Changeset 564 for trunk/kernel/kern/chdev.h

Timestamp:

Oct 4, 2018, 11:47:36 PM (6 years ago)

Author:

alain

Message:

Complete restructuration of kernel locks.

File:

• trunk/kernel/kern/chdev.h (modified) (4 diffs)

trunk/kernel/kern/chdev.h

@@ -28 +28 @@
 #include <hal_kernel_types.h>
 #include <xlist.h>
-#include <remote_spinlock.h>
+#include <remote_busylock.h>
 #include <dev_iob.h>
 #include <dev_ioc.h>
@@ -43 +43 @@
  * ALMOS-MKH supports multi-channels peripherals, and defines one separated chdev 
  * descriptor for each channel (and for each RX/TX direction for the NIC and TXT devices).
- * Each chdev contains a waiting queue, registering the "client threads" requests,
+ * Each chdev contains a trans-clusters waiting queue, registering the "client threads",
  * and an associated "server thread", handling these requests.
  * These descriptors are physically distributed on all clusters to minimize contention.
@@ -116 +116 @@
  * of client threads is associated to each chdev descriptor (not for ICU, PIC, IOB).
  * For each device type ***, the specific extension is defined in the "dev_***.h" file.
+ *
+ * NOTE : For most chdevs, the busylock is used to protect the waiting queue changes,
+ *        when a thread register in this queue, or is removed after service.
+ *        This busylock is also used to protect direct access to the kernel TXT0 terminal
+ *        (without using the server thread).
  *****************************************************************************************/
 
@@ -136 +141 @@
     uint32_t             irq_id;      /*! associated IRQ index in local ICU              */
 
-        remote_spinlock_t    wait_lock;   /*! lock protecting exclusive access to queue      */
-    xlist_entry_t        wait_root;   /*! root of waiting threads queue                  */
+        xlist_entry_t        wait_root;   /*! root of client threads waiting queue           */
+    remote_busylock_t    wait_lock;   /*! lock protecting waiting queue                  */
 
     union