add custom allocation tracking hooks

CMakeLists.txt

@@ -23,8 +23,8 @@ set_property(CACHE MI_OPT_ARCH PROPERTY STRINGS "OFF" "ON" "avx2" "armv8.1" "arm
 set(MI_DEBUG "DEFAULT" CACHE STRING "Enable assertion checks: OFF, ON, INTERNAL, FULL, DEFAULT. INTERNAL adds extra internal invariant checks, while FULL adds expensive heap invariant checks")
 set_property(CACHE MI_DEBUG PROPERTY STRINGS "OFF" "ON" "INTERNAL" "FULL" "DEFAULT")
 
-set(MI_TRACK "OFF" CACHE STRING "Enable tracking: OFF, ASAN (address sanitizer), VALGRIND, ETW (Windows event tracing). Adds a small overhead.")
-set_property(CACHE MI_TRACK PROPERTY STRINGS "OFF" "ASAN" "VALGRIND" "ETW")
+set(MI_TRACK "OFF" CACHE STRING "Enable tracking: OFF, ASAN (address sanitizer), VALGRIND, ETW (Windows event tracing), CUSTOM (application-defined hooks). Adds a small overhead.")
+set_property(CACHE MI_TRACK PROPERTY STRINGS "OFF" "ASAN" "VALGRIND" "ETW" "CUSTOM")
 
 set(MI_STATS "DEFAULT" CACHE STRING "Enable statistics.")
 set_property(CACHE MI_STATS PROPERTY STRINGS "OFF" "ON" "FULL" "DEFAULT")
@@ -385,6 +385,9 @@ elseif(MI_TRACK STREQUAL "ETW")
     message(STATUS "Compile with Windows event tracing support (MI_TRACK=ETW)")
     list(APPEND mi_defines MI_TRACK_ETW=1)
   endif()
+elseif(MI_TRACK STREQUAL "CUSTOM")
+  message(STATUS "Compile with custom allocation hooks (MI_TRACK=CUSTOM)")
+  list(APPEND mi_defines MI_TRACK_CUSTOM=1)
 elseif(MI_TRACK)
   message(STATUS "Invalid option value: MI_TRACK=${MI_TRACK} (ignored)")
 endif()

include/mimalloc.h

@@ -137,6 +137,11 @@ mi_decl_nodiscard mi_decl_export size_t mi_good_size(size_t size)     mi_attr_no
 // `mi_free_size` can be more efficient (as it calls mi_free_small internally).
 mi_decl_export void mi_free_size(void* p, size_t size) mi_attr_noexcept;
 
+#if defined(MI_TRACK_CUSTOM)
+void mi_track_malloc_hook(const void* p, size_t reqsize, size_t size, bool zero) mi_attr_noexcept;
+void mi_track_free_hook(const void* p, size_t size) mi_attr_noexcept;
+#endif
+
 // `mi_free_small` is for special applications like language runtimes.
 // it should only be used to free objects from `mi_*alloc_small` and is potentially a tiny bit faster than `mi_free`
 mi_decl_export void mi_free_small(void* p) mi_attr_noexcept;  

include/mimalloc/track.h

@@ -89,6 +89,16 @@ defined, undefined, or not accessible at all:
 #define mi_track_malloc_size(p,reqsize,size,zero) EventWriteETW_MI_ALLOC((UINT64)(p), size)
 #define mi_track_free_size(p,size)                EventWriteETW_MI_FREE((UINT64)(p), size)
 
+#elif defined(MI_TRACK_CUSTOM)
+// application-defined hooks
+
+#define MI_TRACK_ENABLED      0
+#define MI_TRACK_HEAP_DESTROY 0
+#define MI_TRACK_TOOL         "custom"
+
+#define mi_track_malloc_size(p,reqsize,size,zero) mi_track_malloc_hook((p),(reqsize),(size),(zero))
+#define mi_track_free_size(p,size)                mi_track_free_hook((p),(size))
+
 #else
 // no tracking
 

include/mimalloc/types.h

@@ -54,6 +54,7 @@ terms of the MIT license. A copy of the license can be found in the file
 // #define MI_TRACK_VALGRIND 1
 // #define MI_TRACK_ASAN     1
 // #define MI_TRACK_ETW      1
+// #define MI_TRACK_CUSTOM   1
 
 // Define MI_STATS as 1 to maintain statistics; set it to 2 to have detailed statistics (but costs some performance).
 // #define MI_STATS 1