diff --git a/src/rc/autorelease.rs b/src/rc/autorelease.rs new file mode 100644 index 000000000..3b68b8d76 --- /dev/null +++ b/src/rc/autorelease.rs @@ -0,0 +1,29 @@ +use std::os::raw::c_void; +use runtime::{objc_autoreleasePoolPush, objc_autoreleasePoolPop}; + +// we use a struct to ensure that objc_autoreleasePoolPop during unwinding. +struct AutoReleaseHelper { + context: *mut c_void, +} + +impl AutoReleaseHelper { + unsafe fn new() -> Self { + AutoReleaseHelper { context: objc_autoreleasePoolPush() } + } +} + +impl Drop for AutoReleaseHelper { + fn drop(&mut self) { + unsafe { objc_autoreleasePoolPop(self.context) } + } +} + +/** +Execute `f` in the context of a new autorelease pool. The pool is drained +after the execution of `f` completes. This corresponds to @autoreleasepool blocks +in Objective-c and Swift. +*/ +pub fn autoreleasepool(f: F) { + let _context = unsafe { AutoReleaseHelper::new() }; + f(); +} diff --git a/src/rc/mod.rs b/src/rc/mod.rs index 4eda1b3dd..8f70ece86 100644 --- a/src/rc/mod.rs +++ b/src/rc/mod.rs @@ -11,15 +11,18 @@ For more information on Objective-C's reference counting, see Apple's documentat mod strong; mod weak; +mod autorelease; pub use self::strong::StrongPtr; pub use self::weak::WeakPtr; +pub use self::autorelease::autoreleasepool; // These tests use NSObject, which isn't present for GNUstep #[cfg(all(test, any(target_os = "macos", target_os = "ios")))] mod tests { use runtime::Object; use super::StrongPtr; + use super::autoreleasepool; #[test] fn test_strong_clone() { @@ -66,4 +69,24 @@ mod tests { let strong = weak2.load(); assert!(*strong == *obj); } + + #[test] + fn test_autorelease() { + let obj = unsafe { + StrongPtr::new(msg_send![class!(NSObject), new]) + }; + + fn retain_count(obj: *mut Object) -> usize { + unsafe { msg_send![obj, retainCount] } + } + let cloned = obj.clone(); + + autoreleasepool(|| { + obj.autorelease(); + assert!(retain_count(*cloned) == 2); + }); + + // make sure that the autoreleased value has been released + assert!(retain_count(*cloned) == 1); + } } diff --git a/src/runtime.rs b/src/runtime.rs index 46ae9396e..3b533efe6 100644 --- a/src/runtime.rs +++ b/src/runtime.rs @@ -109,6 +109,9 @@ extern { pub fn objc_allocateProtocol(name: *const c_char) -> *mut Protocol; pub fn objc_registerProtocol(proto: *mut Protocol); + pub fn objc_autoreleasePoolPush() -> *mut c_void; + pub fn objc_autoreleasePoolPop(context: *mut c_void); + pub fn protocol_addMethodDescription(proto: *mut Protocol, name: Sel, types: *const c_char, isRequiredMethod: BOOL, isInstanceMethod: BOOL); pub fn protocol_addProtocol(proto: *mut Protocol, addition: *const Protocol);