Index: benchmark/io/readv.cfa
===================================================================
--- benchmark/io/readv.cfa	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ benchmark/io/readv.cfa	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -59,19 +59,22 @@
 	unsigned long int nthreads = 2;
 	unsigned long int nprocs   = 1;
-	int flags = 0;
+	unsigned flags = 0;
+	unsigned sublen = 16;
 
 	arg_loop:
 	for(;;) {
 		static struct option options[] = {
-			{"duration",   required_argument, 0, 'd'},
-			{"nthreads",   required_argument, 0, 't'},
-			{"nprocs",     required_argument, 0, 'p'},
-			{"bufsize",    required_argument, 0, 'b'},
-			{"userthread", no_argument      , 0, 'u'},
+			{"duration",     required_argument, 0, 'd'},
+			{"nthreads",     required_argument, 0, 't'},
+			{"nprocs",       required_argument, 0, 'p'},
+			{"bufsize",      required_argument, 0, 'b'},
+			{"userthread",   no_argument      , 0, 'u'},
+			{"submitthread", no_argument      , 0, 's'},
+			{"submitlength", required_argument, 0, 'l'},
 			{0, 0, 0, 0}
 		};
 
 		int idx = 0;
-		int opt = getopt_long(argc, argv, "d:t:p:b:u", options, &idx);
+		int opt = getopt_long(argc, argv, "d:t:p:b:usl:", options, &idx);
 
 		const char * arg = optarg ? optarg : "";
@@ -113,4 +116,15 @@
 				flags |= CFA_CLUSTER_IO_POLLER_USER_THREAD;
 				break;
+			case 's':
+				flags |= CFA_CLUSTER_IO_POLLER_THREAD_SUBMITS;
+				break;
+			case 'l':
+				sublen = strtoul(arg, &end, 10);
+				if(*end != '\0' && sublen < 16) {
+					fprintf(stderr, "Submit length must be at least 16, was %s\n", arg);
+					goto usage;
+				}
+				flags |= (sublen << CFA_CLUSTER_IO_BUFFLEN_OFFSET);
+				break;
 			// Other cases
 			default: /* ? */
@@ -123,4 +137,6 @@
 				fprintf(stderr, "  -p, --nprocs=NPROCS      Number of kernel threads\n");
 				fprintf(stderr, "  -b, --buflen=SIZE        Number of bytes to read per request\n");
+				fprintf(stderr, "  -u, --userthread         If set, cluster uses user-thread to poll I/O\n");
+				fprintf(stderr, "  -s, --submitthread       If set, cluster uses polling thread to submit I/O\n");
 				exit(EXIT_FAILURE);
 		}
Index: configure
===================================================================
--- configure	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ configure	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -802,4 +802,5 @@
 with_cfa_name
 enable_distcc
+with_bwlimit
 with_target_hosts
 enable_gprofiler
@@ -1481,4 +1482,5 @@
   --without-PACKAGE       do not use PACKAGE (same as --with-PACKAGE=no)
   --with-cfa-name=NAME     NAME too which cfa will be installed
+  --with-bwlimit=RATE     RATE the maximum rate at which rsync will be limited when using distributed builds
   --with-target-hosts=HOSTS     HOSTS comma seperated list of hosts to build for, format ARCH:debug|nodebug|nolib
   --with-pic[=PKGS]       try to use only PIC/non-PIC objects [default=use
@@ -3198,4 +3200,11 @@
 else
   enable_distcc=no
+fi
+
+
+
+# Check whether --with-bwlimit was given.
+if test "${with_bwlimit+set}" = set; then :
+  withval=$with_bwlimit;
 fi
 
Index: configure.ac
===================================================================
--- configure.ac	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ configure.ac	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -64,4 +64,8 @@
 	[  --enable-distcc     whether or not to enable distributed compilation],
 	enable_distcc=$enableval, enable_distcc=no)
+
+AC_ARG_WITH(bwlimit,
+	[  --with-bwlimit=RATE     RATE the maximum rate at which rsync will be limited when using distributed builds],
+	[], [])
 
 AM_CONDITIONAL([ENABLE_DISTCC], [test x$enable_distcc = xyes])
Index: doc/proposals/vtable.md
===================================================================
--- doc/proposals/vtable.md	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ doc/proposals/vtable.md	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -237,4 +237,34 @@
 default is provided or not, the second syntax can be used to pick a
 parameter on instantiation.
+
+### Extension: Object Access
+This requires that the resolution scope (see below) is at the type level or
+has explicate points with names. These are the tables and table names used
+here.
+
+The system already knows where to find the virtual table and the object. If
+the tables have particular identities, or on the user side names, then it is
+meaningful to check if a binding virtual table is the same* as another. The
+main use of this is virtual table declarations also give the type they bind
+and if a binding table matches a known table then the underlyind object in the
+trait object must be of that type.
+
+* By identity, by value would work and in some senses be more flexiable. But
+  it would be slower and refering to further away functions would be harder.
+
+This gives one of the main new features of the hierarchical use of virtual
+tables (see below); the ability to recover the underlying object. Or a pointer
+of the approprate type it which both reflects the implementation and gives a
+convenent way to encode the boolean/conditional aspect of the operation which
+is that a different virtual table might be in use.
+
+There are two general ways to reperent this; a cast or a field access. The
+cast is traditional and would definitely fit if a single pointer repersents
+a trait object with the virtual table as part of the object. However for a
+double pointer field access might be more approprate. By this system though
+it is not the type that is used as the identifier but the virtual table. If
+there is one table per type than it becomes equivilant again. Otherwise the
+table has to be used as the identifier and the type is just a result of that
+which seems important for syntax.
 
 Hierarchy
@@ -560,5 +590,5 @@
 be used in only some of the declarations.
 
-    trait combiner fee = (summation_instance, sum);
+    trait combiner fee = {summation_instance, sum};
     trait combiner foe = summation_instance;
 
Index: libcfa/Makefile.in
===================================================================
--- libcfa/Makefile.in	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ libcfa/Makefile.in	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -253,4 +253,5 @@
 DEFS = @DEFS@
 DEPDIR = @DEPDIR@
+DIST_BWLIMIT = @DIST_BWLIMIT@
 DLLTOOL = @DLLTOOL@
 DRIVER_DIR = @DRIVER_DIR@
Index: libcfa/configure
===================================================================
--- libcfa/configure	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ libcfa/configure	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -707,4 +707,5 @@
 CONFIG_CFLAGS
 ARCH_FLAGS
+DIST_BWLIMIT
 CFADIR_HASH
 LOCAL_CC1
@@ -789,4 +790,5 @@
 enable_silent_rules
 enable_distcc
+with_bwlimit
 with_cfa_name
 enable_static
@@ -1465,4 +1467,5 @@
   --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
   --without-PACKAGE       do not use PACKAGE (same as --with-PACKAGE=no)
+  --with-bwlimit=RATE     RATE the maximum rate at which rsync will be limited when using distributed builds
   --with-cfa-name=NAME     NAME too which cfa will be installed
   --with-pic[=PKGS]       try to use only PIC/non-PIC objects [default=use
@@ -3047,4 +3050,13 @@
 
