Replace talloc

There are multiple reasons to do this. One big reason is the license:
talloc is LGPLv3+, which forces mpv to be licensed as GPLv3+.

Another one is that our talloc copy contains modifications, which makes
it essentially incompatible with upstream talloc (in particular, our
version aborts on out of memory conditions - well, it wasn't my idea).
Updating from upstream is also a bit involved - the talloc source is
not really organized in a way to allow copying it into projects (and
this isn't an intended use-case).

Finally, talloc is kind of big and bloated. The replacement halves the
amount of code - mainly because we didn't use all talloc features. It's
even more extreme if you compare upstream talloc (~4700 lines) and the
new allocator without talloc compat (~900 lines).

The replacement provides all features we need. It also doesn't clash
with talloc. (The talloc compatibility wrapper uses macros to avoid
introducing linker-level symbols which could clash with libtalloc.)

It also tries to lower the overhead (only 4 words opposed to 10 words
in talloc for leaf nodes in release mode). Debugging features like leak
reporting can be enabled at compile time and add somewhat more overhead.
Though I'm not sure whether the overhead reduction was actually
successful: allocations with children need an "extra" header, which adds
plenty of overhead, and it turns out that almost half of all allocations
have children. Maybe the implementation could be simplified and the
extra header removed - even then, overhead would be lower than talloc's.

Currently, debugging features can be entirely deactivated by defining
NDEBUG - I'm not sure if anything defines this directly yet, though.

Unlike in talloc, the leak reporting stuff is thread-safe. (That's also
why it's far less elegant, and requires extra list pointers.)

Comes with a compatibility layer, so no changes to mpv source code
are needed. The idea is that we will pretend to be using talloc for
a while, so that we can revert to our old talloc implementation at
any time for debugging purposes.

Some inspiration was taken from Mesa's ralloc:

    http://cgit.freedesktop.org/mesa/mesa/tree/src/glsl/ralloc.h

This is another talloc replacement, but lacks some features we need
(getting size of an allocation, debugging features, being able to
access children in the dtor).

There's some information in ta/README what will happen next and how the
transition is expected to progress.

