Do all loggin in main thread

Before this committ, the solver (via the generic solution-appender
routines in src/solve/solutions.h) and the H48 data generator did some
logging in the worker threads, without using any locks. This was not nice,
but in practice it did not cause any problem, because the log messages
were rare.

However, this turned out to be a problem when building to WASM, because
web workers do not have access to the main JS memory, and therefore
they cannot call functions from the main JS. This includes not only the
callback functions for logging, but also those for polling the status
of the solver (run / pause / stop).

This commit fixes this at the cost or being somewhat inelegant: the
solutions are not logged as they are found, but only every 500ms.

1 files changed, 79 insertions, 57 deletions

diff --git a/src/solvers/h48/solve.h b/src/solvers/h48/solve.h
index 2818c09..4d3c451 100644
--- a/src/solvers/h48/solve.h
+++ b/src/solvers/h48/solve.h
@@ -35,10 +35,8 @@ typedef struct {
         solve_h48_task_t *tasks;
         int thread_id;
         pthread_mutex_t *solutions_mutex;
-        int (*poll_status)(void *);
-        void *poll_status_data;
-        _Atomic bool cancelled;
-        _Atomic bool cantsleep;
+        _Atomic int *status;
+        _Atomic bool thread_done;
 } dfsarg_solve_h48_t;
 
 typedef struct {
@@ -58,9 +56,9 @@ STATIC_INLINE bool solve_h48_stop(dfsarg_solve_h48_t [static 1]);
 STATIC int64_t solve_h48_maketasks(
     dfsarg_solve_h48_t [static 1], dfsarg_solve_h48_maketasks_t [static 1],
     solve_h48_task_t [static STARTING_CUBES], int [static 1]);
-STATIC bool solve_h48_runthread_continue(dfsarg_solve_h48_t *);
 STATIC void *solve_h48_runthread(void *);
 STATIC int64_t solve_h48_dfs(dfsarg_solve_h48_t [static 1]);
+STATIC void solve_h48_log_solutions(solution_list_t [static 1], size_t);
 STATIC int64_t solve_h48(oriented_cube_t, uint8_t, uint8_t, uint8_t, uint8_t,
     uint8_t, uint64_t, const unsigned char *, size_t n, char [n],
     long long [static NISSY_SIZE_SOLVE_STATS], int (*)(void *), void *);
@@ -201,7 +199,7 @@ solve_h48_dfs(dfsarg_solve_h48_t arg[static 1])
                         return 0;
                 pthread_mutex_lock(arg->solutions_mutex);
                 ret = appendsolution(arg->solution_moves,
-                    arg->solution_settings, arg->solution_list, true, "H48");
+                    arg->solution_settings, arg->solution_list);
                 pthread_mutex_unlock(arg->solutions_mutex);
                 return ret;
         }
@@ -271,41 +269,20 @@ solve_h48_dfs(dfsarg_solve_h48_t arg[static 1])
         return ret;
 }
 
-STATIC bool
-solve_h48_runthread_continue(dfsarg_solve_h48_t *arg)
-{
-        int status;
-
-        for (status = NISSY_STATUS_PAUSE; status == NISSY_STATUS_PAUSE; ) {
-                status = arg->poll_status == NULL ? NISSY_STATUS_RUN :
-                    arg->poll_status(arg->poll_status_data);
-                msleep(500);
-        }
-
-        return status == NISSY_STATUS_RUN;
-}
-
 STATIC void *
 solve_h48_runthread(void *arg)
 {
-        int i, j, status;
+        int i, j;
         solve_h48_task_t task;
         dfsarg_solve_h48_t *dfsarg;
 
         dfsarg = (dfsarg_solve_h48_t *)arg;
 
         for (i = dfsarg->thread_id; i < dfsarg->ntasks; i += dfsarg->threads) {
-                status = dfsarg->poll_status == NULL ? NISSY_STATUS_RUN :
-                    dfsarg->poll_status(dfsarg->poll_status_data);
-                switch (status) {
-                case NISSY_STATUS_STOP:
-                        goto solve_h48_runthread_cancel;
-                case NISSY_STATUS_PAUSE:
-                        if (!NISSY_CANSLEEP)
-                                goto solve_h48_runthread_cantsleep;
-                        if (!solve_h48_runthread_continue(dfsarg))
-                                goto solve_h48_runthread_cancel;
-                }
+                if (*dfsarg->status == NISSY_STATUS_STOP)
+                        goto solve_h48_runthread_end;
+                while (*dfsarg->status == NISSY_STATUS_PAUSE)
+                        msleep(BASE_SLEEP_TIME);
 
                 task = dfsarg->tasks[i];
 
@@ -329,12 +306,8 @@ solve_h48_runthread(void *arg)
                 solve_h48_dfs(dfsarg);
         }
 
-        return NULL;
-
-solve_h48_runthread_cantsleep:
-        dfsarg->cantsleep = true;
-solve_h48_runthread_cancel:
-        dfsarg->cancelled = true;
+solve_h48_runthread_end:
+        dfsarg->thread_done = true;
         return NULL;
 }
 
