Changeset f835806 for libcfa/src/concurrency

Timestamp:

Jun 2, 2022, 2:39:11 PM (2 years ago)

Author:

caparsons <caparson@…>

Branches:

ADT, ast-experimental, master, pthread-emulation, qualifiedEnum

Children:

fb63c70

Parents:

e5628db

Message:

added some locks and cleaned up unused seqable field in thread block

Location:

libcfa/src/concurrency

Files:

• invoke.h (modified) (3 diffs)
• locks.hfa (modified) (6 diffs)
• thread.cfa (modified) (2 diffs)

libcfa/src/concurrency/invoke.h

@@ -195 +195 @@
                 struct __monitor_group_t monitors;
 
-                // used to put threads on user data structures
-                struct {
-                        struct thread$ * next;
-                        struct thread$ * back;
-                } seqable;
-
                 // used to put threads on dlist data structure
                 __cfa_dlink(thread$);
@@ -208 +202 @@
                         struct thread$ * prev;
                 } node;
+
+                // used to store state between clh lock/unlock
+                volatile bool * clh_prev;
+
+                // used to point to this thd's current clh node
+                volatile bool * clh_node;
 
                 struct processor * last_proc;
@@ -240 +240 @@
                 }
 
-                static inline thread$ * volatile & ?`next ( thread$ * this )  __attribute__((const)) {
-                        return this->seqable.next;
-                }
-
-                static inline thread$ *& Back( thread$ * this ) __attribute__((const)) {
-                        return this->seqable.back;
-                }
-
-                static inline thread$ *& Next( thread$ * this ) __attribute__((const)) {
-                                return this->seqable.next;
-                }
-
-                static inline bool listed( thread$ * this ) {
-                        return this->seqable.next != 0p;
-                }
-
                 static inline void ?{}(__monitor_group_t & this) {
                         (this.data){0p};

libcfa/src/concurrency/locks.hfa

@@ -101 +101 @@
 
 //-----------------------------------------------------------------------------
+// MCS Spin Lock
+// - No recursive acquisition
+// - Needs to be released by owner
+
+struct mcs_spin_node {
+        mcs_spin_node * volatile next;
+        bool locked:1;
+};
+
+struct mcs_spin_queue {
+        mcs_spin_node * volatile tail;
+};
+
+static inline void ?{}(mcs_spin_node & this) { this.next = 0p; this.locked = true; }
+
+static inline mcs_spin_node * volatile & ?`next ( mcs_spin_node * node ) {
+        return node->next;
+}
+
+struct mcs_spin_lock {
+        mcs_spin_queue queue;
+};
+
+static inline void lock(mcs_spin_lock & l, mcs_spin_node & n) {
+        mcs_spin_node * prev = __atomic_exchange_n(&l.queue.tail, &n, __ATOMIC_SEQ_CST);
+        if(prev != 0p) {
+                prev->next = &n;
+                while(n.locked) Pause();
+        }
+}
+
+static inline void unlock(mcs_spin_lock & l, mcs_spin_node & n) {
+        mcs_spin_node * n_ptr = &n;
+        if (!__atomic_compare_exchange_n(&l.queue.tail, &n_ptr, 0p, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST) ) {
+                while (n.next == 0p) {}
+                n.next->locked = false;
+        }
+}
+
+//-----------------------------------------------------------------------------
+// CLH Spinlock
+// - No recursive acquisition
+// - Needs to be released by owner
+
+struct clh_lock {
+        volatile bool * volatile tail;
+};
+
+static inline void  ?{}( clh_lock & this ) { this.tail = malloc(); *this.tail = true; }
+static inline void ^?{}( clh_lock & this ) { free(this.tail); }
+
+static inline void lock(clh_lock & l) {
+        thread$ * curr_thd = active_thread();
+        *(curr_thd->clh_node) = false;
+        volatile bool * prev = __atomic_exchange_n((bool **)(&l.tail), (bool *)(curr_thd->clh_node), __ATOMIC_SEQ_CST);
+        while(!__atomic_load_n(prev, __ATOMIC_ACQUIRE)) Pause();
+        curr_thd->clh_prev = prev;
+}
+
+static inline void unlock(clh_lock & l) {
+        thread$ * curr_thd = active_thread();
+        __atomic_store_n(curr_thd->clh_node, true, __ATOMIC_RELEASE);
+        curr_thd->clh_node = curr_thd->clh_prev;
+}
+
+//-----------------------------------------------------------------------------
 // Linear backoff Spinlock
 struct linear_backoff_then_block_lock {
@@ -205 +271 @@
 // Fast Block Lock
 
