Changeset 9b1dcc2

Timestamp:

Jun 12, 2020, 1:49:17 PM (3 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, arm-eh, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, master, new-ast, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

cb196f2

Parents:

b388ee81

Message:

Changed scheduling API to adapt to non-Processors scheduling threads.

Location:

libcfa/src/concurrency

Files:

• kernel.cfa (modified) (12 diffs)
• kernel.hfa (modified) (3 diffs)
• kernel_private.hfa (modified) (8 diffs)
• preemption.cfa (modified) (7 diffs)
• ready_queue.cfa (modified) (17 diffs)
• thread.cfa (modified) (1 diff)

libcfa/src/concurrency/kernel.cfa

@@ -300 +300 @@
         // register the processor unless it's the main thread which is handled in the boot sequence
         if(this != mainProcessor) {
-                this->id = doregister(this);
+                this->id = doregister((__processor_id_t*)this);
                 ready_queue_grow( this->cltr );
         }
@@ -346 +346 @@
         if(this != mainProcessor) {
                 ready_queue_shrink( this->cltr );
-                unregister(this);
+                unregister((__processor_id_t*)this);
         }
         else {
@@ -416 +416 @@
                 if(unlikely(thrd_dst->preempted != __NO_PREEMPTION)) {
                         // The thread was preempted, reschedule it and reset the flag
-                        __schedule_thread( thrd_dst );
+                        __schedule_thread( (__processor_id_t*)this, thrd_dst );
                         break RUNNING;
                 }
@@ -609 +609 @@
 // Scheduler routines
 // KERNEL ONLY
-void __schedule_thread( $thread * thrd ) {
+void __schedule_thread( struct __processor_id_t * id, $thread * thrd ) {
         /* paranoid */ verify( thrd );
         /* paranoid */ verify( thrd->state != Halted );
@@ -623 +623 @@
         if (thrd->preempted == __NO_PREEMPTION) thrd->state = Ready;
 
-        ready_schedule_lock( kernelTLS.this_processor );
+        ready_schedule_lock  ( id );
                 push( thrd->curr_cluster, thrd );
 
                 __wake_one(thrd->curr_cluster);
-        ready_schedule_unlock( kernelTLS.this_processor );
+        ready_schedule_unlock( id );
 
         /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
@@ -636 +636 @@
         /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
 
-        ready_schedule_lock( kernelTLS.this_processor );
+        ready_schedule_lock  ( (__processor_id_t*)kernelTLS.this_processor );
                 $thread * head = pop( this );
-        ready_schedule_unlock( kernelTLS.this_processor );
+        ready_schedule_unlock( (__processor_id_t*)kernelTLS.this_processor );
 
         /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
@@ -645 +645 @@
 
 // KERNEL ONLY unpark with out disabling interrupts
-void __unpark( $thread * thrd __cfaabi_dbg_ctx_param2 ) {
+void __unpark(  struct __processor_id_t * id, $thread * thrd __cfaabi_dbg_ctx_param2 ) {
         static_assert(sizeof(thrd->state) == sizeof(int));
 
@@ -663 +663 @@
                         // Wake lost the race,
                         thrd->state = Blocked;
-                        __schedule_thread( thrd );
+                        __schedule_thread( id, thrd );
                         break;
                 case Rerun:
@@ -681 +681 @@
 
         disable_interrupts();
-        __unpark( thrd __cfaabi_dbg_ctx_fwd2 );
+        __unpark( (__processor_id_t*)kernelTLS.this_processor, thrd __cfaabi_dbg_ctx_fwd2 );
         enable_interrupts( __cfaabi_dbg_ctx );
 }
@@ -798 +798 @@
         (*mainProcessor){};
 
-        mainProcessor->id = doregister(mainProcessor);
+        mainProcessor->id = doregister( (__processor_id_t*)mainProcessor);
 
         //initialize the global state variables
@@ -809 +809 @@
         // Add the main thread to the ready queue
         // once resume is called on mainProcessor->runner the mainThread needs to be scheduled like any normal thread
-        __schedule_thread(mainThread);
+        __schedule_thread((__processor_id_t *)mainProcessor, mainThread);
 
