Implement reentrant mutexes and make stdio use them

write_fmt calls write for each formatted field. The default implementation of write_fmt is used,
which will call write on not-yet-locked stdout (and write locking after), therefore making print!
in multithreaded environment still interleave contents of two separate prints.

This patch implements reentrant mutexes, changes stdio handles to use these mutexes and overrides
write_fmt to lock the stdio handle for the whole duration of the call.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/libstd/sys/common/mod.rs b/src/libstd/sys/common/mod.rs
index d2e2f1044d6..8a01eace889 100644
--- a/src/libstd/sys/common/mod.rs
+++ b/src/libstd/sys/common/mod.rs
@@ -29,6 +29,8 @@ pub mod condvar;
 pub mod mutex;
 pub mod net;
 pub mod net2;
+pub mod poison;
+pub mod remutex;
 pub mod rwlock;
 pub mod stack;
 pub mod thread;