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-rw-r--r--src/pl_alloc.c313
1 files changed, 313 insertions, 0 deletions
diff --git a/src/pl_alloc.c b/src/pl_alloc.c
new file mode 100644
index 0000000..64eeda7
--- /dev/null
+++ b/src/pl_alloc.c
@@ -0,0 +1,313 @@
+/*
+ * This file is part of libplacebo.
+ *
+ * libplacebo 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 2.1 of the License, or (at your option) any later version.
+ *
+ * libplacebo 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with libplacebo. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "common.h"
+
+struct header {
+#ifndef NDEBUG
+#define MAGIC 0x20210119LU
+ uint32_t magic;
+#endif
+ size_t size;
+ struct header *parent;
+ struct ext *ext;
+
+ // Pointer to actual data, for alignment purposes
+ max_align_t data[];
+};
+
+// Lazily allocated, to save space for leaf allocations and allocations which
+// don't need fancy requirements
+struct ext {
+ size_t num_children;
+ size_t children_size; // total allocated size of `children`
+ struct header *children[];
+};
+
+#define PTR_OFFSET offsetof(struct header, data)
+#define MAX_ALLOC (SIZE_MAX - PTR_OFFSET)
+#define MINIMUM_CHILDREN 4
+
+static inline struct header *get_header(void *ptr)
+{
+ if (!ptr)
+ return NULL;
+
+ struct header *hdr = (struct header *) ((uintptr_t) ptr - PTR_OFFSET);
+#ifndef NDEBUG
+ assert(hdr->magic == MAGIC);
+#endif
+
+ return hdr;
+}
+
+static inline void *oom(void)
+{
+ fprintf(stderr, "out of memory\n");
+ abort();
+}
+
+static inline struct ext *alloc_ext(struct header *h)
+{
+ if (!h)
+ return NULL;
+
+ if (!h->ext) {
+ h->ext = malloc(sizeof(struct ext) + MINIMUM_CHILDREN * sizeof(void *));
+ if (!h->ext)
+ oom();
+ h->ext->num_children = 0;
+ h->ext->children_size = MINIMUM_CHILDREN;
+ }
+
+ return h->ext;
+}
+
+static inline void attach_child(struct header *parent, struct header *child)
+{
+ child->parent = parent;
+ if (!parent)
+ return;
+
+
+ struct ext *ext = alloc_ext(parent);
+ if (ext->num_children == ext->children_size) {
+ size_t new_size = ext->children_size * 2;
+ ext = realloc(ext, sizeof(struct ext) + new_size * sizeof(void *));
+ if (!ext)
+ oom();
+ ext->children_size = new_size;
+ parent->ext = ext;
+ }
+
+ ext->children[ext->num_children++] = child;
+}
+
+static inline void unlink_child(struct header *parent, struct header *child)
+{
+ child->parent = NULL;
+ if (!parent)
+ return;
+
+ struct ext *ext = parent->ext;
+ for (size_t i = 0; i < ext->num_children; i++) {
+ if (ext->children[i] == child) {
+ memmove(&ext->children[i], &ext->children[i + 1],
+ (--ext->num_children - i) * sizeof(ext->children[0]));
+ return;
+ }
+ }
+
+ assert(!"unlinking orphaned child?");
+}
+
+void *pl_alloc(void *parent, size_t size)
+{
+ if (size >= MAX_ALLOC)
+ return oom();
+
+ struct header *h = malloc(PTR_OFFSET + size);
+ if (!h)
+ return oom();
+
+#ifndef NDEBUG
+ h->magic = MAGIC;
+#endif
+ h->size = size;
+ h->ext = NULL;
+
+ attach_child(get_header(parent), h);
+ return h->data;
+}
+
+void *pl_zalloc(void *parent, size_t size)
+{
+ if (size >= MAX_ALLOC)
+ return oom();
+
+ struct header *h = calloc(1, PTR_OFFSET + size);
+ if (!h)
+ return oom();
+
+#ifndef NDEBUG
+ h->magic = MAGIC;
+#endif