 
+
+# Check whether --with-bwlimit was given.
+if test "${with_bwlimit+set}" = set; then :
+  withval=$with_bwlimit; DIST_BWLIMIT=$withval
+else
+  DIST_BWLIMIT=0
+fi
+
+
 echo -n "checking for distributated build... "
 if test x$enable_distcc = xno; then
@@ -3070,4 +3082,5 @@
   ENABLE_DISTCC_FALSE=
 fi
+
 
 
Index: libcfa/configure.ac
===================================================================
--- libcfa/configure.ac	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ libcfa/configure.ac	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -31,4 +31,8 @@
 	enable_distcc=$enableval, enable_distcc=no)
 
+AC_ARG_WITH(bwlimit,
+	[  --with-bwlimit=RATE     RATE the maximum rate at which rsync will be limited when using distributed builds],
+	DIST_BWLIMIT=$withval, DIST_BWLIMIT=0)
+
 echo -n "checking for distributated build... "
 if test x$enable_distcc = xno; then
@@ -55,4 +59,5 @@
 AC_SUBST(CFADIR_HASH)
 AC_SUBST(CFA_VERSION)
+AC_SUBST(DIST_BWLIMIT)
 
 #==============================================================================
Index: libcfa/prelude/Makefile.am
===================================================================
--- libcfa/prelude/Makefile.am	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ libcfa/prelude/Makefile.am	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -72,5 +72,5 @@
 if ENABLE_DISTCC
 distribution: @LOCAL_CFACC@ @LOCAL_CC1@ @CFACPP@ gcc-builtins.cf builtins.cf extras.cf prelude.cfa bootloader.c $(srcdir)/../../tools/build/push2dist.sh
-	${AM_V_GEN}$(srcdir)/../../tools/build/push2dist.sh @CFADIR_HASH@
+	${AM_V_GEN}$(srcdir)/../../tools/build/push2dist.sh @CFADIR_HASH@ @DIST_BWLIMIT@
 	@echo "Dummy file to track distribution to remote hosts" > ${@}
 
Index: libcfa/prelude/Makefile.in
===================================================================
--- libcfa/prelude/Makefile.in	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ libcfa/prelude/Makefile.in	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -215,4 +215,5 @@
 DEFS = @DEFS@
 DEPDIR = @DEPDIR@
+DIST_BWLIMIT = @DIST_BWLIMIT@
 DLLTOOL = @DLLTOOL@
 DRIVER_DIR = @DRIVER_DIR@
@@ -655,5 +656,5 @@
 
 @ENABLE_DISTCC_TRUE@distribution: @LOCAL_CFACC@ @LOCAL_CC1@ @CFACPP@ gcc-builtins.cf builtins.cf extras.cf prelude.cfa bootloader.c $(srcdir)/../../tools/build/push2dist.sh
-@ENABLE_DISTCC_TRUE@	${AM_V_GEN}$(srcdir)/../../tools/build/push2dist.sh @CFADIR_HASH@
+@ENABLE_DISTCC_TRUE@	${AM_V_GEN}$(srcdir)/../../tools/build/push2dist.sh @CFADIR_HASH@ @DIST_BWLIMIT@
 @ENABLE_DISTCC_TRUE@	@echo "Dummy file to track distribution to remote hosts" > ${@}
 
Index: libcfa/src/Makefile.in
===================================================================
--- libcfa/src/Makefile.in	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ libcfa/src/Makefile.in	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -307,4 +307,5 @@
 DEFS = @DEFS@
 DEPDIR = @DEPDIR@
+DIST_BWLIMIT = @DIST_BWLIMIT@
 DLLTOOL = @DLLTOOL@
 DRIVER_DIR = @DRIVER_DIR@
Index: libcfa/src/concurrency/io.cfa
===================================================================
--- libcfa/src/concurrency/io.cfa	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ libcfa/src/concurrency/io.cfa	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -18,7 +18,8 @@
 
 #include "kernel.hfa"
+#include "bitmanip.hfa"
 
 #if !defined(HAVE_LINUX_IO_URING_H)
-	void __kernel_io_startup( cluster &, int, bool ) {
+	void __kernel_io_startup( cluster &, unsigned, bool ) {
 		// Nothing to do without io_uring
 	}
@@ -91,5 +92,4 @@
 	struct __io_poller_fast {
 		struct __io_data * ring;
-		bool waiting;
 		$thread thrd;
 	};
@@ -97,5 +97,4 @@
 	void ?{}( __io_poller_fast & this, struct cluster & cltr ) {
 		this.ring = cltr.io;
-		this.waiting = true;
 		(this.thrd){ "Fast I/O Poller", cltr };
 	}
@@ -126,5 +125,6 @@
 		// Like head/tail but not seen by the kernel
 		volatile uint32_t alloc;
-		volatile uint32_t ready;
+		volatile uint32_t * ready;
+		uint32_t ready_cnt;
 
 		__spinlock_t lock;
@@ -145,4 +145,9 @@
 					volatile unsigned long long int block;
 				} submit_avg;
+				struct {
+					volatile unsigned long long int val;
+					volatile unsigned long long int cnt;
+					volatile unsigned long long int block;
+				} look_avg;
 			} stats;
 		#endif
@@ -192,4 +197,5 @@
 				void * stack;
 				pthread_t kthrd;
+				volatile bool blocked;
 			} slow;
 			__io_poller_fast fast;
@@ -201,5 +207,5 @@
 // I/O Startup / Shutdown logic
 //=============================================================================================
-	void __kernel_io_startup( cluster & this, int io_flags, bool main_cluster ) {
+	void __kernel_io_startup( cluster & this, unsigned io_flags, bool main_cluster ) {
 		this.io = malloc();
 
@@ -274,5 +280,17 @@
 		sq.array   = (         uint32_t *)(((intptr_t)sq.ring_ptr) + params.sq_off.array);
 		sq.alloc = *sq.tail;
-		sq.ready = *sq.tail;
+
+		if( io_flags & CFA_CLUSTER_IO_POLLER_THREAD_SUBMITS ) {
+			/* paranoid */ verify( is_pow2( io_flags >> CFA_CLUSTER_IO_BUFFLEN_OFFSET ) || ((io_flags >> CFA_CLUSTER_IO_BUFFLEN_OFFSET) < 8)  );
+			sq.ready_cnt = max(io_flags >> CFA_CLUSTER_IO_BUFFLEN_OFFSET, 8);
+			sq.ready = alloc_align( 64, sq.ready_cnt );
+			for(i; sq.ready_cnt) {
+				sq.ready[i] = -1ul32;
+			}
+		}
+		else {
+			sq.ready_cnt = 0;
+			sq.ready = 0p;
+		}
 
 		// completion queue
@@ -307,4 +325,7 @@
 			this.io->submit_q.stats.submit_avg.cnt   = 0;
 			this.io->submit_q.stats.submit_avg.block = 0;
+			this.io->submit_q.stats.look_avg.val   = 0;
+			this.io->submit_q.stats.look_avg.cnt   = 0;
+			this.io->submit_q.stats.look_avg.block = 0;
 			this.io->completion_q.stats.completed_avg.val = 0;
 			this.io->completion_q.stats.completed_avg.slow_cnt = 0;
@@ -326,4 +347,5 @@
 		// Create the poller thread
 		__cfadbg_print_safe(io_core, "Kernel I/O : Creating slow poller for cluter %p\n", &this);
+		this.io->poller.slow.blocked = false;
 		this.io->poller.slow.stack = __create_pthread( &this.io->poller.slow.kthrd, __io_poller_slow, &this );
 	}
@@ -347,14 +369,12 @@
 		if( this.io->cltr_flags & CFA_CLUSTER_IO_POLLER_USER_THREAD ) {
 			with( this.io->poller.fast ) {
-				/* paranoid */ verify( waiting ); // The thread shouldn't be in a system call
 				/* paranoid */ verify( this.procs.head == 0p || &this == mainCluster );
 				/* paranoid */ verify( this.idles.head == 0p || &this == mainCluster );
 
