Changeset 111b9b9 in mainline for kernel/generic/include/proc/thread.h

Timestamp:

2023-02-11T19:13:44Z (22 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/proc/thread.h (modified) (4 diffs)

kernel/generic/include/proc/thread.h

@@ -79 +79 @@
         odlink_t lthreads;
 
+        /** Tracking variable for thread_wait/thread_wakeup */
+        atomic_int sleep_state;
+
         /**
          * If true, the thread is terminating.
@@ -85 +88 @@
          */
         volatile bool interrupted;
+
+        /** Wait queue in which this thread sleeps. Used for debug printouts. */
+        _Atomic(waitq_t *) sleep_queue;
 
         /** Waitq for thread_join_timeout(). */
@@ -108 +114 @@
         context_t saved_context;
         ipl_t saved_ipl;
-
-        /**
-         * From here, the stored timeout context
-         * is restored when sleep times out.
-         */
-        context_t sleep_timeout_context;
-
-        /**
-         * From here, the stored interruption context
-         * is restored when sleep is interrupted.
-         */
-        context_t sleep_interruption_context;
-
-        /** If true, the thread can be interrupted from sleep. */
-        bool sleep_interruptible;
-
-        /**
-         * If true, and this thread's sleep returns without a wakeup
-         * (timed out or interrupted), waitq ignores the next wakeup.
-         * This is necessary for futex to be able to handle those conditions.
-         */
-        bool sleep_composable;
-
-        /** Wait queue in which this thread sleeps. */
-        waitq_t *sleep_queue;
 
         /**
@@ -216 +197 @@
 extern void thread_ready(thread_t *);
 extern void thread_exit(void) __attribute__((noreturn));
-extern void thread_interrupt(thread_t *, bool);
+extern void thread_interrupt(thread_t *);
+
+typedef enum {
+        THREAD_OK,
+        THREAD_TERMINATING,
+} thread_termination_state_t;
+
+typedef enum {
+        THREAD_WAIT_SUCCESS,
+        THREAD_WAIT_TIMEOUT,
+} thread_wait_result_t;
+
+extern thread_termination_state_t thread_wait_start(void);
+extern thread_wait_result_t thread_wait_finish(deadline_t);
+extern void thread_wakeup(thread_t *);
 
 static inline thread_t *thread_ref(thread_t *thread)