anchao commented on code in PR #18148:
URL: https://github.com/apache/nuttx/pull/18148#discussion_r2730153243
##########
include/nuttx/spinlock.h:
##########
@@ -617,6 +617,76 @@ irqstate_t rspin_lock_irqsave_nopreempt(FAR rspinlock_t
*lock)
return flags;
}
+/****************************************************************************
+ * Name: rspin_trylock/rspin_trylock_irqsave/rspin_trylock_irqsave_nopreempt
+ *
+ * Description:
+ * Nest supported spinlock, try once to lock the rspinlock, can support
+ * UINT16_MAX max depth.
+ * As we should not disable irq for long time, sched also locked.
+ * Similar feature with enter_critical_section, but isolate by instance.
+ *
+ * If SPINLOCK is enabled:
+ * Will take spinlock each cpu first call.
+ *
+ * If SPINLOCK is not enabled:
+ * Equivalent to up_irq_save() + sched_lock().
+ * Will only sched_lock once when first called.
+ *
+ * Input Parameters:
+ * lock - Caller specific rspinlock_s. not NULL.
+ *
+ * Returned Value:
+ * true - Success, the spinlock was successfully locked
+ * false - Failure, the spinlock was already locked
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_SPINLOCK
+static inline_function bool rspin_trylock(FAR rspinlock_t *lock)
+{
+ rspinlock_t new_val;
+ rspinlock_t old_val = RSPINLOCK_INITIALIZER;
+ int cpu = this_cpu() + 1;
+
+ /* Already owned this lock. */
+
+ if (lock->owner == cpu)
+ {
+ lock->count += 1;
+ return true;
+ }
+
+ new_val.count = 1;
+ new_val.owner = cpu;
+
+ /* Try seize the ownership of the lock. */
+
+ return atomic_cmpxchg_acquire((FAR atomic_t *)&lock->val,
+ (FAR atomic_t *)&old_val.val, new_val.val);
+}
+
+# define rspin_trylock_irqsave(l, f) \
+ ({ \
+ (f) = up_irq_save(); \
+ rspin_trylock(l) ? \
+ true : ({ up_irq_restore(f); false; }); \
+ })
+#else
+# define rspin_trylock_irqsave(l, f) \
+ ({ \
+ (void)(l); \
+ (f) = up_irq_save(); \
+ true; \
+ })
+#endif
+
+#define rspin_trylock_irqsave_nopreempt(l, f) \
Review Comment:
oops, I lost endif above
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