---

yaml
---
r: 11292
b: refs/heads/master
c: a53a08e
h: refs/heads/master
v: v3

Author: brson

[refs]

@@ -1,5 +1,5 @@
 ---
-refs/heads/master: 44d4889bc24a09259cf8a7fbf89ded78ab1e64bc
+refs/heads/master: a53a08e1b980e5cf5f9707ef1d1f27b89ff7ed99
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: 4a81779abd786ff22d71434c6d9a5917ea4cdfff
 refs/heads/try: 2898dcc5d97da9427ac367542382b6239d9c0bbf

trunk/src/rt/rust_task.h

@@ -205,6 +205,7 @@ rust_task : public kernel_owned<rust_task>, rust_cond
 
     void call_on_c_stack(void *args, void *fn_ptr);
     void call_on_rust_stack(void *args, void *fn_ptr);
+    bool have_c_stack() { return c_stack != NULL; }
 };
 
 // This stuff is on the stack-switching fast path

trunk/src/rt/rust_task_thread.cpp

@@ -70,7 +70,7 @@ rust_task_thread::activate(rust_task *task) {
     task->ctx.next = &c_context;
     DLOG(this, task, "descheduling...");
     lock.unlock();
-    prepare_c_stack();
+    prepare_c_stack(task);
     task->ctx.swap(c_context);
     unprepare_c_stack();
     lock.lock();
@@ -367,9 +367,9 @@ rust_task_thread::exit() {
 // stack), because once we're on the Rust stack we won't have enough
 // room to do the allocation
 void
-rust_task_thread::prepare_c_stack() {
+rust_task_thread::prepare_c_stack(rust_task *task) {
     I(this, !extra_c_stack);
-    if (!cached_c_stack) {
+    if (!cached_c_stack && !task->have_c_stack()) {
         cached_c_stack = create_stack(kernel, C_STACK_SIZE);
         prepare_valgrind_stack(cached_c_stack);
     }

trunk/src/rt/rust_task_thread.h

@@ -98,7 +98,7 @@ struct rust_task_thread : public kernel_owned<rust_task_thread>,
     stk_seg *cached_c_stack;
     stk_seg *extra_c_stack;
 
-    void prepare_c_stack();
+    void prepare_c_stack(rust_task *task);
     void unprepare_c_stack();
 
 public: