Panic the task or ISR upon trying to block when it must not.

src/sync/mailbox.rs

@@ -3,7 +3,7 @@ use crate::{
     interrupt::context_switch,
     schedule::{current, scheduler::Scheduler},
     task::{Task, TaskState},
-    time, unrecoverable,
+    time,
 };
 use alloc::sync::Arc;
 use core::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
@@ -178,7 +178,12 @@ impl Mailbox {
     ///
     /// NOTE: *must not* call this method in ISR context.
     pub fn wait(&self) {
-        unrecoverable::die_if_in_isr();
+        // The application logic must have gone terribly wrong if the task
+        // tries to block when the scheduler is suspended or if an ISR
+        // tries to block. In this case, panic the task or ISR.
+        if Scheduler::is_suspended() || current::is_in_isr_context() {
+            panic!();
+        }
 
         let mut should_block = true;
 
@@ -230,7 +235,12 @@ impl Mailbox {
     ///
     /// NOTE: *must not* call this method in ISR context.
     pub fn wait_until_timeout(&self, timeout_ms: u32) -> bool {
-        unrecoverable::die_if_in_isr();
+        // The application logic must have gone terribly wrong if the task
+        // tries to block when the scheduler is suspended or if an ISR
+        // tries to block. In this case, panic the task or ISR.
+        if Scheduler::is_suspended() || current::is_in_isr_context() {
+            panic!();
+        }
 
         let mut should_block = true;
 

src/sync/wait_queue.rs

@@ -5,7 +5,6 @@ use crate::{
     interrupt::context_switch,
     schedule::{current, scheduler::Scheduler},
     task::{TaskListAdapter, TaskListInterfaces, TaskState},
-    unrecoverable,
 };
 use core::sync::atomic::{AtomicUsize, Ordering};
 use intrusive_collections::LinkedList;
@@ -97,8 +96,6 @@ impl WaitQueue {
     #[inline]
     #[allow(unused)]
     pub(super) fn wait(&self) {
-        unrecoverable::die_if_in_isr();
-
         add_cur_task_to_block_queue(self);
 
         // We have put the current task to the wait queue.
@@ -108,6 +105,13 @@ impl WaitQueue {
         // Outline the logic to reduce the stack frame size of `.wait()`.
         #[inline(never)]
         fn add_cur_task_to_block_queue(wq: &WaitQueue) {
+            // The application logic must have gone terribly wrong if the task
+            // tries to block when the scheduler is suspended or if an ISR
+            // tries to block. In this case, panic the task or ISR.
+            if Scheduler::is_suspended() || current::is_in_isr_context() {
+                panic!();
+            }
+
             // Should always grant full access to a task.
             wq.inner.with_suspended_scheduler(|queue, sched_guard| {
                 queue.must_with_full_access(|full_access| {
@@ -140,8 +144,6 @@ impl WaitQueue {
     where
         F: FnMut() -> Option<R>,
     {
-        unrecoverable::die_if_in_isr();
-
         // Keep blocking until the predicate is satisfied.
         loop {
             let res = add_cur_task_to_block_queue_with_condition(self, &mut condition);
@@ -165,6 +167,13 @@ impl WaitQueue {
         where
             F: FnMut() -> Option<R>,
         {
+            // The application logic must have gone terribly wrong if the task
+            // tries to block when the scheduler is suspended or if an ISR
+            // tries to block. In this case, panic the task or ISR.
+            if Scheduler::is_suspended() || current::is_in_isr_context() {
+                panic!();
+            }
+
             // Should always grant full access to a task.
             wq.inner.with_suspended_scheduler(|queue, sched_guard| {
                 queue.must_with_full_access(|full_access| {
@@ -216,8 +225,6 @@ impl WaitQueue {
         G: UnlockableGuard<'a, LockType = L>,
         L: Lockable<GuardType<'a> = G> + 'a,
     {
-        unrecoverable::die_if_in_isr();
-
         // Keep blocking until the predicate is satisfied.
         loop {
             let res = add_cur_task_to_block_queue_and_unlock(self, guard, &mut condition);
@@ -248,6 +255,13 @@ impl WaitQueue {
             G: UnlockableGuard<'a, LockType = L>,
             L: Lockable<GuardType<'a> = G> + 'a,
         {
+            // The application logic must have gone terribly wrong if the task
+            // tries to block when the scheduler is suspended or if an ISR
+            // tries to block. In this case, panic the task or ISR.
+            if Scheduler::is_suspended() || current::is_in_isr_context() {
+                panic!();
+            }
+
             // Should always grant full access to a task.
             wq.inner.with_suspended_scheduler(|queue, sched_guard| {
                 queue.must_with_full_access(|full_access| {

src/time/mod.rs

@@ -156,6 +156,13 @@ fn sleep_ms_unchecked(ms: u32) {
     // Outline the logic to reduce the stack frame size of `sleep_ms`.
     #[inline(never)]
     fn add_cur_task_to_sleep_queue(wake_at_tick: u32) {
+        // The application logic must have gone terribly wrong if the task
+        // tries to block when the scheduler is suspended or if an ISR
+        // tries to block. In this case, panic the task or ISR.
+        if Scheduler::is_suspended() || current::is_in_isr_context() {
+            panic!();
+        }
+
         current::with_cur_task_arc(|cur_task| {
             cur_task.set_state(TaskState::Blocked);
             add_task_to_sleep_queue(cur_task, wake_at_tick);

src/unrecoverable/mod.rs

@@ -1,5 +1,3 @@
-use crate::schedule::current;
-
 pub trait Lethal {
     type T;
     fn unwrap_or_die(self) -> Self::T;
@@ -36,9 +34,3 @@ where
         die()
     }
 }
-
-pub fn die_if_in_isr() {
-    if current::is_in_isr_context() {
-        die();
-    }
-}