Replace os_event types with callback functions.

All scheduled events contain a pointer to a callback function.  When a
task dequeues an event, it just executes the callback.  Before this
change, the task would inspect the event type and use it to decide what
action to take.

The reason for this change is to allow "taskless" packages to seamlessly
use any task's eventq.  With event codes, there would be conflicts in
the global event ID number space.

X-Original-Commit: 918811f826f9308e0b0b5abb0c0328be3c4dc6f4

nimble/host/pkg.yml

@@ -26,10 +26,11 @@ pkg.keywords:
     - bluetooth
 
 pkg.deps:
-    - sys/log
-    - sys/stats
     - kernel/os
     - net/nimble
+    - sys/log
+    - sys/stats
+    - util/childq
 
 pkg.deps.BLE_SM:
     - crypto/mbedtls

nimble/host/src/ble_hs.c

@@ -24,6 +24,7 @@
 #include "bsp/bsp.h"
 #include "stats/stats.h"
 #include "os/os.h"
+#include "childq/childq.h"
 #include "nimble/ble_hci_trans.h"
 #include "ble_hs_priv.h"
 
@@ -64,17 +65,14 @@ static int ble_hs_reset_reason;
 
 static struct os_task *ble_hs_parent_task;
 
-#define BLE_HS_SYNC_RETRY_RATE          (OS_TICKS_PER_SEC / 10)
-
 /**
  * Handles unresponsive timeouts and periodic retries in case of resource
  * shortage.
  */
 static struct os_callout_func ble_hs_heartbeat_timer;
-static struct os_callout_func ble_hs_event_co;
 
 /* Queue for host-specific OS events. */
-static struct os_eventq ble_hs_evq;
+static struct childq ble_hs_cq;
 
 static struct os_mqueue ble_hs_rx_q;
 static struct os_mqueue ble_hs_tx_q;
@@ -337,76 +335,52 @@ ble_hs_heartbeat(void *unused)
 }
 
 static void
-ble_hs_event_handle(void *unused)
+ble_hs_event_handle(struct os_event *ev)
 {
     struct os_callout_func *cf;
-    struct os_eventq *evqp;
-    struct os_event *ev;
     uint8_t *hci_evt;
     int rc;
-    int i;
 
-    evqp = &ble_hs_evq;
+    switch (ev->ev_type) {
+    case OS_EVENT_T_TIMER:
+        cf = (struct os_callout_func *)ev;
+        assert(cf->cf_func);
+        cf->cf_func(ev->ev_arg);
+        break;
 
-    i = 0;
-    while (1) {
-        /* If the host has already processed several consecutive events, stop
-         * and return control to the parent task.  Put an event on the parent
-         * task's eventq to indicate that more host events are enqueued.
-         */
-        if (i >= BLE_HS_MAX_EVS_IN_A_ROW) {
-            os_eventq_put(ble_hs_cfg.parent_evq, &ble_hs_event_co.cf_c.c_ev);
-            break;
-        }
-        i++;
+    case BLE_HOST_HCI_EVENT_CTLR_EVENT:
+        hci_evt = ev->ev_arg;
+        rc = os_memblock_put(&ble_hs_hci_ev_pool, ev);
+        BLE_HS_DBG_ASSERT_EVAL(rc == 0);
 
-        ev = os_eventq_poll(&evqp, 1, 0);
-        if (ev == NULL) {
-            break;
-        }
+        ble_hs_hci_evt_process(hci_evt);
+        break;
 
-        switch (ev->ev_type) {
-        case OS_EVENT_T_TIMER:
-            cf = (struct os_callout_func *)ev;
-            assert(cf->cf_func);
-            cf->cf_func(ev->ev_arg);
-            break;
+    case BLE_HS_EVENT_TX_NOTIFICATIONS:
+        BLE_HS_DBG_ASSERT(ev == &ble_hs_event_tx_notifications);
+        ble_gatts_tx_notifications();
+        break;
 
