From 3937ff69ebbeeca3d228e6c80f87997e1120e288 Mon Sep 17 00:00:00 2001
From: Alexey Gerasev <alexey.gerasev@gmail.com>
Date: Fri, 23 Dec 2022 19:27:59 +0700
Subject: [PATCH 1/2] Fix semaphore guard lifetime issue

---
 freertos-rust/src/semaphore.rs | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/freertos-rust/src/semaphore.rs b/freertos-rust/src/semaphore.rs
index afa9e16..ad989c8 100644
--- a/freertos-rust/src/semaphore.rs
+++ b/freertos-rust/src/semaphore.rs
@@ -47,9 +47,7 @@ impl Semaphore {
                 return Err(FreeRtosError::Timeout);
             }
 
-            Ok(SemaphoreGuard {
-                __semaphore: self.semaphore,
-            })
+            Ok(SemaphoreGuard { owner: self })
         }
     }
 }
@@ -63,14 +61,14 @@ impl Drop for Semaphore {
 }
 
 /// Holds the lock to the semaphore until we are dropped
-pub struct SemaphoreGuard {
-    __semaphore: FreeRtosSemaphoreHandle,
+pub struct SemaphoreGuard<'a> {
+    owner: &'a Semaphore,
 }
 
-impl Drop for SemaphoreGuard {
+impl<'a> Drop for SemaphoreGuard<'a> {
     fn drop(&mut self) {
         unsafe {
-            freertos_rs_give_mutex(self.__semaphore);
+            freertos_rs_give_mutex(self.owner.semaphore);
         }
     }
 }

From aded7941eb9ddae7b0a1e30c0c2f7dbe3409898d Mon Sep 17 00:00:00 2001
From: Alexey Gerasev <alexey.gerasev@gmail.com>
Date: Fri, 23 Dec 2022 19:28:52 +0700
Subject: [PATCH 2/2] Allow non-RAII semaphore usage

---
 freertos-rust/src/semaphore.rs | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/freertos-rust/src/semaphore.rs b/freertos-rust/src/semaphore.rs
index ad989c8..1c98b8c 100644
--- a/freertos-rust/src/semaphore.rs
+++ b/freertos-rust/src/semaphore.rs
@@ -40,6 +40,15 @@ impl Semaphore {
 
     /// Lock this semaphore in a RAII fashion
     pub fn lock<D: DurationTicks>(&self, max_wait: D) -> Result<SemaphoreGuard, FreeRtosError> {
+        self.take(max_wait).map(|()| SemaphoreGuard { owner: self })
+    }
+
+    /// Returns `true` on success, `false` when semaphore count already reached its limit
+    pub fn give(&self) -> bool {
+        unsafe { freertos_rs_give_mutex(self.semaphore) == 0 }
+    }
+
+    pub fn take<D: DurationTicks>(&self, max_wait: D) -> Result<(), FreeRtosError> {
         unsafe {
             let res = freertos_rs_take_mutex(self.semaphore, max_wait.to_ticks());
 
@@ -47,7 +56,7 @@ impl Semaphore {
                 return Err(FreeRtosError::Timeout);
             }
 
-            Ok(SemaphoreGuard { owner: self })
+            Ok(())
         }
     }
 }
@@ -67,8 +76,6 @@ pub struct SemaphoreGuard<'a> {
 
 impl<'a> Drop for SemaphoreGuard<'a> {
     fn drop(&mut self) {
-        unsafe {
-            freertos_rs_give_mutex(self.owner.semaphore);
-        }
+        self.owner.give();
     }
 }