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path: root/vendor/modernc.org/sqlite/lib/mutex.go
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Diffstat (limited to 'vendor/modernc.org/sqlite/lib/mutex.go')
-rw-r--r--vendor/modernc.org/sqlite/lib/mutex.go251
1 files changed, 83 insertions, 168 deletions
diff --git a/vendor/modernc.org/sqlite/lib/mutex.go b/vendor/modernc.org/sqlite/lib/mutex.go
index 0780f5f94..305b24610 100644
--- a/vendor/modernc.org/sqlite/lib/mutex.go
+++ b/vendor/modernc.org/sqlite/lib/mutex.go
@@ -59,170 +59,40 @@ var (
}{mutexNotheld})),
}
- MutexCounters = libc.NewPerfCounter([]string{
- "enter-fast",
- "enter-recursive",
- "enter-recursive-loop",
- "try-fast",
- "try-recursive",
- })
- MutexEnterCallers = libc.NewStackCapture(4)
-
- mutexes mutexPool
-
- mutexApp1 = mutexes.alloc(false)
- mutexApp2 = mutexes.alloc(false)
- mutexApp3 = mutexes.alloc(false)
- mutexLRU = mutexes.alloc(false)
- mutexMaster = mutexes.alloc(false)
- mutexMem = mutexes.alloc(false)
- mutexOpen = mutexes.alloc(false)
- mutexPMem = mutexes.alloc(false)
- mutexPRNG = mutexes.alloc(false)
- mutexVFS1 = mutexes.alloc(false)
- mutexVFS2 = mutexes.alloc(false)
- mutexVFS3 = mutexes.alloc(false)
+ mutexApp10 mutex
+ mutexApp20 mutex
+ mutexApp30 mutex
+ mutexLRU0 mutex
+ mutexMaster0 mutex
+ mutexMem0 mutex
+ mutexOpen0 mutex
+ mutexPMem0 mutex
+ mutexPRNG0 mutex
+ mutexVFS10 mutex
+ mutexVFS20 mutex
+ mutexVFS30 mutex
+
+ mutexApp1 = uintptr(unsafe.Pointer(&mutexApp10))
+ mutexApp2 = uintptr(unsafe.Pointer(&mutexApp20))
+ mutexApp3 = uintptr(unsafe.Pointer(&mutexApp30))
+ mutexLRU = uintptr(unsafe.Pointer(&mutexLRU0))
+ mutexMaster = uintptr(unsafe.Pointer(&mutexMaster0))
+ mutexMem = uintptr(unsafe.Pointer(&mutexMem0))
+ mutexOpen = uintptr(unsafe.Pointer(&mutexOpen0))
+ mutexPMem = uintptr(unsafe.Pointer(&mutexPMem0))
+ mutexPRNG = uintptr(unsafe.Pointer(&mutexPRNG0))
+ mutexVFS1 = uintptr(unsafe.Pointer(&mutexVFS10))
+ mutexVFS2 = uintptr(unsafe.Pointer(&mutexVFS20))
+ mutexVFS3 = uintptr(unsafe.Pointer(&mutexVFS30))
)
-type mutexPool struct {
- sync.Mutex
- a []*[256]mutex
- freeList []int
-}
-
-func mutexFromPtr(p uintptr) *mutex {
- if p == 0 {
- return nil
- }
-
- ix := p - 1
-
- mutexes.Lock()
- defer mutexes.Unlock()
-
- return &mutexes.a[ix>>8][ix&255]
-}
-
-func (m *mutexPool) alloc(recursive bool) uintptr {
- m.Lock()
- defer m.Unlock()
-
- n := len(m.freeList)
- if n == 0 {
- outer := len(m.a) << 8
- m.a = append(m.a, &[256]mutex{})
- for i := 0; i < 256; i++ {
- m.freeList = append(m.freeList, outer+i)
- }
- n = len(m.freeList)
- }
- ix := m.freeList[n-1]
- outer := ix >> 8
- inner := ix & 255
- m.freeList = m.freeList[:n-1]
- p := &m.a[outer][inner]
- p.poolIndex = ix
- p.recursive = recursive
- return uintptr(ix) + 1
-}
-
-func (m *mutexPool) free(p uintptr) {
- ptr := mutexFromPtr(p)
- ix := ptr.poolIndex
- *ptr = mutex{}
-
- m.Lock()
- defer m.Unlock()
-
- m.freeList = append(m.freeList, ix)
-}
-
type mutex struct {
sync.Mutex
- wait sync.Mutex
-
- poolIndex int
-
- cnt int32
- id int32
-
+ cnt int32
+ id int32 // tls.ID
recursive bool
}
-func (m *mutex) enter(id int32) {
- // MutexEnterCallers.Record()
- if !m.recursive {
- // MutexCounters.Inc(0)
- m.Lock()
- m.id = id
- return
- }
-
- // MutexCounters.Inc(1)
- for {
- m.Lock()
- switch m.id {
- case 0:
- m.cnt = 1
- m.id = id
- m.wait.Lock()
- m.Unlock()
- return
- case id:
- m.cnt++
- m.Unlock()
- return
- }
-
- // MutexCounters.Inc(2)
- m.Unlock()
- m.wait.Lock()
- //lint:ignore SA2001 TODO report staticcheck issue
- m.wait.Unlock()
- }
-}
-
-func (m *mutex) try(id int32) int32 {
- if !m.recursive {
- // MutexCounters.Inc(3)
- return SQLITE_BUSY
- }
-
- // MutexCounters.Inc(4)
- m.Lock()
- switch m.id {
- case 0:
- m.cnt = 1
- m.id = id
- m.wait.Lock()
- m.Unlock()
- return SQLITE_OK
- case id:
- m.cnt++
- m.Unlock()
- return SQLITE_OK
- }
-
- m.Unlock()
- return SQLITE_BUSY
-}
-
-func (m *mutex) leave(id int32) {
- if !m.recursive {
- m.id = 0
- m.Unlock()
- return
- }
-
- m.Lock()
- m.cnt--
- if m.cnt == 0 {
- m.id = 0
- m.wait.Unlock()
- }
- m.Unlock()
-}
-
// int (*xMutexInit)(void);
//
// The xMutexInit method defined by this structure is invoked as part of system
@@ -287,14 +157,15 @@ func mutexEnd(tls *libc.TLS) int32 { return SQLITE_OK }
// SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() returns a
// different mutex on every call. For the static mutex types, the same mutex is
// returned on every call that has the same type number.