-// High efficiency minimal blocking lock
+// minimal blocking lock
 // - No reacquire for cond var
 // - No recursive acquisition
 // - No ownership
 struct fast_block_lock {
+        // List of blocked threads
+        dlist( thread$ ) blocked_threads;
+
         // Spin lock used for mutual exclusion
         __spinlock_t lock;
 
-        // List of blocked threads
-        dlist( thread$ ) blocked_threads;
-
+        // flag showing if lock is held
         bool held:1;
+
+        #ifdef __CFA_DEBUG__
+        // for deadlock detection
+        struct thread$ * owner;
+        #endif
 };
 
@@ -231 +303 @@
 static inline void lock(fast_block_lock & this) with(this) {
         lock( lock __cfaabi_dbg_ctx2 );
+
+        #ifdef __CFA_DEBUG__
+        assert(!(held && owner == active_thread()));
+        #endif
         if (held) {
                 insert_last( blocked_threads, *active_thread() );
@@ -238 +314 @@
         }
         held = true;
+        #ifdef __CFA_DEBUG__
+        owner = active_thread();
+        #endif
         unlock( lock );
 }
@@ -246 +325 @@
         thread$ * t = &try_pop_front( blocked_threads );
         held = ( t ? true : false );
+        #ifdef __CFA_DEBUG__
+        owner = ( t ? t : 0p );
+        #endif
         unpark( t );
         unlock( lock );
@@ -253 +335 @@
 static inline size_t on_wait(fast_block_lock & this) { unlock(this); return 0; }
 static inline void on_wakeup(fast_block_lock & this, size_t recursion ) { }
+
+//-----------------------------------------------------------------------------
+// simple_owner_lock
+
+// pthread owner lock
+// - reacquire for cond var
+// - recursive acquisition
+// - ownership
+struct simple_owner_lock {
+        // List of blocked threads
+        dlist( thread$ ) blocked_threads;
+
+        // Spin lock used for mutual exclusion
+        __spinlock_t lock;
+
+        // owner showing if lock is held
+        struct thread$ * owner;
+
+        size_t recursion_count;
+};
+
+static inline void  ?{}( simple_owner_lock & this ) with(this) {
+        lock{};
+        blocked_threads{};
+        owner = 0p;
+        recursion_count = 0;
+}
+static inline void ^?{}( simple_owner_lock & this ) {}
+static inline void ?{}( simple_owner_lock & this, simple_owner_lock this2 ) = void;
+static inline void ?=?( simple_owner_lock & this, simple_owner_lock this2 ) = void;
+
+static inline void lock(simple_owner_lock & this) with(this) {
+        if (owner == active_thread()) {
+                recursion_count++;
+                return;
+        }
+        lock( lock __cfaabi_dbg_ctx2 );
+
+        if (owner != 0p) {
+                insert_last( blocked_threads, *active_thread() );
+                unlock( lock );
+                park( );
+                return;
+        }
+        owner = active_thread();
+        recursion_count = 1;
+        unlock( lock );
+}
+
+void pop_and_set_new_owner( simple_owner_lock & this ) with( this ) {
+        thread$ * t = &try_pop_front( blocked_threads );
+        owner = t;
+        recursion_count = ( t ? 1 : 0 );
+        unpark( t );
+}
+
+static inline void unlock(simple_owner_lock & this) with(this) {
+        lock( lock __cfaabi_dbg_ctx2 );
+        /* paranoid */ verifyf( owner != 0p, "Attempt to release lock %p that isn't held", &this );
+        /* paranoid */ verifyf( owner == active_thread(), "Thread %p other than the owner %p attempted to release owner lock %p", owner, active_thread(), &this );
+        // if recursion count is zero release lock and set new owner if one is waiting