 				// We need to adjust the clean-up based on where the thread is
-				if( thrd.preempted != __NO_PREEMPTION ) {
+				if( thrd.state == Ready || thrd.preempted != __NO_PREEMPTION ) {
 
 					// This is the tricky case
 					// The thread was preempted and now it is on the ready queue
-					/* paranoid */ verify( thrd.state == Active );           // The thread better be in this state
 					/* paranoid */ verify( thrd.next == 1p );                // The thread should be the last on the list
 					/* paranoid */ verify( this.ready_queue.head == &thrd ); // The thread should be the only thing on the list
@@ -405,14 +425,27 @@
 			if(this.print_stats) {
 				with(this.io->submit_q.stats, this.io->completion_q.stats) {
+					double lavgv = 0;
+					double lavgb = 0;
+					if(look_avg.cnt != 0) {
+						lavgv = ((double)look_avg.val  ) / look_avg.cnt;
+						lavgb = ((double)look_avg.block) / look_avg.cnt;
+					}
+
 					__cfaabi_bits_print_safe( STDERR_FILENO,
 						"----- I/O uRing Stats -----\n"
-						"- total submit calls  : %'15llu\n"
-						"- avg submit          : %'18.2lf\n"
-						"- pre-submit block %%  : %'18.2lf\n"
-						"- total wait calls    : %'15llu   (%'llu slow, %'llu fast)\n"
-						"- avg completion/wait : %'18.2lf\n",
+						"- total submit calls     : %'15llu\n"
+						"- avg submit             : %'18.2lf\n"
+						"- pre-submit block %%     : %'18.2lf\n"
+						"- total ready search     : %'15llu\n"
+						"- avg ready search len   : %'18.2lf\n"
+						"- avg ready search block : %'18.2lf\n"
+						"- total wait calls       : %'15llu   (%'llu slow, %'llu fast)\n"
+						"- avg completion/wait    : %'18.2lf\n",
 						submit_avg.cnt,
 						((double)submit_avg.val) / submit_avg.cnt,
 						(100.0 * submit_avg.block) / submit_avg.cnt,
+						look_avg.cnt,
+						lavgv,
+						lavgb,
 						completed_avg.slow_cnt + completed_avg.fast_cnt,
 						completed_avg.slow_cnt,  completed_avg.fast_cnt,
@@ -441,4 +474,5 @@
 		close(this.io->fd);
 
+		free( this.io->submit_q.ready ); // Maybe null, doesn't matter
 		free( this.io );
 	}
@@ -454,6 +488,36 @@
 	// Process a single completion message from the io_uring
 	// This is NOT thread-safe
-	static int __drain_io( struct __io_data & ring, sigset_t * mask, int waitcnt, bool in_kernel ) {
-		int ret = syscall( __NR_io_uring_enter, ring.fd, 0, waitcnt, IORING_ENTER_GETEVENTS, mask, _NSIG / 8);
+	static [int, bool] __drain_io( & struct __io_data ring, * sigset_t mask, int waitcnt, bool in_kernel ) {
+		unsigned to_submit = 0;
+		if( ring.cltr_flags & CFA_CLUSTER_IO_POLLER_THREAD_SUBMITS ) {
+
+			// If the poller thread also submits, then we need to aggregate the submissions which are ready
+			uint32_t * tail = ring.submit_q.tail;
+			const uint32_t mask = *ring.submit_q.mask;
+
+			// Go through the list of ready submissions
+			for( i; ring.submit_q.ready_cnt ) {
+				// replace any submission with the sentinel, to consume it.
+				uint32_t idx = __atomic_exchange_n( &ring.submit_q.ready[i], -1ul32, __ATOMIC_RELAXED);
+
+				// If it was already the sentinel, then we are done
+				if( idx == -1ul32 ) continue;
+
+				// If we got a real submission, append it to the list
+				ring.submit_q.array[ ((*tail) + to_submit) & mask ] = idx & mask;
+				to_submit++;
+			}
+
+			// Increment the tail based on how many we are ready to submit
+			__atomic_fetch_add(tail, to_submit, __ATOMIC_SEQ_CST);
+
+			// update statistics
+			#if !defined(__CFA_NO_STATISTICS__)
+				ring.submit_q.stats.submit_avg.val += to_submit;
+				ring.submit_q.stats.submit_avg.cnt += 1;
+			#endif
+		}
+
+		int ret = syscall( __NR_io_uring_enter, ring.fd, to_submit, waitcnt, IORING_ENTER_GETEVENTS, mask, _NSIG / 8);
 		if( ret < 0 ) {
 			switch((int)errno) {
@@ -497,5 +561,5 @@
 		__atomic_fetch_add( ring.completion_q.head, count, __ATOMIC_RELAXED );
 
-		return count;
+		return [count, count > 0 || to_submit > 0];
 	}
 
@@ -519,7 +583,14 @@
 		if( ring.cltr_flags & CFA_CLUSTER_IO_POLLER_USER_THREAD ) {
 			while(!__atomic_load_n(&ring.done, __ATOMIC_SEQ_CST)) {
+
+				__atomic_store_n( &ring.poller.slow.blocked, true, __ATOMIC_SEQ_CST );
+
 				// In the user-thread approach drain and if anything was drained,
 				// batton pass to the user-thread
-				int count = __drain_io( ring, &mask, 1, true );
+				int count;
+				bool again;
+				[count, again] = __drain_io( ring, &mask, 1, true );
+
+				__atomic_store_n( &ring.poller.slow.blocked, false, __ATOMIC_SEQ_CST );
 
 				// Update statistics
@@ -529,5 +600,5 @@
 				#endif
 
-				if(count > 0) {
+				if(again) {
 					__cfadbg_print_safe(io_core, "Kernel I/O : Moving to ring %p to fast poller\n", &ring);
 					__unpark( &ring.poller.fast.thrd __cfaabi_dbg_ctx2 );
@@ -539,5 +610,7 @@
 			while(!__atomic_load_n(&ring.done, __ATOMIC_SEQ_CST)) {
 				//In the naive approach, just poll the io completion queue directly
-				int count = __drain_io( ring, &mask, 1, true );
+				int count;
+				bool again;
+				[count, again] = __drain_io( ring, &mask, 1, true );
 
 				// Update statistics
@@ -566,8 +639,11 @@
 		// Then loop until we need to start
 		while(!__atomic_load_n(&this.ring->done, __ATOMIC_SEQ_CST)) {
+
 			// Drain the io
-			this.waiting = false;
-			int count = __drain_io( *this.ring, 0p, 0, false );
-			reset += count > 0 ? 1 : 0;
+			int count;
+			bool again;
+			[count, again] = __drain_io( *this.ring, 0p, 0, false );
+
+			if(!again) reset++;
 
