i++
:: i >= NR_READERS -> break
od;
- CACHE_READ_FROM_MEM(generation_ptr, get_pid());
+ CACHE_READ_FROM_MEM(rcu_ptr, get_pid());
+ i = 0;
+ do
+ :: i < SLAB_SIZE ->
+ CACHE_READ_FROM_MEM(rcu_data[i], get_pid());
+ i++
+ :: i >= SLAB_SIZE -> break
+ od;
}
}
i++
:: i >= NR_READERS -> break
od;
- CACHE_WRITE_TO_MEM(generation_ptr, get_pid());
+ CACHE_WRITE_TO_MEM(rcu_ptr, get_pid());
+ i = 0;
+ do
+ :: i < SLAB_SIZE ->
+ CACHE_WRITE_TO_MEM(rcu_data[i], get_pid());
+ i++
+ :: i >= SLAB_SIZE -> break
+ od;
}
}
}
}
-
#ifdef REMOTE_BARRIERS
bit reader_barrier[NR_READERS];
:: (reader_barrier[get_readerid()] == 1) ->
smp_mb(i, j);
reader_barrier[get_readerid()] = 0;
- :: 1 -> skip;
- :: 1 -> break;
+ :: 1 ->
+ /*
+ * Busy-looping waiting for other barrier requests is not considered as
+ * non-progress.
+ */
+#ifdef READER_PROGRESS
+progress_reader2:
+#endif
+#ifdef WRITER_PROGRESS
+//progress_writer_from_reader1:
+#endif
+ skip;
+ :: 1 ->
+ /* We choose to ignore writer's non-progress caused from the
+ * reader ignoring the writer's mb() requests */
+#ifdef WRITER_PROGRESS
+//progress_writer_from_reader2:
+#endif
+ break;
od;
}
-inline smp_mb_send(i, j)
-{
- smp_mb(i, j);
- i = 0;
- do
- :: i < NR_READERS ->
- reader_barrier[i] = 1;
- do
- :: (reader_barrier[i] == 1) -> skip;
- :: (reader_barrier[i] == 0) -> break;
- od;
- i++;
- :: i >= NR_READERS ->
- break
- od;
- smp_mb(i, j);
+#ifdef WRITER_PROGRESS
+#define PROGRESS_LABEL(progressid) progress_writer_progid_##progressid:
+#else
+#define PROGRESS_LABEL(progressid)
+#endif
+
+#define smp_mb_send(i, j, progressid) \
+{ \
+ smp_mb(i, j); \
+ i = 0; \
+ do \
+ :: i < NR_READERS -> \
+ reader_barrier[i] = 1; \
+ /* \
+ * Busy-looping waiting for reader barrier handling is of little\
+ * interest, given the reader has the ability to totally ignore \
+ * barrier requests. \
+ */ \
+PROGRESS_LABEL(progressid) \
+ do \
+ :: (reader_barrier[i] == 1) -> skip; \
+ :: (reader_barrier[i] == 0) -> break; \
+ od; \
+ i++; \
+ :: i >= NR_READERS -> \
+ break \
+ od; \
+ smp_mb(i, j); \
}
#else
-#define smp_mb_send smp_mb
+#define smp_mb_send(i, j, progressid) smp_mb(i, j)
#define smp_mb_reader smp_mb
#define smp_mb_recv(i, j)
#endif
-/* Keep in sync manually with smp_rmb, wmp_wmb, ooo_mem and init() */
+/* Keep in sync manually with smp_rmb, smp_wmb, ooo_mem and init() */
DECLARE_CACHED_VAR(byte, urcu_gp_ctr);
/* Note ! currently only two readers */
DECLARE_CACHED_VAR(byte, urcu_active_readers[NR_READERS]);
-/* pointer generation */
-DECLARE_CACHED_VAR(byte, generation_ptr);
-
-byte last_free_gen = 0;
-bit free_done = 0;
-byte read_generation[NR_READERS];
-bit data_access[NR_READERS];
+/* RCU pointer */
+DECLARE_CACHED_VAR(byte, rcu_ptr);
+/* RCU data */
+DECLARE_CACHED_VAR(byte, rcu_data[SLAB_SIZE]);
-bit write_lock = 0;
+byte ptr_read[NR_READERS];
+byte data_read[NR_READERS];
bit init_done = 0;
-bit sighand_exec = 0;
-
inline wait_init_done()
{
do
i++
:: i >= NR_READERS -> break
od;
