From 87874745c054a872226f00d9b7fe1756ec2c01ab Mon Sep 17 00:00:00 2001
From: Mark Poliakov <mark@alnyan.me>
Date: Fri, 24 Nov 2023 11:06:00 +0200
Subject: [PATCH] Mutexes and threads

---
 src/alloc.rs   | 13 ++++++++++---
 src/process.rs |  3 ++-
 src/sys/mod.rs | 28 ++++++++++++++++++++++++++--
 src/time.rs    |  5 +----
 4 files changed, 39 insertions(+), 10 deletions(-)

diff --git a/src/alloc.rs b/src/alloc.rs
index f74ad3e0..780a1e15 100644
--- a/src/alloc.rs
+++ b/src/alloc.rs
@@ -25,9 +25,16 @@ pub unsafe fn malloc(layout: Layout) -> *mut u8 {
 /// # Safety
 ///
 /// Unsafe.
-pub unsafe fn malloc_zeroed(_layout: Layout) -> *mut u8 {
-    sys::debug_trace("rt::malloc_zeroed()");
-    loop {}
+pub unsafe fn malloc_zeroed(layout: Layout) -> *mut u8 {
+    let ptr = malloc(layout);
+
+    if ptr.is_null() {
+        return ptr;
+    }
+
+    crate::memset(ptr as *mut _, 0, layout.size());
+
+    ptr
 }
 
 /// Frees the memory pointed to by `ptr`.
diff --git a/src/process.rs b/src/process.rs
index e7891faa..29a2085c 100644
--- a/src/process.rs
+++ b/src/process.rs
@@ -1,5 +1,6 @@
 //! Process management data types
 
 pub use abi::process::{
-    ExitCode, ProgramArgumentInner, Signal, SignalEntryData, SpawnOption, SpawnOptions,
+    ExitCode, MutexOperation, ProgramArgumentInner, Signal, SignalEntryData, SpawnOption,
+    SpawnOptions, ThreadSpawnOptions,
 };
diff --git a/src/sys/mod.rs b/src/sys/mod.rs
index 05a76d56..590cd95d 100644
--- a/src/sys/mod.rs
+++ b/src/sys/mod.rs
@@ -1,6 +1,6 @@
 //! System call implementations
 
-use core::{mem::MaybeUninit, time::Duration};
+use core::{mem::MaybeUninit, sync::atomic::AtomicU32, time::Duration};
 
 use abi::{
     error::{Error, SyscallResult},
@@ -8,7 +8,9 @@ use abi::{
         DeviceRequest, DirectoryEntry, FileAttr, FileMode, MountOptions, OpenOptions, RawFd,
         SeekFrom, UnmountOptions,
     },
-    process::{ExitCode, Signal, SignalEntryData, SpawnOptions},
+    process::{
+        ExitCode, MutexOperation, Signal, SignalEntryData, SpawnOptions, ThreadSpawnOptions,
+    },
     syscall::SyscallFunction,
 };
 
@@ -302,6 +304,28 @@ pub unsafe fn spawn_process(options: &SpawnOptions<'_>) -> Result<u32, Error> {
     u32::from_syscall_result(syscall!(SyscallFunction::SpawnProcess, argp!(options as *const _)))
 }
 
+/// System call: spawn a new thread within the caller process.
+///
+/// # Safety
+///
+/// Unsafe: direct system call.
+pub unsafe fn spawn_thread(options: &ThreadSpawnOptions) -> Result<u32, Error> {
+    u32::from_syscall_result(syscall!(SyscallFunction::SpawnThread, argp!(options as *const _)))
+}
+
+/// System call: perform a userspace mutex wait or wake operation.
+///
+/// # Safety
+///
+/// Unsafe: direct system call.
+pub unsafe fn mutex(mutex: &AtomicU32, op: &MutexOperation) -> Result<(), Error> {
+    <()>::from_syscall_result(syscall!(
+        SyscallFunction::Mutex,
+        argp!(mutex as *const _),
+        argp!(op as *const _)
+    ))
+}
+
 /// System call: wait for a process to finish
 ///
 /// # Safety
diff --git a/src/time.rs b/src/time.rs
index 542770d1..5816068d 100644
--- a/src/time.rs
+++ b/src/time.rs
@@ -13,9 +13,6 @@ pub struct Timespec {
 impl Timespec {
     /// Constructs a [Timespec] with all components set to zero
     pub const fn zero() -> Self {
-        Self {
-            seconds: 0,
-            nanoseconds: 0,
-        }
+        Self { seconds: 0, nanoseconds: 0 }
     }
 }