prepare for release, bump version to v3.3.0

Author: daanx

.github/workflows/release.yaml

@@ -19,7 +19,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        branch: [dev,dev2,dev3]
+        branch: [v1.9.8,v2.3.0,v3.3.0]  # [dev,dev2,dev3]
         # we build on the oldest ubuntu version for better binary compatibility.
         os: [windows-latest, macOS-latest, macos-15-intel, ubuntu-22.04, ubuntu-22.04-arm]  
 

cmake/mimalloc-config-version.cmake

@@ -1,6 +1,6 @@
 set(mi_version_major 3)
-set(mi_version_minor 2)
-set(mi_version_patch 8)
+set(mi_version_minor 3)
+set(mi_version_patch 0)
 set(mi_version ${mi_version_major}.${mi_version_minor})
 
 set(PACKAGE_VERSION ${mi_version})

contrib/vcpkg/portfile.cmake

@@ -3,7 +3,7 @@ vcpkg_from_github(
   REPO microsoft/mimalloc
   HEAD_REF master
 
-  # The "REF" can be a commit hash, branch name (dev3), or a version (v3.2.7).
+  # The "REF" can be a commit hash, branch name (dev3), or a version (v3.3.0).
   REF "v${VERSION}"
 
   # The sha512 is the hash of the tar.gz bundle.

contrib/vcpkg/vcpkg.json

@@ -1,6 +1,6 @@
 {
   "name": "mimalloc",
-  "version": "3.2.8",
+  "version": "3.3.0",
   "port-version": 0,
   "description": "Compact general purpose allocator with excellent performance",
   "homepage": "https://github.com/microsoft/mimalloc",

doc/release-notes.md

@@ -10,6 +10,6 @@ Notes:
 - Generally it is recommended to download sources (or use `vcpkg` etc.) and build mimalloc as 
   part of your project.
 - Source releases can also be downloaded directly from github by the tag.  
-  For example <https://github.com/microsoft/mimalloc/archive/v3.2.8.tar.gz>.  
+  For example <https://github.com/microsoft/mimalloc/archive/v3.3.0.tar.gz>.  
 - Binary releases include a release-, debug-, and secure build.
 - Linux binaries are built on Ubuntu 22.

include/mimalloc.h

@@ -8,7 +8,7 @@ terms of the MIT license. A copy of the license can be found in the file
 #ifndef MIMALLOC_H
 #define MIMALLOC_H
 
-#define MI_MALLOC_VERSION 3208   // major + minor + 2 digits patch
+#define MI_MALLOC_VERSION 30300   // major + 2 digits minor + 2 digits patch
 
 // ------------------------------------------------------
 // Compiler specific attributes

readme.md

@@ -15,9 +15,9 @@ is a general purpose allocator with excellent [performance](#performance) charac
 Initially developed by Daan Leijen for the runtime systems of the
 [Koka](https://koka-lang.github.io) and [Lean](https://github.com/leanprover/lean) languages.
 
-Latest release   : `v3.2.8` (2026-02-03) release candidate 3, please report any issues.  
-Latest v2 release: `v2.2.7` (2026-01-15).  
-Latest v1 release: `v1.9.7` (2026-01-15).
+Latest release   : `v3.3.0` (2026-04-15) recommended.  
+Latest v2 release: `v2.3.0` (2026-04-15) stable.  
+Latest v1 release: `v1.9.8` (2026-04-15) legacy.
 
 mimalloc is a drop-in replacement for `malloc` and can be used in other programs
 without code changes, for example, on dynamically linked ELF-based systems (Linux, BSD, etc.) you can use it as:
@@ -79,16 +79,23 @@ Enjoy!
 There are three maintained versions of mimalloc. These are mostly equal except for how the OS memory is handled. 
 New development is mostly on v3, while v1 and v2 are maintained with security and bug fixes. 
 
-- __v1__: initial design of mimalloc (release tags: `v1.9.x`, development branch `dev`). Send PR's against this version if possible.
-- __v2__: main mimalloc version. Uses thread-local segments to reduce fragmentation. (release tags: `v2.2.x`, development branch `dev2` and `main`)
-- __v3__: simplifies the lock-free design of previous versions and improves sharing of 
+- __v3__: recommended: simplifies the lock-free design of previous versions and improves sharing of 
         memory between threads. On certain large workloads this version may use 
         (much) less memory. Also supports true first-class heaps (that can allocate from any thread) 
         and has more efficient heap-walking (for the CPython GC for example).
-        (release tags: `v3.2.x`, development branch `dev3`).
+        (release tags: `v3.x`, development branch `dev3`).
+- __v2__: stable mimalloc version. Uses thread-local segments to reduce fragmentation. (release tags: `v2.x`, development branch `dev2` and `main`)
+- __v1__: legacy version: initial design of mimalloc (release tags: `v1.9.x`, development branch `dev`). Send PR's against this version if possible.
 
