From 4f46f27547d9d8749161f5c9a80108da2522aeb7 Mon Sep 17 00:00:00 2001
From: Patrick Gaskin <patrick@pgaskin.net>
Date: Thu, 9 Dec 2021 22:52:05 -0500
Subject: [PATCH] Allow output plugins to have multiple mixer FD lists

---
 mixer.h         |  7 ++++++-
 op.h            |  2 +-
 op/coreaudio.c  | 13 +++++++++----
 op/mixer_alsa.c | 15 ++++++++++-----
 op/pulse.c      | 11 ++++++++---
 output.c        |  4 ++--
 output.h        |  2 +-
 ui_curses.c     | 18 +++++++++---------
 8 files changed, 46 insertions(+), 26 deletions(-)

diff --git a/mixer.h b/mixer.h
index 20f722980..ed61dba52 100644
--- a/mixer.h
+++ b/mixer.h
@@ -25,12 +25,17 @@
 
 #define NR_MIXER_FDS 4
 
+enum {
+    /* volume changes */
+    MIXER_FDS_VOLUME
+};
+
 struct mixer_plugin_ops {
 	int (*init)(void);
 	int (*exit)(void);
 	int (*open)(int *volume_max);
 	int (*close)(void);
-	int (*get_fds)(int *fds);
+	int (*get_fds)(int what, int *fds);
 	int (*set_volume)(int l, int r);
 	int (*get_volume)(int *l, int *r);
 };
diff --git a/op.h b/op.h
index b79bae85f..2f645d39b 100644
--- a/op.h
+++ b/op.h
@@ -26,7 +26,7 @@
 #include <fcntl.h>
 #endif
 
-#define OP_ABI_VERSION 1
+#define OP_ABI_VERSION 2
 
 enum {
 	/* no error */
diff --git a/op/coreaudio.c b/op/coreaudio.c
index b6b286e6a..adc114f43 100644
--- a/op/coreaudio.c
+++ b/op/coreaudio.c
@@ -864,10 +864,15 @@ static int coreaudio_mixer_dummy(void)
 	return OP_ERROR_SUCCESS;
 }
 
-static int coreaudio_mixer_get_fds(int *fds)
-{
-	fds[0] = coreaudio_mixer_pipe_out;
-	return 1;
+static int coreaudio_mixer_get_fds(int what, int *fds)
+{
+	switch (what) {
+	case MIXER_FDS_VOLUME:
+		fds[0] = coreaudio_mixer_pipe_out;
+		return 1;
+	default:
+		return 0;
+	}
 }
 
 static int coreaudio_pause(void)
diff --git a/op/mixer_alsa.c b/op/mixer_alsa.c
index ed5d3e302..fc90fc01e 100644
--- a/op/mixer_alsa.c
+++ b/op/mixer_alsa.c
@@ -137,15 +137,20 @@ static int alsa_mixer_close(void)
 	return 0;
 }
 
-static int alsa_mixer_get_fds(int *fds)
+static int alsa_mixer_get_fds(int what, int *fds)
 {
 	struct pollfd pfd[NR_MIXER_FDS];
 	int count, i;
 
-	count = snd_mixer_poll_descriptors(alsa_mixer_handle, pfd, NR_MIXER_FDS);
-	for (i = 0; i < count; i++)
-		fds[i] = pfd[i].fd;
-	return count;
+	switch (what) {
+	case MIXER_FDS_VOLUME:
+		count = snd_mixer_poll_descriptors(alsa_mixer_handle, pfd, NR_MIXER_FDS);
+		for (i = 0; i < count; i++)
+			fds[i] = pfd[i].fd;
+		return count;
+	default:
+		return 0;
+	}
 }
 
 static int alsa_mixer_set_volume(int l, int r)
diff --git a/op/pulse.c b/op/pulse.c
index a7b3f641e..4610e67c8 100644
--- a/op/pulse.c
+++ b/op/pulse.c
@@ -524,10 +524,15 @@ static int op_pulse_mixer_close(void)
 	return OP_ERROR_SUCCESS;
 }
 