 			// Update statistics
@@ -577,19 +653,30 @@
 			#endif
 
-			this.waiting = true;
+			// If we got something, just yield and check again
 			if(reset < 5) {
-				// If we got something, just yield and check again
 				yield();
 			}
+			// We didn't get anything baton pass to the slow poller
 			else {
-				// We didn't get anything baton pass to the slow poller
 				__cfadbg_print_safe(io_core, "Kernel I/O : Moving to ring %p to slow poller\n", &this.ring);
+				reset = 0;
+
+				// wake up the slow poller
 				post( this.ring->poller.sem );
+
+				// park this thread
 				park( __cfaabi_dbg_ctx );
-				reset = 0;
 			}
 		}
 
 		__cfadbg_print_safe(io_core, "Kernel I/O : Fast poller for ring %p stopping\n", &this.ring);
+	}
+
+	static inline void __wake_poller( struct __io_data & ring ) __attribute__((artificial));
+	static inline void __wake_poller( struct __io_data & ring ) {
+		if(!__atomic_load_n( &ring.poller.slow.blocked, __ATOMIC_SEQ_CST)) return;
+
+		sigval val = { 1 };
+		pthread_sigqueue( ring.poller.slow.kthrd, SIGUSR1, val );
 	}
 
@@ -632,45 +719,84 @@
 		uint32_t idx = __atomic_fetch_add(&ring.submit_q.alloc, 1ul32, __ATOMIC_SEQ_CST);
 
-		// Validate that we didn't overflow anything
-		// Check that nothing overflowed
-		/* paranoid */ verify( true );
-
-		// Check that it goes head -> tail -> alloc and never head -> alloc -> tail
-		/* paranoid */ verify( true );
+		// Mask the idx now to allow make everything easier to check
+		idx &= *ring.submit_q.mask;
 
 		// Return the sqe
-		return [&ring.submit_q.sqes[ idx & (*ring.submit_q.mask)], idx];
+		return [&ring.submit_q.sqes[ idx ], idx];
 	}
 
 	static inline void __submit( struct __io_data & ring, uint32_t idx ) {
-		// get mutual exclusion
-		lock(ring.submit_q.lock __cfaabi_dbg_ctx2);
-
-		// Append to the list of ready entries
-		uint32_t * tail = ring.submit_q.tail;
+		// Get now the data we definetely need
+		uint32_t * const tail = ring.submit_q.tail;
 		const uint32_t mask = *ring.submit_q.mask;
 
-		ring.submit_q.array[ (*tail) & mask ] = idx & mask;
-		__atomic_fetch_add(tail, 1ul32, __ATOMIC_SEQ_CST);
-
-		// Submit however, many entries need to be submitted
-		int ret = syscall( __NR_io_uring_enter, ring.fd, 1, 0, 0, 0p, 0);
-		if( ret < 0 ) {
-			switch((int)errno) {
-			default:
-				abort( "KERNEL ERROR: IO_URING SUBMIT - %s\n", strerror(errno) );
-			}
-		}
-
-		// update statistics
-		#if !defined(__CFA_NO_STATISTICS__)
-			ring.submit_q.stats.submit_avg.val += 1;
-			ring.submit_q.stats.submit_avg.cnt += 1;
-		#endif
-
-		unlock(ring.submit_q.lock);
-		// Make sure that idx was submitted
-		// Be careful to not get false positive if we cycled the entire list or that someone else submitted for us
-		__cfadbg_print_safe( io, "Kernel I/O : Performed io_submit for %p, returned %d\n", active_thread(), ret );
+		// There are 2 submission schemes, check which one we are using
+		if( ring.cltr_flags & CFA_CLUSTER_IO_POLLER_THREAD_SUBMITS ) {
+			// If the poller thread submits, then we just need to add this to the ready array
+
+			/* paranoid */ verify( idx <= mask   );
+			/* paranoid */ verify( idx != -1ul32 );
+
+			// We need to find a spot in the ready array
+			__attribute((unused)) int len   = 0;
+			__attribute((unused)) int block = 0;
+			uint32_t expected = -1ul32;
+			uint32_t ready_mask = ring.submit_q.ready_cnt - 1;
+			uint32_t off = __tls_rand();
+			LOOKING: for() {
+				for(i; ring.submit_q.ready_cnt) {
+					uint32_t ii = (i + off) & ready_mask;
+					if( __atomic_compare_exchange_n( &ring.submit_q.ready[ii], &expected, idx, true, __ATOMIC_SEQ_CST, __ATOMIC_RELAXED ) ) {
+						break LOOKING;
+					}
+
+					len ++;
+				}
+
+				block++;
+				yield();
+			}
+
+			__wake_poller( ring );
+
+			// update statistics
+			#if !defined(__CFA_NO_STATISTICS__)
+				__atomic_fetch_add( &ring.submit_q.stats.look_avg.val,   len,   __ATOMIC_RELAXED );
+				__atomic_fetch_add( &ring.submit_q.stats.look_avg.block, block, __ATOMIC_RELAXED );
+				__atomic_fetch_add( &ring.submit_q.stats.look_avg.cnt,   1,     __ATOMIC_RELAXED );
+			#endif
+
+			__cfadbg_print_safe( io, "Kernel I/O : Added %u to ready for %p\n", idx, active_thread() );
+		}
+		else {
+			// get mutual exclusion
+			lock(ring.submit_q.lock __cfaabi_dbg_ctx2);
+
+			// Append to the list of ready entries
+
+			/* paranoid */ verify( idx <= mask );
+
+			ring.submit_q.array[ (*tail) & mask ] = idx & mask;
+			__atomic_fetch_add(tail, 1ul32, __ATOMIC_SEQ_CST);
+
+			// Submit however, many entries need to be submitted
+			int ret = syscall( __NR_io_uring_enter, ring.fd, 1, 0, 0, 0p, 0);
+			if( ret < 0 ) {
+				switch((int)errno) {
+				default:
+					abort( "KERNEL ERROR: IO_URING SUBMIT - %s\n", strerror(errno) );
+				}
+			}
+
+			// update statistics
+			#if !defined(__CFA_NO_STATISTICS__)
+				ring.submit_q.stats.submit_avg.val += 1;
+				ring.submit_q.stats.submit_avg.cnt += 1;
+			#endif
+
+			unlock(ring.submit_q.lock);
+
+			__cfadbg_print_safe( io, "Kernel I/O : Performed io_submit for %p, returned %d\n", active_thread(), ret );
+		}
 	}
 
Index: libcfa/src/concurrency/kernel.cfa
===================================================================
--- libcfa/src/concurrency/kernel.cfa	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ libcfa/src/concurrency/kernel.cfa	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -256,5 +256,5 @@
 }
 
-void ?{}(cluster & this, const char name[], Duration preemption_rate, int io_flags) with( this ) {
+void ?{}(cluster & this, const char name[], Duration preemption_rate, unsigned io_flags) with( this ) {
 	this.name = name;
 	this.preemption_rate = preemption_rate;
@@ -374,4 +374,5 @@
 