 ### Releases
-
+* 2026-04-15, `v1.9.8`, `v2.3.0`, `v3.3.0`: fix visiting of full pages during collection (performance),
+  fix THP alignment (performance), fix arm64 cross-compilation on Windows, enable guard pages in debug mode,
+  always use uncommitted areas between arenas (security), enable static overloading of `malloc` etc. on Windows with the 
+  static CRT (by @Noxybot), fix TLS slot leak on Windows (v3), enable clean DLL load/unload with statically linked
+  mimalloc (v3), fix race in `mi_heap_destroy` (v3), by default put page meta info separate from allocated 
+  objects (v3,security), fix C++ overrides for emscripten. Various bugs found by DeepTest include: 
+  fix offset for `mi_heap_realloc_aligned`, fix `mi_(w)dupenv_s` buffer size, fix potential overflow in size options,
+  and error codes for `mi_reallocarr(ay)`. 
 * 2026-02-03, `v3.2.8` (rc3): Fix thread reinitialize issue on macOS. Fix SIMD codegen bug on older
   GCC versions. Extend Windows TLS slot limit from 64 to 1088. Report commit statistics more precise.
   Fixes issue in free-page search in arenas.
@@ -356,7 +363,7 @@ Further options for large workloads and services:
 
 - `MIMALLOC_ALLOW_THP=1`: By default always allow transparent huge pages (THP) on Linux systems. On Android only this is
    by default off. When set to `0`, THP is disabled for the process that mimalloc runs in. If enabled, mimalloc also sets
-   the `MIMALLOC_MINIMAL_PURGE_SIZE` in v3 to 2MiB to avoid potentially breaking up transparent huge pages.
+   the `MIMALLOC_MINIMAL_PURGE_SIZE` in v3 to 2MiB to avoid potentially breaking up transparent huge pages when purging memory.
 - `MIMALLOC_USE_NUMA_NODES=N`: pretend there are at most `N` NUMA nodes. If not set, the actual NUMA nodes are detected
    at runtime. Setting `N` to 1 may avoid problems in some virtual environments. Also, setting it to a lower number than
    the actual NUMA nodes is fine and will only cause threads to potentially allocate more memory across actual NUMA
@@ -416,13 +423,14 @@ various checks are done at runtime to catch development errors.
 ## Guarded Mode
 
 <span id="guarded">_mimalloc_ can be build in guarded mode using the `-DMI_GUARDED=ON` flags in `cmake`.</span>
-This enables placing OS guard pages behind certain object allocations to catch buffer overflows as they occur.
+This is `ON` by default when building a debug version of mimalloc.
+Guarded mode enables placing OS guard pages behind certain object allocations to catch buffer overflows as they occur.
 This can be invaluable to catch buffer-overflow bugs in large programs. However, it also means that any object
 allocated with a guard page takes at least 8 KiB memory for the guard page and its alignment. As such, allocating
 a guard page for every allocation may be too expensive both in terms of memory, and in terms of performance with
 many system calls. Therefore, there are various environment variables (and options) to tune this:
 
-- `MIMALLOC_GUARDED_SAMPLE_RATE=N`: Set the sample rate to `N` (by default 4000). This mode places a guard page
+- `MIMALLOC_GUARDED_SAMPLE_RATE=N`: Set the sample rate to `N` (by default 0). This mode places a guard page
   behind every `N` suitable object allocations (per thread). Since the performance in guarded mode without placing
   guard pages is close to release mode, this can be used to enable guard pages even in production to catch latent 
   buffer overflow bugs. Set the sample rate to `1` to guard every object, and to `0` to place no guard pages at all.
@@ -541,6 +549,9 @@ This is provided by [`mimalloc-override.h`](include/mimalloc-override.h). This o
 reliably though if all sources are
 under your control or otherwise mixing of pointers from different heaps may occur!
 
+Note: recently we also enabled static overloading on Windows. In that case you need
+to link with the static CRT _release_ runtime (`/MT`) and link with the static 
+`mimalloc(-debug).obj` (to take precendence over the definitions in the CRT library).
 
 # Tools
 

src/options.c

@@ -217,8 +217,8 @@ void _mi_options_post_init(void) {
 mi_decl_export void mi_options_print_out(mi_output_fun* out, void* arg) mi_attr_noexcept
 {
   // show version
-  const int vermajor = MI_MALLOC_VERSION/1000;
-  const int verminor = (MI_MALLOC_VERSION%1000)/100;
+  const int vermajor = MI_MALLOC_VERSION/10000;
+  const int verminor = (MI_MALLOC_VERSION%10000)/100;
   const int verpatch = (MI_MALLOC_VERSION%100);
   _mi_fprintf(out, arg, "v%i.%i.%i%s%s (built on %s, %s)\n", vermajor, verminor, verpatch,
       #if defined(MI_CMAKE_BUILD_TYPE)