / synchronization API.
     - Input is an audio file and some events indexed at particular frame - when
@@ -292,6 +288,7 @@ view `coverage/index.html` in a browser.
     `soundio_outstream_start` is called, switch to the real callback, then call
     `pa_stream_flush`, then uncork the stream.
  0. In ALSA do we need to wake up the poll when destroying the in or out stream?
+ 0. Detect PulseAudio server going offline and emit `on_backend_disconnect`.
 
 ## Planned Uses for libsoundio
 

src/alsa.hpp

@@ -9,7 +9,7 @@
 #define SOUNDIO_ALSA_HPP
 
 #include "soundio.h"
-#include "os.hpp"
+#include "os.h"
 #include "atomics.hpp"
 
 #include <alsa/asoundlib.h>

src/dummy.hpp

@@ -9,7 +9,7 @@
 #define SOUNDIO_DUMMY_HPP
 
 #include "soundio.h"
-#include "os.hpp"
+#include "os.h"
 #include "atomics.hpp"
 #include "ring_buffer.hpp"
 

src/jack.hpp

@@ -9,7 +9,7 @@
 #define SOUNDIO_JACK_HPP
 
 #include "soundio.h"
-#include "os.hpp"
+#include "os.h"
 #include "atomics.hpp"
 
 #include <jack/jack.h>

src/os.cpp

@@ -5,7 +5,7 @@
  * See http://opensource.org/licenses/MIT
  */
 
-#include "os.hpp"
+#include "os.h"
 #include "soundio.h"
 #include "util.hpp"
 #include "atomics.hpp"

src/os.h

@@ -5,12 +5,18 @@
  * See http://opensource.org/licenses/MIT
  */
 
-#ifndef SOUNDIO_OS_HPP
-#define SOUNDIO_OS_HPP
+#ifndef SOUNDIO_OS_H
+#define SOUNDIO_OS_H
 
 #include <stdbool.h>
 #include <stddef.h>
 
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+
 // safe to call from any thread(s) multiple times, but
 // must be called at least once before calling any other os functions
 // soundio_create calls this function.
@@ -63,4 +69,8 @@ struct SoundIoOsMirroredMemory {
 int soundio_os_init_mirrored_memory(struct SoundIoOsMirroredMemory *mem, size_t capacity);
 void soundio_os_deinit_mirrored_memory(struct SoundIoOsMirroredMemory *mem);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif

src/ring_buffer.cpp

@@ -8,7 +8,6 @@
 #include "ring_buffer.hpp"
 #include "soundio.hpp"
 #include "util.hpp"
-#include "os.hpp"
 
 #include <stdlib.h>
 

src/ring_buffer.hpp

@@ -9,7 +9,7 @@
 #define SOUNDIO_RING_BUFFER_HPP
 
 #include "atomics.hpp"
-#include "os.hpp"
+#include "os.h"
 
 struct SoundIoRingBuffer {
     SoundIoOsMirroredMemory mem;

src/soundio.cpp

@@ -7,7 +7,7 @@
 
 #include "soundio.hpp"
 #include "util.hpp"
-#include "os.hpp"
+#include "os.h"
 #include "config.h"
 
