Added TCMalloc and JEMalloc projects

BeefRT/JEMalloc/src/sc.c

@@ -0,0 +1,306 @@
+#include "jemalloc/internal/jemalloc_preamble.h"
+
+#include "jemalloc/internal/assert.h"
+#include "jemalloc/internal/bit_util.h"
+#include "jemalloc/internal/bitmap.h"
+#include "jemalloc/internal/pages.h"
+#include "jemalloc/internal/sc.h"
+
+/*
+ * This module computes the size classes used to satisfy allocations.  The logic
+ * here was ported more or less line-by-line from a shell script, and because of
+ * that is not the most idiomatic C.  Eventually we should fix this, but for now
+ * at least the damage is compartmentalized to this file.
+ */
+
+size_t
+reg_size_compute(int lg_base, int lg_delta, int ndelta) {
+	return (ZU(1) << lg_base) + (ZU(ndelta) << lg_delta);
+}
+
+/* Returns the number of pages in the slab. */
+static int
+slab_size(int lg_page, int lg_base, int lg_delta, int ndelta) {
+	size_t page = (ZU(1) << lg_page);
+	size_t reg_size = reg_size_compute(lg_base, lg_delta, ndelta);
+
+	size_t try_slab_size = page;
+	size_t try_nregs = try_slab_size / reg_size;
+	size_t perfect_slab_size = 0;
+	bool perfect = false;
+	/*
+	 * This loop continues until we find the least common multiple of the
+	 * page size and size class size.  Size classes are all of the form
+	 * base + ndelta * delta == (ndelta + base/ndelta) * delta, which is
+	 * (ndelta + ngroup) * delta.  The way we choose slabbing strategies
+	 * means that delta is at most the page size and ndelta < ngroup.  So
+	 * the loop executes for at most 2 * ngroup - 1 iterations, which is
+	 * also the bound on the number of pages in a slab chosen by default.
+	 * With the current default settings, this is at most 7.
+	 */
+	while (!perfect) {
+		perfect_slab_size = try_slab_size;
+		size_t perfect_nregs = try_nregs;
+		try_slab_size += page;
+		try_nregs = try_slab_size / reg_size;
+		if (perfect_slab_size == perfect_nregs * reg_size) {
+			perfect = true;
+		}
+	}
+	return (int)(perfect_slab_size / page);
+}
+
+static void
+size_class(
+    /* Output. */
+    sc_t *sc,
+    /* Configuration decisions. */
+    int lg_max_lookup, int lg_page, int lg_ngroup,
+    /* Inputs specific to the size class. */
+    int index, int lg_base, int lg_delta, int ndelta) {
+	sc->index = index;
+	sc->lg_base = lg_base;
+	sc->lg_delta = lg_delta;
+	sc->ndelta = ndelta;
+	size_t size = reg_size_compute(lg_base, lg_delta, ndelta);
+	sc->psz = (size % (ZU(1) << lg_page) == 0);
+	if (index == 0) {
+		assert(!sc->psz);
+	}
+	if (size < (ZU(1) << (lg_page + lg_ngroup))) {
+		sc->bin = true;
+		sc->pgs = slab_size(lg_page, lg_base, lg_delta, ndelta);
+	} else {
+		sc->bin = false;
+		sc->pgs = 0;
+	}
+	if (size <= (ZU(1) << lg_max_lookup)) {
+		sc->lg_delta_lookup = lg_delta;
+	} else {
+		sc->lg_delta_lookup = 0;
+	}
+}
+
+static void
+size_classes(
+    /* Output. */
+    sc_data_t *sc_data,
+    /* Determined by the system. */
+    size_t lg_ptr_size, int lg_quantum,
+    /* Configuration decisions. */
+    int lg_tiny_min, int lg_max_lookup, int lg_page, int lg_ngroup) {
+	int ptr_bits = (1 << lg_ptr_size) * 8;
+	int ngroup = (1 << lg_ngroup);
+	int ntiny = 0;
+	int nlbins = 0;
+	int lg_tiny_maxclass = (unsigned)-1;
