summaryrefslogtreecommitdiffstats
path: root/ta/ta.c
diff options
context:
space:
mode:
Diffstat (limited to 'ta/ta.c')
-rw-r--r--ta/ta.c439
1 files changed, 439 insertions, 0 deletions
diff --git a/ta/ta.c b/ta/ta.c
new file mode 100644
index 0000000000..568f6d5f1b
--- /dev/null
+++ b/ta/ta.c
@@ -0,0 +1,439 @@
+/* Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <assert.h>
+
+#define TA_NO_WRAPPERS
+#include "ta.h"
+
+// Note: the actual minimum alignment is dictated by malloc(). It doesn't
+// make sense to set this value higher than malloc's alignment.
+#define MIN_ALIGN 16
+
+#ifndef NDEBUG
+#define TA_MEMORY_DEBUGGING
+#endif
+
+struct ta_header {
+ size_t size; // size of the user allocation
+ struct ta_header *prev; // ring list containing siblings
+ struct ta_header *next;
+ struct ta_ext_header *ext;
+#ifdef TA_MEMORY_DEBUGGING
+ unsigned int canary;
+ struct ta_header *leak_next;
+ struct ta_header *leak_prev;
+ const char *name;
+#endif
+};
+
+#define CANARY 0xD3ADB3EF
+
+union aligned_header {
+ struct ta_header ta;
+ // Make sure to satisfy typical alignment requirements
+ void *align_ptr;
+ int align_int;
+ double align_d;
+ long long align_ll;
+ char align_min[(sizeof(struct ta_header) + MIN_ALIGN - 1) & ~(MIN_ALIGN - 1)];
+};
+
+#define PTR_TO_HEADER(ptr) (&((union aligned_header *)(ptr) - 1)->ta)
+#define PTR_FROM_HEADER(h) ((void *)((union aligned_header *)(h) + 1))
+
+#define MAX_ALLOC (((size_t)-1) - sizeof(union aligned_header))
+
+// Needed for non-leaf allocations, or extended features such as destructors.
+struct ta_ext_header {
+ struct ta_header *header; // points back to normal header
+ struct ta_header children; // list of children, with this as sentinel
+ void (*destructor)(void *);
+};
+
+// ta_ext_header.children.size is set to this
+#define CHILDREN_SENTINEL ((size_t)-1)
+
+static void ta_dbg_add(struct ta_header *h);
+static void ta_dbg_check_header(struct ta_header *h);
+static void ta_dbg_remove(struct ta_header *h);
+
+static struct ta_header *get_header(void *ptr)
+{
+ struct ta_header *h = ptr ? PTR_TO_HEADER(ptr) : NULL;
+ ta_dbg_check_header(h);
+ return h;
+}
+
+static struct ta_ext_header *get_or_alloc_ext_header(void *ptr)
+{
+ struct ta_header *h = get_header(ptr);
+ if (!h)
+ return NULL;
+ if (!h->ext) {
+ h->ext = malloc(sizeof(struct ta_ext_header));
+ if (!h->ext)
+ return NULL;
+ *h->ext = (struct ta_ext_header) {
+ .header = h,
+ .children = {
+ .next = &h->ext->children,
+ .prev = &h->ext->children,
+ // Needed by ta_find_parent():
+ .size = CHILDREN_SENTINEL,
+ .ext = h->ext,
+ },
+ };
+ }
+ return h->ext;
+}
+
+/* Set the parent allocation of ptr. If parent==NULL, remove the parent.
+ * Setting parent==NULL (with ptr!=NULL) always succeeds, and unsets the
+ * parent of ptr. Operations ptr==NULL always succeed and do nothing.
+ * Returns true on success, false on OOM.