         // SKULLDUGGERY: Force a context switch to the main processor to set the main thread's context to the current UNIX
@@ -853 +853 @@
         kernel_stop_preemption();
 
-        unregister(mainProcessor);
+        unregister((__processor_id_t*)mainProcessor);
 
         // Destroy the main processor and its context in reverse order of construction

libcfa/src/concurrency/kernel.hfa

@@ -47 +47 @@
 extern struct cluster * mainCluster;
 
-// Processor
+// Processor id, required for scheduling threads
+struct __processor_id_t {
+        unsigned id;
+};
+
 coroutine processorCtx_t {
         struct processor * proc;
@@ -54 +58 @@
 // Wrapper around kernel threads
 struct processor {
+        inline __processor_id_t;
+
         // Main state
         // Coroutine ctx who does keeps the state of the processor
@@ -60 +66 @@
         // Cluster from which to get threads
         struct cluster * cltr;
-        unsigned int id;
 
         // Name of the processor

libcfa/src/concurrency/kernel_private.hfa

@@ -25 +25 @@
 // Scheduler
 
+struct __attribute__((aligned(64))) __scheduler_lock_id_t;
+
 extern "C" {
         void disable_interrupts() OPTIONAL_THREAD;
@@ -31 +33 @@
 }
 
-void __schedule_thread( $thread * ) __attribute__((nonnull (1)));
+void __schedule_thread( struct __processor_id_t *, $thread * ) __attribute__((nonnull (2)));
 
 //Block current thread and release/wake-up the following resources
@@ -73 +75 @@
 
 // KERNEL ONLY unpark with out disabling interrupts
-void __unpark( $thread * thrd __cfaabi_dbg_ctx_param2 );
+void __unpark( struct __processor_id_t *, $thread * thrd __cfaabi_dbg_ctx_param2 );
 
 //-----------------------------------------------------------------------------
@@ -108 +110 @@
 // Cells use by the reader writer lock
 // while not generic it only relies on a opaque pointer
-struct __attribute__((aligned(64))) __processor_id {
-        processor * volatile handle;
+struct __attribute__((aligned(64))) __scheduler_lock_id_t {
+        __processor_id_t * volatile handle;
         volatile bool lock;
 };
@@ -115 +117 @@
 // Lock-Free registering/unregistering of threads
 // Register a processor to a given cluster and get its unique id in return
-unsigned doregister( struct processor * proc );
+unsigned doregister( struct __processor_id_t * proc );
 
 // Unregister a processor from a given cluster using its id, getting back the original pointer
-void     unregister( struct processor * proc );
+void     unregister( struct __processor_id_t * proc );
 
 //=======================================================================
@@ -167 +169 @@
 
         // data pointer
-        __processor_id * data;
+        __scheduler_lock_id_t * data;
 };
 
@@ -178 +180 @@
 // Reader side : acquire when using the ready queue to schedule but not
 //  creating/destroying queues
-static inline void ready_schedule_lock( struct processor * proc) with(*__scheduler_lock) {
+static inline void ready_schedule_lock( struct __processor_id_t * proc) with(*__scheduler_lock) {
         unsigned iproc = proc->id;
         /*paranoid*/ verify(data[iproc].handle == proc);
@@ -197 +199 @@
 }
 
-static inline void ready_schedule_unlock( struct processor * proc) with(*__scheduler_lock) {
+static inline void ready_schedule_unlock( struct __processor_id_t * proc) with(*__scheduler_lock) {
         unsigned iproc = proc->id;
         /*paranoid*/ verify(data[iproc].handle == proc);

libcfa/src/concurrency/preemption.cfa

@@ -39 +39 @@
 // FwdDeclarations : timeout handlers
 static void preempt( processor   * this );
-static void timeout( $thread * this );
+static void timeout( struct __processor_id_t * id, $thread * this );
 
