std: Fix perf of local allocations in newsched

Mostly optimizing TLS accesses to bring local heap allocation performance
closer to that of oldsched. It's not completely at parity but removing the
branches involved in supporting oldsched and optimizing pthread_get/setspecific
to instead use our dedicated TCB slot will probably make up for it.

1 files changed, 32 insertions, 19 deletions

diff --git a/src/libstd/rt/mod.rs b/src/libstd/rt/mod.rs
index 01a52892f63..be71bc651df 100644
--- a/src/libstd/rt/mod.rs
+++ b/src/libstd/rt/mod.rs
@@ -407,14 +407,10 @@ fn run_(main: ~fn(), use_main_sched: bool) -> int {
 /// or the old scheduler.
 #[deriving(Eq)]
 pub enum RuntimeContext {
-    // Only the exchange heap is available
-    GlobalContext,
-    // The scheduler may be accessed
-    SchedulerContext,
-    // Full task services, e.g. local heap, unwinding
-    TaskContext,
     // Running in an old-style task
-    OldTaskContext
+    OldTaskContext,
+    // Not old task context
+    NewRtContext
 }
 
 /// Determine the current RuntimeContext
@@ -424,19 +420,8 @@ pub fn context() -> RuntimeContext {
 
     if unsafe { rust_try_get_task().is_not_null() } {
         return OldTaskContext;
-    } else if Local::exists::<Task>() {
-        // In this case we know it is a new runtime context, but we
-        // need to check which one. Going to try borrowing task to
-        // check. Task should always be in TLS, so hopefully this
-        // doesn't conflict with other ops that borrow.
-        return do Local::borrow::<Task,RuntimeContext> |task| {
-            match task.task_type {
-                SchedTask => SchedulerContext,
-                GreenTask(_) => TaskContext
-            }
-        };
     } else {
-        return GlobalContext;
+        return NewRtContext;
     }
 
     extern {
@@ -444,3 +429,31 @@ pub fn context() -> RuntimeContext {
         pub fn rust_try_get_task() -> *rust_task;
     }
 }
+
+pub fn in_sched_context() -> bool {
+    unsafe {
+        match Local::try_unsafe_borrow::<Task>() {
+            Some(task) => {
+                match (*task).task_type {
+                    SchedTask => true,
+                    _ => false
+                }
+            }
+            None => false
+        }
+    }
+}
+
+pub fn in_green_task_context() -> bool {
+    unsafe {
+        match Local::try_unsafe_borrow::<Task>() {
+            Some(task) => {
+                match (*task).task_type {
+                    GreenTask(_) => true,
+                    _ => false
+                }
+            }
+            None => false
+        }
+    }
+}
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