diff --git a/src/Makefile.am b/src/Makefile.am
index afe4002b29b55a0f5ea4a0aff9ba1dd5adefc005..9b0610667bdcf1f760f6e94d4481848a8fc4d0f0 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -53,8 +53,8 @@ include_HEADERS = space.h runner.h queue.h task.h lock.h cell.h part.h const.h \
# Common source files
AM_SOURCES = space.c runner.c queue.c task.c cell.c engine.c engine_maketasks.c \
- engine_marktasks.c serial_io.c timers.c debug.c scheduler.c proxy.c parallel_io.c \
- units.c common_io.c single_io.c multipole.c version.c map.c \
+ engine_marktasks.c engine_drift.c serial_io.c timers.c debug.c scheduler.c \
+ proxy.c parallel_io.c units.c common_io.c single_io.c multipole.c version.c map.c \
kernel_hydro.c tools.c part.c partition.c clocks.c parser.c \
physical_constants.c potential.c hydro_properties.c \
threadpool.c cooling.c sourceterms.c \
diff --git a/src/engine.c b/src/engine.c
index df2ec2236bc919b694d27e07a26e36fe2df3c7c8..c20b45340617682df53774e0b1dd2eb9cc354296 100644
--- a/src/engine.c
+++ b/src/engine.c
@@ -3400,274 +3400,6 @@ void engine_unskip(struct engine *e) {
clocks_getunit());
}
-/**
- * @brief Mapper function to drift *all* the #part to the current time.
- *
- * @param map_data An array of #cell%s.
- * @param num_elements Chunk size.
- * @param extra_data Pointer to an #engine.
- */
-void engine_do_drift_all_part_mapper(void *map_data, int num_elements,
- void *extra_data) {
-
- const struct engine *e = (const struct engine *)extra_data;
- const int restarting = e->restarting;
- struct space *s = e->s;
- struct cell *cells_top;
- int *local_cells_top;
-
- if (restarting) {
-
- /* When restarting, we loop over all top-level cells */
- cells_top = (struct cell *)map_data;
- local_cells_top = NULL;
-
- } else {
-
- /* In any other case, we use the list of local cells with tasks */
- cells_top = s->cells_top;
- local_cells_top = (int *)map_data;
- }
-
- for (int ind = 0; ind < num_elements; ind++) {
-
- struct cell *c;
-
- /* When restarting, the list of local cells does not
- yet exist. We use the raw list of top-level cells instead */
- if (restarting)
- c = &cells_top[ind];
- else
- c = &cells_top[local_cells_top[ind]];
-
- if (c->nodeID == e->nodeID) {
-
- /* Drift all the particles */
- cell_drift_part(c, e, /* force the drift=*/1);
- }
- }
-}
-
-/**
- * @brief Mapper function to drift *all* the #gpart to the current time.
- *
- * @param map_data An array of #cell%s.
- * @param num_elements Chunk size.
- * @param extra_data Pointer to an #engine.
- */
-void engine_do_drift_all_gpart_mapper(void *map_data, int num_elements,
- void *extra_data) {
-
- const struct engine *e = (const struct engine *)extra_data;
- const int restarting = e->restarting;
- struct space *s = e->s;
- struct cell *cells_top;
- int *local_cells_top;
-
- if (restarting) {
-
- /* When restarting, we loop over all top-level cells */
- cells_top = (struct cell *)map_data;
- local_cells_top = NULL;
-
- } else {
-
- /* In any other case, we use the list of local cells with tasks */
- cells_top = s->cells_top;
- local_cells_top = (int *)map_data;
- }
-
- for (int ind = 0; ind < num_elements; ind++) {
-
- struct cell *c;
-
- /* When restarting, the list of local cells does not
- yet exist. We use the raw list of top-level cells instead */
- if (restarting)
- c = &cells_top[ind];
- else
- c = &cells_top[local_cells_top[ind]];
-
- if (c->nodeID == e->nodeID) {
-
- /* Drift all the particles */
- cell_drift_gpart(c, e, /* force the drift=*/1);
- }
- }
-}
-
-/**
- * @brief Mapper function to drift *all* the multipoles to the current time.