+ */
+bool ta_set_parent(void *ptr, void *ta_parent)
+{
+ struct ta_header *ch = get_header(ptr);
+ if (!ch)
+ return true;
+ struct ta_ext_header *parent_eh = get_or_alloc_ext_header(ta_parent);
+ if (ta_parent && !parent_eh) // do nothing on OOM
+ return false;
+ // Unlink from previous parent
+ if (ch->next) {
+ ch->next->prev = ch->prev;
+ ch->prev->next = ch->next;
+ ch->next = ch->prev = NULL;
+ }
+ // Link to new parent - insert at end of list (possibly orders destructors)
+ if (parent_eh) {
+ struct ta_header *children = &parent_eh->children;
+ ch->next = children;
+ ch->prev = children->prev;
+ children->prev->next = ch;
+ children->prev = ch;
+ }
+ return true;
+}
+
+/* Allocate size bytes of memory. If ta_parent is not NULL, this is used as
+ * parent allocation (if ta_parent is freed, this allocation is automatically
+ * freed as well). size==0 allocates a block of size 0 (i.e. returns non-NULL).
+ * Returns NULL on OOM.
+ */
+void *ta_alloc_size(void *ta_parent, size_t size)
+{
+ if (size >= MAX_ALLOC)
+ return NULL;
+ struct ta_header *h = malloc(sizeof(union aligned_header) + size);
+ if (!h)
+ return NULL;
+ *h = (struct ta_header) {.size = size};
+ ta_dbg_add(h);
+ void *ptr = PTR_FROM_HEADER(h);
+ if (!ta_set_parent(ptr, ta_parent)) {
+ ta_free(ptr);
+ return NULL;
+ }
+ return ptr;
+}
+
+/* Exactly the same as ta_alloc_size(), but the returned memory block is
+ * initialized to 0.
+ */
+void *ta_zalloc_size(void *ta_parent, size_t size)
+{
+ if (size >= MAX_ALLOC)
+ return NULL;
+ struct ta_header *h = calloc(1, sizeof(union aligned_header) + size);
+ if (!h)
+ return NULL;
+ *h = (struct ta_header) {.size = size};
+ ta_dbg_add(h);
+ void *ptr = PTR_FROM_HEADER(h);
+ if (!ta_set_parent(ptr, ta_parent)) {
+ ta_free(ptr);
+ return NULL;
+ }
+ return ptr;
+}
+
+/* Reallocate the allocation given by ptr and return a new pointer. Much like
+ * realloc(), the returned pointer can be different, and on OOM, NULL is
+ * returned.
+ *
+ * size==0 is equivalent to ta_free(ptr).
+ * ptr==NULL is equivalent to ta_alloc_size(ta_parent, size).
+ *
+ * ta_parent is used only in the ptr==NULL case.
+ *
+ * Returns NULL if the operation failed.
+ * NULL is also returned if size==0.
+ */
+void *ta_realloc_size(void *ta_parent, void *ptr, size_t size)
+{
+ if (size >= MAX_ALLOC)
+ return NULL;
+ if (!size) {
+ ta_free(ptr);
+ return NULL;
+ }
+ if (!ptr)
+ return ta_alloc_size(ta_parent, size);
+ struct ta_header *h = get_header(ptr);
+ struct ta_header *old_h = h;
+ if (h->size == size)
+ return ptr;
+ ta_dbg_remove(h);
+ h = realloc(h, sizeof(union aligned_header) + size);
+ ta_dbg_add(h ? h : old_h);
+ if (!h)
+ return NULL;
+ h->size = size;
+ if (h != old_h) {
+ if (h->next) {
+ // Relink siblings
+ h->next->prev = h;
+ h->prev->next = h;
+ }
+ if (h->ext) {
+ // Relink children
+ h->ext->header = h;
+ h->ext->children.next->prev = &h->ext->children;
+ h->ext->children.prev->next = &h->ext->children;
+ }
+ }
+ return PTR_FROM_HEADER(h);
+}
+
+/* Return the allocated size of ptr. This returns the size parameter of the
+ * most recent ta_alloc.../ta_realloc... call.
