From: Mara Bos <m-ou.se@m-ou.se>
Date: Wed, 30 Sep 2020 23:13:26 +0000 (+0200)
Subject: Make it possible to have unboxed condvars on specific platforms.
X-Git-Url: https://git.lizzy.rs/?a=commitdiff_plain;h=b181f5a9231c133e2809277932d3a92cb2627b70;p=rust.git

Make it possible to have unboxed condvars on specific platforms.

This commit keeps all condvars boxed on all platforms, but makes it
trivial to remove the box on some platforms later.
---

diff --git a/library/std/src/sys/cloudabi/condvar.rs b/library/std/src/sys/cloudabi/condvar.rs
index dabdc0c9b51..148a684370e 100644
--- a/library/std/src/sys/cloudabi/condvar.rs
+++ b/library/std/src/sys/cloudabi/condvar.rs
@@ -15,6 +15,8 @@ pub struct Condvar {
     condvar: UnsafeCell<AtomicU32>,
 }
 
+pub type MovableCondvar = Box<Condvar>;
+
 unsafe impl Send for Condvar {}
 unsafe impl Sync for Condvar {}
 
diff --git a/library/std/src/sys/hermit/condvar.rs b/library/std/src/sys/hermit/condvar.rs
index 52c8c3b17e8..b45e8718f08 100644
--- a/library/std/src/sys/hermit/condvar.rs
+++ b/library/std/src/sys/hermit/condvar.rs
@@ -14,6 +14,8 @@ pub struct Condvar {
     sem2: *const c_void,
 }
 
+pub type MovableCondvar = Box<Condvar>;
+
 unsafe impl Send for Condvar {}
 unsafe impl Sync for Condvar {}
 
diff --git a/library/std/src/sys/sgx/condvar.rs b/library/std/src/sys/sgx/condvar.rs
index ed6dbcf4971..dfe22e6a1b3 100644
--- a/library/std/src/sys/sgx/condvar.rs
+++ b/library/std/src/sys/sgx/condvar.rs
@@ -7,6 +7,8 @@ pub struct Condvar {
     inner: SpinMutex<WaitVariable<()>>,
 }
 
+pub type MovableCondvar = Box<Condvar>;
+
 impl Condvar {
     pub const fn new() -> Condvar {
         Condvar { inner: SpinMutex::new(WaitVariable::new(())) }
diff --git a/library/std/src/sys/unix/condvar.rs b/library/std/src/sys/unix/condvar.rs
index 9f1847943f3..e38f91af9f0 100644
--- a/library/std/src/sys/unix/condvar.rs
+++ b/library/std/src/sys/unix/condvar.rs
@@ -6,6 +6,8 @@ pub struct Condvar {
     inner: UnsafeCell<libc::pthread_cond_t>,
 }
 
+pub type MovableCondvar = Box<Condvar>;
+
 unsafe impl Send for Condvar {}
 unsafe impl Sync for Condvar {}
 
diff --git a/library/std/src/sys/unsupported/condvar.rs b/library/std/src/sys/unsupported/condvar.rs
index a578eee8ccc..e49f21bef78 100644
--- a/library/std/src/sys/unsupported/condvar.rs
+++ b/library/std/src/sys/unsupported/condvar.rs
@@ -3,6 +3,8 @@
 
 pub struct Condvar {}
 
+pub type MovableCondvar = Box<Condvar>;
+
 impl Condvar {
     pub const fn new() -> Condvar {
         Condvar {}
diff --git a/library/std/src/sys/vxworks/condvar.rs b/library/std/src/sys/vxworks/condvar.rs
index 5a77966d974..b4724be7c7c 100644
--- a/library/std/src/sys/vxworks/condvar.rs
+++ b/library/std/src/sys/vxworks/condvar.rs
@@ -6,6 +6,8 @@ pub struct Condvar {
     inner: UnsafeCell<libc::pthread_cond_t>,
 }
 
+pub type MovableCondvar = Box<Condvar>;
+
 unsafe impl Send for Condvar {}
 unsafe impl Sync for Condvar {}
 
diff --git a/library/std/src/sys/wasm/condvar_atomics.rs b/library/std/src/sys/wasm/condvar_atomics.rs
index d86bb60507b..304c3bb4c58 100644
--- a/library/std/src/sys/wasm/condvar_atomics.rs
+++ b/library/std/src/sys/wasm/condvar_atomics.rs
@@ -9,6 +9,8 @@ pub struct Condvar {
     cnt: AtomicUsize,
 }
 
+pub type MovableCondvar = Box<Condvar>;
+
 // Condition variables are implemented with a simple counter internally that is
 // likely to cause spurious wakeups. Blocking on a condition variable will first
 // read the value of the internal counter, unlock the given mutex, and then
diff --git a/library/std/src/sys/windows/condvar.rs b/library/std/src/sys/windows/condvar.rs
index 8f7f6854cc2..2b2ff13c78b 100644
--- a/library/std/src/sys/windows/condvar.rs
+++ b/library/std/src/sys/windows/condvar.rs
@@ -8,6 +8,8 @@ pub struct Condvar {
     inner: UnsafeCell<c::CONDITION_VARIABLE>,
 }
 
+pub type MovableCondvar = Box<Condvar>;
+
 unsafe impl Send for Condvar {}
 unsafe impl Sync for Condvar {}
 
diff --git a/library/std/src/sys_common/condvar.rs b/library/std/src/sys_common/condvar.rs
index acd8b69e9ac..2c02e1cd33c 100644
--- a/library/std/src/sys_common/condvar.rs
+++ b/library/std/src/sys_common/condvar.rs
@@ -9,14 +9,14 @@
 
 /// An OS-based condition variable.
 pub struct Condvar {
-    inner: Box<imp::Condvar>,
+    inner: imp::MovableCondvar,
     check: CondvarCheck,
 }
 
 impl Condvar {
     /// Creates a new condition variable for use.
     pub fn new() -> Self {
-        let mut c = box imp::Condvar::new();
+        let mut c = imp::MovableCondvar::from(imp::Condvar::new());
         unsafe { c.init() };
         Self { inner: c, check: CondvarCheck::new() }
     }