>From c79bceb489aa3742e9b9668c84fc1b09613b5fc8 Mon Sep 17 00:00:00 2001
From: Akira Yokosawa <akiyks@xxxxxxxxx>
Date: Sat, 3 Nov 2018 08:25:16 +0900
Subject: [PATCH 7/7] CodeSamples/SMPdesign/maze: Substitute {READ/WRITE}_ONCE() for ACCESS_ONCE()
Also fill in a couple of func prototype in maze.h.
Signed-off-by: Akira Yokosawa <akiyks@xxxxxxxxx>
---
CodeSamples/SMPdesign/maze/maze.h | 6 ++++++
CodeSamples/SMPdesign/maze/maze_fg.c | 18 +++++++++---------
CodeSamples/SMPdesign/maze/maze_part.c | 18 +++++++++---------
3 files changed, 24 insertions(+), 18 deletions(-)
diff --git a/CodeSamples/SMPdesign/maze/maze.h b/CodeSamples/SMPdesign/maze/maze.h
index a256278..f1d1343 100644
--- a/CodeSamples/SMPdesign/maze/maze.h
+++ b/CodeSamples/SMPdesign/maze/maze.h
@@ -79,6 +79,10 @@ struct maze {
};
#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
+#define READ_ONCE(x) \
+ ({ typeof(x) ___x = ACCESS_ONCE(x); ___x; })
+#define WRITE_ONCE(x, val) ({ ACCESS_ONCE(x) = (val); })
+
/* CLOCK_MONOTONIC_RAW prefered, but the older CLOCK_MONOTONIC will do. */
#ifdef CLOCK_MONOTONIC_RAW
@@ -190,8 +194,10 @@ int maze_same_tids(struct maze *mp, int r1, int c1, int r2, int c2);
void new_empty_maze_solve(struct maze *mp);
int maze_try_visit_cell(struct maze *mp, int cr, int cc, int tr, int tc,
int *nextrow, int *nextcol, int distance);
+int maze_row_col_frac(int rc, int num, int den);
int maze_solve(struct maze *mp, int startrow, int startcol,
int endrow, int endcol, unsigned long long *t);
+void usage(char *progname, const char *format, ...);
void maze_solve_usage(void);
int maze_solve_parse(int i, int argc, char *argv[]);
diff --git a/CodeSamples/SMPdesign/maze/maze_fg.c b/CodeSamples/SMPdesign/maze/maze_fg.c
index aa1bafa..69af238 100644
--- a/CodeSamples/SMPdesign/maze/maze_fg.c
+++ b/CodeSamples/SMPdesign/maze/maze_fg.c
@@ -75,7 +75,7 @@ int maze_try_visit_cell(struct maze *mp, int cr, int cc, int tr, int tc,
return -1;
tp = maze_get_cell_addr(mp, tr, tc);
do {
- t = ACCESS_ONCE(*tp);
+ t = READ_ONCE(*tp);
if (t & VISITED)
return 1;
} while (!__sync_bool_compare_and_swap(tp, t, t | VISITED | myid));
@@ -85,7 +85,7 @@ int maze_try_visit_cell(struct maze *mp, int cr, int cc, int tr, int tc,
vi = __sync_add_and_fetch(&mp->vi, 1);
mp->visited[vi].row = tr;
__sync_synchronize();
- ACCESS_ONCE(mp->visited[vi].col) = tc;
+ WRITE_ONCE(mp->visited[vi].col, tc);
return 0;
}
@@ -121,8 +121,8 @@ void *maze_solve_child(void *arg)
* cell to be added to the visited list, we
* are done and the maze has no solution.
*/
- if (vi >= ACCESS_ONCE(mp->vi) + nthreads) {
- ACCESS_ONCE(mcsp->done) = -1;
+ if (vi >= READ_ONCE(mp->vi) + nthreads) {
+ WRITE_ONCE(mcsp->done, -1);
return NULL;
}
@@ -131,11 +131,11 @@ void *maze_solve_child(void *arg)
* for one of the other threads to find the
* end cell.