+ h->size = size;
+
+ attach_child(get_header(parent), h);
+ return h->data;
+}
+
+void *pl_realloc(void *parent, void *ptr, size_t size)
+{
+ if (size >= MAX_ALLOC)
+ return oom();
+ if (!ptr)
+ return pl_alloc(parent, size);
+
+ struct header *h = get_header(ptr);
+ assert(get_header(parent) == h->parent);
+ if (h->size == size)
+ return ptr;
+
+ struct header *old_h = h;
+ h = realloc(h, PTR_OFFSET + size);
+ if (!h)
+ return oom();
+
+ h->size = size;
+
+ if (h != old_h) {
+ if (h->parent) {
+ struct ext *ext = h->parent->ext;
+ for (size_t i = 0; i < ext->num_children; i++) {
+ if (ext->children[i] == old_h) {
+ ext->children[i] = h;
+ goto done_reparenting;
+ }
+ }
+ assert(!"reallocating orphaned child?");
+ }
+done_reparenting:
+
+ if (h->ext) {
+ for (size_t i = 0; i < h->ext->num_children; i++)
+ h->ext->children[i]->parent = h;
+ }
+ }
+
+ return h->data;
+}
+
+void pl_free(void *ptr)
+{
+ struct header *h = get_header(ptr);
+ if (!h)
+ return;
+
+ pl_free_children(ptr);
+ unlink_child(h->parent, h);
+
+ free(h->ext);
+ free(h);
+}
+
+void pl_free_children(void *ptr)
+{
+ struct header *h = get_header(ptr);
+ if (!h || !h->ext)
+ return;
+
+#ifndef NDEBUG
+ // this detects recursive hierarchies
+ h->magic = 0;
+#endif
+
+ for (size_t i = 0; i < h->ext->num_children; i++) {
+ h->ext->children[i]->parent = NULL; // prevent recursive access
+ pl_free(h->ext->children[i]->data);
+ }
+ h->ext->num_children = 0;
+
+#ifndef NDEBUG
+ h->magic = MAGIC;
+#endif
+}
+
+size_t pl_get_size(const void *ptr)
+{
+ const struct header *h = get_header((void *) ptr);
+ return h ? h->size : 0;
+}
+
+void *pl_steal(void *parent, void *ptr)
+{
+ struct header *h = get_header(ptr);
+ if (!h)
+ return NULL;
+
+ struct header *new_par = get_header(parent);
+ if (new_par != h->parent) {
+ unlink_child(h->parent, h);
+ attach_child(new_par, h);
+ }
+
+ return h->data;
+}
+
+void *pl_memdup(void *parent, const void *ptr, size_t size)
+{
+ if (!size)
+ return NULL;
+
+ void *new = pl_alloc(parent, size);
+ if (!new)
+ return oom();
+
+ assert(ptr);
+ memcpy(new, ptr, size);
+ return new;
+}
+
+char *pl_str0dup0(void *parent, const char *str)
+{
+ if (!str)
+ return NULL;
+
+ return pl_memdup(parent, str, strlen(str) + 1);
+}
+
+char *pl_strndup0(void *parent, const char *str, size_t size)
+{
+ if (!str)
+ return NULL;
+
+ size_t str_size = strnlen(str, size);
+ char *new = pl_alloc(parent, str_size + 1);
+ if (!new)
+ return oom();
+ memcpy(new, str, str_size);
+ new[str_size] = '\0';
+ return new;
+}
+
+char *pl_asprintf(void *parent, const char *fmt, ...)
+{
+ char *str;
+ va_list ap;
+ va_start(ap, fmt);
+ str = pl_vasprintf(parent, fmt, ap);
+ va_end(ap);
+ return str;
+}
+
+char *pl_vasprintf(void *parent, const char *fmt, va_list ap)
+{
+ // First, we need to determine the size that will be required for
+ // printing the entire string. Do this by making a copy of the va_list
+ // and printing it to a null buffer.
+ va_list copy;
+ va_copy(copy, ap);
+ int size = vsnprintf(NULL, 0, fmt, copy);
+ va_end(copy);
+ if (size < 0)
+ return NULL;
+
+ char *str = pl_alloc(parent, size + 1);
+ vsnprintf(str, size + 1, fmt, ap);
+ return str;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-14 02:05:27 +0000