Change the backend getLatency method to return the clock time too

This will also allow backends to better synchronize the tracked clock time with
the device output latency, without necessarily needing to lock if the backend
API can allow for it.

1 files changed, 22 insertions, 8 deletions

diff --git a/Alc/backends/alsa.c b/Alc/backends/alsa.c
index 7d23ecc3..280f5019 100644
--- a/Alc/backends/alsa.c
+++ b/Alc/backends/alsa.c
@@ -410,7 +410,7 @@ static ALCboolean ALCplaybackAlsa_start(ALCplaybackAlsa *self);
 static void ALCplaybackAlsa_stop(ALCplaybackAlsa *self);
 static DECLARE_FORWARD2(ALCplaybackAlsa, ALCbackend, ALCenum, captureSamples, void*, ALCuint)
 static DECLARE_FORWARD(ALCplaybackAlsa, ALCbackend, ALCuint, availableSamples)
-static ALint64 ALCplaybackAlsa_getLatency(ALCplaybackAlsa *self);
+static ClockLatency ALCplaybackAlsa_getClockLatency(ALCplaybackAlsa *self);
 static DECLARE_FORWARD(ALCplaybackAlsa, ALCbackend, void, lock)
 static DECLARE_FORWARD(ALCplaybackAlsa, ALCbackend, void, unlock)
 DECLARE_DEFAULT_ALLOCATORS(ALCplaybackAlsa)
@@ -891,18 +891,25 @@ static void ALCplaybackAlsa_stop(ALCplaybackAlsa *self)
     self->buffer = NULL;
 }
 
-static ALint64 ALCplaybackAlsa_getLatency(ALCplaybackAlsa *self)
+static ClockLatency ALCplaybackAlsa_getClockLatency(ALCplaybackAlsa *self)
 {
     ALCdevice *device = STATIC_CAST(ALCbackend, self)->mDevice;
     snd_pcm_sframes_t delay = 0;
+    ClockLatency ret;
     int err;
 
+    ALCplaybackAlsa_lock(self);
+    ret.ClockTime = GetDeviceClockTime(device);
     if((err=snd_pcm_delay(self->pcmHandle, &delay)) < 0)
     {
         ERR("Failed to get pcm delay: %s\n", snd_strerror(err));
-        return 0;
+        delay = 0;
     }
-    return maxi64((ALint64)delay*1000000000/device->Frequency, 0);
+    if(delay < 0) delay = 0;
+    ret.Latency = delay * DEVICE_CLOCK_RES / device->Frequency;
+    ALCplaybackAlsa_unlock(self);
+
+    return ret;
 }
 
 
@@ -929,7 +936,7 @@ static ALCboolean ALCcaptureAlsa_start(ALCcaptureAlsa *self);
 static void ALCcaptureAlsa_stop(ALCcaptureAlsa *self);
 static ALCenum ALCcaptureAlsa_captureSamples(ALCcaptureAlsa *self, ALCvoid *buffer, ALCuint samples);
 static ALCuint ALCcaptureAlsa_availableSamples(ALCcaptureAlsa *self);
-static ALint64 ALCcaptureAlsa_getLatency(ALCcaptureAlsa *self);
+static ClockLatency ALCcaptureAlsa_getClockLatency(ALCcaptureAlsa *self);
 static DECLARE_FORWARD(ALCcaptureAlsa, ALCbackend, void, lock)
 static DECLARE_FORWARD(ALCcaptureAlsa, ALCbackend, void, unlock)
 DECLARE_DEFAULT_ALLOCATORS(ALCcaptureAlsa)
@@ -1277,18 +1284,25 @@ static ALCuint ALCcaptureAlsa_availableSamples(ALCcaptureAlsa *self)
     return ll_ringbuffer_read_space(self->ring);
 }
 
-static ALint64 ALCcaptureAlsa_getLatency(ALCcaptureAlsa *self)
+static ClockLatency ALCcaptureAlsa_getClockLatency(ALCcaptureAlsa *self)
 {
     ALCdevice *device = STATIC_CAST(ALCbackend, self)->mDevice;
     snd_pcm_sframes_t delay = 0;
+    ClockLatency ret;
     int err;
 
+    ALCcaptureAlsa_lock(self);
+    ret.ClockTime = GetDeviceClockTime(device);
     if((err=snd_pcm_delay(self->pcmHandle, &delay)) < 0)
     {
         ERR("Failed to get pcm delay: %s\n", snd_strerror(err));
-        return 0;
+        delay = 0;
     }
-    return maxi64((ALint64)delay*1000000000/device->Frequency, 0);
+    if(delay < 0) delay = 0;
+    ret.Latency = delay * DEVICE_CLOCK_RES / device->Frequency;
+    ALCcaptureAlsa_unlock(self);
+
+    return ret;
 }