- *
- * @param map_data An array of #cell%s.
- * @param num_elements Chunk size.
- * @param extra_data Pointer to an #engine.
- */
-void engine_do_drift_all_multipole_mapper(void *map_data, int num_elements,
- void *extra_data) {
-
- const struct engine *e = (const struct engine *)extra_data;
- const int restarting = e->restarting;
- struct space *s = e->s;
- struct cell *cells_top;
- int *local_cells_with_tasks_top;
-
- if (restarting) {
-
- /* When restarting, we loop over all top-level cells */
- cells_top = (struct cell *)map_data;
- local_cells_with_tasks_top = NULL;
-
- } else {
-
- /* In any other case, we use the list of local cells with tasks */
- cells_top = s->cells_top;
- local_cells_with_tasks_top = (int *)map_data;
- }
-
- for (int ind = 0; ind < num_elements; ind++) {
-
- struct cell *c;
-
- /* When restarting, the list of local cells does not
- yet exist. We use the raw list of top-level cells instead */
- if (restarting)
- c = &cells_top[ind];
- else
- c = &cells_top[local_cells_with_tasks_top[ind]];
-
- cell_drift_all_multipoles(c, e);
- }
-}
-
-/**
- * @brief Drift *all* particles and multipoles at all levels
- * forward to the current time.
- *
- * @param e The #engine.
- * @param drift_mpoles Do we want to drift all the multipoles as well?
- */
-void engine_drift_all(struct engine *e, const int drift_mpoles) {
-
- const ticks tic = getticks();
-
-#ifdef SWIFT_DEBUG_CHECKS
- if (e->nodeID == 0) {
- if (e->policy & engine_policy_cosmology)
- message("Drifting all to a=%e",
- exp(e->ti_current * e->time_base) * e->cosmology->a_begin);
- else
- message("Drifting all to t=%e",
- e->ti_current * e->time_base + e->time_begin);
- }
-#endif
-
- if (!e->restarting) {
-
- /* Normal case: We have a list of local cells with tasks to play with */
-
- if (e->s->nr_parts > 0) {
- threadpool_map(&e->threadpool, engine_do_drift_all_part_mapper,
- e->s->local_cells_top, e->s->nr_local_cells, sizeof(int),
- /* default chunk */ 0, e);
- }
- if (e->s->nr_gparts > 0) {
- threadpool_map(&e->threadpool, engine_do_drift_all_gpart_mapper,
- e->s->local_cells_top, e->s->nr_local_cells, sizeof(int),
- /* default chunk */ 0, e);
- }
- if (drift_mpoles && (e->policy & engine_policy_self_gravity)) {
- threadpool_map(&e->threadpool, engine_do_drift_all_multipole_mapper,
- e->s->local_cells_with_tasks_top,
- e->s->nr_local_cells_with_tasks, sizeof(int),
- /* default chunk */ 0, e);
- }
-
- } else {
-
- /* When restarting, the list of local cells with tasks does not yet
- exist. We use the raw list of top-level cells instead */
-
- if (e->s->nr_parts > 0) {
- threadpool_map(&e->threadpool, engine_do_drift_all_part_mapper,
- e->s->cells_top, e->s->nr_cells, sizeof(struct cell),
- /* default chunk */ 0, e);
- }
- if (e->s->nr_gparts > 0) {
- threadpool_map(&e->threadpool, engine_do_drift_all_gpart_mapper,
- e->s->cells_top, e->s->nr_cells, sizeof(struct cell),
- /* default chunk */ 0, e);
- }
- if (e->policy & engine_policy_self_gravity) {
- threadpool_map(&e->threadpool, engine_do_drift_all_multipole_mapper,
- e->s->cells_top, e->s->nr_cells, sizeof(struct cell),
- /* default chunk */ 0, e);
- }
- }
-
- /* Synchronize particle positions */
- space_synchronize_particle_positions(e->s);
-
-#ifdef SWIFT_DEBUG_CHECKS
- /* Check that all cells have been drifted to the current time. */
- space_check_drift_point(
- e->s, e->ti_current,
- drift_mpoles && (e->policy & engine_policy_self_gravity));
- part_verify_links(e->s->parts, e->s->gparts, e->s->sparts, e->s->nr_parts,
- e->s->nr_gparts, e->s->nr_sparts, e->verbose);
-#endif
-
- if (e->verbose)
- message("took %.3f %s.", clocks_from_ticks(getticks() - tic),
- clocks_getunit());
-}
-
-/**
- * @brief Mapper function to drift *all* top-level multipoles forward in
- * time.
