From fee78d296c66e0b10600c7fefbbe07f33406fe97 Mon Sep 17 00:00:00 2001
From: Tim Chevalier <chevalier@alum.wellesley.edu>
Date: Thu, 21 Jun 2012 21:30:16 -0700
Subject: [PATCH] Port resources to classes in libcore

---
 src/libcore/io.rs     | 34 +++++++++++++++++++++++-----------
 src/libcore/option.rs |  6 ++++--
 src/libcore/sys.rs    | 22 +++++++++++++---------
 src/libcore/task.rs   |  7 +++++--
 4 files changed, 45 insertions(+), 24 deletions(-)

diff --git a/src/libcore/io.rs b/src/libcore/io.rs
index 635b3f9ebf4..df1cf16781d 100644
--- a/src/libcore/io.rs
+++ b/src/libcore/io.rs
@@ -224,7 +224,11 @@ impl <T: reader, C> of reader for {base: T, cleanup: C} {
     fn tell() -> uint { self.base.tell() }
 }
 
-resource FILE_res(f: *libc::FILE) { libc::fclose(f); }
+class FILE_res {
+    let f: *libc::FILE;
+    new(f: *libc::FILE) { self.f = f; }
+    drop { libc::fclose(self.f); }
+}
 
 fn FILE_reader(f: *libc::FILE, cleanup: bool) -> reader {
     if cleanup {
@@ -383,7 +387,11 @@ impl of writer for fd_t {
     fn flush() -> int { 0 }
 }
 
-resource fd_res(fd: fd_t) { libc::close(fd); }
+class fd_res {
+    let fd: fd_t;
+    new(fd: fd_t) { self.fd = fd; }
+    drop { libc::close(self.fd); }
+}
 
 fn fd_writer(fd: fd_t, cleanup: bool) -> writer {
     if cleanup {
@@ -695,13 +703,17 @@ mod fsync {
     }
 
 
-    // Resource of artifacts that need to fsync on destruction
-    resource res<t>(arg: arg<t>) {
-        alt arg.opt_level {
-          option::none { }
-          option::some(level) {
-            // fail hard if not succesful
-            assert(arg.fsync_fn(arg.val, level) != -1);
+    // Artifacts that need to fsync on destruction
+    class res<t> {
+        let arg: arg<t>;
+        new(-arg: arg<t>) { self.arg <- arg; }
+        drop {
+          alt self.arg.opt_level {
+            option::none { }
+            option::some(level) {
+              // fail hard if not succesful
+              assert(self.arg.fsync_fn(self.arg.val, level) != -1);
+            }
           }
         }
     }
@@ -718,7 +730,7 @@ mod fsync {
     fn FILE_res_sync(&&file: FILE_res, opt_level: option<level>,
                   blk: fn(&&res<*libc::FILE>)) {
         blk(res({
-            val: *file, opt_level: opt_level,
+            val: file.f, opt_level: opt_level,
             fsync_fn: fn@(&&file: *libc::FILE, l: level) -> int {
                 ret os::fsync_fd(libc::fileno(file), l) as int;
             }
@@ -729,7 +741,7 @@ mod fsync {
     fn fd_res_sync(&&fd: fd_res, opt_level: option<level>,
                    blk: fn(&&res<fd_t>)) {
         blk(res({
-            val: *fd, opt_level: opt_level,
+            val: fd.fd, opt_level: opt_level,
             fsync_fn: fn@(&&fd: fd_t, l: level) -> int {
                 ret os::fsync_fd(fd, l) as int;
             }
diff --git a/src/libcore/option.rs b/src/libcore/option.rs
index 98090ba8514..72305906010 100644
--- a/src/libcore/option.rs
+++ b/src/libcore/option.rs
@@ -140,8 +140,10 @@ fn test_unwrap_str() {
 
 #[test]
 fn test_unwrap_resource() {
-    resource r(i: @mut int) {
-        *i += 1;
+    class r {
+       let i: @mut int;
+       new(i: @mut int) { self.i = i; }
+       drop { *(self.i) += 1; }
     }
     let i = @mut 0;
     {
diff --git a/src/libcore/sys.rs b/src/libcore/sys.rs
index 77207d8aebf..53e8e4017ba 100644
--- a/src/libcore/sys.rs
+++ b/src/libcore/sys.rs
@@ -85,16 +85,20 @@ pure fn log_str<T>(t: T) -> str {
     }
 }
 
-resource lock_and_signal(lock: rust_cond_lock) {
-    rustrt::rust_destroy_cond_lock(lock);
+class lock_and_signal {
+    let lock: rust_cond_lock;
+    new(lock: rust_cond_lock) { self.lock = lock; }
+    drop { rustrt::rust_destroy_cond_lock(self.lock); }
 }
 
 enum condition {
     condition_(rust_cond_lock)
 }
 
-resource unlock(lock: rust_cond_lock) {
-    rustrt::rust_unlock_cond_lock(lock);
+class unlock {
+    let lock: rust_cond_lock;
+    new(lock: rust_cond_lock) { self.lock = lock; }
+    drop { rustrt::rust_unlock_cond_lock(self.lock); }
 }
 
 fn create_lock() -> lock_and_signal {
@@ -103,15 +107,15 @@ fn create_lock() -> lock_and_signal {
 
 impl methods for lock_and_signal {
     fn lock<T>(f: fn() -> T) -> T {
-        rustrt::rust_lock_cond_lock(*self);
-        let _r = unlock(*self);
+        rustrt::rust_lock_cond_lock(self.lock);
+        let _r = unlock(self.lock);
         f()
     }
 
     fn lock_cond<T>(f: fn(condition) -> T) -> T {
-        rustrt::rust_lock_cond_lock(*self);
-        let _r = unlock(*self);
-        f(condition_(*self))
+        rustrt::rust_lock_cond_lock(self.lock);
+        let _r = unlock(self.lock);
+        f(condition_(self.lock))
     }
 }
 
diff --git a/src/libcore/task.rs b/src/libcore/task.rs
index ab9b4f7d3d7..2a746d76127 100644
--- a/src/libcore/task.rs
+++ b/src/libcore/task.rs
@@ -482,9 +482,12 @@ Temporarily make the task unkillable
 
 "]
 unsafe fn unkillable(f: fn()) {
-    resource allow_failure(_i: ()) {
-        rustrt::rust_task_allow_kill();
+    class allow_failure {
+      let i: (); // since a class must have at least one field
+      new(_i: ()) { self.i = (); }
+      drop { rustrt::rust_task_allow_kill(); }
     }
+
     let _allow_failure = allow_failure(());
     rustrt::rust_task_inhibit_kill();
     f();