+	int nbins = 0;
+	int npsizes = 0;
+
+	int index = 0;
+
+	int ndelta = 0;
+	int lg_base = lg_tiny_min;
+	int lg_delta = lg_base;
+
+	/* Outputs that we update as we go. */
+	size_t lookup_maxclass = 0;
+	size_t small_maxclass = 0;
+	int lg_large_minclass = 0;
+	size_t large_maxclass = 0;
+
+	/* Tiny size classes. */
+	while (lg_base < lg_quantum) {
+		sc_t *sc = &sc_data->sc[index];
+		size_class(sc, lg_max_lookup, lg_page, lg_ngroup, index,
+		    lg_base, lg_delta, ndelta);
+		if (sc->lg_delta_lookup != 0) {
+			nlbins = index + 1;
+		}
+		if (sc->psz) {
+			npsizes++;
+		}
+		if (sc->bin) {
+			nbins++;
+		}
+		ntiny++;
+		/* Final written value is correct. */
+		lg_tiny_maxclass = lg_base;
+		index++;
+		lg_delta = lg_base;
+		lg_base++;
+	}
+
+	/* First non-tiny (pseudo) group. */
+	if (ntiny != 0) {
+		sc_t *sc = &sc_data->sc[index];
+		/*
+		 * See the note in sc.h; the first non-tiny size class has an
+		 * unusual encoding.
+		 */
+		lg_base--;
+		ndelta = 1;
+		size_class(sc, lg_max_lookup, lg_page, lg_ngroup, index,
+		    lg_base, lg_delta, ndelta);
+		index++;
+		lg_base++;
+		lg_delta++;
+		if (sc->psz) {
+			npsizes++;
+		}
+		if (sc->bin) {
+			nbins++;
+		}
+	}
+	while (ndelta < ngroup) {
+		sc_t *sc = &sc_data->sc[index];
+		size_class(sc, lg_max_lookup, lg_page, lg_ngroup, index,
+		    lg_base, lg_delta, ndelta);
+		index++;
+		ndelta++;
+		if (sc->psz) {
+			npsizes++;
+		}
+		if (sc->bin) {
+			nbins++;
+		}
+	}
+
+	/* All remaining groups. */
+	lg_base = lg_base + lg_ngroup;
+	while (lg_base < ptr_bits - 1) {
+		ndelta = 1;
+		int ndelta_limit;
+		if (lg_base == ptr_bits - 2) {
+			ndelta_limit = ngroup - 1;
+		} else {
+			ndelta_limit = ngroup;
+		}
+		while (ndelta <= ndelta_limit) {
+			sc_t *sc = &sc_data->sc[index];
+			size_class(sc, lg_max_lookup, lg_page, lg_ngroup, index,
+			    lg_base, lg_delta, ndelta);
+			if (sc->lg_delta_lookup != 0) {
+				nlbins = index + 1;
+				/* Final written value is correct. */
+				lookup_maxclass = (ZU(1) << lg_base)
+				    + (ZU(ndelta) << lg_delta);
+			}
+			if (sc->psz) {
+				npsizes++;
+			}
+			if (sc->bin) {
+				nbins++;
+				/* Final written value is correct. */
+				small_maxclass = (ZU(1) << lg_base)
+				    + (ZU(ndelta) << lg_delta);
+				if (lg_ngroup > 0) {
+					lg_large_minclass = lg_base + 1;
+				} else {
+					lg_large_minclass = lg_base + 2;
+				}
+			}
+			large_maxclass = (ZU(1) << lg_base)
+			    + (ZU(ndelta) << lg_delta);
+			index++;
+			ndelta++;
+		}
+		lg_base++;
+		lg_delta++;
+	}
+	/* Additional outputs. */
+	int nsizes = index;
+	unsigned lg_ceil_nsizes = lg_ceil(nsizes);
+
+	/* Fill in the output data. */
+	sc_data->ntiny = ntiny;
+	sc_data->nlbins = nlbins;
+	sc_data->nbins = nbins;
+	sc_data->nsizes = nsizes;
+	sc_data->lg_ceil_nsizes = lg_ceil_nsizes;
+	sc_data->npsizes = npsizes;
+	sc_data->lg_tiny_maxclass = lg_tiny_maxclass;
+	sc_data->lookup_maxclass = lookup_maxclass;
+	sc_data->small_maxclass = small_maxclass;
+	sc_data->lg_large_minclass = lg_large_minclass;
+	sc_data->large_minclass = (ZU(1) << lg_large_minclass);
+	sc_data->large_maxclass = large_maxclass;
+
+	/*
+	 * We compute these values in two ways:
+	 *   - Incrementally, as above.