- *
- * @param map_data An array of #cell%s.
- * @param num_elements Chunk size.
- * @param extra_data Pointer to an #engine.
- */
-void engine_do_drift_top_multipoles_mapper(void *map_data, int num_elements,
- void *extra_data) {
-
- struct engine *e = (struct engine *)extra_data;
- struct cell *cells = (struct cell *)map_data;
-
- for (int ind = 0; ind < num_elements; ind++) {
- struct cell *c = &cells[ind];
- if (c != NULL) {
-
- /* Drift the multipole at this level only */
- if (c->grav.ti_old_multipole != e->ti_current) cell_drift_multipole(c, e);
- }
- }
-}
-
-/**
- * @brief Drift *all* top-level multipoles forward to the current time.
- *
- * @param e The #engine.
- */
-void engine_drift_top_multipoles(struct engine *e) {
-
- const ticks tic = getticks();
-
- threadpool_map(&e->threadpool, engine_do_drift_top_multipoles_mapper,
- e->s->cells_top, e->s->nr_cells, sizeof(struct cell), 0, e);
-
-#ifdef SWIFT_DEBUG_CHECKS
- /* Check that all cells have been drifted to the current time. */
- space_check_top_multipoles_drift_point(e->s, e->ti_current);
-#endif
-
- if (e->verbose)
- message("took %.3f %s.", clocks_from_ticks(getticks() - tic),
- clocks_getunit());
-}
-
void engine_do_reconstruct_multipoles_mapper(void *map_data, int num_elements,
void *extra_data) {
diff --git a/src/engine_drift.c b/src/engine_drift.c
new file mode 100644
index 0000000000000000000000000000000000000000..7a842068b57813575c33dd670172059abb1e8fc0
--- /dev/null
+++ b/src/engine_drift.c
@@ -0,0 +1,297 @@
+/*******************************************************************************
+ * This file is part of SWIFT.
+ * Copyright (c) 2012 Pedro Gonnet (pedro.gonnet@durham.ac.uk)
+ * Matthieu Schaller (matthieu.schaller@durham.ac.uk)
+ * 2015 Peter W. Draper (p.w.draper@durham.ac.uk)
+ * Angus Lepper (angus.lepper@ed.ac.uk)
+ * 2016 John A. Regan (john.a.regan@durham.ac.uk)
+ * Tom Theuns (tom.theuns@durham.ac.uk)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ ******************************************************************************/
+
+/* Config parameters. */
+#include "../config.h"
+
+/* This object's header. */
+#include "engine.h"
+
+/**
+ * @brief Mapper function to drift *all* the #part to the current time.
+ *
+ * @param map_data An array of #cell%s.
+ * @param num_elements Chunk size.
+ * @param extra_data Pointer to an #engine.
+ */
+void engine_do_drift_all_part_mapper(void *map_data, int num_elements,
+ void *extra_data) {
+
+ const struct engine *e = (const struct engine *)extra_data;
+ const int restarting = e->restarting;
+ struct space *s = e->s;
+ struct cell *cells_top;
+ int *local_cells_top;
+
+ if (restarting) {
+
+ /* When restarting, we loop over all top-level cells */
+ cells_top = (struct cell *)map_data;
+ local_cells_top = NULL;
+
+ } else {
+
+ /* In any other case, we use the list of local cells with tasks */
+ cells_top = s->cells_top;
+ local_cells_top = (int *)map_data;
+ }
+
+ for (int ind = 0; ind < num_elements; ind++) {
+
+ struct cell *c;
+
+ /* When restarting, the list of local cells does not
+ yet exist. We use the raw list of top-level cells instead */
+ if (restarting)
+ c = &cells_top[ind];
+ else
+ c = &cells_top[local_cells_top[ind]];
+
+ if (c->nodeID == e->nodeID) {
+
+ /* Drift all the particles */
+ cell_drift_part(c, e, /* force the drift=*/1);
+ }
+ }
+}
+
+/**
+ * @brief Mapper function to drift *all* the #gpart to the current time.