-static int op_pulse_mixer_get_fds(int *fds)
+static int op_pulse_mixer_get_fds(int what, int *fds)
 {
-	fds[0] = mixer_notify_out;
-	return 1;
+	switch (what) {
+	case MIXER_FDS_VOLUME:
+		fds[0] = mixer_notify_out;
+		return 1;
+	default:
+		return 0;
+	}
 }
 
 static int op_pulse_mixer_set_volume(int l, int r)
diff --git a/output.c b/output.c
index a080dc2ac..81c6d2649 100644
--- a/output.c
+++ b/output.c
@@ -316,7 +316,7 @@ int mixer_read_volume(void)
 	return op->mixer_ops->get_volume(&volume_l, &volume_r);
 }
 
-int mixer_get_fds(int *fds)
+int mixer_get_fds(int what, int *fds)
 {
 	if (op == NULL)
 		return -OP_ERROR_NOT_INITIALIZED;
@@ -324,7 +324,7 @@ int mixer_get_fds(int *fds)
 		return -OP_ERROR_NOT_OPEN;
 	if (!op->mixer_ops->get_fds)
 		return -OP_ERROR_NOT_SUPPORTED;
-	return op->mixer_ops->get_fds(fds);
+	return op->mixer_ops->get_fds(what, fds);
 }
 
 extern int soft_vol;
diff --git a/output.h b/output.h
index 6cf26a388..369230a66 100644
--- a/output.h
+++ b/output.h
@@ -85,7 +85,7 @@ void mixer_open(void);
 void mixer_close(void);
 int mixer_set_volume(int left, int right);
 int mixer_read_volume(void);
-int mixer_get_fds(int *fds);
+int mixer_get_fds(int what, int *fds);
 
 void op_add_options(void);
 char *op_get_error_msg(int rc, const char *arg);
diff --git a/ui_curses.c b/ui_curses.c
index 5371b4022..d3cb5ae0f 100644
--- a/ui_curses.c
+++ b/ui_curses.c
@@ -2138,8 +2138,8 @@ static void main_loop(void)
 		fd_set set;
 		struct timeval tv;
 		int poll_mixer = 0;
-		int i, nr_fds = 0;
-		int fds[NR_MIXER_FDS];
+		int i;
+		int nr_fds_vol = 0, fds_vol[NR_MIXER_FDS];
 		struct list_head *item;
 		struct client *client;
 
@@ -2174,15 +2174,15 @@ static void main_loop(void)
 			SELECT_ADD_FD(client->fd);
 		}
 		if (!soft_vol) {
-			nr_fds = mixer_get_fds(fds);
-			if (nr_fds <= 0) {
+			nr_fds_vol = mixer_get_fds(MIXER_FDS_VOLUME, fds_vol);
+			if (nr_fds_vol <= 0) {
 				poll_mixer = 1;
 				if (!tv.tv_usec)
 					tv.tv_usec = 500e3;
 			}
-			for (i = 0; i < nr_fds; i++) {
-				BUG_ON(fds[i] <= 0);
-				SELECT_ADD_FD(fds[i]);
+			for (i = 0; i < nr_fds_vol; i++) {
+				BUG_ON(fds_vol[i] <= 0);
+				SELECT_ADD_FD(fds_vol[i]);
 			}
 		}
 
@@ -2207,8 +2207,8 @@ static void main_loop(void)
 			continue;
 		}
 
-		for (i = 0; i < nr_fds; i++) {
-			if (FD_ISSET(fds[i], &set)) {
+		for (i = 0; i < nr_fds_vol; i++) {
+			if (FD_ISSET(fds_vol[i], &set)) {
 				d_print("vol changed\n");
 				mixer_read_volume();
 				mpris_volume_changed();