diff --git a/src/libnative/io/net.rs b/src/libnative/io/net.rs index aaa95ce0cfb..9f307fcebb0 100644 --- a/src/libnative/io/net.rs +++ b/src/libnative/io/net.rs @@ -164,19 +164,14 @@ pub fn init() { } unsafe { - use std::unstable::mutex::{Mutex, MUTEX_INIT}; - static mut LOCK: Mutex = MUTEX_INIT; - static mut INITIALIZED: bool = false; - if INITIALIZED { return } - LOCK.lock(); - if !INITIALIZED { + use std::unstable::mutex::{Once, ONCE_INIT}; + static mut INIT: Once = ONCE_INIT; + INIT.doit(|| { let mut data: WSADATA = intrinsics::init(); let ret = WSAStartup(0x202, // version 2.2 &mut data); assert_eq!(ret, 0); - INITIALIZED = true; - } - LOCK.unlock(); + }); } } diff --git a/src/librustc/back/link.rs b/src/librustc/back/link.rs index e761a14a3ac..75edf6c80e6 100644 --- a/src/librustc/back/link.rs +++ b/src/librustc/back/link.rs @@ -310,9 +310,8 @@ pub mod write { } unsafe fn configure_llvm(sess: Session) { - use std::unstable::mutex::{MUTEX_INIT, Mutex}; - static mut LOCK: Mutex = MUTEX_INIT; - static mut CONFIGURED: bool = false; + use std::unstable::mutex::{Once, ONCE_INIT}; + static mut INIT: Once = ONCE_INIT; // Copy what clan does by turning on loop vectorization at O2 and // slp vectorization at O3 @@ -341,8 +340,7 @@ pub mod write { add(*arg); } - LOCK.lock(); - if !CONFIGURED { + INIT.doit(|| { llvm::LLVMInitializePasses(); // Only initialize the platforms supported by Rust here, because @@ -369,9 +367,7 @@ pub mod write { llvm::LLVMRustSetLLVMOptions(llvm_args.len() as c_int, llvm_args.as_ptr()); - CONFIGURED = true; - } - LOCK.unlock(); + }); } unsafe fn populate_llvm_passes(fpm: lib::llvm::PassManagerRef, diff --git a/src/librustc/lib/llvm.rs b/src/librustc/lib/llvm.rs index 50a35e9d1bf..46bc79e3e3d 100644 --- a/src/librustc/lib/llvm.rs +++ b/src/librustc/lib/llvm.rs @@ -1455,6 +1455,9 @@ pub mod llvm { BufferName: *c_char) -> MemoryBufferRef; + pub fn LLVMIsMultithreaded() -> Bool; + pub fn LLVMStartMultithreaded() -> Bool; + /** Returns a string describing the last error caused by an LLVMRust* call. */ pub fn LLVMRustGetLastError() -> *c_char; @@ -1462,8 +1465,6 @@ pub mod llvm { /// Print the pass timings since static dtors aren't picking them up. pub fn LLVMRustPrintPassTimings(); - pub fn LLVMRustStartMultithreading() -> bool; - pub fn LLVMStructCreateNamed(C: ContextRef, Name: *c_char) -> TypeRef; pub fn LLVMStructSetBody(StructTy: TypeRef, diff --git a/src/librustc/middle/trans/base.rs b/src/librustc/middle/trans/base.rs index 0b2ee710e99..f308b8a0291 100644 --- a/src/librustc/middle/trans/base.rs +++ b/src/librustc/middle/trans/base.rs @@ -3189,8 +3189,21 @@ pub fn trans_crate(sess: session::Session, analysis: &CrateAnalysis, output: &Path) -> CrateTranslation { // Before we touch LLVM, make sure that multithreading is enabled. - if unsafe { !llvm::LLVMRustStartMultithreading() } { - sess.bug("couldn't enable multi-threaded LLVM"); + unsafe { + use std::unstable::mutex::{Once, ONCE_INIT}; + static mut INIT: Once = ONCE_INIT; + static mut POISONED: bool = false; + INIT.doit(|| { + if llvm::LLVMStartMultithreaded() != 1 { + // use an extra bool to make sure that all future usage of LLVM + // cannot proceed despite the Once not running more than once. + POISONED = true; + } + }); + + if POISONED { + sess.bug("couldn't enable multi-threaded LLVM"); + } } let mut symbol_hasher = Sha256::new(); diff --git a/src/libstd/rt/local_ptr.rs b/src/libstd/rt/local_ptr.rs index 42cce272e44..f13691a7bfe 100644 --- a/src/libstd/rt/local_ptr.rs +++ b/src/libstd/rt/local_ptr.rs @@ -160,30 +160,20 @@ pub mod native { use option::{Option, Some, None}; use ptr; use tls = rt::thread_local_storage; - use unstable::mutex::{Mutex, MUTEX_INIT}; - static mut LOCK: Mutex = MUTEX_INIT; - static mut INITIALIZED: bool = false; static mut RT_TLS_KEY: tls::Key = -1; /// Initialize the TLS key. Other ops will fail if this isn't executed /// first. pub fn init() { unsafe { - LOCK.lock(); - if !INITIALIZED { - tls::create(&mut RT_TLS_KEY); - INITIALIZED = true; - } - LOCK.unlock(); + tls::create(&mut RT_TLS_KEY); } } pub unsafe fn cleanup() { - rtassert!