libcxx initial import

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@103490 91177308-0d34-0410-b5e6-96231b3b80d8

src/mutex.cpp

@@ -0,0 +1,246 @@
+//===------------------------- mutex.cpp ----------------------------------===//
+//
+// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "mutex"
+#include "limits"
+#include "system_error"
+#include "cassert"
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+const defer_lock_t  defer_lock = {};
+const try_to_lock_t try_to_lock = {};
+const adopt_lock_t  adopt_lock = {};
+
+mutex::~mutex()
+{
+    int e = pthread_mutex_destroy(&__m_);
+//     assert(e == 0);
+}
+
+void
+mutex::lock()
+{
+    int ec = pthread_mutex_lock(&__m_);
+    if (ec)
+        __throw_system_error(ec, "mutex lock failed");
+}
+
+bool
+mutex::try_lock()
+{
+    return pthread_mutex_trylock(&__m_) == 0;
+}
+
+void
+mutex::unlock()
+{
+    int ec = pthread_mutex_unlock(&__m_);
+    assert(ec == 0);
+}
+
+// recursive_mutex
+
+recursive_mutex::recursive_mutex()
+{
+    pthread_mutexattr_t attr;
+    int ec = pthread_mutexattr_init(&attr);
+    if (ec)
+        goto fail;
+    ec = pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
+    if (ec)
+    {
+        pthread_mutexattr_destroy(&attr);
+        goto fail;
+    }
+    ec = pthread_mutex_init(&__m_, &attr);
+    if (ec)
+    {
+        pthread_mutexattr_destroy(&attr);
+        goto fail;
+    }
+    ec = pthread_mutexattr_destroy(&attr);
+    if (ec)
+    {
+        pthread_mutex_destroy(&__m_);
+        goto fail;
+    }
+    return;
+fail:
+    __throw_system_error(ec, "recursive_mutex constructor failed");
+}
+
+recursive_mutex::~recursive_mutex()
+{
+    int e = pthread_mutex_destroy(&__m_);
+    assert(e == 0);
+}
+
+void
+recursive_mutex::lock()
+{
+    int ec = pthread_mutex_lock(&__m_);
+    if (ec)
+        __throw_system_error(ec, "recursive_mutex lock failed");
+}
+
+void
+recursive_mutex::unlock()
+{
+    int e = pthread_mutex_unlock(&__m_);
+    assert(e == 0);
+}
+
+bool
+recursive_mutex::try_lock()
+{
+    return pthread_mutex_trylock(&__m_) == 0;
+}
+
+// timed_mutex
+
+timed_mutex::timed_mutex()
+    : __locked_(false)
+{
+}
+
+timed_mutex::~timed_mutex()
+{
+    lock_guard<mutex> _(__m_);
+}
+
+void
+timed_mutex::lock()
+{
+    unique_lock<mutex> lk(__m_);
+    while (__locked_)
+        __cv_.wait(lk);
+    __locked_ = true;
+}
+
+bool
+timed_mutex::try_lock()
+{
+    unique_lock<mutex> lk(__m_, try_to_lock);
+    if (lk.owns_lock() && !__locked_)
+    {
+        __locked_ = true;
+        return true;
+    }
+    return false;
+}
+
+void
+timed_mutex::unlock()
+{
+    lock_guard<mutex> _(__m_);
+    __locked_ = false;
+    __cv_.notify_one();
+}
+
+// recursive_timed_mutex
+
+recursive_timed_mutex::recursive_timed_mutex()
+    : __count_(0),
+      __id_(nullptr)
+{
+}
+
+recursive_timed_mutex::~recursive_timed_mutex()
+{
+    lock_guard<mutex> _(__m_);
+}
+
+void
+recursive_timed_mutex::lock()
+{
+    pthread_t id = pthread_self();
+    unique_lock<mutex> lk(__m_);
+    if (pthread_equal(id, __id_))
+    {
+        if (__count_ == numeric_limits<size_t>::max())
+            __throw_system_error(EAGAIN, "recursive_timed_mutex lock limit reached");
+        ++__count_;
+        return;
+    }
+    while (__count_ != 0)
+        __cv_.wait(lk);
+    __count_ = 1;
+    __id_ = id;
+}
+
+bool
+recursive_timed_mutex::try_lock()
+{
+    pthread_t id = pthread_self();
+    unique_lock<mutex> lk(__m_, try_to_lock);
+    if (lk.owns_lock() && (__count_ == 0 || pthread_equal(id, __id_)))
+    {
+        if (__count_ == numeric_limits<size_t>::max())
+            return false;
+        ++__count_;
+        __id_ = id;
+        return true;
+    }
+    return false;
+}
+
+void
+recursive_timed_mutex::unlock()
+{
+    unique_lock<mutex> lk(__m_);
+    if (--__count_ == 0)
+    {
+        __id_ = nullptr;
+        lk.unlock();
+        __cv_.notify_one();
+    }
+}
+
+// If dispatch_once_f ever handles C++ exceptions, and if one can get to it
+// without illegal macros (unexpected macros not beginning with _UpperCase or
+// __lowercase), and if it stops spinning waiting threads, then call_once should
+// call into dispatch_once_f instead of here. Relevant radar this code needs to
+// keep in sync with:  7741191.
+
+static pthread_mutex_t mut = PTHREAD_MUTEX_INITIALIZER;
+static pthread_cond_t  cv  = PTHREAD_COND_INITIALIZER;
+
+void
+__call_once(volatile unsigned long& flag, void* arg, void(*func)(void*))
+{
+    pthread_mutex_lock(&mut);
+    while (flag == 1)
+        pthread_cond_wait(&cv, &mut);
+    if (flag == 0)
+    {
+        try
+        {
+            flag = 1;
+            pthread_mutex_unlock(&mut);
+            func(arg);
+            pthread_mutex_lock(&mut);
+            flag = ~0ul;
+            pthread_mutex_unlock(&mut);
+            pthread_cond_broadcast(&cv);
+        }
+        catch (...)
+        {
+            pthread_mutex_lock(&mut);
+            flag = 0ul;
+            pthread_mutex_unlock(&mut);
+            pthread_cond_signal(&cv);
+            throw;
+        }
+    }
+    else
+        pthread_mutex_unlock(&mut);
+}
+
+_LIBCPP_END_NAMESPACE_STD