Changeset 7d9598d for libcfa/src

Timestamp:

Dec 14, 2022, 12:23:26 PM (17 months ago)

Author:

caparson <caparson@…>

Branches:

ADT, ast-experimental, master

Children:

2dcd80a

Parents:

63be3387

Message:

small lock cleanup

Location:

libcfa/src/concurrency

Files:

• locks.cfa (modified) (1 diff)
• locks.hfa (modified) (3 diffs)

libcfa/src/concurrency/locks.cfa

@@ -414 +414 @@
                 #ifdef __CFA_DEBUG__
                         if ( lock_used == 0p ) lock_used = &l;
-                        else { assert(lock_used == &l); }
+                        else assert(lock_used == &l);
                 #endif
                 info_thread( L ) i = { active_thread(), info, &l };

libcfa/src/concurrency/locks.hfa

@@ -162 +162 @@
 
 // to use for FUTEX_WAKE and FUTEX_WAIT (other futex calls will need more params)
-static int futex(int *uaddr, int futex_op, int val) {
+static inline int futex(int *uaddr, int futex_op, int val) {
     return syscall(SYS_futex, uaddr, futex_op, val, NULL, NULL, 0);
 }
@@ -181 +181 @@
 
         
-        // linear backoff
-        for( int spin = 4; spin < 1024; spin += spin) {
-                state = 0;
-                // if unlocked, lock and return
-                if (internal_try_lock(this, state)) return;
-                if (2 == state) break;
-                for (int i = 0; i < spin; i++) Pause();
-        }
-        // if (internal_try_lock(this, state)) return;
+        // // linear backoff omitted for now
+        // for( int spin = 4; spin < 1024; spin += spin) {
+        //      state = 0;
+        //      // if unlocked, lock and return
+        //      if (internal_try_lock(this, state)) return;
+        //      if (2 == state) break;
+        //      for (int i = 0; i < spin; i++) Pause();
+        // }
+
+        // no contention try to acquire
+        if (internal_try_lock(this, state)) return;
         
         // if not in contended state, set to be in contended state
@@ -290 +292 @@
 
 static inline bool block(linear_backoff_then_block_lock & this) with(this) {
-        lock( spinlock __cfaabi_dbg_ctx2 );
+        lock( spinlock __cfaabi_dbg_ctx2 ); // TODO change to lockfree queue (MPSC)
         if (lock_value != 2) {
                 unlock( spinlock );