+ *
+ * @param map_data An array of #cell%s.
+ * @param num_elements Chunk size.
+ * @param extra_data Pointer to an #engine.
+ */
+void engine_do_drift_all_gpart_mapper(void *map_data, int num_elements,
+ void *extra_data) {
+
+ const struct engine *e = (const struct engine *)extra_data;
+ const int restarting = e->restarting;
+ struct space *s = e->s;
+ struct cell *cells_top;
+ int *local_cells_top;
+
+ if (restarting) {
+
+ /* When restarting, we loop over all top-level cells */
+ cells_top = (struct cell *)map_data;
+ local_cells_top = NULL;
+
+ } else {
+
+ /* In any other case, we use the list of local cells with tasks */
+ cells_top = s->cells_top;
+ local_cells_top = (int *)map_data;
+ }
+
+ for (int ind = 0; ind < num_elements; ind++) {
+
+ struct cell *c;
+
+ /* When restarting, the list of local cells does not
+ yet exist. We use the raw list of top-level cells instead */
+ if (restarting)
+ c = &cells_top[ind];
+ else
+ c = &cells_top[local_cells_top[ind]];
+
+ if (c->nodeID == e->nodeID) {
+
+ /* Drift all the particles */
+ cell_drift_gpart(c, e, /* force the drift=*/1);
+ }
+ }
+}
+
+/**
+ * @brief Mapper function to drift *all* the multipoles to the current time.
+ *
+ * @param map_data An array of #cell%s.
+ * @param num_elements Chunk size.
+ * @param extra_data Pointer to an #engine.
+ */
+void engine_do_drift_all_multipole_mapper(void *map_data, int num_elements,
+ void *extra_data) {
+
+ const struct engine *e = (const struct engine *)extra_data;
+ const int restarting = e->restarting;
+ struct space *s = e->s;
+ struct cell *cells_top;
+ int *local_cells_with_tasks_top;
+
+ if (restarting) {
+
+ /* When restarting, we loop over all top-level cells */
+ cells_top = (struct cell *)map_data;
+ local_cells_with_tasks_top = NULL;
+
+ } else {
+
+ /* In any other case, we use the list of local cells with tasks */
+ cells_top = s->cells_top;
+ local_cells_with_tasks_top = (int *)map_data;
+ }
+
+ for (int ind = 0; ind < num_elements; ind++) {
+
+ struct cell *c;
+
+ /* When restarting, the list of local cells does not
+ yet exist. We use the raw list of top-level cells instead */
+ if (restarting)
+ c = &cells_top[ind];
+ else
+ c = &cells_top[local_cells_with_tasks_top[ind]];
+
+ cell_drift_all_multipoles(c, e);
+ }
+}
+
+/**
+ * @brief Drift *all* particles and multipoles at all levels
+ * forward to the current time.
+ *
+ * @param e The #engine.
+ * @param drift_mpoles Do we want to drift all the multipoles as well?