+        recursion_count--;
+        if ( recursion_count == 0 ) {
+                pop_and_set_new_owner( this );
+        }
+        unlock( lock );
+}
+
+static inline void on_notify(simple_owner_lock & this, struct thread$ * t ) with(this) {
+        lock( lock __cfaabi_dbg_ctx2 );
+        // lock held
+        if ( owner != 0p ) {
+                insert_last( blocked_threads, *t );
+                unlock( lock );
+        }
+        // lock not held
+        else {
+                owner = t;
+                recursion_count = 1;
+                unpark( t );
+                unlock( lock );
+        }
+}
+
+static inline size_t on_wait(simple_owner_lock & this) with(this) { 
+        lock( lock __cfaabi_dbg_ctx2 );
+        /* paranoid */ verifyf( owner != 0p, "Attempt to release lock %p that isn't held", &this );
+        /* paranoid */ verifyf( owner == active_thread(), "Thread %p other than the owner %p attempted to release owner lock %p", owner, active_thread(), &this );
+
+        size_t ret = recursion_count;
+
+        pop_and_set_new_owner( this );
+
+        unlock( lock );
+        return ret;
+}
+
+static inline void on_wakeup(simple_owner_lock & this, size_t recursion ) with(this) { recursion_count = recursion; }
+
+//-----------------------------------------------------------------------------
+// Spin Queue Lock
+
+// - No reacquire for cond var
+// - No recursive acquisition
+// - No ownership
+// - spin lock with no locking/atomics in unlock
+struct spin_queue_lock {
+        // Spin lock used for mutual exclusion
+        mcs_spin_lock lock;
+
+        // flag showing if lock is held
+        bool held:1;
+
+        #ifdef __CFA_DEBUG__
+        // for deadlock detection
+        struct thread$ * owner;
+        #endif
+};
+
+static inline void  ?{}( spin_queue_lock & this ) with(this) {
+        lock{};
+        held = false;
+}
+static inline void ^?{}( spin_queue_lock & this ) {}
+static inline void ?{}( spin_queue_lock & this, spin_queue_lock this2 ) = void;
+static inline void ?=?( spin_queue_lock & this, spin_queue_lock this2 ) = void;
+
+// if this is called recursively IT WILL DEADLOCK!!!!!
+static inline void lock(spin_queue_lock & this) with(this) {
+        mcs_spin_node node;
+        #ifdef __CFA_DEBUG__
+        assert(!(held && owner == active_thread()));
+        #endif
+        lock( lock, node );
+        while(held) Pause();
+        held = true;
+        unlock( lock, node );
+        #ifdef __CFA_DEBUG__
+        owner = active_thread();
+        #endif
+}
+
+static inline void unlock(spin_queue_lock & this) with(this) {
+        #ifdef __CFA_DEBUG__
+        owner = 0p;
+        #endif
+        held = false;
+}
+
+static inline void on_notify(spin_queue_lock & this, struct thread$ * t ) { unpark(t); }
+static inline size_t on_wait(spin_queue_lock & this) { unlock(this); return 0; }
+static inline void on_wakeup(spin_queue_lock & this, size_t recursion ) { }
+
+
+//-----------------------------------------------------------------------------
+// MCS Block Spin Lock
+
+// - No reacquire for cond var
+// - No recursive acquisition
+// - No ownership
+// - Blocks but first node spins (like spin queue but blocking for not first thd)
+struct mcs_block_spin_lock {
+        // Spin lock used for mutual exclusion
+        mcs_lock lock;
+
+        // flag showing if lock is held
+        bool held:1;
+
+        #ifdef __CFA_DEBUG__
+        // for deadlock detection