+	 *   - In macros, in sc.h.
+	 * The computation is easier when done incrementally, but putting it in
+	 * a constant makes it available to the fast paths without having to
+	 * touch the extra global cacheline.  We assert, however, that the two
+	 * computations are equivalent.
+	 */
+	assert(sc_data->npsizes == SC_NPSIZES);
+	assert(sc_data->lg_tiny_maxclass == SC_LG_TINY_MAXCLASS);
+	assert(sc_data->small_maxclass == SC_SMALL_MAXCLASS);
+	assert(sc_data->large_minclass == SC_LARGE_MINCLASS);
+	assert(sc_data->lg_large_minclass == SC_LG_LARGE_MINCLASS);
+	assert(sc_data->large_maxclass == SC_LARGE_MAXCLASS);
+
+	/*
+	 * In the allocation fastpath, we want to assume that we can
+	 * unconditionally subtract the requested allocation size from
+	 * a ssize_t, and detect passing through 0 correctly.  This
+	 * results in optimal generated code.  For this to work, the
+	 * maximum allocation size must be less than SSIZE_MAX.
+	 */
+	assert(SC_LARGE_MAXCLASS < SSIZE_MAX);
+}
+
+void
+sc_data_init(sc_data_t *sc_data) {
+	size_classes(sc_data, LG_SIZEOF_PTR, LG_QUANTUM, SC_LG_TINY_MIN,
+	    SC_LG_MAX_LOOKUP, LG_PAGE, SC_LG_NGROUP);
+
+	sc_data->initialized = true;
+}
+
+static void
+sc_data_update_sc_slab_size(sc_t *sc, size_t reg_size, size_t pgs_guess) {
+	size_t min_pgs = reg_size / PAGE;
+	if (reg_size % PAGE != 0) {
+		min_pgs++;
+	}
+	/*
+	 * BITMAP_MAXBITS is actually determined by putting the smallest
+	 * possible size-class on one page, so this can never be 0.
+	 */
+	size_t max_pgs = BITMAP_MAXBITS * reg_size / PAGE;
+
+	assert(min_pgs <= max_pgs);
+	assert(min_pgs > 0);
+	assert(max_pgs >= 1);
+	if (pgs_guess < min_pgs) {
+		sc->pgs = (int)min_pgs;
+	} else if (pgs_guess > max_pgs) {
+		sc->pgs = (int)max_pgs;
+	} else {
+		sc->pgs = (int)pgs_guess;
+	}
+}
+
+void
+sc_data_update_slab_size(sc_data_t *data, size_t begin, size_t end, int pgs) {
+	assert(data->initialized);
+	for (int i = 0; i < data->nsizes; i++) {
+		sc_t *sc = &data->sc[i];
+		if (!sc->bin) {
+			break;
+		}
+		size_t reg_size = reg_size_compute(sc->lg_base, sc->lg_delta,
+		    sc->ndelta);
+		if (begin <= reg_size && reg_size <= end) {
+			sc_data_update_sc_slab_size(sc, reg_size, pgs);
+		}
+	}
+}
+
+void
+sc_boot(sc_data_t *data) {
+	sc_data_init(data);
+}