xiaoxiang781216 commented on code in PR #15075:
URL: https://github.com/apache/nuttx/pull/15075#discussion_r1877801792
##########
sched/semaphore/sem_trywait.c:
##########
@@ -38,6 +38,76 @@
#include "sched/sched.h"
#include "semaphore/semaphore.h"
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: nxsem_trywait_slow
+ *
+ * Description:
+ * This function locks the specified semaphore in slow mode.
+ *
+ * Input Parameters:
+ * sem - the semaphore descriptor
+ *
+ * Returned Value:
+ *
+ * EINVAL - Invalid attempt to get the semaphore
+ * EAGAIN - The semaphore is not available.
+ *
+ * Assumptions:
+ *
+ ****************************************************************************/
+
+static int nxsem_trywait_slow(FAR sem_t *sem)
+{
+ FAR struct tcb_s *rtcb;
+ irqstate_t flags;
+ int32_t semcount;
+ int ret;
+
+ /* The following operations must be performed with interrupts disabled
+ * because sem_post() may be called from an interrupt handler.
+ */
+
+ flags = enter_critical_section();
+ rtcb = this_task();
+
+ /* If the semaphore is available, give it to the requesting task */
+
+ semcount = atomic_read(NXSEM_COUNT(sem));
+ do
+ {
+ if (semcount <= 0)
+ {
+ leave_critical_section(flags);
+ return -EAGAIN;
+ }
+ }
+ while (!atomic_try_cmpxchg_acquire(NXSEM_COUNT(sem),
+ &semcount, semcount - 1));
+
+ /* It is, let the task take the semaphore */
+
+ ret = nxsem_protect_wait(sem);
+ if (ret < 0)
+ {
+ atomic_fetch_add(NXSEM_COUNT(sem), 1);
+ leave_critical_section(flags);
+ return ret;
+ }
+
+ nxsem_add_holder(sem);
+ rtcb->waitobj = NULL;
+ ret = OK;
Review Comment:
remove
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