ramlog: remove sched_[un]lock and rl_nwaiters

Signed-off-by: hujun5 <[email protected]>

drivers/syslog/ramlog.c

@@ -59,9 +59,6 @@
 
 struct ramlog_dev_s
 {
-#ifndef CONFIG_RAMLOG_NONBLOCKING
-  volatile uint8_t  rl_nwaiters; /* Number of threads waiting for data */
-#endif
   volatile size_t   rl_head;     /* The head index (where data is added) */
   volatile size_t   rl_tail;     /* The tail index (where data is removed) */
   mutex_t           rl_lock;     /* Enforces mutually exclusive access */
@@ -139,9 +136,6 @@ static char g_sysbuffer[CONFIG_RAMLOG_BUFSIZE];
 
 static struct ramlog_dev_s g_sysdev =
 {
-#  ifndef CONFIG_RAMLOG_NONBLOCKING
-  0,                             /* rl_nwaiters */
-#  endif
   CONFIG_RAMLOG_BUFSIZE,         /* rl_head */
   CONFIG_RAMLOG_BUFSIZE,         /* rl_tail */
   NXMUTEX_INITIALIZER,           /* rl_lock */
@@ -180,8 +174,17 @@ static int ramlog_readnotify(FAR struct ramlog_dev_s *priv)
   /* Notify all waiting readers that they can read from the FIFO */
 
   flags = enter_critical_section();
-  for (i = 0; i < priv->rl_nwaiters; i++)
+
+  for (i = 0; ; i++)
     {
+      int semcount = 0;
+
+      sem_getvalue(&priv->rl_waitsem, &semcount);
+      if (semcount >= 0)
+        {
+          break;
+        }
+
       nxsem_post(&priv->rl_waitsem);
     }
 
@@ -518,8 +521,6 @@ static ssize_t ramlog_file_read(FAR struct file *filep, FAR char *buffer,
            * semaphore to wake us up.
            */
 
-          sched_lock();
-          priv->rl_nwaiters++;
           nxmutex_unlock(&priv->rl_lock);
 
           /* We may now be pre-empted!  But that should be okay because we
@@ -529,13 +530,6 @@ static ssize_t ramlog_file_read(FAR struct file *filep, FAR char *buffer,
 
           ret = nxsem_wait(&priv->rl_waitsem);
 
-          /* Interrupts will be disabled when we return.  So the decrementing
-           * rl_nwaiters here is safe.
-           */
-
-          priv->rl_nwaiters--;
-          sched_unlock();
-
           /* Did we successfully get the rl_waitsem? */
 
           if (ret >= 0)