- RANDOM_CACHE_WRITE_TO_MEM(generation_ptr, get_pid());
+ RANDOM_CACHE_WRITE_TO_MEM(rcu_ptr, get_pid());
+ i = 0;
+ do
+ :: i < SLAB_SIZE ->
+ RANDOM_CACHE_WRITE_TO_MEM(rcu_data[i], get_pid());
+ i++
+ :: i >= SLAB_SIZE -> break
+ od;
RANDOM_CACHE_READ_FROM_MEM(urcu_gp_ctr, get_pid());
i = 0;
do
i++
:: i >= NR_READERS -> break
od;
- RANDOM_CACHE_READ_FROM_MEM(generation_ptr, get_pid());
+ RANDOM_CACHE_READ_FROM_MEM(rcu_ptr, get_pid());
+ i = 0;
+ do
+ :: i < SLAB_SIZE ->
+ RANDOM_CACHE_READ_FROM_MEM(rcu_data[i], get_pid());
+ i++
+ :: i >= SLAB_SIZE -> break
+ od;
}
}
goto non_atomic3_skip;
non_atomic3:
- smp_mb_recv(i, j);
+ smp_mb_recv(i, j);
goto non_atomic3_end;
non_atomic3_skip:
READ_PROC_FIRST_MB, /* mb() orders reads */
READ_PROC_READ_GEN) ->
ooo_mem(i);
- read_generation[get_readerid()] =
- READ_CACHED_VAR(generation_ptr);
+ ptr_read[get_readerid()] =
+ READ_CACHED_VAR(rcu_ptr);
PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_READ_GEN);
:: CONSUME_TOKENS(proc_urcu_reader,
READ_PROC_FIRST_MB /* mb() orders reads */
| READ_PROC_READ_GEN,
READ_PROC_ACCESS_GEN) ->
- ooo_mem(i);
- goto non_atomic;
-non_atomic_end:
+ /* smp_read_barrier_depends */
+ goto rmb1;
+rmb1_end:
+ data_read[get_readerid()] =
+ READ_CACHED_VAR(rcu_data[ptr_read[get_readerid()]]);
PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_ACCESS_GEN);
| READ_PROC_THIRD_MB, /* mb() orders reads */
READ_PROC_READ_GEN_UNROLL) ->
ooo_mem(i);
- read_generation[get_readerid()] =
- READ_CACHED_VAR(generation_ptr);
+ ptr_read[get_readerid()] = READ_CACHED_VAR(rcu_ptr);
PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_READ_GEN_UNROLL);
:: CONSUME_TOKENS(proc_urcu_reader,
| READ_PROC_SECOND_MB /* mb() orders reads */
| READ_PROC_THIRD_MB, /* mb() orders reads */
READ_PROC_ACCESS_GEN_UNROLL) ->
- ooo_mem(i);
- goto non_atomic2;
-non_atomic2_end:
+ /* smp_read_barrier_depends */
+ goto rmb2;
+rmb2_end:
+ data_read[get_readerid()] =
+ READ_CACHED_VAR(rcu_data[ptr_read[get_readerid()]]);
PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_ACCESS_GEN_UNROLL);
:: CONSUME_TOKENS(proc_urcu_reader,
* to spill its execution on other loop's execution.
*/
goto end;
-non_atomic:
- data_access[get_readerid()] = 1;
- data_access[get_readerid()] = 0;
- goto non_atomic_end;
-non_atomic2:
- data_access[get_readerid()] = 1;
- data_access[get_readerid()] = 0;
- goto non_atomic2_end;
+rmb1:
+#ifndef NO_RMB
+ smp_rmb(i, j);
+#else
+ ooo_mem();
+#endif
+ goto rmb1_end;
+rmb2:
+#ifndef NO_RMB
+ smp_rmb(i, j);
+#else
+ ooo_mem();
+#endif
+ goto rmb2_end;
end:
skip;
}
#define WRITE_PROC_ALL_TOKENS_CLEAR ((1 << 11) - 1)
+/*
+ * Mutexes are implied around writer execution. A single writer at a time.
+ */
active proctype urcu_writer()
{
byte i, j;
byte tmp, tmp2, tmpa;
- byte old_gen;
+ byte cur_data = 0, old_data, loop_nr = 0;
+ byte cur_gp_val = 0; /*
+ * Keep a local trace of the current parity so
+ * we don't add non-existing dependencies on the global
+ * GP update. Needed to test single flip case.