 		/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
+		/* paranoid */ verify( kernelTLS.this_thread == thrd_dst );
 		/* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) < ((uintptr_t)__get_stack(thrd_dst->curr_cor)->base ) || thrd_dst->curr_cor == proc_cor, "ERROR : Destination $thread %p has been corrupted.\n StackPointer too small.\n", thrd_dst ); // add escape condition if we are setting up the processor
 		/* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) > ((uintptr_t)__get_stack(thrd_dst->curr_cor)->limit) || thrd_dst->curr_cor == proc_cor, "ERROR : Destination $thread %p has been corrupted.\n StackPointer too large.\n", thrd_dst ); // add escape condition if we are setting up the processor
@@ -384,4 +385,5 @@
 		/* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) > ((uintptr_t)__get_stack(thrd_dst->curr_cor)->limit), "ERROR : Destination $thread %p has been corrupted.\n StackPointer too large.\n", thrd_dst );
 		/* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) < ((uintptr_t)__get_stack(thrd_dst->curr_cor)->base ), "ERROR : Destination $thread %p has been corrupted.\n StackPointer too small.\n", thrd_dst );
+		/* paranoid */ verify( kernelTLS.this_thread == thrd_dst );
 		/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
 
Index: libcfa/src/concurrency/kernel.hfa
===================================================================
--- libcfa/src/concurrency/kernel.hfa	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ libcfa/src/concurrency/kernel.hfa	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -116,6 +116,8 @@
 struct __io_data;
 
-#define CFA_CLUSTER_IO_POLLER_USER_THREAD 1 << 0
-// #define CFA_CLUSTER_IO_POLLER_KERNEL_SIDE 1 << 1
+#define CFA_CLUSTER_IO_POLLER_USER_THREAD    1 << 0 // 0x1
+#define CFA_CLUSTER_IO_POLLER_THREAD_SUBMITS 1 << 1 // 0x2
+// #define CFA_CLUSTER_IO_POLLER_KERNEL_SIDE 1 << 2 // 0x4
+#define CFA_CLUSTER_IO_BUFFLEN_OFFSET        16
 
 //-----------------------------------------------------------------------------
@@ -159,13 +161,13 @@
 extern Duration default_preemption();
 
-void ?{} (cluster & this, const char name[], Duration preemption_rate, int flags);
+void ?{} (cluster & this, const char name[], Duration preemption_rate, unsigned flags);
 void ^?{}(cluster & this);
 
-static inline void ?{} (cluster & this)                                      { this{"Anonymous Cluster", default_preemption(), 0}; }
-static inline void ?{} (cluster & this, Duration preemption_rate)            { this{"Anonymous Cluster", preemption_rate, 0}; }
-static inline void ?{} (cluster & this, const char name[])                   { this{name, default_preemption(), 0}; }
-static inline void ?{} (cluster & this, int flags)                           { this{"Anonymous Cluster", default_preemption(), flags}; }
-static inline void ?{} (cluster & this, Duration preemption_rate, int flags) { this{"Anonymous Cluster", preemption_rate, flags}; }
-static inline void ?{} (cluster & this, const char name[], int flags)        { this{name, default_preemption(), flags}; }
+static inline void ?{} (cluster & this)                                           { this{"Anonymous Cluster", default_preemption(), 0}; }
+static inline void ?{} (cluster & this, Duration preemption_rate)                 { this{"Anonymous Cluster", preemption_rate, 0}; }
+static inline void ?{} (cluster & this, const char name[])                        { this{name, default_preemption(), 0}; }
+static inline void ?{} (cluster & this, unsigned flags)                           { this{"Anonymous Cluster", default_preemption(), flags}; }
+static inline void ?{} (cluster & this, Duration preemption_rate, unsigned flags) { this{"Anonymous Cluster", preemption_rate, flags}; }
+static inline void ?{} (cluster & this, const char name[], unsigned flags)        { this{name, default_preemption(), flags}; }
 
 static inline [cluster *&, cluster *& ] __get( cluster & this ) __attribute__((const)) { return this.node.[next, prev]; }
Index: libcfa/src/concurrency/kernel_private.hfa
===================================================================
--- libcfa/src/concurrency/kernel_private.hfa	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ libcfa/src/concurrency/kernel_private.hfa	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -77,5 +77,5 @@
 //-----------------------------------------------------------------------------
 // I/O
-void __kernel_io_startup     ( cluster &, int, bool );
+void __kernel_io_startup     ( cluster &, unsigned, bool );
 void __kernel_io_finish_start( cluster & );
 void __kernel_io_prepare_stop( cluster & );
Index: libcfa/src/containers/list.hfa
===================================================================
--- libcfa/src/containers/list.hfa	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ libcfa/src/containers/list.hfa	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -301,4 +301,41 @@
 		$prev_link(list_pos) = (Telem*) 0p;
 	}
+
+	static inline bool ?`is_empty(dlist(Tnode, Telem) &list) {
+		assert( &list != 0p );
+		$dlinks(Telem) *listLinks = & list.$links;
+		if (listLinks->next.is_terminator) {
+			assert(listLinks->prev.is_terminator);
+			assert(listLinks->next.terminator);
+			assert(listLinks->prev.terminator);
+			return true;
+		} else {
+			assert(!listLinks->prev.is_terminator);
+			assert(listLinks->next.elem);
+			assert(listLinks->prev.elem);
+			return false;
+		}
+	}
+
+	static inline Telem & pop_first(dlist(Tnode, Telem) &list) {
+		assert( &list != 0p );
+		assert( !list`is_empty );
+		$dlinks(Telem) *listLinks = & list.$links;
+		Telem & first = *listLinks->next.elem;
+		Tnode & list_pos_first  = $tempcv_e2n( first );
+		remove(list_pos_first);
+		return first;
+	}
+
+	static inline Telem & pop_last(dlist(Tnode, Telem) &list) {
+		assert( &list != 0p );
+		assert( !list`is_empty );
+		$dlinks(Telem) *listLinks = & list.$links;
+		Telem & last = *listLinks->prev.elem;
+		Tnode & list_pos_last  = $tempcv_e2n( last );
+		remove(list_pos_last);
+		return last;
+	}
+
 }
 
Index: libcfa/src/exception.c
===================================================================
--- libcfa/src/exception.c	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ libcfa/src/exception.c	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -121,8 +121,5 @@
 
 
-// TERMINATION ===============================================================
-
-// MEMORY MANAGEMENT (still for integers)
-// May have to move to cfa for constructors and destructors (references).
+// MEMORY MANAGEMENT =========================================================
 
 // How to clean up an exception in various situations.
@@ -203,8 +200,5 @@
 }
 
-// If this isn't a rethrow (*except==0), delete the provided exception.
-void __cfaehm_cleanup_terminate( void * except ) {
-	if ( *(void**)except ) __cfaehm_delete_exception( *(exception_t **)except );
-}
+// CANCELLATION ==============================================================
 
 // Function needed by force unwind
@@ -228,4 +222,21 @@
 }
 
+// Cancel the current stack, prefroming approprate clean-up and messaging.
+void __cfaehm_cancel_stack( exception_t * exception ) {
+	// TODO: Detect current stack and pick a particular stop-function.
+	_Unwind_Reason_Code ret;
+	ret = _Unwind_ForcedUnwind( &this_exception_storage, _Stop_Fn, (void*)0x22 );
+	printf("UNWIND ERROR %d after force unwind\n", ret);
+	abort();
+}
+
+
+// TERMINATION ===============================================================
+
+// If this isn't a rethrow (*except==0), delete the provided exception.
+void __cfaehm_cleanup_terminate( void * except ) {
+	if ( *(void**)except ) __cfaehm_delete_exception( *(exception_t **)except );
+}
+
 // The exception that is being thrown must already be stored.
 static __attribute__((noreturn)) void __cfaehm_begin_unwind(void) {
@@ -245,12 +256,10 @@
 	// the whole stack.
 
