From 5ae7b7efe777af393e486129827850098fcc3daf Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jeremy@system76.com>
Date: Wed, 23 Dec 2020 12:20:19 -0700
Subject: [PATCH] Use new semaphore to prevent spinning
---
src/platform/pte.rs | 28 ++++------------------------
1 file changed, 4 insertions(+), 24 deletions(-)
diff --git a/src/platform/pte.rs b/src/platform/pte.rs
index ea0d209be..39e004582 100644
--- a/src/platform/pte.rs
+++ b/src/platform/pte.rs
@@ -16,15 +16,10 @@ use crate::{
types::{c_int, c_uint, c_void, pid_t, size_t},
Pal, Sys,
},
- sync::Mutex,
+ sync::{Mutex, Semaphore},
ALLOCATOR,
};
-pub struct Semaphore {
- lock: Mutex<()>,
- count: i32,
-}
-
type pte_osThreadHandle = pid_t;
type pte_osMutexHandle = *mut Mutex<()>;
type pte_osSemaphoreHandle = *mut Semaphore;
@@ -324,10 +319,7 @@ pub unsafe extern "C" fn pte_osSemaphoreCreate(
initialValue: c_int,
pHandle: *mut pte_osSemaphoreHandle,
) -> pte_osResult {
- *pHandle = Box::into_raw(Box::new(Semaphore {
- lock: Mutex::new(()),
- count: initialValue,
- }));
+ *pHandle = Box::into_raw(Box::new(Semaphore::new(initialValue)));
PTE_OS_OK
}
@@ -342,9 +334,7 @@ pub unsafe extern "C" fn pte_osSemaphorePost(
handle: pte_osSemaphoreHandle,
count: c_int,
) -> pte_osResult {
- let semaphore = &mut *handle;
- let _guard = semaphore.lock.lock();
- intrinsics::atomic_xadd(&mut semaphore.count, 1);
+ (*handle).post();
PTE_OS_OK
}
@@ -354,17 +344,7 @@ pub unsafe extern "C" fn pte_osSemaphorePend(
pTimeout: *mut c_uint,
) -> pte_osResult {
//TODO: pTimeout
- let semaphore = &mut *handle;
- loop {
- {
- let _guard = semaphore.lock.lock();
- if intrinsics::atomic_load(&semaphore.count) > 0 {
- intrinsics::atomic_xsub(&mut semaphore.count, 1);
- break;
- }
- }
- Sys::sched_yield();
- }
+ (*handle).wait();
PTE_OS_OK
}
--
GitLab