rts: Introduce stgMallocAlignedBytes

(cherry picked from commit 04336d2f11e49f7d00392f05d4fd48abdd231fc0)
(cherry picked from commit 48ecd4b4dca42cf482847d7629c91d2b44eae252)

2 files changed, 53 insertions, 2 deletions

diff --git a/rts/RtsUtils.c b/rts/RtsUtils.c
index ca01bdb6e0..d72a6a4be4 100644
--- a/rts/RtsUtils.c
+++ b/rts/RtsUtils.c
@@ -59,9 +59,9 @@ extern char *ctime_r(const time_t *, char *);
 void *
 stgMallocBytes (size_t n, char *msg)
 {
-    void *space;
+    void *space = malloc(n);
 
-    if ((space = malloc(n)) == NULL) {
+    if (space == NULL) {
       /* Quoting POSIX.1-2008 (which says more or less the same as ISO C99):
        *
        *   "Upon successful completion with size not equal to 0, malloc() shall
@@ -130,6 +130,53 @@ stgFree(void* p)
   free(p);
 }
 
+// N.B. Allocations resulting from this function must be freed by
+// `stgFreeAligned`, not `stgFree`. This is necessary due to the properties of Windows' `_aligned_malloc`
+void *
+stgMallocAlignedBytes (size_t n, size_t align, char *msg)
+{
+    void *space;
+
+#if defined(mingw32_HOST_OS)
+    space = _aligned_malloc(n, align);
+#else
+    if (posix_memalign(&space, align, n)) {
+        space = NULL; // Allocation failed
+    }
+#endif
+
+    if (space == NULL) {
+      /* Quoting POSIX.1-2008 (which says more or less the same as ISO C99):
+       *
+       *   "Upon successful completion with size not equal to 0, malloc() shall
+       *   return a pointer to the allocated space. If size is 0, either a null
+       *   pointer or a unique pointer that can be successfully passed to free()
+       *   shall be returned. Otherwise, it shall return a null pointer and set
+       *   errno to indicate the error."
+       *
+       * Consequently, a NULL pointer being returned by `malloc()` for a 0-size
+       * allocation is *not* to be considered an error.
+       */
+      if (n == 0) return NULL;
+
+      /* don't fflush(stdout); WORKAROUND bug in Linux glibc */
+      rtsConfig.mallocFailHook((W_) n, msg);
+      stg_exit(EXIT_INTERNAL_ERROR);
+    }
+    IF_DEBUG(zero_on_gc, memset(space, 0xbb, n));
+    return space;
+}
+
+void
+stgFreeAligned (void *p)
+{
+#if defined(mingw32_HOST_OS)
+    _aligned_free(p);
+#else
+    free(p);
+#endif
+}
+
 /* -----------------------------------------------------------------------------
    Stack/heap overflow
    -------------------------------------------------------------------------- */
diff --git a/rts/RtsUtils.h b/rts/RtsUtils.h
index c87aedb3a7..41120b0417 100644
--- a/rts/RtsUtils.h
+++ b/rts/RtsUtils.h
@@ -29,6 +29,10 @@ char *stgStrndup(const char *s, size_t n);
 
 void stgFree(void* p);
 
+void *stgMallocAlignedBytes(size_t n, size_t align, char *msg);
+
+void stgFreeAligned(void *p);
+
 /* -----------------------------------------------------------------------------
  * Misc other utilities
  * -------------------------------------------------------------------------- */