Changeset 111b9b9 in mainline for kernel/generic/include/synch/waitq.h

Timestamp:

2023-02-11T19:13:44Z (20 months ago)

Author:

Jiří Zárevúcky <zarevucky.jiri@…>

Branches:

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

Children:

4777e02

Parents:

76e17d7c

git-author:

Jiří Zárevúcky <zarevucky.jiri@…> (2022-08-15 17:46:39)

git-committer:

Jiří Zárevúcky <zarevucky.jiri@…> (2023-02-11 19:13:44)

Message:

Reimplement waitq using thread_wait/wakeup

This adds a few functions to the thread API which can be
summarized as "stop running until woken up by others".
The ordering and context-switching concerns are thus yeeted
to this abstraction and waitq only deals with maintaining
the queues. Overall, this makes the control flow in waitq
much easier to navigate.

File:

• kernel/generic/include/synch/waitq.h (modified) (3 diffs)

kernel/generic/include/synch/waitq.h

@@ -41 +41 @@
 #include <adt/list.h>
 
-typedef enum {
-        WAKEUP_FIRST = 0,
-        WAKEUP_ALL,
-        WAKEUP_CLOSE,
-} wakeup_mode_t;
-
 /** Wait queue structure.
  *
@@ -58 +52 @@
 
         /**
-         * Number of waitq_wakeup() calls that didn't find a thread to wake up.
-         *
+         * If negative, number of wakeups that are to be ignored (necessary for futex operation).
+         * If positive, number of wakeups that weren't able to wake a thread.
          */
-        int missed_wakeups;
-
-        /** Number of wakeups that need to be ignored due to futex timeout. */
-        int ignore_wakeups;
+        int wakeup_balance;
 
         /** List of sleeping threads for which there was no missed_wakeup. */
         list_t sleepers;
+
+        bool closed;
 } waitq_t;
+
+typedef struct wait_guard {
+        ipl_t ipl;
+} wait_guard_t;
 
 struct thread;
@@ -75 +72 @@
 extern void waitq_initialize_with_count(waitq_t *, int);
 extern errno_t waitq_sleep(waitq_t *);
-extern errno_t waitq_sleep_timeout(waitq_t *, uint32_t, unsigned int, bool *);
-extern ipl_t waitq_sleep_prepare(waitq_t *);
-extern errno_t waitq_sleep_unsafe(waitq_t *, bool *);
-extern errno_t waitq_sleep_timeout_unsafe(waitq_t *, uint32_t, unsigned int, bool *);
-extern void waitq_sleep_finish(waitq_t *, bool, ipl_t);
-extern void waitq_wakeup(waitq_t *, wakeup_mode_t);
-extern void _waitq_wakeup_unsafe(waitq_t *, wakeup_mode_t);
-extern void waitq_interrupt_sleep(struct thread *);
+extern errno_t _waitq_sleep_timeout(waitq_t *, uint32_t, unsigned int);
+extern errno_t waitq_sleep_timeout(waitq_t *, uint32_t);
+extern wait_guard_t waitq_sleep_prepare(waitq_t *);
+extern errno_t waitq_sleep_unsafe(waitq_t *, wait_guard_t);
+extern errno_t waitq_sleep_timeout_unsafe(waitq_t *, uint32_t, unsigned int, wait_guard_t);
+
+extern void waitq_wake_one(waitq_t *);
+extern void waitq_wake_all(waitq_t *);
+extern void waitq_signal(waitq_t *);
+extern void waitq_close(waitq_t *);
 
 #endif