aaudio: control MMAP mode using system properties
To facilitate testing of MMAP mode.
Bug: 38268547
Test: set properties, see framesPerBurst in write_sine_callback.cpp
Change-Id: I6e15c563215017f6a5020d89ac312ff8331afc4f
Signed-off-by: Phil Burk <philburk@google.com>
diff --git a/media/libaaudio/src/utility/AAudioUtilities.h b/media/libaaudio/src/utility/AAudioUtilities.h
index 0078cbb..7c383c7 100644
--- a/media/libaaudio/src/utility/AAudioUtilities.h
+++ b/media/libaaudio/src/utility/AAudioUtilities.h
@@ -170,4 +170,54 @@
*/
int32_t AAudioConvert_formatToSizeInBytes(aaudio_audio_format_t format);
+
+// Note that this code may be replaced by Settings or by some other system configuration tool.
+
+enum : int32_t {
+ // Related feature is disabled
+ AAUDIO_USE_NEVER = 0,
+ // If related feature works then use it. Otherwise fall back to something else.
+ AAUDIO_USE_AUTO = 1,
+ // Related feature must be used. If not available then fail.
+ AAUDIO_USE_ALWAYS = 2
+};
+
+#define AAUDIO_PROP_MMAP_ENABLED "aaudio.mmap_enabled"
+
+/**
+ * Read system property.
+ * @return AAUDIO_USE_NEVER or AAUDIO_USE_AUTO or AAUDIO_USE_ALWAYS
+ */
+int32_t AAudioProperty_getMMapEnabled();
+
+#define AAUDIO_PROP_MMAP_EXCLUSIVE_ENABLED "aaudio.mmap_exclusive_enabled"
+
+/**
+ * Read system property.
+ * @return AAUDIO_USE_NEVER or AAUDIO_USE_AUTO or AAUDIO_USE_ALWAYS
+ */
+int32_t AAudioProperty_getMMapExclusiveEnabled();
+
+#define AAUDIO_PROP_MIXER_BURSTS "aaudio.mixer_bursts"
+
+/**
+ * Read system property.
+ * @return number of bursts per mixer cycle
+ */
+int32_t AAudioProperty_getMixerBursts();
+
+#define AAUDIO_PROP_HW_BURST_MIN_USEC "aaudio.hw_burst_min_usec"
+
+/**
+ * Read system property.
+ * This is handy in case the DMA is bursting too quickly for the CPU to keep up.
+ * For example, there may be a DMA burst every 100 usec but you only
+ * want to feed the MMAP buffer every 2000 usec.
+ *
+ * This will affect the framesPerBurst for an MMAP stream.
+ *
+ * @return minimum number of microseconds for a MMAP HW burst
+ */
+int32_t AAudioProperty_getHardwareBurstMinMicros();
+
#endif //UTILITY_AAUDIO_UTILITIES_H