 // FwdDeclarations : Signal handlers
@@ -90 +90 @@
 
 // Tick one frame of the Discrete Event Simulation for alarms
-static void tick_preemption() {
+static void tick_preemption( struct __processor_id_t * id ) {
         alarm_node_t * node = 0p;                                                       // Used in the while loop but cannot be declared in the while condition
         alarm_list_t * alarms = &event_kernel->alarms;          // Local copy for ease of reading
@@ -108 +108 @@
                 }
                 else {
-                        timeout( node->thrd );
+                        timeout( id, node->thrd );
                 }
 
@@ -268 +268 @@
 
 // reserved for future use
-static void timeout( $thread * this ) {
-        __unpark( this __cfaabi_dbg_ctx2 );
+static void timeout( struct __processor_id_t * id, $thread * this ) {
+        __unpark( id, this __cfaabi_dbg_ctx2 );
 }
 
@@ -405 +405 @@
 // Waits on SIGALRM and send SIGUSR1 to whom ever needs it
 static void * alarm_loop( __attribute__((unused)) void * args ) {
+        __processor_id_t id;
+        id.id = doregister(&id);
+
         // Block sigalrms to control when they arrive
         sigset_t mask;
@@ -449 +452 @@
                         // __cfaabi_dbg_print_safe( "Kernel : Preemption thread tick\n" );
                         lock( event_kernel->lock __cfaabi_dbg_ctx2 );
-                        tick_preemption();
+                        tick_preemption( &id );
                         unlock( event_kernel->lock );
                         break;
@@ -462 +465 @@
 EXIT:
         __cfaabi_dbg_print_safe( "Kernel : Preemption thread stopping\n" );
+        unregister(&id);
         return 0p;
 }

libcfa/src/concurrency/ready_queue.cfa

@@ -74 +74 @@
 }
 
-void ?{}( __processor_id & this, struct processor * proc ) {
+void ?{}( __scheduler_lock_id_t & this, __processor_id_t * proc ) {
         this.handle = proc;
         this.lock   = false;
@@ -81 +81 @@
 //=======================================================================
 // Lock-Free registering/unregistering of threads
-unsigned doregister( struct processor * proc ) with(*__scheduler_lock) {
+unsigned doregister( struct __processor_id_t * proc ) with(*__scheduler_lock) {
         __cfadbg_print_safe(ready_queue, "Kernel : Registering proc %p for RW-Lock\n", proc);
 
@@ -89 +89 @@
         // Check among all the ready
         for(uint_fast32_t i = 0; i < s; i++) {
-                processor * null = 0p; // Re-write every loop since compare thrashes it
+                __processor_id_t * null = 0p; // Re-write every loop since compare thrashes it
                 if( __atomic_load_n(&data[i].handle, (int)__ATOMIC_RELAXED) == null
                         && __atomic_compare_exchange_n( &data[i].handle, &null, proc, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) {
@@ -106 +106 @@
 
         // Step - 3 : Mark space as used and then publish it.
-        __processor_id * storage = (__processor_id *)&data[n];
+        __scheduler_lock_id_t * storage = (__scheduler_lock_id_t *)&data[n];
         (*storage){ proc };
         while(true) {
@@ -125 +125 @@
 }
 
-void unregister( struct processor * proc ) with(*__scheduler_lock) {
+void unregister( struct __processor_id_t * proc ) with(*__scheduler_lock) {
         unsigned id = proc->id;
         /*paranoid*/ verify(id < ready);
@@ -188 +188 @@
         } before, after;
 
-#if defined(__CFA_WITH_VERIFY__)
-        // id of last processor to acquire the lock
-        // needed only to check for mutual exclusion violations
-        unsigned int last_id;
-
-        // number of items on this list
-        // needed only to check for deadlocks
-        unsigned int count;
-#endif
-
         // Optional statistic counters
         #if !defined(__CFA_NO_SCHED_STATS__)
@@ -235 +225 @@
 void ?{}( __intrusive_lane_t & this ) {
         this.lock = false;
-        #if defined(__CFA_WITH_VERIFY__)
-                this.last_id = -1u;
-                this.count = 0u;
-        #endif
 
         this.before.link.prev = 0p;
@@ -279 +265 @@
         /* paranoid */ verify(tail(this)->link.next == 0p );
         /* paranoid */ verify(tail(this)->link.prev == head(this) );
-        /* paranoid */ verify(this.count == 0u );
 }
 
