zig/lib/tsan/tsan_sync.h

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//===-- tsan_sync.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
//
//===----------------------------------------------------------------------===//
//
// This file is a part of ThreadSanitizer (TSan), a race detector.
//
//===----------------------------------------------------------------------===//
#ifndef TSAN_SYNC_H
#define TSAN_SYNC_H
#include "sanitizer_common/sanitizer_atomic.h"
#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_deadlock_detector_interface.h"
#include "tsan_defs.h"
#include "tsan_clock.h"
#include "tsan_dense_alloc.h"
namespace __tsan {
// These need to match __tsan_mutex_* flags defined in tsan_interface.h.
// See documentation there as well.
enum MutexFlags {
MutexFlagLinkerInit = 1 << 0, // __tsan_mutex_linker_init
MutexFlagWriteReentrant = 1 << 1, // __tsan_mutex_write_reentrant
MutexFlagReadReentrant = 1 << 2, // __tsan_mutex_read_reentrant
MutexFlagReadLock = 1 << 3, // __tsan_mutex_read_lock
MutexFlagTryLock = 1 << 4, // __tsan_mutex_try_lock
MutexFlagTryLockFailed = 1 << 5, // __tsan_mutex_try_lock_failed
MutexFlagRecursiveLock = 1 << 6, // __tsan_mutex_recursive_lock
MutexFlagRecursiveUnlock = 1 << 7, // __tsan_mutex_recursive_unlock
MutexFlagNotStatic = 1 << 8, // __tsan_mutex_not_static
// The following flags are runtime private.
// Mutex API misuse was detected, so don't report any more.
MutexFlagBroken = 1 << 30,
// We did not intercept pre lock event, so handle it on post lock.
MutexFlagDoPreLockOnPostLock = 1 << 29,
// Must list all mutex creation flags.
MutexCreationFlagMask = MutexFlagLinkerInit |
MutexFlagWriteReentrant |
MutexFlagReadReentrant |
MutexFlagNotStatic,
};
struct SyncVar {
SyncVar();
uptr addr; // overwritten by DenseSlabAlloc freelist
Mutex mtx;
u64 uid; // Globally unique id.
u32 creation_stack_id;
u32 owner_tid; // Set only by exclusive owners.
u64 last_lock;
int recursion;
atomic_uint32_t flags;
u32 next; // in MetaMap
DDMutex dd;
SyncClock read_clock; // Used for rw mutexes only.
// The clock is placed last, so that it is situated on a different cache line
// with the mtx. This reduces contention for hot sync objects.
SyncClock clock;
void Init(ThreadState *thr, uptr pc, uptr addr, u64 uid);
void Reset(Processor *proc);
u64 GetId() const {
// 48 lsb is addr, then 14 bits is low part of uid, then 2 zero bits.
return GetLsb((u64)addr | (uid << 48), 60);
}
bool CheckId(u64 uid) const {
CHECK_EQ(uid, GetLsb(uid, 14));
return GetLsb(this->uid, 14) == uid;
}
static uptr SplitId(u64 id, u64 *uid) {
*uid = id >> 48;
return (uptr)GetLsb(id, 48);
}
bool IsFlagSet(u32 f) const {
return atomic_load_relaxed(&flags) & f;
}
void SetFlags(u32 f) {
atomic_store_relaxed(&flags, atomic_load_relaxed(&flags) | f);
}
void UpdateFlags(u32 flagz) {
// Filter out operation flags.
if (!(flagz & MutexCreationFlagMask))
return;
u32 current = atomic_load_relaxed(&flags);
if (current & MutexCreationFlagMask)
return;
// Note: this can be called from MutexPostReadLock which holds only read
// lock on the SyncVar.
atomic_store_relaxed(&flags, current | (flagz & MutexCreationFlagMask));
}
};
/* MetaMap allows to map arbitrary user pointers onto various descriptors.
Currently it maps pointers to heap block descriptors and sync var descs.
It uses 1/2 direct shadow, see tsan_platform.h.
*/
class MetaMap {
public:
MetaMap();
void AllocBlock(ThreadState *thr, uptr pc, uptr p, uptr sz);
uptr FreeBlock(Processor *proc, uptr p);
bool FreeRange(Processor *proc, uptr p, uptr sz);
void ResetRange(Processor *proc, uptr p, uptr sz);
MBlock* GetBlock(uptr p);
SyncVar* GetOrCreateAndLock(ThreadState *thr, uptr pc,
uptr addr, bool write_lock);
SyncVar* GetIfExistsAndLock(uptr addr, bool write_lock);
void MoveMemory(uptr src, uptr dst, uptr sz);
void OnProcIdle(Processor *proc);
private:
static const u32 kFlagMask = 3u << 30;
static const u32 kFlagBlock = 1u << 30;
static const u32 kFlagSync = 2u << 30;
typedef DenseSlabAlloc<MBlock, 1 << 18, 1 << 12, kFlagMask> BlockAlloc;
typedef DenseSlabAlloc<SyncVar, 1 << 20, 1 << 10, kFlagMask> SyncAlloc;
BlockAlloc block_alloc_;
SyncAlloc sync_alloc_;
atomic_uint64_t uid_gen_;
SyncVar* GetAndLock(ThreadState *thr, uptr pc, uptr addr, bool write_lock,
bool create);
};
} // namespace __tsan
#endif // TSAN_SYNC_H