+ * If ptr==NULL, return 0.
+ */
+size_t ta_get_size(void *ptr)
+{
+ struct ta_header *h = get_header(ptr);
+ return h ? h->size : 0;
+}
+
+/* Free all allocations that (recursively) have ptr as parent allocation, but
+ * do not free ptr itself.
+ */
+void ta_free_children(void *ptr)
+{
+ struct ta_header *h = get_header(ptr);
+ struct ta_ext_header *eh = h ? h->ext : NULL;
+ if (!eh)
+ return;
+ while (eh->children.next != &eh->children)
+ ta_free(PTR_FROM_HEADER(eh->children.next));
+}
+
+/* Free the given allocation, and all of its direct and indirect children.
+ */
+void ta_free(void *ptr)
+{
+ struct ta_header *h = get_header(ptr);
+ if (!h)
+ return;
+ if (h->ext && h->ext->destructor)
+ h->ext->destructor(ptr);
+ ta_free_children(ptr);
+ if (h->next) {
+ // Unlink from sibling list
+ h->next->prev = h->prev;
+ h->prev->next = h->next;
+ }
+ ta_dbg_remove(h);
+ free(h->ext);
+ free(h);
+}
+
+/* Set a destructor that is to be called when the given allocation is freed.
+ * (Whether the allocation is directly freed with ta_free() or indirectly by
+ * freeing its parent does not matter.) There is only one destructor. If an
+ * destructor was already set, it's overwritten.
+ *
+ * The destructor will be called with ptr as argument. The destructor can do
+ * almost anything, but it must not attempt to free or realloc ptr. The
+ * destructor is run before the allocation's children are freed (also, before
+ * their destructors are run).
+ *
+ * Returns false if ptr==NULL, or on OOM.
+ */
+bool ta_set_destructor(void *ptr, void (*destructor)(void *))
+{
+ struct ta_ext_header *eh = get_or_alloc_ext_header(ptr);
+ if (!eh)
+ return false;
+ eh->destructor = destructor;
+ return true;
+}
+
+/* Return the ptr's parent allocation, or NULL if there isn't any.
+ *
+ * Warning: this has O(N) runtime complexity with N sibling allocations!
+ */
+void *ta_find_parent(void *ptr)
+{
+ struct ta_header *h = get_header(ptr);
+ if (!h || !h->next)
+ return NULL;
+ for (struct ta_header *cur = h->next; cur != h; cur = cur->next) {
+ if (cur->size == CHILDREN_SENTINEL)
+ return PTR_FROM_HEADER(cur->ext->header);
+ }
+ return NULL;
+}
+
+#ifdef TA_MEMORY_DEBUGGING
+
+#include <pthread.h>
+
+static pthread_mutex_t ta_dbg_mutex = PTHREAD_MUTEX_INITIALIZER;
+static bool enable_leak_check; // pretty much constant
+static struct ta_header leak_node;
+static char allocation_is_string;
+
+static void ta_dbg_add(struct ta_header *h)
+{
+ h->canary = CANARY;
+ if (enable_leak_check) {
+ pthread_mutex_lock(&ta_dbg_mutex);
+ h->leak_next = &leak_node;
+ h->leak_prev = leak_node.leak_prev;
+ leak_node.leak_prev->leak_next = h;
+ leak_node.leak_prev = h;
+ pthread_mutex_unlock(&ta_dbg_mutex);
+ }
+}
+
+static void ta_dbg_check_header(struct ta_header *h)
+{
+ if (h)
+ assert(h->canary == CANARY);
+}
+
+static void ta_dbg_remove(struct ta_header *h)
+{
+ ta_dbg_check_header(h);
+ if (h->leak_next) { // assume checking for !=NULL invariant ok without lock
+ pthread_mutex_lock(&ta_dbg_mutex);
+ h->leak_next->leak_prev = h->leak_prev;
