mirror of
https://github.com/llvm/llvm-project.git
synced 2025-04-27 14:46:10 +00:00
a45877eea8
Now that everything is forcibly linker initialized, it feels like a good time to get rid of the `init`/`initLinkerInitialized` split. This allows to get rid of various `memset` construct in `init` that gcc complains about (this fixes a Fuchsia open issue). I added various `DCHECK`s to ensure that we would get a zero-inited object when entering `init`, which required ensuring that `unmapTestOnly` leaves the object in a good state (tests are currently the only location where an allocator can be "de-initialized"). Running the tests with `--gtest_repeat=` showed no issue. Differential Revision: https://reviews.llvm.org/D103119
73 lines
1.7 KiB
C++
73 lines
1.7 KiB
C++
//===-- mutex.h -------------------------------------------------*- C++ -*-===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef SCUDO_MUTEX_H_
|
|
#define SCUDO_MUTEX_H_
|
|
|
|
#include "atomic_helpers.h"
|
|
#include "common.h"
|
|
|
|
#include <string.h>
|
|
|
|
#if SCUDO_FUCHSIA
|
|
#include <lib/sync/mutex.h> // for sync_mutex_t
|
|
#endif
|
|
|
|
namespace scudo {
|
|
|
|
class HybridMutex {
|
|
public:
|
|
bool tryLock();
|
|
NOINLINE void lock() {
|
|
if (LIKELY(tryLock()))
|
|
return;
|
|
// The compiler may try to fully unroll the loop, ending up in a
|
|
// NumberOfTries*NumberOfYields block of pauses mixed with tryLocks. This
|
|
// is large, ugly and unneeded, a compact loop is better for our purpose
|
|
// here. Use a pragma to tell the compiler not to unroll the loop.
|
|
#ifdef __clang__
|
|
#pragma nounroll
|
|
#endif
|
|
for (u8 I = 0U; I < NumberOfTries; I++) {
|
|
yieldProcessor(NumberOfYields);
|
|
if (tryLock())
|
|
return;
|
|
}
|
|
lockSlow();
|
|
}
|
|
void unlock();
|
|
|
|
private:
|
|
static constexpr u8 NumberOfTries = 8U;
|
|
static constexpr u8 NumberOfYields = 8U;
|
|
|
|
#if SCUDO_LINUX
|
|
atomic_u32 M = {};
|
|
#elif SCUDO_FUCHSIA
|
|
sync_mutex_t M = {};
|
|
#endif
|
|
|
|
void lockSlow();
|
|
};
|
|
|
|
class ScopedLock {
|
|
public:
|
|
explicit ScopedLock(HybridMutex &M) : Mutex(M) { Mutex.lock(); }
|
|
~ScopedLock() { Mutex.unlock(); }
|
|
|
|
private:
|
|
HybridMutex &Mutex;
|
|
|
|
ScopedLock(const ScopedLock &) = delete;
|
|
void operator=(const ScopedLock &) = delete;
|
|
};
|
|
|
|
} // namespace scudo
|
|
|
|
#endif // SCUDO_MUTEX_H_
|