Changeset d23712e in mainline

Timestamp:

2024-01-21T16:23:24Z (11 months ago)

Author:

Jiří Zárevúcky <zarevucky.jiri@…>

Branches:

master

Children:

a5b5f17

Parents:

dfa4be62

git-author:

Jiří Zárevúcky <zarevucky.jiri@…> (2024-01-20 18:01:21)

git-committer:

Jiří Zárevúcky <zarevucky.jiri@…> (2024-01-21 16:23:24)

Message:

Use thread state variable instead of a cpu local variable to pass state

Location:

kernel/generic

Files:

• include/cpu.h (modified) (1 diff)
• include/proc/thread.h (modified) (1 diff)
• src/proc/scheduler.c (modified) (8 diffs)

kernel/generic/include/cpu.h

@@ -78 +78 @@
 
         struct thread *prev_thread;
-        state_t exiting_state;
 } cpu_local_t;
 

kernel/generic/include/proc/thread.h

@@ -193 +193 @@
         bool stolen;
 
-        /** Thread state. */
+        /**
+         * Thread state (state_t).
+         * This is atomic because we read it via some commands for debug output,
+         * otherwise it could just be a regular local.
+         */
         atomic_int_fast32_t state;
 

kernel/generic/src/proc/scheduler.c

@@ -383 +383 @@
 static void thread_requeue_preempted(thread_t *thread)
 {
+        assert(interrupts_disabled());
         assert(atomic_get_unordered(&thread->state) == Running);
         assert(atomic_get_unordered(&thread->cpu) == CPU);
@@ -420 +421 @@
 }
 
-static void cleanup_after_thread(thread_t *thread, state_t out_state)
+static void cleanup_after_thread(thread_t *thread)
 {
         assert(CURRENT->mutex_locks == 0);
@@ -427 +428 @@
         int expected;
 
-        switch (out_state) {
+        switch (atomic_get_unordered(&thread->state)) {
         case Running:
                 thread_requeue_preempted(thread);
@@ -462 +463 @@
                  */
                 panic("tid%" PRIu64 ": unexpected state %s.",
-                    thread->tid, thread_states[out_state]);
+                    thread->tid, thread_states[atomic_get_unordered(&thread->state)]);
                 break;
         }
@@ -501 +502 @@
          */
         after_thread_ran_arch();
-
-        CPU_LOCAL->exiting_state = new_state;
 
         if (new_thread) {
@@ -527 +526 @@
         /* Check if we need to clean up after another thread. */
         if (CPU_LOCAL->prev_thread) {
-                cleanup_after_thread(CPU_LOCAL->prev_thread, CPU_LOCAL->exiting_state);
+                cleanup_after_thread(CPU_LOCAL->prev_thread);
                 CPU_LOCAL->prev_thread = NULL;
         }
@@ -573 +572 @@
                 assert(interrupts_disabled());
 
-                cleanup_after_thread(THREAD, CPU_LOCAL->exiting_state);
+                cleanup_after_thread(THREAD);
 
                 /*
@@ -601 +600 @@
         /* Check if we need to clean up after another thread. */
         if (CPU_LOCAL->prev_thread) {
-                cleanup_after_thread(CPU_LOCAL->prev_thread, CPU_LOCAL->exiting_state);
+                cleanup_after_thread(CPU_LOCAL->prev_thread);
                 CPU_LOCAL->prev_thread = NULL;
         }