+ */
wait_init_done();
assert(get_pid() < NR_PROCS);
do
- :: (READ_CACHED_VAR(generation_ptr) < 5) ->
+ :: (loop_nr < 3) ->
#ifdef WRITER_PROGRESS
progress_writer1:
#endif
+ loop_nr = loop_nr + 1;
+
+ /* TODO : add instruction scheduling to this code path to test
+ * missing wmb effect. */
+ /* smp_wmb() ensures order of the following instructions */
+ /* malloc */
+ cur_data = (cur_data + 1) % SLAB_SIZE;
ooo_mem(i);
- atomic {
- old_gen = READ_CACHED_VAR(generation_ptr);
- WRITE_CACHED_VAR(generation_ptr, old_gen + 1);
- }
+ WRITE_CACHED_VAR(rcu_data[cur_data], WINE);
+#ifndef NO_WMB
+ smp_wmb(i, j);
+#else
+ ooo_mem(i);
+#endif
+ old_data = READ_CACHED_VAR(rcu_ptr);
+ ooo_mem(i);
+ WRITE_CACHED_VAR(rcu_ptr, cur_data); /* rcu_assign_pointer() */
ooo_mem(i);
- do
- :: 1 ->
- atomic {
- if
- :: write_lock == 0 ->
- write_lock = 1;
- break;
- :: else ->
- skip;
- fi;
- }
- od;
PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROD_NONE);
PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_READ_GP);
PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_WRITE_GP);
PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_WAIT);
+ /* For single flip, we need to know the current parity */
+ cur_gp_val = cur_gp_val ^ RCU_GP_CTR_BIT;
#endif
- do
+ do :: 1 ->
+ atomic {
+ if
:: CONSUME_TOKENS(proc_urcu_writer,
WRITE_PROD_NONE,
WRITE_PROC_FIRST_MB) ->
- smp_mb_send(i, j);
+ goto smp_mb_send1;
+smp_mb_send1_end:
PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_MB);
/* first flip */
ooo_mem(i);
/* ONLY WAITING FOR READER 0 */
tmp2 = READ_CACHED_VAR(urcu_active_readers[0]);
+#ifndef SINGLE_FLIP
+ /* In normal execution, we are always starting by
+ * waiting for the even parity.
+ */
+ cur_gp_val = RCU_GP_CTR_BIT;
+#endif
if
:: (tmp2 & RCU_GP_CTR_NEST_MASK)
- && ((tmp2 ^ RCU_GP_CTR_BIT) & RCU_GP_CTR_BIT) ->
+ && ((tmp2 ^ cur_gp_val) & RCU_GP_CTR_BIT) ->
PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_WAIT_LOOP);
:: else ->
PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_WAIT);
| WRITE_PROC_FIRST_MB, /* can be reordered before/after flips */
0) ->
#ifndef GEN_ERROR_WRITER_PROGRESS
- smp_mb_send(i, j);
+ goto smp_mb_send2;
+smp_mb_send2_end:
#else
ooo_mem(i);
#endif
| WRITE_PROC_FIRST_READ_GP
| WRITE_PROC_FIRST_MB,
WRITE_PROC_SECOND_READ_GP) ->
- //smp_mb_send(i, j); //TEST
ooo_mem(i);
tmpa = READ_CACHED_VAR(urcu_gp_ctr);
PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_READ_GP);
| WRITE_PROC_FIRST_MB, /* can be reordered before/after flips */
0) ->
#ifndef GEN_ERROR_WRITER_PROGRESS
- smp_mb_send(i, j);
+ goto smp_mb_send3;
+smp_mb_send3_end:
#else
ooo_mem(i);
#endif
| WRITE_PROC_SECOND_WRITE_GP
| WRITE_PROC_FIRST_MB,
WRITE_PROC_SECOND_MB) ->
- smp_mb_send(i, j);
+ goto smp_mb_send4;
+smp_mb_send4_end:
PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_MB);
:: CONSUME_TOKENS(proc_urcu_writer, WRITE_PROC_ALL_TOKENS, 0) ->
CLEAR_TOKENS(proc_urcu_writer, WRITE_PROC_ALL_TOKENS_CLEAR);
break;
+ fi;
+ }
od;
- write_lock = 0;
- /* free-up step, e.g., kfree(). */
- atomic {
- last_free_gen = old_gen;
- free_done = 1;
- }
+ WRITE_CACHED_VAR(rcu_data[old_data], POISON);
+
:: else -> break;
od;
/*
#endif
skip;
od;
+
+ /* Non-atomic parts of the loop */
+ goto end;
+smp_mb_send1:
+ smp_mb_send(i, j, 1);
+ goto smp_mb_send1_end;
+#ifndef GEN_ERROR_WRITER_PROGRESS
+smp_mb_send2:
+ smp_mb_send(i, j, 2);
+ goto smp_mb_send2_end;
+smp_mb_send3:
+ smp_mb_send(i, j, 3);
+ goto smp_mb_send3_end;
+#endif
+smp_mb_send4:
+ smp_mb_send(i, j, 4);
+ goto smp_mb_send4_end;
+end:
+ skip;
}
/* no name clash please */
atomic {
INIT_CACHED_VAR(urcu_gp_ctr, 1, j);
- INIT_CACHED_VAR(generation_ptr, 0, j);
+ INIT_CACHED_VAR(rcu_ptr, 0, j);
i = 0;
do
:: i < NR_READERS ->
INIT_CACHED_VAR(urcu_active_readers[i], 0, j);
- read_generation[i] = 1;
- data_access[i] = 0;
+ data_read[i] = 0;
i++;
:: i >= NR_READERS -> break
od;
+ INIT_CACHED_VAR(rcu_data[0], WINE, j);
+ i = 1;
+ do
+ :: i < SLAB_SIZE ->
+ INIT_CACHED_VAR(rcu_data[i], POISON, j);
+ i++
+ :: i >= SLAB_SIZE -> break
+ od;
+
init_done = 1;
}
}
projects / urcu.git / blobdiff