+	// No handler found, go to the default operation.
+	// Currently this will always be a cancellation.
 	if ( ret == _URC_END_OF_STACK ) {
-		// No proper handler was found. This can be handled in many ways, C++ calls std::terminate.
-		// Here we force unwind the stack, basically raising a cancellation.
-		printf("Uncaught exception %p\n", &this_exception_storage);
-
-		ret = _Unwind_ForcedUnwind( &this_exception_storage, _Stop_Fn, (void*)0x22 );
-		printf("UNWIND ERROR %d after force unwind\n", ret);
-		abort();
+		__cfadbg_print_safe(exception, "Uncaught exception %p\n", &this_exception_storage);
+
+		__cfaehm_cancel_stack(this_exception_context()->current_exception);
 	}
 
Index: libcfa/src/exception.h
===================================================================
--- libcfa/src/exception.h	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ libcfa/src/exception.h	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -38,4 +38,6 @@
 
 
+void __cfaehm_cancel_stack(exception_t * except) __attribute__((noreturn));
+
 // Used in throw statement translation.
 void __cfaehm_throw_terminate(exception_t * except) __attribute__((noreturn));
Index: libcfa/src/exception.hfa
===================================================================
--- libcfa/src/exception.hfa	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ libcfa/src/exception.hfa	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -10,7 +10,19 @@
 // Created On       : Thu Apr  7 10:25:00 2020
 // Last Modified By : Andrew Beach
-// Last Modified On : Thu Apr  7 10:25:00 2020
-// Update Count     : 0
+// Last Modified On : Wed Apr 13 15:42:00 2020
+// Update Count     : 1
 //
+
+// WARNING: This is for documentation as it will match ANY type.
+trait is_exception(dtype T) {
+	/* The first field must be a pointer to a virtual table.
+	 * That virtual table must be a decendent of the base exception virtual table.
+	 */
+};
+
+forall(dtype T | is_exception(T))
+inline void cancel_stack(T & except) __attribute__((noreturn)) {
+	__cfaehm_cancel_stack( (exception_t *)&except );
+}
 
 // Everything below this line should be considered a patch while the exception
Index: libcfa/src/executor.cfa
===================================================================
--- libcfa/src/executor.cfa	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ libcfa/src/executor.cfa	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -4,35 +4,33 @@
 // buffer.
 
-#include <bits/containers.hfa>
+#include <containers/list.hfa>
 #include <thread.hfa>
 #include <stdio.h>
 
-forall( dtype T )
-monitor Buffer {					// unbounded buffer
-    __queue_t( T ) queue;				// unbounded list of work requests
-    condition delay;
-}; // Buffer
-forall( dtype T | is_node(T) ) {
-    void insert( Buffer( T ) & mutex buf, T * elem ) with(buf) {
-	append( queue, elem );				// insert element into buffer
-	signal( delay );				// restart
-    } // insert
-
-    T * remove( Buffer( T ) & mutex buf ) with(buf) {
-	if ( queue.head != 0 ) wait( delay );			// no request to process ? => wait
-//	return pop_head( queue );
-    } // remove
-} // distribution
-
 struct WRequest {					// client request, no return
     void (* action)( void );
-    WRequest * next;					// intrusive queue field
+    DLISTED_MGD_IMPL_IN(WRequest)
 }; // WRequest
+DLISTED_MGD_IMPL_OUT(WRequest)
 
-WRequest *& get_next( WRequest & this ) { return this.next; }
-void ?{}( WRequest & req ) with(req) { action = 0; next = 0; }
-void ?{}( WRequest & req, void (* action)( void ) ) with(req) { req.action = action; next = 0; }
+void ?{}( WRequest & req ) with(req) { action = 0; }
+void ?{}( WRequest & req, void (* action)( void ) ) with(req) { req.action = action; }
 bool stop( WRequest & req ) { return req.action == 0; }
 void doit( WRequest & req ) { req.action(); }
+
+monitor WRBuffer {					// unbounded buffer
+    dlist( WRequest, WRequest ) queue;			// unbounded list of work requests
+    condition delay;
+}; // WRBuffer
+
+void insert( WRBuffer & mutex buf, WRequest * elem ) with(buf) {
+    insert_last( queue, *elem );			// insert element into buffer
+    signal( delay );				        // restart
+} // insert
+
+WRequest * remove( WRBuffer & mutex buf ) with(buf) {
+    if ( queue`is_empty ) wait( delay );	        // no request to process ? => wait
+    return & pop_first( queue );
+} // remove
 
 // Each worker has its own work buffer to reduce contention between client and server. Hence, work requests arrive and
@@ -40,5 +38,5 @@
 
 thread Worker {
-    Buffer( WRequest ) * requests;
+    WRBuffer * requests;
     unsigned int start, range;
 }; // Worker
@@ -54,5 +52,5 @@
 } // Worker::main
 
-void ?{}( Worker & worker, cluster * wc, Buffer( WRequest ) * requests, unsigned int start, unsigned int range ) {
+void ?{}( Worker & worker, cluster * wc, WRBuffer * requests, unsigned int start, unsigned int range ) {
     (*get_thread(worker)){ *wc };			// create on given cluster
     worker.[requests, start, range] = [requests, start, range];
@@ -62,5 +60,5 @@
     cluster * cluster;					// if workers execute on separate cluster
     processor ** processors;				// array of virtual processors adding parallelism for workers
-    Buffer( WRequest ) * requests;			// list of work requests
+    WRBuffer * requests;			        // list of work requests
     Worker ** workers;					// array of workers executing work requests
     unsigned int nprocessors, nworkers, nmailboxes;	// number of mailboxes/workers/processor tasks
@@ -79,5 +77,5 @@
     cluster = sepClus ? new( "Executor" ) : active_cluster();
     processors = (processor **)anew( nprocessors );
-    requests = anew( nmailboxes );
+    requests = (WRBuffer *)anew( nmailboxes );
     workers = (Worker **)anew( nworkers );
 
