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-rw-r--r--src/basic/mempool.c99
1 files changed, 99 insertions, 0 deletions
diff --git a/src/basic/mempool.c b/src/basic/mempool.c
new file mode 100644
index 0000000..159c963
--- /dev/null
+++ b/src/basic/mempool.c
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "env-util.h"
+#include "macro.h"
+#include "mempool.h"
+#include "process-util.h"
+#include "util.h"
+
+struct pool {
+ struct pool *next;
+ size_t n_tiles;
+ size_t n_used;
+};
+
+void* mempool_alloc_tile(struct mempool *mp) {
+ size_t i;
+
+ /* When a tile is released we add it to the list and simply
+ * place the next pointer at its offset 0. */
+
+ assert(mp->tile_size >= sizeof(void*));
+ assert(mp->at_least > 0);
+
+ if (mp->freelist) {
+ void *r;
+
+ r = mp->freelist;
+ mp->freelist = * (void**) mp->freelist;
+ return r;
+ }
+
+ if (_unlikely_(!mp->first_pool) ||
+ _unlikely_(mp->first_pool->n_used >= mp->first_pool->n_tiles)) {
+ size_t size, n;
+ struct pool *p;
+
+ n = mp->first_pool ? mp->first_pool->n_tiles : 0;
+ n = MAX(mp->at_least, n * 2);
+ size = PAGE_ALIGN(ALIGN(sizeof(struct pool)) + n*mp->tile_size);
+ n = (size - ALIGN(sizeof(struct pool))) / mp->tile_size;
+
+ p = malloc(size);
+ if (!p)
+ return NULL;
+
+ p->next = mp->first_pool;
+ p->n_tiles = n;
+ p->n_used = 0;
+
+ mp->first_pool = p;
+ }
+
+ i = mp->first_pool->n_used++;
+
+ return ((uint8_t*) mp->first_pool) + ALIGN(sizeof(struct pool)) + i*mp->tile_size;
+}
+
+void* mempool_alloc0_tile(struct mempool *mp) {
+ void *p;
+
+ p = mempool_alloc_tile(mp);
+ if (p)
+ memzero(p, mp->tile_size);
+ return p;
+}
+
+void mempool_free_tile(struct mempool *mp, void *p) {
+ * (void**) p = mp->freelist;
+ mp->freelist = p;
+}
+
+bool mempool_enabled(void) {
+ static int b = -1;
+
+ if (!is_main_thread())
+ return false;
+
+ if (!mempool_use_allowed)
+ b = false;
+ if (b < 0)
+ b = getenv_bool("SYSTEMD_MEMPOOL") != 0;
+
+ return b;
+}
+
+#if VALGRIND
+void mempool_drop(struct mempool *mp) {
+ struct pool *p = mp->first_pool;
+ while (p) {
+ struct pool *n;
+ n = p->next;
+ free(p);
+ p = n;
+ }
+}
+#endif