+        struct thread$ * owner;
+        #endif
+};
+
+static inline void  ?{}( mcs_block_spin_lock & this ) with(this) {
+        lock{};
+        held = false;
+}
+static inline void ^?{}( mcs_block_spin_lock & this ) {}
+static inline void ?{}( mcs_block_spin_lock & this, mcs_block_spin_lock this2 ) = void;
+static inline void ?=?( mcs_block_spin_lock & this, mcs_block_spin_lock this2 ) = void;
+
+// if this is called recursively IT WILL DEADLOCK!!!!!
+static inline void lock(mcs_block_spin_lock & this) with(this) {
+        mcs_node node;
+        #ifdef __CFA_DEBUG__
+        assert(!(held && owner == active_thread()));
+        #endif
+        lock( lock, node );
+        while(held) Pause();
+        held = true;
+        unlock( lock, node );
+        #ifdef __CFA_DEBUG__
+        owner = active_thread();
+        #endif
+}
+
+static inline void unlock(mcs_block_spin_lock & this) with(this) {
+        #ifdef __CFA_DEBUG__
+        owner = 0p;
+        #endif
+        held = false;
+}
+
+static inline void on_notify(mcs_block_spin_lock & this, struct thread$ * t ) { unpark(t); }
+static inline size_t on_wait(mcs_block_spin_lock & this) { unlock(this); return 0; }
+static inline void on_wakeup(mcs_block_spin_lock & this, size_t recursion ) { }
+
+//-----------------------------------------------------------------------------
+// Block Spin Lock
+
+// - No reacquire for cond var
+// - No recursive acquisition
+// - No ownership
+// - Blocks but first node spins (like spin queue but blocking for not first thd)
+struct block_spin_lock {
+        // Spin lock used for mutual exclusion
+        fast_block_lock lock;
+
+        // flag showing if lock is held
+        bool held:1;
+
+        #ifdef __CFA_DEBUG__
+        // for deadlock detection
+        struct thread$ * owner;
+        #endif
+};
+
+static inline void  ?{}( block_spin_lock & this ) with(this) {
+        lock{};
+        held = false;
+}
+static inline void ^?{}( block_spin_lock & this ) {}
+static inline void ?{}( block_spin_lock & this, block_spin_lock this2 ) = void;
+static inline void ?=?( block_spin_lock & this, block_spin_lock this2 ) = void;
+
+// if this is called recursively IT WILL DEADLOCK!!!!!
+static inline void lock(block_spin_lock & this) with(this) {
+        #ifdef __CFA_DEBUG__
+        assert(!(held && owner == active_thread()));
+        #endif
+        lock( lock );
+        while(held) Pause();
+        held = true;
+        unlock( lock );
+        #ifdef __CFA_DEBUG__
+        owner = active_thread();
+        #endif
+}
+
+static inline void unlock(block_spin_lock & this) with(this) {
+        #ifdef __CFA_DEBUG__
+        owner = 0p;
+        #endif
+        held = false;
+}
+
+static inline void on_notify(block_spin_lock & this, struct thread$ * t ) { unpark(t); }
+static inline size_t on_wait(block_spin_lock & this) { unlock(this); return 0; }
+static inline void on_wakeup(block_spin_lock & this, size_t recursion ) { }
 
 //-----------------------------------------------------------------------------

libcfa/src/concurrency/thread.cfa

@@ -50 +50 @@
         #endif
 
-        seqable.next = 0p;
-        seqable.back = 0p;
-
         node.next = 0p;
         node.prev = 0p;
+
+        clh_node = new( false );
+
         doregister(curr_cluster, this);
-
         monitors{ &self_mon_p, 1, (fptr_t)0 };
 }
@@ -64 +63 @@
                 canary = 0xDEADDEADDEADDEADp;
         #endif
+        delete(clh_node);
         unregister(curr_cluster, this);
         ^self_cor{};