From 62b51d9152e3289c8054792035ea63088247fead Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Philipp=20Br=C3=BCschweiler?= <blei42@gmail.com>
Date: Thu, 13 Sep 2012 20:47:35 +0200
Subject: [PATCH] rt: Implement ThreadPerCore scheduling mode

Fixes #3465.
---
 src/libcore/task.rs     | 18 ++++++++++++++----
 src/rt/rust_builtin.cpp |  8 +++++++-
 src/rt/rustrt.def.in    |  1 +
 3 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/src/libcore/task.rs b/src/libcore/task.rs
index 8f186d86168ce..2780836599e31 100644
--- a/src/libcore/task.rs
+++ b/src/libcore/task.rs
@@ -1403,11 +1403,9 @@ fn spawn_raw(+opts: TaskOpts, +f: fn~()) {
 
         let num_threads = match opts.mode {
           SingleThreaded => 1u,
-          ThreadPerCore => {
-            fail ~"thread_per_core scheduling mode unimplemented"
-          }
+          ThreadPerCore => rustrt::rust_num_threads(),
           ThreadPerTask => {
-            fail ~"thread_per_task scheduling mode unimplemented"
+            fail ~"ThreadPerTask scheduling mode unimplemented"
           }
           ManualThreads(threads) => {
             if threads == 0u {
@@ -1657,6 +1655,8 @@ extern mod rustrt {
 
     fn rust_get_sched_id() -> sched_id;
     fn rust_new_sched(num_threads: libc::uintptr_t) -> sched_id;
+    fn sched_threads() -> libc::size_t;
+    fn rust_num_threads() -> libc::uintptr_t;
 
     fn get_task_id() -> task_id;
     #[rust_stack]
@@ -2422,3 +2422,13 @@ fn test_tls_cleanup_on_failure() unsafe {
     local_data_set(int_key, @31337);
     fail;
 }
+
+#[test]
+fn test_sched_thread_per_core() {
+    let cores = rustrt::rust_num_threads();
+    let mut reported_threads = 0u;
+    do spawn_sched(ThreadPerCore) {
+        reported_threads = rustrt::sched_threads();
+    }
+    assert(cores == reported_threads);
+}
diff --git a/src/rt/rust_builtin.cpp b/src/rt/rust_builtin.cpp
index b72fdd15e3c0a..a601908359c8c 100644
--- a/src/rt/rust_builtin.cpp
+++ b/src/rt/rust_builtin.cpp
@@ -572,6 +572,12 @@ rust_get_sched_id() {
     return task->sched->get_id();
 }
 
+extern "C" CDECL uintptr_t
+rust_num_threads() {
+    rust_task *task = rust_get_current_task();
+    return task->kernel->env->num_sched_threads;
+}
+
 extern "C" CDECL rust_sched_id
 rust_new_sched(uintptr_t threads) {
     rust_task *task = rust_get_current_task();
@@ -620,7 +626,7 @@ start_task(rust_task *target, fn_env_pair *f) {
     target->start(f->f, f->env, NULL);
 }
 
-extern "C" CDECL int
+extern "C" CDECL size_t
 sched_threads() {
     rust_task *task = rust_get_current_task();
     return task->sched->number_of_threads();
diff --git a/src/rt/rustrt.def.in b/src/rt/rustrt.def.in
index 6a72726b0ae0f..cb2f36fe31ba4 100644
--- a/src/rt/rustrt.def.in
+++ b/src/rt/rustrt.def.in
@@ -32,6 +32,7 @@ rand_seed
 rust_get_sched_id
 rust_new_sched
 rust_new_task_in_sched
+rust_num_threads
 rust_path_is_dir
 rust_path_exists
 rust_getcwd