From b26213731c7a459f54ed80eabd0cfe584ca7d01e Mon Sep 17 00:00:00 2001
From: jD91mZM2 <me@krake.one>
Date: Wed, 8 Aug 2018 13:25:26 +0200
Subject: [PATCH] Don't forget to lock stdout when printfing
---
src/platform/src/lib.rs | 34 +++++++++++++++--------------
src/stdio/src/lib.rs | 48 ++++++++++++++++++++++++++---------------
src/stdio/src/scanf.rs | 12 +++++++----
3 files changed, 57 insertions(+), 37 deletions(-)
diff --git a/src/platform/src/lib.rs b/src/platform/src/lib.rs
index 1921a024..37964737 100644
--- a/src/platform/src/lib.rs
+++ b/src/platform/src/lib.rs
@@ -129,12 +129,12 @@ impl<'a, W: Write> Write for &'a mut W {
}
pub trait Read {
- fn read_u8(&mut self, byte: &mut u8) -> bool;
+ fn read_u8(&mut self) -> Result<Option<u8>, ()>;
}
impl<'a, R: Read> Read for &'a mut R {
- fn read_u8(&mut self, byte: &mut u8) -> bool {
- (**self).read_u8(byte)
+ fn read_u8(&mut self) -> Result<Option<u8>, ()> {
+ (**self).read_u8()
}
}
@@ -169,11 +169,13 @@ impl FileReader {
}
impl Read for FileReader {
- fn read_u8(&mut self, byte: &mut u8) -> bool {
- let mut buf = [*byte];
- let n = self.read(&mut buf);
- *byte = buf[0];
- n > 0
+ fn read_u8(&mut self) -> Result<Option<u8>, ()> {
+ let mut buf = [0];
+ match self.read(&mut buf) {
+ 0 => Ok(None),
+ n if n < 0 => Err(()),
+ _ => Ok(Some(buf[0]))
+ }
}
}
@@ -241,13 +243,13 @@ impl Write for UnsafeStringWriter {
pub struct StringReader<'a>(pub &'a [u8]);
impl<'a> Read for StringReader<'a> {
- fn read_u8(&mut self, byte: &mut u8) -> bool {
+ fn read_u8(&mut self) -> Result<Option<u8>, ()> {
if self.0.is_empty() {
- false
+ Ok(None)
} else {
- *byte = self.0[0];
+ let byte = self.0[0];
self.0 = &self.0[1..];
- true
+ Ok(Some(byte))
}
}
}
@@ -255,14 +257,14 @@ impl<'a> Read for StringReader<'a> {
pub struct UnsafeStringReader(pub *const u8);
impl Read for UnsafeStringReader {
- fn read_u8(&mut self, byte: &mut u8) -> bool {
+ fn read_u8(&mut self) -> Result<Option<u8>, ()> {
unsafe {
if *self.0 == 0 {
- false
+ Ok(None)
} else {
- *byte = *self.0;
+ let byte = *self.0;
self.0 = self.0.offset(1);
- true
+ Ok(Some(byte))
}
}
}
diff --git a/src/stdio/src/lib.rs b/src/stdio/src/lib.rs
index e9b25a8f..993a88ff 100644
--- a/src/stdio/src/lib.rs
+++ b/src/stdio/src/lib.rs
@@ -16,7 +16,7 @@ extern crate string;
extern crate va_list as vl;
use core::fmt::Write as WriteFmt;
-use core::fmt::{self, Error, Result};
+use core::fmt::{self, Error};
use core::sync::atomic::{AtomicBool, Ordering};
use core::{ptr, str};
@@ -171,38 +171,52 @@ impl FILE {
pub fn seek(&self, off: off_t, whence: c_int) -> off_t {
platform::lseek(self.fd, off, whence)
}
+
+ pub fn lock(&mut self) -> LockGuard {
+ flockfile(self);
+ LockGuard(self)
+ }
+}
+
+pub struct LockGuard<'a>(&'a mut FILE);
+impl<'a> Drop for LockGuard<'a> {
+ fn drop(&mut self) {
+ funlockfile(self.0);
+ }
}
-impl fmt::Write for FILE {
- fn write_str(&mut self, s: &str) -> Result {
- if !self.can_write() {
+
+impl<'a> fmt::Write for LockGuard<'a> {
+ fn write_str(&mut self, s: &str) -> fmt::Result {
+ if !self.0.can_write() {
return Err(Error);
}
let s = s.as_bytes();
- if self.write(s) != s.len() {
+ if self.0.write(s) != s.len() {
Err(Error)
} else {
Ok(())
}
}
}
-impl Write for FILE {
- fn write_u8(&mut self, byte: u8) -> Result {
- if !self.can_write() {
+impl<'a> Write for LockGuard<'a> {
+ fn write_u8(&mut self, byte: u8) -> fmt::Result {
+ if !self.0.can_write() {
return Err(Error);
}
- if self.write(&[byte]) != 1 {
+ if self.0.write(&[byte]) != 1 {
Err(Error)
} else {
Ok(())
}
}
}
-impl Read for FILE {
- fn read_u8(&mut self, byte: &mut u8) -> bool {
- let mut buf = [*byte];
- let n = self.read(&mut buf);
- *byte = buf[0];
- n > 0
+impl<'a> Read for LockGuard<'a> {
+ fn read_u8(&mut self) -> Result<Option<u8>, ()> {
+ let mut buf = [0];
+ match self.0.read(&mut buf) {
+ 0 => Ok(None),
+ _ => Ok(Some(buf[0]))
+ }
}
}
@@ -913,7 +927,7 @@ pub extern "C" fn ungetc(c: c_int, stream: &mut FILE) -> c_int {
#[no_mangle]
pub unsafe extern "C" fn vfprintf(file: &mut FILE, format: *const c_char, ap: va_list) -> c_int {
- printf::printf(file, format, ap)
+ printf::printf(file.lock(), format, ap)
}
#[no_mangle]
@@ -942,7 +956,7 @@ pub unsafe extern "C" fn vsprintf(s: *mut c_char, format: *const c_char, ap: va_
#[no_mangle]
pub unsafe extern "C" fn vfscanf(file: &mut FILE, format: *const c_char, ap: va_list) -> c_int {
- scanf::scanf(file, format, ap)
+ scanf::scanf(file.lock(), format, ap)
}
#[no_mangle]
diff --git a/src/stdio/src/scanf.rs b/src/stdio/src/scanf.rs
index 2a1ae921..2652c141 100644
--- a/src/stdio/src/scanf.rs
+++ b/src/stdio/src/scanf.rs
@@ -39,11 +39,15 @@ unsafe fn inner_scanf<R: Read>(
macro_rules! read {
() => {{
- let n = r.read_u8(&mut byte);
- if n {
- count += 1;
+ match r.read_u8() {
+ Ok(Some(b)) => {
+ byte = b;
+ count += 1;
+ true
+ },
+ Ok(None) => false,
+ Err(()) => return Err(-1)
}
- n
}};
}
--
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