 #include <string.h>

test/underflow.c

@@ -0,0 +1,163 @@
+/*
+ * Copyright (c) 2015 Andrew Kelley
+ *
+ * This file is part of libsoundio, which is MIT licensed.
+ * See http://opensource.org/licenses/MIT
+ */
+
+#include <soundio.h>
+#include <os.h>
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+__attribute__ ((cold))
+__attribute__ ((noreturn))
+__attribute__ ((format (printf, 1, 2)))
+static void panic(const char *format, ...) {
+    va_list ap;
+    va_start(ap, format);
+    vfprintf(stderr, format, ap);
+    fprintf(stderr, "\n");
+    va_end(ap);
+    abort();
+}
+
+static int usage(char *exe) {
+    fprintf(stderr, "Usage: %s [--dummy] [--alsa] [--pulseaudio] [--jack]\n", exe);
+    return 1;
+}
+
+static const float PI = 3.1415926535f;
+static float seconds_offset = 0.0f;
+static bool caused_underflow = false;
+static struct SoundIoOsCond *cond = NULL;
+static struct SoundIo *soundio = NULL;
+static float seconds_end = 9.0f;
+
+static void write_callback(struct SoundIoOutStream *outstream, int requested_frame_count) {
+    float float_sample_rate = outstream->sample_rate;
+    float seconds_per_frame = 1.0f / float_sample_rate;
+    int err;
+
+    if (!caused_underflow && seconds_offset >= 3.0f) {
+        caused_underflow = true;
+        soundio_os_cond_timed_wait(cond, NULL, 3.0);
+    }
+
+    if (seconds_offset >= seconds_end) {
+        soundio_wakeup(soundio);
+        return;
+    }
+
+    for (;;) {
+        int frame_count = requested_frame_count;
+
+        struct SoundIoChannelArea *areas;
+        if ((err = soundio_outstream_begin_write(outstream, &areas, &frame_count)))
+            panic("%s", soundio_strerror(err));
+
+        if (!frame_count)
+            break;
+
+        const struct SoundIoChannelLayout *layout = &outstream->layout;
+
+        float pitch = 440.0f;
+        float radians_per_second = pitch * 2.0f * PI;
+        for (int frame = 0; frame < frame_count; frame += 1) {
+            float sample = sinf((seconds_offset + frame * seconds_per_frame) * radians_per_second);
+            for (int channel = 0; channel < layout->channel_count; channel += 1) {
+                float *ptr = (float*)(areas[channel].ptr + areas[channel].step * frame);
+                *ptr = sample;
+            }
+        }
+        seconds_offset += seconds_per_frame * frame_count;
+
+        if ((err = soundio_outstream_end_write(outstream, frame_count))) {
+            if (err == SoundIoErrorUnderflow)
+                return;
+            panic("%s", soundio_strerror(err));
+        }
+
+        requested_frame_count -= frame_count;
+        if (requested_frame_count <= 0)
+            break;
+    }
+}
+
+static void underflow_callback(struct SoundIoOutStream *outstream) {
+    static int count = 0;
+    fprintf(stderr, "underflow %d\n", count++);
+}
+
+int main(int argc, char **argv) {
+    char *exe = argv[0];
+    enum SoundIoBackend backend = SoundIoBackendNone;
+    for (int i = 1; i < argc; i += 1) {
+        char *arg = argv[i];
+        if (strcmp("--dummy", arg) == 0) {
+            backend = SoundIoBackendDummy;
+        } else if (strcmp("--alsa", arg) == 0) {
+            backend = SoundIoBackendAlsa;
+        } else if (strcmp("--pulseaudio", arg) == 0) {
+            backend = SoundIoBackendPulseAudio;
+        } else if (strcmp("--jack", arg) == 0) {
+            backend = SoundIoBackendJack;
+        } else {
+            return usage(exe);
+        }
+    }
+
+    fprintf(stderr, "You should hear a sine wave for 3 seconds, then some period of silence or glitches,\n"
+                    "then you should see at least one buffer underflow message, then hear a sine\n"
+                    "wave for 3 seconds, then the program should exit successfully.\n");
+
+    if (!(soundio = soundio_create()))
+        panic("out of memory");
+
+    int err = (backend == SoundIoBackendNone) ?
+        soundio_connect(soundio) : soundio_connect_backend(soundio, backend);
+
+    if (err)
+        panic("error connecting: %s", soundio_strerror(err));
+
+    int default_out_device_index = soundio_default_output_device_index(soundio);
+    if (default_out_device_index < 0)
+        panic("no output device found");
+
+    struct SoundIoDevice *device = soundio_get_output_device(soundio, default_out_device_index);
+    if (!device)
+        panic("out of memory");
+
+    fprintf(stderr, "Output device: %s\n", device->name);
+
+    cond = soundio_os_cond_create();
+    if (!cond)
+        panic("out of memory");
+
+    struct SoundIoOutStream *outstream = soundio_outstream_create(device);
+    outstream->format = SoundIoFormatFloat32NE;
+    outstream->write_callback = write_callback;
+    outstream->underflow_callback = underflow_callback;
+
+    if ((err = soundio_outstream_open(outstream)))
+        panic("unable to open device: %s", soundio_strerror(err));
+
+    if (outstream->layout_error)
+        fprintf(stderr, "unable to set channel layout: %s\n", soundio_strerror(outstream->layout_error));
+
+    if ((err = soundio_outstream_start(outstream)))
+        panic("unable to start device: %s", soundio_strerror(err));
+
+    while (seconds_offset < seconds_end)
+        soundio_wait_events(soundio);
+
+    soundio_outstream_destroy(outstream);
+    soundio_device_unref(device);
+    soundio_os_cond_destroy(cond);
+    soundio_destroy(soundio);
+    return 0;
+}

test/unit_tests.cpp

@@ -1,7 +1,7 @@
 #undef NDEBUG
 
 #include "soundio.hpp"
-#include "os.hpp"
+#include "os.h"
 #include "util.hpp"
 #include "atomics.hpp"