Adding a function to stdlib to set the min stack size, for programs

that absolutely will not succeed with a large default stack. This
should be removed once we have stack grown working.

Also updated word-count to succeed under the new test framework.

Author: Eric Holk

src/lib/task.rs

@@ -8,6 +8,8 @@ native "rust" mod rustrt {
     fn clone_chan(c: *rust_chan) -> *rust_chan;
 
     type rust_chan;
+
+    fn set_min_stack(stack_size: uint);
 }
 
 /**
@@ -40,6 +42,10 @@ fn send[T](c: chan[T], v: &T) { c <| v; }
 
 fn recv[T](p: port[T]) -> T { let v; p |> v; v }
 
+fn set_min_stack(uint stack_size) {
+    rustrt::set_min_stack(stack_size);
+}
+
 // Local Variables:
 // mode: rust;
 // fill-column: 78;

src/rt/rust_builtin.cpp

@@ -856,6 +856,13 @@ clone_chan(rust_task *task, rust_chan *chan) {
     return chan->clone(task);
 }
 
+// defined in rust_task.cpp
+extern size_t g_min_stack_size;
+extern "C" CDECL void
+set_min_stack(rust_task *task, uintptr_t stack_size) {
+    g_min_stack_size = stack_size;
+}
+
 //
 // Local Variables:
 // mode: C++

src/rt/rust_task.cpp

@@ -14,14 +14,15 @@
 
 // FIXME (issue #151): This should be 0x300; the change here is for
 // practicality's sake until stack growth is working.
+size_t g_min_stack_size = 0x300000;
 
 static size_t get_min_stk_size() {
     char *stack_size = getenv("RUST_MIN_STACK");
     if(stack_size) {
         return strtol(stack_size, NULL, 0);
     }
     else {
-        return 0x300000;
+        return g_min_stack_size;
     }
 }
 

src/rt/rustrt.def.in

@@ -37,6 +37,7 @@ rust_ptr_eq
 rust_run_program
 rust_start
 rust_getcwd
+set_min_stack
 size_of
 squareroot
 str_alloc

src/test/bench/task-perf-word-count.rs

@@ -1,6 +1,3 @@
-// xfail-stage1
-// xfail-stage2
-// xfail-stage3
 /**
    A parallel word-frequency counting program.
 
@@ -233,10 +230,19 @@ fn main(argv: vec[str]) {
         let out = io::stdout();
 
         out.write_line(#fmt("Usage: %s <filename> ...", argv.(0)));
-        fail;
+
+        // TODO: run something just to make sure the code hasn't
+        // broken yet. This is the unit test mode of this program.
+
+        ret;
     }
 
+    // We can get by with 8k stacks, and we'll probably exhaust our
+    // address space otherwise.
+    task::set_min_stack(8192u);
+
     let start = time::precise_time_ns();
+
     map_reduce::map_reduce(vec::slice(argv, 1u, vec::len(argv)));
     let stop = time::precise_time_ns();
 
@@ -342,4 +348,4 @@ fn is_alpha_upper(c: char) -> bool {
 
 fn is_alpha(c: char) -> bool { is_alpha_upper(c) || is_alpha_lower(c) }
 
-fn is_word_char(c: char) -> bool { is_alpha(c) || is_digit(c) || c == '_' }
+fn is_word_char(c: char) -> bool { is_alpha(c) || is_digit(c) || c == '_' }