-func mutexAlloc(tls *libc.TLS, typ int32) uintptr {
- defer func() {
- }()
+func mutexAlloc(tls *libc.TLS, typ int32) (r uintptr) {
switch typ {
case SQLITE_MUTEX_FAST:
- return mutexes.alloc(false)
+ r = libc.Xcalloc(tls, 1, types.Size_t(unsafe.Sizeof(mutex{})))
+ return r
case SQLITE_MUTEX_RECURSIVE:
- return mutexes.alloc(true)
+ r = libc.Xcalloc(tls, 1, types.Size_t(unsafe.Sizeof(mutex{})))
+ (*mutex)(unsafe.Pointer(r)).recursive = true
+ return r
case SQLITE_MUTEX_STATIC_MASTER:
return mutexMaster
case SQLITE_MUTEX_STATIC_MEM:
@@ -325,7 +196,9 @@ func mutexAlloc(tls *libc.TLS, typ int32) uintptr {
}
// void (*xMutexFree)(sqlite3_mutex *);
-func mutexFree(tls *libc.TLS, m uintptr) { mutexes.free(m) }
+func mutexFree(tls *libc.TLS, m uintptr) {
+ libc.Xfree(tls, m)
+}
// The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt to enter
// a mutex. If another thread is already within the mutex,
@@ -346,7 +219,34 @@ func mutexEnter(tls *libc.TLS, m uintptr) {
if m == 0 {
return
}
- mutexFromPtr(m).enter(tls.ID)
+
+ if !(*mutex)(unsafe.Pointer(m)).recursive {
+ (*mutex)(unsafe.Pointer(m)).Lock()
+ (*mutex)(unsafe.Pointer(m)).id = tls.ID
+ return
+ }
+
+ id := tls.ID
+ if atomic.CompareAndSwapInt32(&(*mutex)(unsafe.Pointer(m)).id, 0, id) {
+ (*mutex)(unsafe.Pointer(m)).cnt = 1
+ (*mutex)(unsafe.Pointer(m)).Lock()
+ return
+ }
+
+ if atomic.LoadInt32(&(*mutex)(unsafe.Pointer(m)).id) == id {
+ (*mutex)(unsafe.Pointer(m)).cnt++
+ return
+ }
+
+ for {
+ (*mutex)(unsafe.Pointer(m)).Lock()
+ if atomic.CompareAndSwapInt32(&(*mutex)(unsafe.Pointer(m)).id, 0, id) {
+ (*mutex)(unsafe.Pointer(m)).cnt = 1
+ return
+ }
+
+ (*mutex)(unsafe.Pointer(m)).Unlock()
+ }
}
// int (*xMutexTry)(sqlite3_mutex *);
@@ -355,7 +255,13 @@ func mutexTry(tls *libc.TLS, m uintptr) int32 {
return SQLITE_OK
}
- return mutexFromPtr(m).try(tls.ID)
+ if !(*mutex)(unsafe.Pointer(m)).recursive {
+ if (*mutex)(unsafe.Pointer(m)).TryLock() {
+ return SQLITE_OK
+ }
+ }
+
+ return SQLITE_BUSY
}
// void (*xMutexLeave)(sqlite3_mutex *);
@@ -364,7 +270,16 @@ func mutexLeave(tls *libc.TLS, m uintptr) {
return
}
- mutexFromPtr(m).leave(tls.ID)
+ if !(*mutex)(unsafe.Pointer(m)).recursive {
+ (*mutex)(unsafe.Pointer(m)).id = 0
+ (*mutex)(unsafe.Pointer(m)).Unlock()
+ return
+ }
+
+ if atomic.AddInt32(&(*mutex)(unsafe.Pointer(m)).cnt, -1) == 0 {
+ atomic.StoreInt32(&(*mutex)(unsafe.Pointer(m)).id, 0)
+ (*mutex)(unsafe.Pointer(m)).Unlock()
+ }
}
// The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines are intended
@@ -397,7 +312,7 @@ func mutexHeld(tls *libc.TLS, m uintptr) int32 {
return 1
}
- return libc.Bool32(atomic.LoadInt32(&mutexFromPtr(m).id) == tls.ID)
+ return libc.Bool32(atomic.LoadInt32(&(*mutex)(unsafe.Pointer(m)).id) == tls.ID)
}
// int (*xMutexNotheld)(sqlite3_mutex *);
@@ -406,5 +321,5 @@ func mutexNotheld(tls *libc.TLS, m uintptr) int32 {
return 1
}
- return libc.Bool32(atomic.LoadInt32(&mutexFromPtr(m).id) != tls.ID)
+ return libc.Bool32(atomic.LoadInt32(&(*mutex)(unsafe.Pointer(m)).id) != tls.ID)
}
generated by cgit v1.2.3 (git 2.46.0) at 2025-12-02 08:01:27 +0000