Changes in libcfa/src/concurrency/io.cfa [11054eb:dddb3dd0]

File:

• libcfa/src/concurrency/io.cfa (modified) (7 diffs)

libcfa/src/concurrency/io.cfa

@@ -80 +80 @@
         };
 
-        static $io_context * __ioarbiter_allocate( $io_arbiter & this, __u32 idxs[], __u32 want );
-        static void __ioarbiter_submit( $io_context * , __u32 idxs[], __u32 have, bool lazy );
-        static void __ioarbiter_flush ( $io_context & );
+        static $io_context * __ioarbiter_allocate( $io_arbiter & mutex this, processor *, __u32 idxs[], __u32 want );
+        static void __ioarbiter_submit( $io_arbiter & mutex this, $io_context * , __u32 idxs[], __u32 have, bool lazy );
+        static void __ioarbiter_flush ( $io_arbiter & mutex this, $io_context * );
         static inline void __ioarbiter_notify( $io_context & ctx );
 //=============================================================================================
@@ -134 +134 @@
                 $io_context & ctx = *proc->io.ctx;
 
-                __ioarbiter_flush( ctx );
+                if(!ctx.ext_sq.empty) {
+                        __ioarbiter_flush( *ctx.arbiter, &ctx );
+                }
 
                 __STATS__( true, io.calls.flush++; )
@@ -261 +263 @@
                 __cfadbg_print_safe(io, "Kernel I/O : falling back on arbiter for allocation\n");
 
-                struct $io_context * ret = __ioarbiter_allocate(*ioarb, idxs, want);
+                struct $io_context * ret = __ioarbiter_allocate(*ioarb, proc, idxs, want);
 
                 __cfadbg_print_safe(io, "Kernel I/O : slow allocation completed from ring %d\n", ret->fd);
@@ -324 +326 @@
                 __cfadbg_print_safe(io, "Kernel I/O : falling back on arbiter for submission\n");
 
-                __ioarbiter_submit(inctx, idxs, have, lazy);
+                __ioarbiter_submit(*inctx->arbiter, inctx, idxs, have, lazy);
         }
 
@@ -382 +384 @@
 // I/O Arbiter
 //=============================================================================================
-        static inline void block(__outstanding_io_queue & queue, __outstanding_io & item) {
-                // Lock the list, it's not thread safe
-                lock( queue.lock __cfaabi_dbg_ctx2 );
-                {
-                        // Add our request to the list
-                        add( queue.queue, item );
-
-                        // Mark as pending
-                        __atomic_store_n( &queue.empty, false, __ATOMIC_SEQ_CST );
-                }
-                unlock( queue.lock );
-
-                wait( item.sem );
-        }
-
-        static inline bool empty(__outstanding_io_queue & queue ) {
-                return __atomic_load_n( &queue.empty, __ATOMIC_SEQ_CST);
-        }
-
-        static $io_context * __ioarbiter_allocate( $io_arbiter & this, __u32 idxs[], __u32 want ) {
+        static $io_context * __ioarbiter_allocate( $io_arbiter & mutex this, processor * proc, __u32 idxs[], __u32 want ) {
                 __cfadbg_print_safe(io, "Kernel I/O : arbiter allocating\n");
 
