From ad152ad968b7c5f9bbaf99aefe9f91f701cf1179 Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Thu, 20 Oct 2016 21:50:11 -0600
Subject: [PATCH] Remove unnecessary context switch in waitpid
---
syscall/process.rs | 42 +++++++++++++++++++-----------------------
1 file changed, 19 insertions(+), 23 deletions(-)
diff --git a/syscall/process.rs b/syscall/process.rs
index ddd2cec9..5d35af6c 100644
--- a/syscall/process.rs
+++ b/syscall/process.rs
@@ -896,33 +896,29 @@ pub fn virttophys(virtual_address: usize) -> Result<usize> {
pub fn waitpid(pid: usize, status_ptr: usize, flags: usize) -> Result<usize> {
loop {
+ let mut exited = false;
+ let waitpid;
{
- let mut exited = false;
- let waitpid;
- {
- let contexts = context::contexts();
- let context_lock = contexts.get(pid).ok_or(Error::new(ESRCH))?;
- let context = context_lock.read();
- if let context::Status::Exited(status) = context.status {
- if status_ptr != 0 {
- let status_slice = validate_slice_mut(status_ptr as *mut usize, 1)?;
- status_slice[0] = status;
- }
- exited = true;
+ let contexts = context::contexts();
+ let context_lock = contexts.get(pid).ok_or(Error::new(ESRCH))?;
+ let context = context_lock.read();
+ if let context::Status::Exited(status) = context.status {
+ if status_ptr != 0 {
+ let status_slice = validate_slice_mut(status_ptr as *mut usize, 1)?;
+ status_slice[0] = status;
}
- waitpid = context.waitpid.clone();
- }
-
- if exited {
- let mut contexts = context::contexts_mut();
- return contexts.remove(pid).ok_or(Error::new(ESRCH)).and(Ok(pid));
- } else if flags & WNOHANG == WNOHANG {
- return Ok(0);
- } else {
- waitpid.wait();
+ exited = true;
}
+ waitpid = context.waitpid.clone();
}
- unsafe { context::switch(); } //TODO: Block
+ if exited {
+ let mut contexts = context::contexts_mut();
+ return contexts.remove(pid).ok_or(Error::new(ESRCH)).and(Ok(pid));
+ } else if flags & WNOHANG == WNOHANG {
+ return Ok(0);
+ } else {
+ waitpid.wait();
+ }
}
}
--
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