@@ -141,5 +139,8 @@
 	for ( i; 3000 ) {
 	    send( exector, workie );
-	    if ( i % 100 ) yield();
+	    if ( i % 100 == 0 ) {
+//              fprintf( stderr, "%d\n", i );
+                yield();
+            }
 	} // for
     }
Index: tests/exceptions/.expect/resume.txt
===================================================================
--- tests/exceptions/.expect/resume.txt	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ tests/exceptions/.expect/resume.txt	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -4,4 +4,6 @@
 end of try clause
 Exiting: simple try clause
+
+catch-all
 
 throwing child exception
Index: tests/exceptions/.expect/terminate.txt
===================================================================
--- tests/exceptions/.expect/terminate.txt	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ tests/exceptions/.expect/terminate.txt	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -3,4 +3,6 @@
 simple catch
 Exiting: simple catch clause
+
+catch-all
 
 throwing child exception
Index: tests/exceptions/resume.cfa
===================================================================
--- tests/exceptions/resume.cfa	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ tests/exceptions/resume.cfa	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -19,4 +19,12 @@
 		loud_exit a = "simple catch clause";
 		printf("simple catch\n");
+	}
+	printf("\n");
+
+	// Throw catch-all test.
+	try {
+		throwResume &(zen){};
+	} catchResume (exception_t * error) {
+		printf("catch-all\n");
 	}
 	printf("\n");
Index: tests/exceptions/terminate.cfa
===================================================================
--- tests/exceptions/terminate.cfa	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ tests/exceptions/terminate.cfa	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -17,6 +17,14 @@
 		printf("end of try clause\n");
 	} catch (zen * error) {
-        loud_exit a = "simple catch clause";
+		loud_exit a = "simple catch clause";
 		printf("simple catch\n");
+	}
+	printf("\n");
+
+	// Throw catch-all test.
+	try {
+		throw &(zen){};
+	} catch (exception_t * error) {
+		printf("catch-all\n");
 	}
 	printf("\n");
Index: tests/list/.expect/dlist-insert-remove.txt
===================================================================
--- tests/list/.expect/dlist-insert-remove.txt	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ tests/list/.expect/dlist-insert-remove.txt	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -1464,2 +1464,316 @@
 0.7
 -
+
+~~~~~~~~~~ End removal tests on Headed List: First ~~~~~~~~~~
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Test 16-i.  Modifying Freds on MINE
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+==== fred by MINE before 
+1.7
+2.7
+3.7
+-
+1.7
+-
+3.7
+-
+3.7
+2.7
+1.7
+-
+==== fred by YOURS before 
+1.7
+2.7
+3.7
+-
+1.7
+-
+3.7
+-
+3.7
+2.7
+1.7
+-
+==== fred by MINE after 
+2.7
+3.7
+-
+2.7
+-
+3.7
+-
+3.7
+2.7
+-
+==== fred by YOURS after 
+1.7
+2.7
+3.7
+-
+1.7
+-
+3.7
+-
+3.7
+2.7
+1.7
+-
+==== fred by MINE after 
+1.7
+-
+1.7
+-
+-
+-
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Test 16-ii.  Modifying Freds on YOURS
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+==== fred by MINE before 
+1.7
+2.7
+3.7
+-
+1.7
+-
+3.7
+-
+3.7
+2.7
+1.7
+-
+==== fred by YOURS before 
+1.7
+2.7
+3.7
+-
+1.7
+-
+3.7
+-
+3.7
+2.7
+1.7
+-
+==== fred by MINE after 
+1.7
+2.7
+3.7
+-
+1.7
+-
+3.7
+-
+3.7
+2.7
+1.7
+-
+==== fred by YOURS after 
+2.7
+3.7
+-
+2.7
+-
+3.7
+-
+3.7
+2.7
+-
+==== fred by YOURS after 
+1.7
+-
+1.7
+-
+-
+-
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Test 16-iii.  Modifying Maries
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+==== mary before 
+1.7
+2.7
+3.7
+-
+1.7
+-
+3.7
+-
+3.7
+2.7
+1.7
+-
+==== mary after 
+2.7
+3.7
+-
+2.7
+-
+3.7
+-
+3.7
+2.7
+-
+==== mary after 
+1.7
+-
+1.7
+-
+-
+-
+
+~~~~~~~~~~ End removal tests on Headed List: Last ~~~~~~~~~~
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Test 17-i.  Modifying Freds on MINE
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+==== fred by MINE before 
+1.7
+2.7
+3.7
+-
+1.7
+-
+3.7
+-
+3.7
+2.7
+1.7
+-
+==== fred by YOURS before 
+1.7
+2.7
+3.7
+-
+1.7
+-
+3.7
+-
+3.7
+2.7
+1.7
+-
+==== fred by MINE after 
+1.7
+2.7
+-
+1.7
+-
+2.7
+-
+2.7
+1.7
+-
+==== fred by YOURS after 
+1.7
+2.7
+3.7
+-
+1.7
+-
+3.7
+-
+3.7
+2.7
+1.7
+-
+==== fred by MINE after 
+3.7
+-
+3.7
+-
+-
+-
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Test 17-ii.  Modifying Freds on YOURS
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+==== fred by MINE before 
+1.7
+2.7
+3.7
+-
+1.7
+-
+3.7
+-
+3.7
+2.7
+1.7
+-
+==== fred by YOURS before 
+1.7
+2.7
+3.7
+-
+1.7
+-
+3.7
+-
+3.7
+2.7
+1.7
+-
+==== fred by MINE after 
+1.7
+2.7
+3.7
+-
+1.7
+-
+3.7
+-
+3.7
+2.7
+1.7
+-
+==== fred by YOURS after 
+1.7
+2.7
+-
+1.7
+-
+2.7
+-
+2.7
+1.7
+-
+==== fred by YOURS after 
+3.7
+-
+3.7
+-
+-
+-
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Test 17-iii.  Modifying Maries
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+==== mary before 
+1.7
+2.7
+3.7
+-
+1.7
+-
+3.7
+-
+3.7
+2.7
+1.7
+-
+==== mary after 
+1.7
+2.7
+-
+1.7
+-
+2.7
+-
+2.7
+1.7
+-
+==== mary after 
+3.7
+-
+3.7
+-
+-
+-
Index: tests/list/dlist-insert-remove.cfa
===================================================================
--- tests/list/dlist-insert-remove.cfa	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ tests/list/dlist-insert-remove.cfa	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -1187,4 +1187,214 @@
 ////////////////////////////////////////////////////////////
 //
+// Section 4f
+//
+// Test cases of pop_first, pop_last
+//
+// Example of call-side user code
+//
+////////////////////////////////////////////////////////////
+
+// These cases assume element removal at first-last is correct
+
+void test__pop_first__fred_mine() {
+
+	fred f1 = {1.7};
+	fred f2 = {2.7};
+	fred f3 = {3.7};
+
+	dlist(fred_in_mine, fred) flm;
+	insert_last(flm, f1);
+	insert_last(flm, f2);
+	insert_last(flm, f3);
+
+	dlist(fred_in_yours, fred) fly;
+	insert_last(fly, f1);
+	insert_last(fly, f2);
+	insert_last(fly, f3);
+
+	printMyFreddies(flm`first, flm`last, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 
+	printYourFreddies(fly`first, fly`last, 1);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 
+
+	verify(validate(fly));
+	verify(validate(flm));
+
+	fred & popped = pop_first(flm);
+
+	verify(validate(fly));
+	verify(validate(flm));
+
+	printMyFreddies(flm`first, flm`last, 0);     // 2.7, 3.7;       2.7;  3.7;  3.7, 2.7      (modified)
+	printYourFreddies(fly`first, fly`last, 0);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 (unmodified)
+
+	// observe f1 is now solo in mine; in yours, it was just traversed
+	printMyFreddies(f1, *0p, 0);    // 1.7; 1.7; ;
+
+	assert( &popped == & f1 );
+}
+
+void test__pop_first__fred_yours() {
+
+	fred f1 = {1.7};
+	fred f2 = {2.7};
+	fred f3 = {3.7};
+
+	dlist(fred_in_mine, fred) flm;
+	insert_last(flm, f1);
+	insert_last(flm, f2);
+	insert_last(flm, f3);
+
+	dlist(fred_in_yours, fred) fly;
+	insert_last(fly, f1);
+	insert_last(fly, f2);
+	insert_last(fly, f3);
+
+	printMyFreddies(flm`first, flm`last, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 
+	printYourFreddies(fly`first, fly`last, 1);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 
+
+	verify(validate(fly));
+	verify(validate(flm));
+
+	fred & popped = pop_first(fly);
+
+	verify(validate(fly));
+	verify(validate(flm));
+
+	printMyFreddies(flm`first, flm`last, 0);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 (unmodified)
+	printYourFreddies(fly`first, fly`last, 0);   // 2.7, 3.7;       2.7;  3.7;  3.7, 2.7      (modified)
+
+	// observe f1 is now solo in yours; in mine, it was just traversed
+	printYourFreddies(f1, *0p, 0);    // 1.7; 1.7; ;
+
+	assert( &popped == &f1 );
+}
+
+void test__pop_first__maries() {
+
+	mary m1 = {1.7};
+	mary m2 = {2.7};
+	mary m3 = {3.7};
+
+	dlist(mary, mary) ml;
+	insert_last(ml, m1);
+	insert_last(ml, m2);
+	insert_last(ml, m3);
+
+	printMariatheotokos(ml`first, ml`last, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 
+
+	verify(validate(ml));
+
+	mary & popped = pop_first(ml);
+
+	verify(validate(ml));
+
+	printMariatheotokos(ml`first, ml`last, 0);     // 2.7, 3.7;       2.7;  3.7;  3.7, 2.7      (modified)
+
+	// observe m1 is now solo
+	printMariatheotokos(m1, *0p, 0);               // 1.7; 1.7; ;
+
+	assert( &popped == &m1 );
+}
+
+void test__pop_last__fred_mine() {
+
+	fred f1 = {1.7};
+	fred f2 = {2.7};
+	fred f3 = {3.7};
+
+	dlist(fred_in_mine, fred) flm;
+	insert_last(flm, f1);
+	insert_last(flm, f2);
+	insert_last(flm, f3);
+
+	dlist(fred_in_yours, fred) fly;
+	insert_last(fly, f1);
+	insert_last(fly, f2);
+	insert_last(fly, f3);
+
+	printMyFreddies(flm`first, flm`last, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 
+	printYourFreddies(fly`first, fly`last, 1);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 
+
+	verify(validate(fly));
+	verify(validate(flm));
+
+	fred & popped = pop_last(flm);
+
+	verify(validate(fly));
+	verify(validate(flm));
+
+	printMyFreddies(flm`first, flm`last, 0);     // 1.7, 2.7;       1.7;  2.7;  2.7, 1.7      (modified)
+	printYourFreddies(fly`first, fly`last, 0);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 (unmodified)
+
+	// observe f3 is now solo in mine; in yours, it was just traversed
+	printMyFreddies(f3, *0p, 0);    // 3.7; 3.7; ;
+
+	assert( &popped == & f3 );
+}
+
+void test__pop_last__fred_yours() {
+
+	fred f1 = {1.7};
+	fred f2 = {2.7};
+	fred f3 = {3.7};
+
+	dlist(fred_in_mine, fred) flm;
+	insert_last(flm, f1);
+	insert_last(flm, f2);
+	insert_last(flm, f3);
+
+	dlist(fred_in_yours, fred) fly;
+	insert_last(fly, f1);
+	insert_last(fly, f2);
+	insert_last(fly, f3);
+
+	printMyFreddies(flm`first, flm`last, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 
+	printYourFreddies(fly`first, fly`last, 1);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 
+
+	verify(validate(fly));
+	verify(validate(flm));
+
+	fred & popped = pop_last(fly);
+
+	verify(validate(fly));
+	verify(validate(flm));
+
+	printMyFreddies(flm`first, flm`last, 0);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 (unmodified)
+	printYourFreddies(fly`first, fly`last, 0);   // 1.7, 2.7;       1.7;  2.7;  2.7, 1.7      (modified)
+
+	// observe f3 is now solo in yours; in mine, it was just traversed
+	printYourFreddies(f3, *0p, 0);    // 3.7; 3.7; ;
+
+	assert( &popped == & f3 );
+}
+
+void test__pop_last__maries() {
+
+	mary m1 = {1.7};
+	mary m2 = {2.7};
+	mary m3 = {3.7};
+
+	dlist(mary, mary) ml;
+	insert_last(ml, m1);
+	insert_last(ml, m2);
+	insert_last(ml, m3);
+
+	printMariatheotokos(ml`first, ml`last, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 
+
+	verify(validate(ml));
+
+	mary & popped = pop_last(ml);
+
+	verify(validate(ml));
+
+	printMariatheotokos(ml`first, ml`last, 0);     // 1.7, 1.7;       1.7;  2.7;  2.7, 1.7      (modified)
+
+	// observe m1 is now solo
+	printMariatheotokos(m3, *0p, 0);               // 3.7; 3.7; ;
+
+	assert( &popped == &m3 );
+}
+
+////////////////////////////////////////////////////////////
+//
 // Section 5
 //
@@ -1422,4 +1632,42 @@
 	test__remove_of_sole__mary();
 
