From 94a0819fe3a0d679c3042a77bfe6a2afc505daea Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Wed, 17 Apr 2024 14:11:28 +0200
Subject: Adding upstream version 1.66.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 library/std/src/sys/hermit/futex.rs | 39 +++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 library/std/src/sys/hermit/futex.rs

(limited to 'library/std/src/sys/hermit/futex.rs')

diff --git a/library/std/src/sys/hermit/futex.rs b/library/std/src/sys/hermit/futex.rs
new file mode 100644
index 000000000..b64c174b0
--- /dev/null
+++ b/library/std/src/sys/hermit/futex.rs
@@ -0,0 +1,39 @@
+use super::abi;
+use crate::ptr::null;
+use crate::sync::atomic::AtomicU32;
+use crate::time::Duration;
+
+pub fn futex_wait(futex: &AtomicU32, expected: u32, timeout: Option<Duration>) -> bool {
+    // Calculate the timeout as a relative timespec.
+    //
+    // Overflows are rounded up to an infinite timeout (None).
+    let timespec = timeout.and_then(|dur| {
+        Some(abi::timespec {
+            tv_sec: dur.as_secs().try_into().ok()?,
+            tv_nsec: dur.subsec_nanos().into(),
+        })
+    });
+
+    let r = unsafe {
+        abi::futex_wait(
+            futex.as_mut_ptr(),
+            expected,
+            timespec.as_ref().map_or(null(), |t| t as *const abi::timespec),
+            abi::FUTEX_RELATIVE_TIMEOUT,
+        )
+    };
+
+    r != -abi::errno::ETIMEDOUT
+}
+
+#[inline]
+pub fn futex_wake(futex: &AtomicU32) -> bool {
+    unsafe { abi::futex_wake(futex.as_mut_ptr(), 1) > 0 }
+}
+
+#[inline]
+pub fn futex_wake_all(futex: &AtomicU32) {
+    unsafe {
+        abi::futex_wake(futex.as_mut_ptr(), i32::MAX);
+    }
+}
-- 
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