std: Fail more gracefully on thread spawn errors

On windows, correctly check for errors when spawning threads, and on both
windows and unix handle the error more gracefully rather than printing an opaque
assertion failure.

Closes #13589

diff --git a/src/libstd/rt/thread.rs b/src/libstd/rt/thread.rs
index 4aa85bc4c72a624431ee6ce97217592ae4762c4c..2d952b2a9db17d462a8ff9c1eee58d6fc5a70ed5 100644 (file)
--- a/src/libstd/rt/thread.rs
+++ b/src/libstd/rt/thread.rs
@@ -150,6 +150,7 @@ mod imp {
     use libc;
     use libc::types::os::arch::extra::{LPSECURITY_ATTRIBUTES, SIZE_T, BOOL,
                                        LPVOID, DWORD, LPDWORD, HANDLE};
+    use os;
     use ptr;
     use rt::stack::RED_ZONE;
 
@@ -168,8 +169,15 @@ pub unsafe fn create(stack: uint, p: ~proc():Send) -> rust_thread {
         // kernel does, might as well make it explicit.  With the current
         // 20 kB red zone, that makes for a 64 kB minimum stack.
         let stack_size = (cmp::max(stack, RED_ZONE) + 0xfffe) & (-0xfffe - 1);
-        CreateThread(ptr::mut_null(), stack_size as libc::size_t,
-                     super::thread_start, arg, 0, ptr::mut_null())
+        let ret = CreateThread(ptr::mut_null(), stack_size as libc::size_t,
+                               super::thread_start, arg, 0, ptr::mut_null());
+
+        if ret as uint == 0 {
+            // be sure to not leak the closure
+            let _p: ~proc():Send = cast::transmute(arg);
+            fail!("failed to spawn native thread: {}", os::last_os_error());
+        }
+        return ret;
     }
 
     pub unsafe fn join(native: rust_thread) {
@@ -243,9 +251,14 @@ pub unsafe fn create(stack: uint, p: ~proc():Send) -> rust_thread {
         };
 
         let arg: *libc::c_void = cast::transmute(p);
-        assert_eq!(pthread_create(&mut native, &attr,
-                                  super::thread_start, arg), 0);
+        let ret = pthread_create(&mut native, &attr, super::thread_start, arg);
         assert_eq!(pthread_attr_destroy(&mut attr), 0);
+
+        if ret != 0 {
+            // be sure to not leak the closure
+            let _p: ~proc():Send = cast::transmute(arg);
+            fail!("failed to spawn native thread: {}", os::last_os_error());
+        }
         native
     }