[alsa-devel] [ucm] Adding list for caching multiple opened control devices

[sajeesh sidharthan]

Hello.

I would like to contribute to alsa development. As a first step, I have made changes for caching control devices in ucm.

Please review the following changes and let me know if I can check in the changes and how to check in?


----------------------

diff --git a/src/ucm/main.c b/src/ucm/main.c
index 030c9b1..3219778 100644
--- a/src/ucm/main.c
+++ b/src/ucm/main.c
@@ -131,31 +131,33 @@ static int open_ctl(snd_use_case_mgr_t *uc_mgr,
             const char *ctl_dev)
 {
     int err;
+    struct list_head *pos;
+    struct snd_ctl_list *snd_ctl;
 
-    /* FIXME: add a list of ctl devices to uc_mgr structure and
-           cache accesses for multiple opened ctl devices */
-    if (uc_mgr->ctl_dev != NULL && strcmp(ctl_dev, uc_mgr->ctl_dev) == 0) {
-        *ctl = uc_mgr->ctl;
-        return 0;
-    }
-    if (uc_mgr->ctl_dev) {
-        free(uc_mgr->ctl_dev);
-        uc_mgr->ctl_dev = NULL;
-        snd_ctl_close(uc_mgr->ctl);
-    
+    list_for_each(pos, &uc_mgr->ctl_list) {
+        snd_ctl = list_entry(pos, struct snd_ctl_list, list);
+        if(!snd_ctl)
+            break;
+        if(!strcmp(snd_ctl->ctl_dev, ctl_dev)) {
+            *ctl = snd_ctl->ctl;
+            return 0;
+        }
     }
     err = snd_ctl_open(ctl, ctl_dev, 0);
     if (err < 0)
         return err;
-    uc_mgr->ctl_dev = strdup(ctl_dev);
-    if (uc_mgr->ctl_dev == NULL) {
-        snd_ctl_close(*ctl);
-        return -ENOMEM;
-    }
-    uc_mgr->ctl = *ctl;
+
+    if (*ctl) {
+        snd_ctl = malloc(sizeof(struct snd_ctl_list));
+        snd_ctl->ctl_dev = strdup(ctl_dev);
+        snd_ctl->ctl = *ctl;
+        list_add_tail(&snd_ctl->list, &uc_mgr->ctl_list);
+    }
+
     return 0;
 }
 
+
 static int execute_cset(snd_ctl_t *ctl, char *cset)
 {
     char *pos;
@@ -622,6 +624,7 @@ int snd_use_case_mgr_open(snd_use_case_mgr_t **mgr,
     INIT_LIST_HEAD(&uc_mgr->value_list);
     INIT_LIST_HEAD(&uc_mgr->active_modifiers);
     INIT_LIST_HEAD(&uc_mgr->active_devices);
+    INIT_LIST_HEAD(&uc_mgr->ctl_list);
     pthread_mutex_init(&uc_mgr->mutex, NULL);
 
     uc_mgr->card_name = strdup(card_name);
diff --git a/src/ucm/ucm_local.h b/src/ucm/ucm_local.h
index 13e82da..86a51c7 100644
--- a/src/ucm/ucm_local.h
+++ b/src/ucm/ucm_local.h
@@ -82,6 +82,12 @@ struct dev_list {
 };
 
 
+struct snd_ctl_list {
+    snd_ctl_t *ctl;
+    char *ctl_dev;
+    struct list_head list;
+};
+
 /*
  * Describes a Use Case Modifier and it's enable and disable sequences.
  * A use case verb can have N modifiers.
@@ -183,8 +189,8 @@ struct snd_use_case_mgr {
     pthread_mutex_t mutex;
 
     /* change to list of ctl handles */
-    snd_ctl_t *ctl;
-    char *ctl_dev;
+    
+    struct list_head ctl_list;
 };
 
 #define uc_error SNDERR
diff --git a/src/ucm/utils.c b/src/ucm/utils.c
index 2def0b8..f18a2ac 100644
--- a/src/ucm/utils.c
+++ b/src/ucm/utils.c
@@ -99,6 +99,21 @@ void uc_mgr_free_value(struct list_head *base)
     }
 }
 
+
+void uc_mgr_free_ctl(struct list_head *base)
+{
+    struct list_head *pos, *npos;
+    struct snd_ctl_list *ctl_list;
+    
+    list_for_each_safe(pos, npos, base) {
+        ctl_list = list_entry(pos, struct snd_ctl_list, list);
+        free(ctl_list->ctl_dev);
+        snd_ctl_close(ctl_list->ctl);
+        list_del(&ctl_list->list);
+        free(ctl_list);
+    }
+}
+
 void uc_mgr_free_dev_list(struct list_head *base)
 {
     struct list_head *pos, *npos;
@@ -220,12 +235,7 @@ void uc_mgr_free_verb(snd_use_case_mgr_t *uc_mgr)
     uc_mgr->active_verb = NULL;
     INIT_LIST_HEAD(&uc_mgr->active_devices);
     INIT_LIST_HEAD(&uc_mgr->active_modifiers);
-    if (uc_mgr->ctl != NULL) {
-        snd_ctl_close(uc_mgr->ctl);
-        uc_mgr->ctl = NULL;
-    }
-    free(uc_mgr->ctl_dev);
-    uc_mgr->ctl_dev = NULL;
+    uc_mgr_free_ctl(&uc_mgr->ctl_list);
 }
 
 void uc_mgr_free(snd_use_case_mgr_t *uc_mgr)




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Sajeesh