+	sout | "";
+	sout | "~~~~~~~~~~ End removal tests on Headed List: First ~~~~~~~~~~";
+	sout | "";
+
+	sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
+	sout | "Test 16-i.  Modifying Freds on MINE";
+	sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
+	test__pop_first__fred_mine();
+
+	sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
+	sout | "Test 16-ii.  Modifying Freds on YOURS";
+	sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
+	test__pop_first__fred_yours();
+
+	sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
+	sout | "Test 16-iii.  Modifying Maries";
+	sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
+	test__pop_first__maries();
+
+	sout | "";
+	sout | "~~~~~~~~~~ End removal tests on Headed List: Last ~~~~~~~~~~";
+	sout | "";
+
+	sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
+	sout | "Test 17-i.  Modifying Freds on MINE";
+	sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
+	test__pop_last__fred_mine();
+
+	sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
+	sout | "Test 17-ii.  Modifying Freds on YOURS";
+	sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
+	test__pop_last__fred_yours();
+
+	sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
+	sout | "Test 17-iii.  Modifying Maries";
+	sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
+	test__pop_last__maries();
+
 	return 0;
 }
Index: tools/build/push2dist.sh
===================================================================
--- tools/build/push2dist.sh	(revision 856fe3e61a2862cb2fb75b99c62e6a042adeb092)
+++ tools/build/push2dist.sh	(revision 2223c8098e0dfae91c6eecb79a740021ef48f3d2)
@@ -2,4 +2,5 @@
 
 hash="$1"
+bwlim="$2"
 valid=$(distcc -j 2> /dev/null)
 # if test "${valid}" != 0
@@ -24,5 +25,5 @@
 function push() {
 	ssh ${host} "mkdir -p ~/.cfadistcc/${hash}/"
-	rsync -a ${dV} ${files} ${host}:~/.cfadistcc/${hash}/.
+	rsync --bwlimit=${bwlim} -a ${dV} ${files} ${host}:~/.cfadistcc/${hash}/.
 }