*/
- while ((vi > ACCESS_ONCE(mp->vi) ||
- ACCESS_ONCE(mp->visited[vi].col) < 0) &&
- !ACCESS_ONCE(mcsp->done))
+ while ((vi > READ_ONCE(mp->vi) ||
+ READ_ONCE(mp->visited[vi].col) < 0) &&
+ !READ_ONCE(mcsp->done))
continue;
- if (ACCESS_ONCE(mcsp->done))
+ if (READ_ONCE(mcsp->done))
return NULL;
/* check of .col before read of .row. */
@@ -151,7 +151,7 @@ void *maze_solve_child(void *arg)
do {
/* Did we find the solution? */
if (nr == mcsp->endrow && nc == mcsp->endcol) {
- ACCESS_ONCE(mcsp->done) = 1;
+ WRITE_ONCE(mcsp->done, 1);
return NULL;
}
diff --git a/CodeSamples/SMPdesign/maze/maze_part.c b/CodeSamples/SMPdesign/maze/maze_part.c
index 16080d4..2f92e11 100644
--- a/CodeSamples/SMPdesign/maze/maze_part.c
+++ b/CodeSamples/SMPdesign/maze/maze_part.c
@@ -85,12 +85,12 @@ void maze_solve_propagate(struct maze_child *mcp1, struct maze_child *mcp2)
if (__sync_fetch_and_add(&mcp1->see_start, 0)) {
(void)__sync_lock_test_and_set(&mcp2->see_start, 1);
if (__sync_fetch_and_add(&mcp2->see_end, 0))
- ACCESS_ONCE(mcsp->done) = 1;
+ WRITE_ONCE(mcsp->done, 1);
}
if (__sync_fetch_and_add(&mcp1->see_end, 0)) {
(void)__sync_lock_test_and_set(&mcp2->see_end, 1);
if (__sync_fetch_and_add(&mcp2->see_start, 0))
- ACCESS_ONCE(mcsp->done) = 1;
+ WRITE_ONCE(mcsp->done, 1);
}
}
@@ -111,7 +111,7 @@ void record_encounter(struct maze *mp, int cr, int cc, int tr, int tc)
mymcp->adj[theirtid].tr = tr;
mymcp->adj[theirtid].tc = tc;
if (nthreads == 2)
- ACCESS_ONCE(mcsp->done) = 1;
+ WRITE_ONCE(mcsp->done, 1);
maze_solve_propagate(mymcp, &mymcp->mcp0[theirtid]);
maze_solve_propagate(&mymcp->mcp0[theirtid], mymcp);
}
@@ -128,7 +128,7 @@ int maze_try_visit_cell(struct maze *mp, int cr, int cc, int tr, int tc,
return -1;
tp = maze_get_cell_addr(mp, tr, tc);
do {
- t = ACCESS_ONCE(*tp);
+ t = READ_ONCE(*tp);
if (t & VISITED) {
record_encounter(mp, cr, cc, tr, tc);
return 1;
@@ -496,7 +496,7 @@ int maze_solve_child_done_check(void)
struct maze_child *theirmcp;
if (nthreads <= 2)
- return ACCESS_ONCE(mcsp->done);
+ return READ_ONCE(mcsp->done);
if (!mymcp->see_start_snap &&
__sync_fetch_and_add(&mymcp->see_start, 0)) {
mymcp->see_start_snap = 1;
@@ -508,7 +508,7 @@ int maze_solve_child_done_check(void)
need_propagate = 1;
}
if (!need_propagate)
- return ACCESS_ONCE(mcsp->done);
+ return READ_ONCE(mcsp->done);
for (i = 0; i < nthreads; i++) {
if (i == mymcp->myid)
continue;
@@ -517,7 +517,7 @@ int maze_solve_child_done_check(void)
__sync_fetch_and_add(&theirmcp->adj[myid].mr, 0) != -1)
maze_solve_propagate(mymcp, theirmcp);
}
- return ACCESS_ONCE(mcsp->done);
+ return READ_ONCE(mcsp->done);
}
/*
@@ -555,7 +555,7 @@ void *maze_solve_child(void *arg)
* go to the following loop to do the exploration.
*/
while (!maze_find_any_next_cell(mp, cr, cc, &nr, &nc)) {
- if (++vi >= mcp->vi || ACCESS_ONCE(mcsp->done))
+ if (++vi >= mcp->vi || READ_ONCE(mcsp->done))
goto done;
cr = mcp->visited[vi].row;
cc = mcp->visited[vi].col;
@@ -566,7 +566,7 @@ void *maze_solve_child(void *arg)
* the current path one cell.
*/
do {
- if (ACCESS_ONCE(mcsp->done))
+ if (READ_ONCE(mcsp->done))
goto done;
cr = nr;
cc = nc;
--
2.7.4
