Changeset f9d0a86 in mainline for kernel/generic/src/synch/mutex.c

Timestamp:

2017-11-14T12:24:42Z (6 years ago)

Author:

Aearsis <Hlavaty.Ondrej@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

6cad776

Parents:

887c9de (diff), d2d142a (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

git-author:

Aearsis <Hlavaty.Ondrej@…> (2017-11-14 01:04:19)

git-committer:

Aearsis <Hlavaty.Ondrej@…> (2017-11-14 12:24:42)

Message:

Merge tag '0.7.1'

The merge wasn't clean, because of changes in build system. The most
significant change was partial revert of usbhc callback refactoring,
which now does not take usb transfer batch, but few named fields again.

File:

• kernel/generic/src/synch/mutex.c (modified) (5 diffs)

kernel/generic/src/synch/mutex.c

@@ -46 +46 @@
 /** Initialize mutex.
  *
- * @param mtx  Mutex.
- * @param type Type of the mutex.
+ * @param mtx   Mutex.
+ * @param type  Type of the mutex.
  */
 void mutex_initialize(mutex_t *mtx, mutex_type_t type)
 {
         mtx->type = type;
+        mtx->owner = NULL;
+        mtx->nesting = 0;
         semaphore_initialize(&mtx->sem, 1);
 }
@@ -57 +59 @@
 /** Find out whether the mutex is currently locked.
  *
- * @param mtx           Mutex.
- * @return              True if the mutex is locked, false otherwise.
+ * @param mtx  Mutex.
+ *
+ * @return  True if the mutex is locked, false otherwise.
  */
 bool mutex_locked(mutex_t *mtx)
@@ -71 +74 @@
  * Timeout mode and non-blocking mode can be requested.
  *
- * @param mtx   Mutex.
- * @param usec  Timeout in microseconds.
- * @param flags Specify mode of operation.
+ * @param mtx    Mutex.
+ * @param usec   Timeout in microseconds.
+ * @param flags  Specify mode of operation.
  *
- * For exact description of possible combinations of
- * usec and flags, see comment for waitq_sleep_timeout().
+ * For exact description of possible combinations of usec and flags, see
+ * comment for waitq_sleep_timeout().
  *
  * @return See comment for waitq_sleep_timeout().
@@ -85 +88 @@
         int rc;
 
-        if ((mtx->type == MUTEX_PASSIVE) && (THREAD)) {
+        if (mtx->type == MUTEX_PASSIVE && THREAD) {
                 rc = _semaphore_down_timeout(&mtx->sem, usec, flags);
+        } else if (mtx->type == MUTEX_RECURSIVE) {
+                assert(THREAD);
+
+                if (mtx->owner == THREAD) {
+                        mtx->nesting++;
+                        return ESYNCH_OK_ATOMIC;
+                } else {
+                        rc = _semaphore_down_timeout(&mtx->sem, usec, flags);
+                        if (SYNCH_OK(rc)) {
+                                mtx->owner = THREAD;
+                                mtx->nesting = 1;
+                        }
+                }
         } else {
-                assert((mtx->type == MUTEX_ACTIVE) || (!THREAD));
+                assert((mtx->type == MUTEX_ACTIVE) || !THREAD);
                 assert(usec == SYNCH_NO_TIMEOUT);
                 assert(!(flags & SYNCH_FLAGS_INTERRUPTIBLE));
@@ -114 +130 @@
 /** Release mutex.
  *
- * @param mtx Mutex.
+ * @param mtx  Mutex.
  */
 void mutex_unlock(mutex_t *mtx)
 {
+        if (mtx->type == MUTEX_RECURSIVE) {
+                assert(mtx->owner == THREAD);
+                if (--mtx->nesting > 0)
+                        return;
+                mtx->owner = NULL;
+        }
         semaphore_up(&mtx->sem);
 }