feat(library/std safaos): impl Futex, Mutex, RwLock, Once, and CondVar support

Author: safiworks

library/std/src/sys/pal/safaos/futex.rs

@@ -0,0 +1,34 @@
+use crate::sync::atomic::Atomic;
+use crate::time::Duration;
+
+/// An atomic for use as a futex that is at least 32-bits but may be larger
+pub type Futex = Atomic<Primitive>;
+/// Must be the underlying type of Futex
+pub type Primitive = u32;
+
+/// An atomic for use as a futex that is at least 8-bits but may be larger.
+pub type SmallFutex = Atomic<SmallPrimitive>;
+/// Must be the underlying type of SmallFutex
+pub type SmallPrimitive = u32;
+
+pub fn futex_wait(futex: &Atomic<u32>, expected: u32, timeout: Option<Duration>) -> bool {
+ // FIXME: Infinite timeout is just the max for now
+ let timeout_duration = timeout.unwrap_or(Duration::MAX);
+ let results = safa_api::syscalls::futex::futex_wait(futex, expected, timeout_duration)
+ .expect("FATAL System error while waiting for Futex");
+ results
+}
+
+#[inline]
+pub fn futex_wake(futex: &Atomic<u32>) -> bool {
+ let results = safa_api::syscalls::futex::futex_wake(futex, 1)
+ .expect("FATAL System error while waking 1 Futex")
+ > 0;
+ results
+}
+
+#[inline]
+pub fn futex_wake_all(futex: &Atomic<u32>) {
+ safa_api::syscalls::futex::futex_wake(futex, usize::MAX)
+ .expect("FATAL System error while waking all Futexes");
+}

library/std/src/sys/pal/safaos/mod.rs

@@ -1,5 +1,6 @@
 #![deny(unsafe_op_in_unsafe_fn)]
 
+pub mod futex;
 pub mod os;
 pub mod pipe;
 pub mod resources;

library/std/src/sys/sync/condvar/mod.rs

@@ -9,6 +9,7 @@ cfg_if::cfg_if! {
  target_os = "fuchsia",
  all(target_family = "wasm", target_feature = "atomics"),
  target_os = "hermit",
+ target_os = "safaos",
  ))] {
  mod futex;
  pub use futex::Condvar;

library/std/src/sys/sync/mutex/mod.rs

@@ -8,6 +8,7 @@ cfg_if::cfg_if! {
  target_os = "dragonfly",
  all(target_family = "wasm", target_feature = "atomics"),
  target_os = "hermit",
+ target_os = "safaos",
  ))] {
  mod futex;
  pub use futex::Mutex;

library/std/src/sys/sync/once/mod.rs

@@ -18,6 +18,7 @@ cfg_if::cfg_if! {
  target_os = "dragonfly",
  target_os = "fuchsia",
  target_os = "hermit",
+ target_os = "safaos",
  ))] {
  mod futex;
  pub use futex::{Once, OnceState};

library/std/src/sys/sync/rwlock/mod.rs

@@ -9,6 +9,7 @@ cfg_if::cfg_if! {
  target_os = "fuchsia",
  all(target_family = "wasm", target_feature = "atomics"),
  target_os = "hermit",
+ target_os = "safaos",
  ))] {
  mod futex;
  pub use futex::RwLock;

library/std/src/sys/sync/thread_parking/mod.rs

@@ -9,6 +9,7 @@ cfg_if::cfg_if! {
  target_os = "dragonfly",
  target_os = "fuchsia",
  target_os = "hermit",
+ target_os = "safaos",
  ))] {
  mod futex;
  pub use futex::Parker;