Changeset 5a40e4e for libcfa/src/concurrency

Timestamp:

Sep 9, 2021, 3:56:32 PM (4 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, ast-experimental, enum, forall-pointer-decay, master, pthread-emulation, qualifiedEnum, stuck-waitfor-destruct

Children:

d0b9247

Parents:

dd1cc02 (diff), d8d512e (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge branch 'master' of plg.uwaterloo.ca:software/cfa/cfa-cc

Location:

libcfa/src/concurrency

Files:

• kernel/startup.cfa (modified) (2 diffs)
• locks.hfa (modified) (2 diffs)
• monitor.cfa (modified) (2 diffs)
• monitor.hfa (modified) (2 diffs)
• mutex_stmt.hfa (added)
• thread.cfa (modified) (1 diff)

libcfa/src/concurrency/kernel/startup.cfa

@@ -235 +235 @@
 
         register_tls( mainProcessor );
+        mainThread->last_cpu = __kernel_getcpu();
 
         //initialize the global state variables
@@ -478 +479 @@
         state = Start;
         self_cor{ info };
-        last_cpu = __kernel_getcpu();
         curr_cor = &self_cor;
         curr_cluster = mainCluster;

libcfa/src/concurrency/locks.hfa

@@ -324 +324 @@
         }
 
-        // linear backoff bounded by spin_count
-        spin = spin_start;
-        int spin_counter = 0;
-        int yield_counter = 0;
-        for ( ;; ) {
-                if(try_lock_contention(this)) return true;
-                if(spin_counter < spin_count) {
-                        for (int i = 0; i < spin; i++) Pause();
-                        if (spin < spin_end) spin += spin;
-                        else spin_counter++;
-                } else if (yield_counter < yield_count) {
-                        // after linear backoff yield yield_count times
-                        yield_counter++;
-                        yield();
-                } else { break; }
-        }
-
-        // block until signalled
-        while (block(this)) if(try_lock_contention(this)) return true;
-
-        // this should never be reached as block(this) always returns true
-        return false;
-}
-
-static inline bool lock_improved(linear_backoff_then_block_lock & this) with(this) {
-        // if owner just return
-        if (active_thread() == owner) return true;
-        size_t compare_val = 0;
-        int spin = spin_start;
-        // linear backoff
-        for( ;; ) {
-                compare_val = 0;
-                if (internal_try_lock(this, compare_val)) return true;
-                if (2 == compare_val) break;
-                for (int i = 0; i < spin; i++) Pause();
-                if (spin >= spin_end) break;
-                spin += spin;
-        }
-
-        // linear backoff bounded by spin_count
-        spin = spin_start;
-        int spin_counter = 0;
-        int yield_counter = 0;
-        for ( ;; ) {
-                compare_val = 0;
-                if(internal_try_lock(this, compare_val)) return true;
-                if (2 == compare_val) break;
-                if(spin_counter < spin_count) {
-                        for (int i = 0; i < spin; i++) Pause();
-                        if (spin < spin_end) spin += spin;
-                        else spin_counter++;
-                } else if (yield_counter < yield_count) {
-                        // after linear backoff yield yield_count times
-                        yield_counter++;
-                        yield();
-                } else { break; }
-        }
-
         if(2 != compare_val && try_lock_contention(this)) return true;
         // block until signalled
@@ -402 +344 @@
 static inline void on_notify(linear_backoff_then_block_lock & this, struct thread$ * t ) { unpark(t); }
 static inline size_t on_wait(linear_backoff_then_block_lock & this) { unlock(this); return 0; }
-static inline void on_wakeup(linear_backoff_then_block_lock & this, size_t recursion ) { lock_improved(this); }
+static inline void on_wakeup(linear_backoff_then_block_lock & this, size_t recursion ) { lock(this); }
 
 //-----------------------------------------------------------------------------

libcfa/src/concurrency/monitor.cfa

@@ -367 +367 @@
 
         // __cfaabi_dbg_print_safe( "MGUARD : entered\n" );
+}
+
+void ?{}( monitor_guard_t & this, monitor$ * m [], __lock_size_t count ) {
+        this{ m, count, 0p };
 }
 
@@ -986 +990 @@
 }
 
+//-----------------------------------------------------------------------------
+// Enter routine for mutex stmt
+// Can't be accepted since a mutex stmt is effectively an anonymous routine
+// Thus we do not need a monitor group
+void lock( monitor$ * this ) {
+        thread$ * thrd = active_thread();
+
+        // Lock the monitor spinlock
+        lock( this->lock __cfaabi_dbg_ctx2 );
+
+        __cfaabi_dbg_print_safe( "Kernel : %10p Entering mon %p (%p)\n", thrd, this, this->owner);
+
+        if( unlikely(0 != (0x1 & (uintptr_t)this->owner)) ) {
+                abort( "Attempt by thread \"%.256s\" (%p) to access joined monitor %p.", thrd->self_cor.name, thrd, this );
+        }
+        else if( !this->owner ) {
+                // No one has the monitor, just take it
+                __set_owner( this, thrd );
+
+                __cfaabi_dbg_print_safe( "Kernel :  mon is free \n" );
+        }
+        else if( this->owner == thrd) {
+                // We already have the monitor, just note how many times we took it
+                this->recursion += 1;
+
+                __cfaabi_dbg_print_safe( "Kernel :  mon already owned \n" );
+        }
+        else {
+                __cfaabi_dbg_print_safe( "Kernel :  blocking \n" );
+
+                // Some one else has the monitor, wait in line for it
+                /* paranoid */ verify( thrd->link.next == 0p );
+                append( this->entry_queue, thrd );
+                /* paranoid */ verify( thrd->link.next == 1p );
+
+                unlock( this->lock );
+                park();
+
+                __cfaabi_dbg_print_safe( "Kernel : %10p Entered  mon %p\n", thrd, this);
+
+                /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
+                return;
+        }
+
+        __cfaabi_dbg_print_safe( "Kernel : %10p Entered  mon %p\n", thrd, this);
+
+        /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
+        /* paranoid */ verify( this->lock.lock );
+
+        // Release the lock and leave
+        unlock( this->lock );
+        return;
+}
+
+// Leave routine for mutex stmt
+// Is just a wrapper around __leave for the is_lock trait to see
+void unlock( monitor$ * this ) { __leave( this ); }
+
 // Local Variables: //
 // mode: c //

libcfa/src/concurrency/monitor.hfa

@@ -48 +48 @@
 
 void ?{}( monitor_guard_t & this, monitor$ ** m, __lock_size_t count, void (*func)() );
+void ?{}( monitor_guard_t & this, monitor$ ** m, __lock_size_t count );
 void ^?{}( monitor_guard_t & this );
 
@@ -148 +149 @@
 void __waitfor_internal( const __waitfor_mask_t & mask, int duration );
 
+// lock and unlock routines for mutex statements to use
+void lock( monitor$ * this );
+void unlock( monitor$ * this );
+
 // Local Variables: //
 // mode: c //

libcfa/src/concurrency/thread.cfa

@@ -34 +34 @@
         preempted = __NO_PREEMPTION;
         corctx_flag = false;
+        disable_interrupts();
         last_cpu = __kernel_getcpu();
+        enable_interrupts();
         curr_cor = &self_cor;
         self_mon.owner = &this;