Revert "posix: rwlock: Refactor locking using k_timepoint_t"

This reverts commit 833eacc.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

Author: nashif

lib/posix/options/rwlock.c

@@ -359,14 +359,24 @@ static uint32_t read_lock_acquire(struct posix_rwlock *rwl, uint32_t timeout)
 static uint32_t write_lock_acquire(struct posix_rwlock *rwl, uint32_t timeout)
 {
 	uint32_t ret = 0U;
-	k_timepoint_t deadline;
+	int64_t elapsed_time, st_time = k_uptime_get();
+	k_timeout_t k_timeout;
 
-	deadline = sys_timepoint_calc(SYS_TIMEOUT_MS(timeout));
+	k_timeout = SYS_TIMEOUT_MS(timeout);
 
 	/* waiting for release of write lock */
-	if (sys_sem_take(&rwl->wr_sem, sys_timepoint_timeout(deadline)) == 0) {
+	if (sys_sem_take(&rwl->wr_sem, k_timeout) == 0) {
+		/* update remaining timeout time for 2nd sem */
+		if (timeout != SYS_FOREVER_MS) {
+			elapsed_time = k_uptime_get() - st_time;
+			timeout = timeout <= elapsed_time ? 0 :
+				  timeout - elapsed_time;
+		}
+
+		k_timeout = SYS_TIMEOUT_MS(timeout);
+
 		/* waiting for reader to complete operation */
-		if (sys_sem_take(&rwl->reader_active, sys_timepoint_timeout(deadline)) == 0) {
+		if (sys_sem_take(&rwl->reader_active, k_timeout) == 0) {
 			rwl->wr_owner = k_current_get();
 		} else {
 			(void)sys_sem_give(&rwl->wr_sem);