(INITIALIZED); + rtassert!(RT_TLS_KEY != -1); tls::destroy(RT_TLS_KEY); - LOCK.destroy(); - INITIALIZED = false; } /// Give a pointer to thread-local storage. diff --git a/src/libstd/unstable/mutex.rs b/src/libstd/unstable/mutex.rs index 0361296ff38..6dbac90ef66 100644 --- a/src/libstd/unstable/mutex.rs +++ b/src/libstd/unstable/mutex.rs @@ -47,6 +47,7 @@ #[allow(non_camel_case_types)]; +use int; use libc::c_void; use sync::atomics; @@ -339,15 +340,15 @@ mod imp { /// ``` pub struct Once { priv mutex: Mutex, - priv cnt: AtomicInt, - priv lock_cnt: AtomicInt, + priv cnt: atomics::AtomicInt, + priv lock_cnt: atomics::AtomicInt, } /// Initialization value for static `Once` values. pub static ONCE_INIT: Once = Once { mutex: MUTEX_INIT, - cnt: INIT_ATOMIC_INT, - lock_cnt: INIT_ATOMIC_INT, + cnt: atomics::INIT_ATOMIC_INT, + lock_cnt: atomics::INIT_ATOMIC_INT, }; impl Once { @@ -388,11 +389,11 @@ impl Once { // calling `doit` will return immediately before the initialization has // completed. - let prev = self.cnt.fetch_add(1, SeqCst); + let prev = self.cnt.fetch_add(1, atomics::SeqCst); if prev < 0 { // Make sure we never overflow, we'll never have int::min_value // simultaneous calls to `doit` to make this value go back to 0 - self.cnt.store(int::min_value, SeqCst); + self.cnt.store(int::min_value, atomics::SeqCst); return } @@ -400,15 +401,15 @@ impl Once { // otherwise we run the job and record how many people will try to grab // this lock unsafe { self.mutex.lock() } - if self.cnt.load(SeqCst) > 0 { + if self.cnt.load(atomics::SeqCst) > 0 { f(); - let prev = self.cnt.swap(int::min_value, SeqCst); - self.lock_cnt.store(prev, SeqCst); + let prev = self.cnt.swap(int::min_value, atomics::SeqCst); + self.lock_cnt.store(prev, atomics::SeqCst); } unsafe { self.mutex.unlock() } // Last one out cleans up after everyone else, no leaks! - if self.lock_cnt.fetch_add(-1, SeqCst) == 1 { + if self.lock_cnt.fetch_add(-1, atomics::SeqCst) == 1 { unsafe { self.mutex.destroy() } } } @@ -416,6 +417,8 @@ impl Once { #[cfg(test)] mod test { + use prelude::*; + use rt::thread::Thread; use super::{ONCE_INIT, Once, Mutex, MUTEX_INIT}; use task; diff --git a/src/rustllvm/RustWrapper.cpp b/src/rustllvm/RustWrapper.cpp index d66f90a5352..335c7b2c65b 100644 --- a/src/rustllvm/RustWrapper.cpp +++ b/src/rustllvm/RustWrapper.cpp @@ -149,28 +149,6 @@ extern "C" LLVMValueRef LLVMInlineAsm(LLVMTypeRef Ty, IsAlignStack, (InlineAsm::AsmDialect) Dialect)); } -/** - * This function is intended to be a threadsafe interface into enabling a - * multithreaded LLVM. This is invoked at the start of the translation phase of - * compilation to ensure that LLVM is ready. - * - * All of trans properly isolates LLVM with the use of a different - * LLVMContextRef per task, thus allowing parallel compilation of different - * crates in the same process. At the time of this writing, the use case for - * this is unit tests for rusti, but there are possible other applications. - */ -extern "C" bool LLVMRustStartMultithreading() { - static Mutex lock; - bool ret = true; - assert(lock.acquire()); - if (!LLVMIsMultithreaded()) { - ret = LLVMStartMultithreaded(); - } - assert(lock.release()); - return ret; -} - - typedef DIBuilder* DIBuilderRef; template