+ h->leak_prev->leak_next = h->leak_next;
+ pthread_mutex_unlock(&ta_dbg_mutex);
+ h->leak_next = h->leak_prev = NULL;
+ }
+ h->canary = 0;
+}
+
+static size_t get_children_size(struct ta_header *h)
+{
+ size_t size = 0;
+ if (h->ext) {
+ struct ta_header *s;
+ for (s = h->ext->children.next; s != &h->ext->children; s = s->next)
+ size += s->size + get_children_size(s);
+ }
+ return size;
+}
+
+static void print_leak_report(void)
+{
+ pthread_mutex_lock(&ta_dbg_mutex);
+ if (leak_node.leak_next && leak_node.leak_next != &leak_node) {
+ size_t size = 0;
+ size_t num_blocks = 0;
+ fprintf(stderr, "Blocks not freed:\n");
+ fprintf(stderr, " %-20s %10s %10s %s\n",
+ "Ptr", "Bytes", "C. Bytes", "Name");
+ while (leak_node.leak_next != &leak_node) {
+ struct ta_header *cur = leak_node.leak_next;
+ // Don't list those with parent; logically, only parents are listed
+ if (!cur->next) {
+ size_t c_size = get_children_size(cur);
+ char name[30] = {0};
+ if (cur->name)
+ snprintf(name, sizeof(name), "%s", cur->name);
+ if (cur->name == &allocation_is_string) {
+ snprintf(name, sizeof(name), "'%.*s'",
+ (int)cur->size, (char *)PTR_FROM_HEADER(cur));
+ }
+ for (int n = 0; n < sizeof(name); n++) {
+ if (name[n] && name[n] < 0x20)
+ name[n] = '.';
+ }
+ fprintf(stderr, " %-20p %10zu %10zu %s\n",
+ cur, cur->size, c_size, name);
+ }
+ size += cur->size;
+ num_blocks += 1;
+ // Unlink, and don't confuse valgrind by leaving live pointers.
+ cur->leak_next->leak_prev = cur->leak_prev;
+ cur->leak_prev->leak_next = cur->leak_next;
+ cur->leak_next = cur->leak_prev = NULL;
+ }
+ fprintf(stderr, "%zu bytes in %zu blocks.\n", size, num_blocks);
+ }
+ pthread_mutex_unlock(&ta_dbg_mutex);
+}
+
+void ta_enable_leak_report(void)
+{
+ pthread_mutex_lock(&ta_dbg_mutex);
+ enable_leak_check = true;
+ if (!leak_node.leak_prev && !leak_node.leak_next) {
+ leak_node.leak_prev = &leak_node;
+ leak_node.leak_next = &leak_node;
+ atexit(print_leak_report);
+ }
+ pthread_mutex_unlock(&ta_dbg_mutex);
+}
+
+/* Set a (static) string that will be printed if the memory allocation in ptr
+ * shows up on the leak report. The string must stay valid until ptr is freed.
+ * Calling it on ptr==NULL does nothing.
+ * Typically used to set location info.
+ * Always returns ptr (useful for chaining function calls).
+ */
+void *ta_dbg_set_loc(void *ptr, const char *loc)
+{
+ struct ta_header *h = get_header(ptr);
+ if (h)
+ h->name = loc;
+ return ptr;
+}
+
+/* Mark the allocation as string. The leak report will print it literally.
+ */
+void *ta_dbg_mark_as_string(void *ptr)
+{
+ // Specially handled by leak report code.
+ return ta_dbg_set_loc(ptr, &allocation_is_string);
+}
+
+#else
+
+static void ta_dbg_add(struct ta_header *h){}
+static void ta_dbg_check_header(struct ta_header *h){}
+static void ta_dbg_remove(struct ta_header *h){}
+
+void ta_enable_leak_report(void){}
+void *ta_dbg_set_name(void *ptr, const char *name){return ptr;}
+
+#endif
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-24 19:21:59 +0000