-        case BLE_HOST_HCI_EVENT_CTLR_EVENT:
-            hci_evt = ev->ev_arg;
-            rc = os_memblock_put(&ble_hs_hci_ev_pool, ev);
-            BLE_HS_DBG_ASSERT_EVAL(rc == 0);
+    case OS_EVENT_T_MQUEUE_DATA:
+        ble_hs_process_tx_data_queue();
+        ble_hs_process_rx_data_queue();
+        break;
 
-            ble_hs_hci_evt_process(hci_evt);
-            break;
+    case BLE_HS_EVENT_RESET:
+        BLE_HS_DBG_ASSERT(ev == &ble_hs_event_reset);
+        ble_hs_reset();
+        break;
 
-        case BLE_HS_EVENT_TX_NOTIFICATIONS:
-            BLE_HS_DBG_ASSERT(ev == &ble_hs_event_tx_notifications);
-            ble_gatts_tx_notifications();
-            break;
-
-        case OS_EVENT_T_MQUEUE_DATA:
-            ble_hs_process_tx_data_queue();
-            ble_hs_process_rx_data_queue();
-            break;
-
-        case BLE_HS_EVENT_RESET:
-            BLE_HS_DBG_ASSERT(ev == &ble_hs_event_reset);
-            ble_hs_reset();
-            break;
-
-        default:
-            BLE_HS_DBG_ASSERT(0);
-            break;
-        }
+    default:
+        BLE_HS_DBG_ASSERT(0);
+        break;
     }
 }
 
 void
 ble_hs_event_enqueue(struct os_event *ev)
 {
-    os_eventq_put(&ble_hs_evq, ev);
-    os_eventq_put(ble_hs_cfg.parent_evq, &ble_hs_event_co.cf_c.c_ev);
+    childq_put(&ble_hs_cq, ev);
 }
 
 void
@@ -516,14 +490,13 @@ ble_hs_rx_data(struct os_mbuf *om, void *arg)
 {
     int rc;
 
-    rc = os_mqueue_put(&ble_hs_rx_q, &ble_hs_evq, om);
-    if (rc == 0) {
-        os_eventq_put(ble_hs_cfg.parent_evq, &ble_hs_event_co.cf_c.c_ev);
-    } else {
+    rc = childq_put_mqueue(&ble_hs_cq, &ble_hs_rx_q, om);
+    if (rc != 0) {
         os_mbuf_free_chain(om);
-        rc = BLE_HS_EOS;
+        return BLE_HS_EOS;
     }
-    return rc;
+
+    return 0;
 }
 
 /**
@@ -540,12 +513,11 @@ ble_hs_tx_data(struct os_mbuf *om)
 {
     int rc;
 
-    rc = os_mqueue_put(&ble_hs_tx_q, &ble_hs_evq, om);
+    rc = childq_put_mqueue(&ble_hs_cq, &ble_hs_tx_q, om);
     if (rc != 0) {
         os_mbuf_free_chain(om);
         return BLE_HS_EOS;
     }
-    os_eventq_put(ble_hs_cfg.parent_evq, &ble_hs_event_co.cf_c.c_ev);
 
     return 0;
 }
@@ -570,8 +542,7 @@ ble_hs_init(void)
                          "ble_hs_hci_ev_pool");
     SYSINIT_PANIC_ASSERT(rc == 0);
 
-    /* Initialize eventq */
-    os_eventq_init(&ble_hs_evq);
+    childq_init(&ble_hs_cq, ble_hs_cfg.parent_evq, ble_hs_event_handle);
 
     ble_hs_hci_init();
 
@@ -604,9 +575,6 @@ ble_hs_init(void)
         STATS_SIZE_32), STATS_NAME_INIT_PARMS(ble_hs_stats), "ble_hs");
     SYSINIT_PANIC_ASSERT(rc == 0);
 
-    os_callout_func_init(&ble_hs_event_co, &ble_hs_evq,
-                         ble_hs_event_handle, NULL);
-
     rc = os_mutex_init(&ble_hs_mutex);
     SYSINIT_PANIC_ASSERT(rc == 0);