@@ -293 +278 @@
                 /* paranoid */ verify(head(this)->link.prev == 0p);
 
-                this.count++;
-
                 if(this.before.link.ts == 0l) {
                         /* paranoid */ verify(tail(this)->link.prev == head(this));
@@ -346 +329 @@
         $thread * next = node->link.next;
 
-        #if defined(__CFA_WITH_VERIFY__)
-                this.count--;
-                /* paranoid */ verify(node != tail);
-                /* paranoid */ verify(node);
-        #endif
+        /* paranoid */ verify(node != tail);
+        /* paranoid */ verify(node);
 
         // Do the pop
@@ -637 +617 @@
         } while( !__atomic_try_acquire( &lanes.data[i].lock ) );
 
-        #if defined(__CFA_WITH_VERIFY__)
-                /* paranoid */ verify(lanes.data[i].last_id == -1u);
-                /* paranoid */ lanes.data[i].last_id = kernelTLS.this_processor->id;
-        #endif
-
         bool first = false;
 
@@ -655 +630 @@
                 arrive( snzi, i );
         }
-
-        #if defined(__CFA_WITH_VERIFY__)
-                /* paranoid */ verifyf( lanes.data[i].last_id == kernelTLS.this_processor->id, "Expected last processor to lock queue %u to be %u, was %u\n", i, lanes.data[i].last_id, kernelTLS.this_processor->id );
-                /* paranoid */ verifyf( lanes.data[i].lock, "List %u is not locked\n", i );
-                /* paranoid */ lanes.data[i].last_id = -1u;
-        #endif
 
         // Unlock and return
@@ -698 +667 @@
         if( !__atomic_try_acquire(&lane.lock) ) return 0p;
 
-        #if defined(__CFA_WITH_VERIFY__)
-                /* paranoid */ verify(lane.last_id == -1u);
-                /* paranoid */ lane.last_id = kernelTLS.this_processor->id;
-        #endif
-
 
         // If list is empty, unlock and retry
         if( is_empty(lane) ) {
-                #if defined(__CFA_WITH_VERIFY__)
-                        /* paranoid */ verify(lane.last_id == kernelTLS.this_processor->id);
-                        /* paranoid */ lane.last_id = -1u;
-                #endif
-
                 __atomic_unlock(&lane.lock);
                 return 0p;
@@ -721 +680 @@
 
         /* paranoid */ verify(thrd);
-        /* paranoid */ verify(lane.last_id == kernelTLS.this_processor->id);
         /* paranoid */ verify(lane.lock);
 
@@ -728 +686 @@
                 depart( snzi, w );
         }
-
-        #if defined(__CFA_WITH_VERIFY__)
-                /* paranoid */ verify(lane.last_id == kernelTLS.this_processor->id);
-                /* paranoid */ lane.last_id = -1u;
-        #endif
 
         // Unlock and return
@@ -874 +827 @@
                 ^(snzi){};
 
-                // Make sure that the total thread count stays the same
-                #if defined(__CFA_WITH_VERIFY__)
-                        size_t nthreads = 0;
-                        for( idx; (size_t)lanes.count ) {
-                                nthreads += lanes.data[idx].count;
-                        }
-                #endif
-
                 size_t ocount = lanes.count;
                 // Check that we have some space left
@@ -940 +885 @@
                         }
                 }
-
-                // Make sure that the total thread count stayed the same
-                #if defined(__CFA_WITH_VERIFY__)
-                        for( idx; (size_t)lanes.count ) {
-                                nthreads -= lanes.data[idx].count;
-                        }
-                        verifyf(nthreads == 0, "Shrinking changed number of threads");
-                #endif
         }
 

libcfa/src/concurrency/thread.cfa

@@ -62 +62 @@
         verify( this_thrd->context.SP );
 
-        __schedule_thread(this_thrd);
+        __schedule_thread( (__processor_id_t *)kernelTLS.this_processor, this_thrd);
         enable_interrupts( __cfaabi_dbg_ctx );
 }