Changeset bdeba0b for src/libcfa/concurrency

Timestamp:

Jul 6, 2017, 4:18:43 PM (7 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, aaron-thesis, arm-eh, ast-experimental, cleanup-dtors, deferred_resn, demangler, enum, forall-pointer-decay, jacob/cs343-translation, jenkins-sandbox, master, new-ast, new-ast-unique-expr, new-env, no_list, persistent-indexer, pthread-emulation, qualifiedEnum, resolv-new, with_gc

Children:

955d27e9

Parents:

b877fa8

Message:

Removed signal_once type, use semaphore instead

Location:

src/libcfa/concurrency

Files:

• kernel (modified) (2 diffs)
• kernel.c (modified) (5 diffs)

src/libcfa/concurrency/kernel

@@ -33 +33 @@
 void unlock    ( spinlock * );
 
-struct signal_once {
-        volatile bool cond;
-        struct spinlock lock;
-        struct __thread_queue_t blocked;
+struct semaphore {
+        spinlock lock;
+        int count;
+        __thread_queue_t waiting;
 };
 
-void ?{}(signal_once * this);
-void ^?{}(signal_once * this);
+void  ?{}(semaphore * this, int count = 1);
+void ^?{}(semaphore * this);
+void P(semaphore * this);
+void V(semaphore * this);
 
-void wait( signal_once * );
-void signal( signal_once * );
 
 //-----------------------------------------------------------------------------
@@ -81 +81 @@
         pthread_t kernel_thread;
 
-        signal_once terminated;
+        semaphore terminated;
         volatile bool is_terminated;
 

src/libcfa/concurrency/kernel.c

@@ -129 +129 @@
 void ?{}(processor * this, cluster * cltr) {
         this->cltr = cltr;
-        (&this->terminated){};
+        (&this->terminated){ 0 };
         this->is_terminated = false;
         this->preemption_alarm = NULL;
@@ -140 +140 @@
 void ?{}(processor * this, cluster * cltr, processorCtx_t * runner) {
         this->cltr = cltr;
-        (&this->terminated){};
+        (&this->terminated){ 0 };
         this->is_terminated = false;
         this->preemption_alarm = NULL;
@@ -168 +168 @@
                 LIB_DEBUG_PRINT_SAFE("Kernel : core %p signaling termination\n", this);
                 this->is_terminated = true;
-                wait( &this->terminated );
+                P( &this->terminated );
+                pthread_join( this->kernel_thread, NULL );
         }
 }
@@ -223 +224 @@
         }
 
-        signal( &this->terminated );
+        V( &this->terminated );
+
         LIB_DEBUG_PRINT_SAFE("Kernel : core %p terminated\n", this);
 }
@@ -607 +609 @@
 }
 
-void ?{}( signal_once * this ) {
-        this->cond = false;
-}
-void ^?{}( signal_once * this ) {
-
-}
-
-void wait( signal_once * this ) {
+void  ?{}( semaphore * this, int count = 1 ) {
+        (&this->lock){};
+        this->count = count;
+        (&this->waiting){};
+}
+void ^?{}(semaphore * this) {}
+
+void P(semaphore * this) {
         lock( &this->lock DEBUG_CTX2 );
-        if( !this->cond ) {
-                append( &this->blocked, (thread_desc*)this_thread );
+        this->count -= 1;
+        if ( this->count < 0 ) {
+                // queue current task
+                append( &this->waiting, (thread_desc *)this_thread );
+
+                // atomically release spin lock and block
                 BlockInternal( &this->lock );
         }
         else {
-                unlock( &this->lock );
-        }
-}
-
-void signal( signal_once * this ) {
+            unlock( &this->lock );
+        }
+}
+
+void V(semaphore * this) {
+        thread_desc * thrd = NULL;
         lock( &this->lock DEBUG_CTX2 );
-        {
-                this->cond = true;
-
-                disable_interrupts();
-                thread_desc * it;
-                while( it = pop_head( &this->blocked) ) {
-                        ScheduleThread( it );
-                }
-                enable_interrupts( DEBUG_CTX );
-        }
+        this->count += 1;
+        if ( this->count <= 0 ) {
+                // remove task at head of waiting list
+                thrd = pop_head( &this->waiting );
+        }
+
         unlock( &this->lock );
+
+        // make new owner
+        WakeThread( thrd );
 }