1 files changed, 146 insertions, 0 deletions

diff --git a/ta/ta.h b/ta/ta.h
new file mode 100644
index 0000000000..1a9738a9f0
--- /dev/null
+++ b/ta/ta.h
@@ -0,0 +1,146 @@
+/* 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.
+ */
+
+#ifndef TA_H_
+#define TA_H_
+
+#include <stddef.h>
+#include <stdbool.h>
+#include <stdarg.h>
+
+#ifdef __GNUC__
+#define TA_PRF(a1, a2) __attribute__ ((format(printf, a1, a2)))
+#define TA_TYPEOF(t) __typeof__(t)
+#else
+#define TA_PRF(a1, a2)
+#define TA_TYPEOF(t) void *
+#endif
+
+#define TA_STRINGIFY_(x) # x
+#define TA_STRINGIFY(x) TA_STRINGIFY_(x)
+
+#ifdef NDEBUG
+#define TA_LOC ""
+#else
+#define TA_LOC __FILE__ ":" TA_STRINGIFY(__LINE__)
+#endif
+
+// Core functions
+void *ta_alloc_size(void *ta_parent, size_t size);
+void *ta_zalloc_size(void *ta_parent, size_t size);
+void *ta_realloc_size(void *ta_parent, void *ptr, size_t size);
+size_t ta_get_size(void *ptr);
+void ta_free(void *ptr);
+void ta_free_children(void *ptr);
+bool ta_set_destructor(void *ptr, void (*destructor)(void *));
+bool ta_set_parent(void *ptr, void *ta_parent);
+void *ta_find_parent(void *ptr);
+
+// Utility functions
+size_t ta_calc_array_size(size_t element_size, size_t count);
+void *ta_new_context(void *ta_parent);
+void *ta_steal_(void *ta_parent, void *ptr);
+void *ta_memdup(void *ta_parent, void *ptr, size_t size);
+char *ta_strdup(void *ta_parent, const char *str);
+bool ta_strdup_append(char **str, const char *a);
+bool ta_strdup_append_buffer(char **str, const char *a);
+char *ta_strndup(void *ta_parent, const char *str, size_t n);
+bool ta_strndup_append(char **str, const char *a, size_t n);
+bool ta_strndup_append_buffer(char **str, const char *a, size_t n);
+char *ta_asprintf(void *ta_parent, const char *fmt, ...) TA_PRF(2, 3);
+char *ta_vasprintf(void *ta_parent, const char *fmt, va_list ap) TA_PRF(2, 0);
+bool ta_asprintf_append(char **str, const char *fmt, ...) TA_PRF(2, 3);
+bool ta_vasprintf_append(char **str, const char *fmt, va_list ap) TA_PRF(2, 0);
+bool ta_asprintf_append_buffer(char **str, const char *fmt, ...) TA_PRF(2, 3);
+bool ta_vasprintf_append_buffer(char **str, const char *fmt, va_list ap) TA_PRF(2, 0);
+
+#define ta_new(ta_parent, type)  (type *)ta_alloc_size(ta_parent, sizeof(type))
+#define ta_znew(ta_parent, type) (type *)ta_zalloc_size(ta_parent, sizeof(type))
+
+#define ta_new_array(ta_parent, type, count) \
+    (type *)ta_alloc_size(ta_parent, ta_calc_array_size(sizeof(type), count))
+
+#define ta_znew_array(ta_parent, type, count) \
+    (type *)ta_zalloc_size(ta_parent, ta_calc_array_size(sizeof(type), count))
+
+#define ta_new_array_size(ta_parent, element_size, count) \
+    ta_alloc_size(ta_parent, ta_calc_array_size(element_size, count))
+
+#define ta_realloc(ta_parent, ptr, type, count) \
+    (type *)ta_realloc_size(ta_parent, ptr, ta_calc_array_size(sizeof(type), count))
+
+#define ta_new_ptrtype(ta_parent, ptr) \
+    (TA_TYPEOF(ptr))ta_alloc_size(ta_parent, sizeof(*ptr))
+
+#define ta_new_array_ptrtype(ta_parent, ptr, count) \
+    (TA_TYPEOF(ptr))ta_new_array_size(ta_parent, sizeof(*(ptr)), count)
+
+#define ta_steal(ta_parent, ptr) (TA_TYPEOF(ptr))ta_steal_(ta_parent, ptr)
+
+// Ugly macros that crash on OOM.
+// All of these mirror real functions (with a 'x' added after the 'ta_'
+// prefix), and the only difference is that they will call abort() on allocation
+// failures (such as out of memory conditions), instead of returning an error
+// code.
+#define ta_xalloc_size(...)             ta_oom_p(ta_alloc_size(__VA_ARGS__))
+#define ta_xzalloc_size(...)            ta_oom_p(ta_zalloc_size(__VA_ARGS__))
+#define ta_xset_destructor(...)         ta_oom_b(ta_set_destructor(__VA_ARGS__))
+#define ta_xset_parent(...)             ta_oom_b(ta_set_parent(__VA_ARGS__))
+#define ta_xnew_context(...)            ta_oom_p(ta_new_context(__VA_ARGS__))
+#define ta_xstrdup_append(...)          ta_oom_b(ta_strdup_append(__VA_ARGS__))
+#define ta_xstrdup_append_buffer(...)   ta_oom_b(ta_strdup_append_buffer(__VA_ARGS__))
+#define ta_xstrndup_append(...)         ta_oom_b(ta_strndup_append(__VA_ARGS__))
+#define ta_xstrndup_append_buffer(...)  ta_oom_b(ta_strndup_append_buffer(__VA_ARGS__))
+#define ta_xasprintf(...)               ta_oom_s(ta_asprintf(__VA_ARGS__))
+#define ta_xvasprintf(...)              ta_oom_s(ta_vasprintf(__VA_ARGS__))
+#define ta_xasprintf_append(...)        ta_oom_b(ta_asprintf_append(__VA_ARGS__))
+#define ta_xvasprintf_append(...)       ta_oom_b(ta_vasprintf_append(__VA_ARGS__))
+#define ta_xasprintf_append_buffer(...) ta_oom_b(ta_asprintf_append_buffer(__VA_ARGS__))
+#define ta_xvasprintf_append_buffer(...) ta_oom_b(ta_vasprintf_append_buffer(__VA_ARGS__))
+#define ta_xnew(...)                    ta_oom_g(ta_new(__VA_ARGS__))
+#define ta_xznew(...)                   ta_oom_g(ta_znew(__VA_ARGS__))
+#define ta_xnew_array(...)              ta_oom_g(ta_new_array(__VA_ARGS__))
+#define ta_xznew_array(...)             ta_oom_g(ta_znew_array(__VA_ARGS__))
+#define ta_xnew_array_size(...)         ta_oom_p(ta_new_array_size(__VA_ARGS__))
+#define ta_xnew_ptrtype(...)            ta_oom_g(ta_new_ptrtype(__VA_ARGS__))
+#define ta_xnew_array_ptrtype(...)      ta_oom_g(ta_new_array_ptrtype(__VA_ARGS__))
+
+#define ta_xsteal(ta_parent, ptr) (TA_TYPEOF(ptr))ta_xsteal_(ta_parent, ptr)
+#define ta_xrealloc(ta_parent, ptr, type, count) \
+    (type *)ta_xrealloc_size(ta_parent, ptr, ta_calc_array_size(sizeof(type), count))
+
+// Can't be macros, because the OOM logic is slightly less trivial.
+char *ta_xstrdup(void *ta_parent, const char *str);
+char *ta_xstrndup(void *ta_parent, const char *str, size_t n);
+void *ta_xsteal_(void *ta_parent, void *ptr);
+void *ta_xmemdup(void *ta_parent, void *ptr, size_t size);
+void *ta_xrealloc_size(void *ta_parent, void *ptr, size_t size);
+
+#ifndef TA_NO_WRAPPERS
+#define ta_alloc_size(...)      ta_dbg_set_loc(ta_alloc_size(__VA_ARGS__), TA_LOC)
+#define ta_zalloc_size(...)     ta_dbg_set_loc(ta_zalloc_size(__VA_ARGS__), TA_LOC)
+#define ta_realloc_size(...)    ta_dbg_set_loc(ta_realloc_size(__VA_ARGS__), TA_LOC)
+#define ta_memdup(...)          ta_dbg_set_loc(ta_memdup(__VA_ARGS__), TA_LOC)
+#endif
+
+void ta_oom_b(bool b);
+char *ta_oom_s(char *s);
+void *ta_oom_p(void *p);
+// Generic pointer
+#define ta_oom_g(ptr) (TA_TYPEOF(ptr))ta_oom_p(ptr)
+
+void ta_enable_leak_report(void);
+void *ta_dbg_set_loc(void *ptr, const char *name);
+void *ta_dbg_mark_as_string(void *ptr);
+
+#endif