@@ -407 +390 @@
 
                 // No one has any resources left, wait for something to finish
-                // We need to add ourself to a list of pending allocs and wait for an answer
-                __pending_alloc pa;
-                pa.idxs = idxs;
-                pa.want = want;
-
-                block(this.pending, (__outstanding_io&)pa);
-
-                return pa.ctx;
-
-        }
-
-        static void __ioarbiter_notify( $io_arbiter & this, $io_context * ctx ) {
-                /* paranoid */ verify( !empty(this.pending.queue) );
-
-                lock( this.pending.lock __cfaabi_dbg_ctx2 );
-                {
-                        while( !empty(this.pending.queue) ) {
-                                __cfadbg_print_safe(io, "Kernel I/O : notifying\n");
-                                __u32 have = ctx->sq.free_ring.tail - ctx->sq.free_ring.head;
-                                __pending_alloc & pa = (__pending_alloc&)head( this.pending.queue );
-
-                                if( have > pa.want ) goto DONE;
-                                drop( this.pending.queue );
-
-                                /* paranoid */__attribute__((unused)) bool ret =
-
-                                __alloc(ctx, pa.idxs, pa.want);
-
-                                /* paranoid */ verify( ret );
-
-                                pa.ctx = ctx;
-
-                                post( pa.sem );
-                        }
-
-                        this.pending.empty = true;
-                        DONE:;
-                }
-                unlock( this.pending.lock );
+                // Mark as pending
+                __atomic_store_n( &this.pending.flag, true, __ATOMIC_SEQ_CST );
+
+                // Wait for our turn to submit
+                wait( this.pending.blocked, want );
+
+                __attribute((unused)) bool ret =
+                __alloc( this.pending.ctx, idxs, want);
+                /* paranoid */ verify( ret );
+
+                return this.pending.ctx;
+
+        }
+
+        static void __ioarbiter_notify( $io_arbiter & mutex this, $io_context * ctx ) {
+                /* paranoid */ verify( !is_empty(this.pending.blocked) );
+                this.pending.ctx = ctx;
+
+                while( !is_empty(this.pending.blocked) ) {
+                        __cfadbg_print_safe(io, "Kernel I/O : notifying\n");
+                        __u32 have = ctx->sq.free_ring.tail - ctx->sq.free_ring.head;
+                        __u32 want = front( this.pending.blocked );
+
+                        if( have > want ) return;
+
+                        signal_block( this.pending.blocked );
+                }
+
+                this.pending.flag = false;
         }
 
         static void __ioarbiter_notify( $io_context & ctx ) {
-                if(!empty( ctx.arbiter->pending )) {
+                if(__atomic_load_n( &ctx.arbiter->pending.flag, __ATOMIC_SEQ_CST)) {
                         __ioarbiter_notify( *ctx.arbiter, &ctx );
                 }
@@ -455 +428 @@
 
         // Simply append to the pending
-        static void __ioarbiter_submit( $io_context * ctx, __u32 idxs[], __u32 have, bool lazy ) {
+        static void __ioarbiter_submit( $io_arbiter & mutex this, $io_context * ctx, __u32 idxs[], __u32 have, bool lazy ) {
                 __cfadbg_print_safe(io, "Kernel I/O : submitting %u from the arbiter to context %u\n", have, ctx->fd);
 
+                /* paranoid */ verify( &this == ctx->arbiter );
+
+                // Mark as pending
+                __atomic_store_n( &ctx->ext_sq.empty, false, __ATOMIC_SEQ_CST );
+
                 __cfadbg_print_safe(io, "Kernel I/O : waiting to submit %u\n", have);
 
-                __external_io ei;
-                ei.idxs = idxs;
-                ei.have = have;
-                ei.lazy = lazy;
-
-                block(ctx->ext_sq, (__outstanding_io&)ei);
+                // Wait for our turn to submit
+                wait( ctx->ext_sq.blocked );
+
+                // Submit our indexes
+                __submit(ctx, idxs, have, lazy);
 
                 __cfadbg_print_safe(io, "Kernel I/O : %u submitted from arbiter\n", have);
         }
 
-        static void __ioarbiter_flush( $io_context & ctx ) {
-                if(!empty( ctx.ext_sq )) {
-                        __STATS__( false, io.flush.external += 1; )
-
-                        __cfadbg_print_safe(io, "Kernel I/O : arbiter flushing\n");
-
-                        lock( ctx.ext_sq.lock __cfaabi_dbg_ctx2 );
-                        {
-                                while( !empty(ctx.ext_sq.queue) ) {
-                                        __external_io & ei = (__external_io&)drop( ctx.ext_sq.queue );
-
-                                        __submit(&ctx, ei.idxs, ei.have, ei.lazy);
-
-                                        post( ei.sem );
-                                }
-
-                                ctx.ext_sq.empty = true;
-                        }
-                        unlock(ctx.ext_sq.lock );
-                }
+        static void __ioarbiter_flush( $io_arbiter & mutex this, $io_context * ctx ) {
+                /* paranoid */ verify( &this == ctx->arbiter );
+
+                __STATS__( false, io.flush.external += 1; )
+
+                __cfadbg_print_safe(io, "Kernel I/O : arbiter flushing\n");
+
+                condition & blcked = ctx->ext_sq.blocked;
+                /* paranoid */ verify( ctx->ext_sq.empty == is_empty( blcked ) );
+                while(!is_empty( blcked )) {
+                        signal_block( blcked );
+                }
+
+                ctx->ext_sq.empty = true;
         }
 #endif