+ */
+void engine_drift_all(struct engine *e, const int drift_mpoles) {
+
+ const ticks tic = getticks();
+
+#ifdef SWIFT_DEBUG_CHECKS
+ if (e->nodeID == 0) {
+ if (e->policy & engine_policy_cosmology)
+ message("Drifting all to a=%e",
+ exp(e->ti_current * e->time_base) * e->cosmology->a_begin);
+ else
+ message("Drifting all to t=%e",
+ e->ti_current * e->time_base + e->time_begin);
+ }
+#endif
+
+ if (!e->restarting) {
+
+ /* Normal case: We have a list of local cells with tasks to play with */
+
+ if (e->s->nr_parts > 0) {
+ threadpool_map(&e->threadpool, engine_do_drift_all_part_mapper,
+ e->s->local_cells_top, e->s->nr_local_cells, sizeof(int),
+ /* default chunk */ 0, e);
+ }
+ if (e->s->nr_gparts > 0) {
+ threadpool_map(&e->threadpool, engine_do_drift_all_gpart_mapper,
+ e->s->local_cells_top, e->s->nr_local_cells, sizeof(int),
+ /* default chunk */ 0, e);
+ }
+ if (drift_mpoles && (e->policy & engine_policy_self_gravity)) {
+ threadpool_map(&e->threadpool, engine_do_drift_all_multipole_mapper,
+ e->s->local_cells_with_tasks_top,
+ e->s->nr_local_cells_with_tasks, sizeof(int),
+ /* default chunk */ 0, e);
+ }
+
+ } else {
+
+ /* When restarting, the list of local cells with tasks does not yet
+ exist. We use the raw list of top-level cells instead */
+
+ if (e->s->nr_parts > 0) {
+ threadpool_map(&e->threadpool, engine_do_drift_all_part_mapper,
+ e->s->cells_top, e->s->nr_cells, sizeof(struct cell),
+ /* default chunk */ 0, e);
+ }
+ if (e->s->nr_gparts > 0) {
+ threadpool_map(&e->threadpool, engine_do_drift_all_gpart_mapper,
+ e->s->cells_top, e->s->nr_cells, sizeof(struct cell),
+ /* default chunk */ 0, e);
+ }
+ if (e->policy & engine_policy_self_gravity) {
+ threadpool_map(&e->threadpool, engine_do_drift_all_multipole_mapper,
+ e->s->cells_top, e->s->nr_cells, sizeof(struct cell),
+ /* default chunk */ 0, e);
+ }
+ }
+
+ /* Synchronize particle positions */
+ space_synchronize_particle_positions(e->s);
+
+#ifdef SWIFT_DEBUG_CHECKS
+ /* Check that all cells have been drifted to the current time. */
+ space_check_drift_point(
+ e->s, e->ti_current,
+ drift_mpoles && (e->policy & engine_policy_self_gravity));
+ part_verify_links(e->s->parts, e->s->gparts, e->s->sparts, e->s->nr_parts,
+ e->s->nr_gparts, e->s->nr_sparts, e->verbose);
+#endif
+
+ if (e->verbose)
+ message("took %.3f %s.", clocks_from_ticks(getticks() - tic),
+ clocks_getunit());
+}
+
+/**
+ * @brief Mapper function to drift *all* top-level multipoles forward in
+ * time.
+ *
+ * @param map_data An array of #cell%s.
+ * @param num_elements Chunk size.
+ * @param extra_data Pointer to an #engine.
+ */
+void engine_do_drift_top_multipoles_mapper(void *map_data, int num_elements,
+ void *extra_data) {
+
+ struct engine *e = (struct engine *)extra_data;
+ struct cell *cells = (struct cell *)map_data;
+
+ for (int ind = 0; ind < num_elements; ind++) {
+ struct cell *c = &cells[ind];
+ if (c != NULL) {
+
+ /* Drift the multipole at this level only */
+ if (c->grav.ti_old_multipole != e->ti_current) cell_drift_multipole(c, e);
+ }
+ }
+}
+
+/**
+ * @brief Drift *all* top-level multipoles forward to the current time.
+ *
+ * @param e The #engine.
+ */
+void engine_drift_top_multipoles(struct engine *e) {
+
+ const ticks tic = getticks();
+
+ threadpool_map(&e->threadpool, engine_do_drift_top_multipoles_mapper,
+ e->s->cells_top, e->s->nr_cells, sizeof(struct cell), 0, e);
+
+#ifdef SWIFT_DEBUG_CHECKS
+ /* Check that all cells have been drifted to the current time. */
+ space_check_top_multipoles_drift_point(e->s, e->ti_current);
+#endif
+
+ if (e->verbose)
+ message("took %.3f %s.", clocks_from_ticks(getticks() - tic),
+ clocks_getunit());
+}