sched/signal: Initialize signal action pool during init phase

Initialize the signal action pool during the signal initialization
phase to improve performance and reduce footprint.

Signed-off-by: Chengdong Wang <wangchengdong@lixiang.com>

sched/signal/sig_action.c

@@ -62,11 +62,6 @@
 
 static spinlock_t g_sigaction_spin;
 
-#if CONFIG_SIG_PREALLOC_ACTIONS > 0
-static sigactq_t  g_sigactions[CONFIG_SIG_PREALLOC_ACTIONS];
-static bool       g_sigactions_used = false;
-#endif
-
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
@@ -86,23 +81,6 @@ static void nxsig_alloc_actionblock(void)
   irqstate_t flags;
   int i;
 
-  /* Use pre-allocated instances only once */
-
-#if CONFIG_SIG_PREALLOC_ACTIONS > 0
-  flags = spin_lock_irqsave(&g_sigaction_spin);
-  if (!g_sigactions_used)
-    {
-      for (i = 0; i < CONFIG_SIG_PREALLOC_ACTIONS; i++)
-        {
-          sq_addlast((FAR sq_entry_t *)(g_sigactions + i), &g_sigfreeaction);
-        }
-
-      g_sigactions_used = true;
-    }
-
-  spin_unlock_irqrestore(&g_sigaction_spin, flags);
-#endif
-
   /* Allocate a block of signal actions */
 
   sigact = kmm_malloc((sizeof(sigactq_t)) * CONFIG_SIG_ALLOC_ACTIONS);

sched/signal/sig_initialize.c

@@ -51,6 +51,12 @@ struct sigpool_s
  * Public Data
  ****************************************************************************/
 
+/* This is a pool of pre-allocated signal action structures buffers */
+
+#if CONFIG_SIG_PREALLOC_ACTIONS > 0
+sigactq_t  g_sigactions[CONFIG_SIG_PREALLOC_ACTIONS];
+#endif
+
 /* The g_sigfreeaction data structure is a list of available signal
  * action structures.
  */
@@ -94,6 +100,22 @@ static struct sigpool_s g_sigpool;
  * Private Functions
  ****************************************************************************/
 
+#if CONFIG_SIG_PREALLOC_ACTIONS > 0
+static void nxsig_init_signalactionblock(sq_queue_t *siglist,
+                                         FAR sigactq_t *sigact,
+                                         uint16_t nsigs)
+{
+  int i;
+
+  for (i = 0; i < nsigs; i++)
+    {
+      sq_addlast((FAR sq_entry_t *)sigact++, siglist);
+    }
+}
+#else
+#  define nxsig_init_signalactionblock(x, y, z)
+#endif
+
 /****************************************************************************
  * Name: nxsig_init_block
  *
@@ -168,6 +190,9 @@ void nxsig_initialize(void)
   sq_init(&g_sigpendingsignal);
   sq_init(&g_sigpendingirqsignal);
 
+  nxsig_init_signalactionblock(&g_sigfreeaction,
+                               g_sigactions,
+                               CONFIG_SIG_PREALLOC_ACTIONS);
   sigpool = nxsig_init_block(&g_sigpendingaction, sigpool,
                              NUM_PENDING_ACTIONS, SIG_ALLOC_FIXED);
   sigpool = nxsig_init_block(&g_sigpendingirqaction, sigpool,

sched/signal/signal.h

@@ -116,6 +116,12 @@ typedef struct sigq_s sigq_t;
  * Public Data
  ****************************************************************************/
 
+/* The g_sigactions data structure a pool of pre-allocated signal action
+ * structures buffers structures.
+ */
+
+extern  sigactq_t  g_sigactions[CONFIG_SIG_PREALLOC_ACTIONS];
+
 /* The g_sigfreeaction data structure is a list of available signal action
  * structures.
  */