From c06f403dd2e64b438792fcee4f0a257892d4043f Mon Sep 17 00:00:00 2001
From: 17liamnaddell <liamnprg@gmail.com>
Date: Sat, 21 Jul 2018 20:48:33 -0400
Subject: [PATCH] second round of documentation
---
src/context/mod.rs | 2 ++
src/syscall/mod.rs | 5 +++++
src/syscall/time.rs | 2 ++
3 files changed, 9 insertions(+)
diff --git a/src/context/mod.rs b/src/context/mod.rs
index f0bd6c07..e2f09ac0 100644
--- a/src/context/mod.rs
+++ b/src/context/mod.rs
@@ -70,6 +70,8 @@ fn init_contexts() -> RwLock<ContextList> {
/// Get the global schemes list, const
pub fn contexts() -> RwLockReadGuard<'static, ContextList> {
+ //call once will init_contexts only once during the kernel's exececution, otherwise it will return the current context via a
+ //cache.
CONTEXTS.call_once(init_contexts).read()
}
diff --git a/src/syscall/mod.rs b/src/syscall/mod.rs
index b3043b58..4881acd8 100644
--- a/src/syscall/mod.rs
+++ b/src/syscall/mod.rs
@@ -170,6 +170,11 @@ pub fn syscall(a: usize, b: usize, c: usize, d: usize, e: usize, f: usize, bp: u
}
*/
+ // The next lines set the current syscall in the context struct, then once the inner() function
+ // completes, we set the current syscall to none.
+ //
+ // When the code below falls out of scope it will release the lock
+ // see the spin crate for details
{
let contexts = ::context::contexts();
if let Some(context_lock) = contexts.current() {
diff --git a/src/syscall/time.rs b/src/syscall/time.rs
index cef0bba9..e40c2711 100644
--- a/src/syscall/time.rs
+++ b/src/syscall/time.rs
@@ -16,7 +16,9 @@ pub fn clock_gettime(clock: usize, time: &mut TimeSpec) -> Result<usize> {
Ok(0)
}
+/// Nanosleep will sleep by switching the current context
pub fn nanosleep(req: &TimeSpec, rem_opt: Option<&mut TimeSpec>) -> Result<usize> {
+ //start is a tuple of (seconds, nanoseconds)
let start = time::monotonic();
let sum = start.1 + req.tv_nsec as u64;
let end = (start.0 + req.tv_sec as u64 + sum / 1_000_000_000, sum % 1_000_000_000);
--
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