@@ -366,7 +339,7 @@ solve_h48_maketasks(
                     maketasks_arg->moves, maketasks_arg->nmoves);
 
                 appret = appendsolution(&moves, solve_arg->solution_settings,
-                    solve_arg->solution_list, true, "H48");
+                    solve_arg->solution_list);
                 return appret < 0 ? appret : NISSY_OK;
         }
 
@@ -410,6 +383,22 @@ solve_h48_maketasks(
         return NISSY_OK;
 }
 
+STATIC void
+solve_h48_log_solutions(solution_list_t s[static 1], size_t e)
+{
+        size_t i;
+        char b;
+        while (e != s->used) {
+                LOG("[h48 solve] Found solution: ");
+                for (i = e; s->buf[i] != '\n' && s->buf[i] != '\0'; i++) ;
+                b = s->buf[i];
+                s->buf[i] = '\0';
+                LOG("%s\n", s->buf + e);
+                s->buf[i] = b;
+                e = i + 1;
+        }
+}
+
 STATIC int64_t
 solve_h48(
         oriented_cube_t oc,
@@ -427,8 +416,10 @@ solve_h48(
         void *poll_status_data
 )
 {
-        bool anycancelled, anycantsleep;
         int i, ntasks, eoesep_table_index;
+        bool td, fp;
+        _Atomic int status;
+        size_t lastused;
         int8_t d;
         dfsarg_solve_h48_t arg[THREADS];
         solve_h48_task_t tasks[STARTING_CUBES];
@@ -508,10 +499,7 @@ solve_h48(
                         .threads = threads,
                         .thread_id = i,
                         .solutions_mutex = &solutions_mutex,
-                        .poll_status = poll_status,
-                        .poll_status_data = poll_status_data,
-                        .cancelled = false,
-                        .cantsleep = false,
+                        .status = &status,
                 };
 
         }
@@ -538,35 +526,69 @@ solve_h48(
 
         LOG("[H48 solve] Prepared %d tasks\n", ntasks);
 
-        anycancelled = anycantsleep = false;
+        solve_h48_log_solutions(&sollist, 0);
+        lastused = sollist.used;
+        status = poll_status == NULL ? NISSY_STATUS_RUN :
+            poll_status(poll_status_data);
+        if (!NISSY_CANSLEEP) {
+                LOG("[solve h48] Pause / Stop / Resume functionality won't "
+                    "be available on this system (can't sleep()).\n");
+        }
         for (
             d = MAX(minmoves, STARTING_MOVES + 1);
-            !(solutions_done(&sollist, &settings, d) || anycancelled);
+            !(solutions_done(&sollist, &settings, d)) &&
+                status != NISSY_STATUS_STOP;
             d++
         ) {
-                if (d >= 15)
+                if (d >= 15) {
                         LOG("[H48 solve] Found %" PRId64 " solutions, "
                             "searching at depth %" PRId8 "\n",
                             sollist.nsols, d);
+                }
+
                 for (i = 0; i < threads; i++) {
                         arg[i].target_depth = d;
+                        arg[i].thread_done = false;
                         pthread_create(
                             &thread[i], NULL, solve_h48_runthread, &arg[i]);
                 }
-                for (i = 0; i < threads; i++) {
-                        pthread_join(thread[i], NULL);
-                        anycancelled = anycancelled || arg[i].cancelled;
-                        anycantsleep = anycantsleep || arg[i].cantsleep;
+
+                /* Log solutions and handle pause / stop / resume */
+                if (d >= 15 && NISSY_CANSLEEP) {
+                        td = false;
+                        fp = true;
+                        while (!td && status != NISSY_STATUS_STOP) {
+                                msleep(BASE_SLEEP_TIME);
+
+                                pthread_mutex_lock(&solutions_mutex);
+                                solve_h48_log_solutions(&sollist, lastused);
+                                lastused = sollist.used;
+                                pthread_mutex_unlock(&solutions_mutex);
+
+                                if (poll_status == NULL)
+                                        continue;
+
+                                status = poll_status(poll_status_data);
+                                if (status == NISSY_STATUS_PAUSE && fp) {
+                                        LOG("[H48 solve] Paused\n");
+                                        fp = false;
+                                }
+                                if (status == NISSY_STATUS_RUN)
+                                        fp = true;
+
+                                for (td = true, i = 0; i < threads; i++)
+                                        td = td && arg[i].thread_done;
+                        }
                 }
-        }
 
-        if (anycantsleep) {
-                LOG("[H48 solve] Received pause request, but this feature is "
-                    "not available on this system. "
-                    "Taking it as a stop request.\n");
+                for (i = 0; i < threads; i++)
+                        pthread_join(thread[i], NULL);
+
+                solve_h48_log_solutions(&sollist, lastused);
+                lastused = sollist.used;
         }
 
-        if (anycancelled) {
+        if (status == NISSY_STATUS_STOP) {
                 LOG("[H48 solve] Received stop request, ending solution "
                     "search early.\n");
         }