1 files changed, 277 insertions, 0 deletions

diff --git a/examples/redis-unstable/deps/jemalloc/src/extent_dss.c b/examples/redis-unstable/deps/jemalloc/src/extent_dss.c
new file mode 100644
index 0000000..9a35bac
--- /dev/null
+++ b/examples/redis-unstable/deps/jemalloc/src/extent_dss.c
@@ -0,0 +1,277 @@
+#include "jemalloc/internal/jemalloc_preamble.h"
+#include "jemalloc/internal/jemalloc_internal_includes.h"
+
+#include "jemalloc/internal/assert.h"
+#include "jemalloc/internal/extent_dss.h"
+#include "jemalloc/internal/spin.h"
+
+/******************************************************************************/
+/* Data. */
+
+const char      *opt_dss = DSS_DEFAULT;
+
+const char      *dss_prec_names[] = {
+        "disabled",
+        "primary",
+        "secondary",
+        "N/A"
+};
+
+/*
+ * Current dss precedence default, used when creating new arenas.  NB: This is
+ * stored as unsigned rather than dss_prec_t because in principle there's no
+ * guarantee that sizeof(dss_prec_t) is the same as sizeof(unsigned), and we use
+ * atomic operations to synchronize the setting.
+ */
+static atomic_u_t       dss_prec_default = ATOMIC_INIT(
+    (unsigned)DSS_PREC_DEFAULT);
+
+/* Base address of the DSS. */
+static void             *dss_base;
+/* Atomic boolean indicating whether a thread is currently extending DSS. */
+static atomic_b_t       dss_extending;
+/* Atomic boolean indicating whether the DSS is exhausted. */
+static atomic_b_t       dss_exhausted;
+/* Atomic current upper limit on DSS addresses. */
+static atomic_p_t       dss_max;
+
+/******************************************************************************/
+
+static void *
+extent_dss_sbrk(intptr_t increment) {
+#ifdef JEMALLOC_DSS
+        return sbrk(increment);
+#else
+        not_implemented();
+        return NULL;
+#endif
+}
+
+dss_prec_t
+extent_dss_prec_get(void) {
+        dss_prec_t ret;
+
+        if (!have_dss) {
+                return dss_prec_disabled;
+        }
+        ret = (dss_prec_t)atomic_load_u(&dss_prec_default, ATOMIC_ACQUIRE);
+        return ret;
+}
+
+bool
+extent_dss_prec_set(dss_prec_t dss_prec) {
+        if (!have_dss) {
+                return (dss_prec != dss_prec_disabled);
+        }
+        atomic_store_u(&dss_prec_default, (unsigned)dss_prec, ATOMIC_RELEASE);
+        return false;
+}
+
+static void
+extent_dss_extending_start(void) {
+        spin_t spinner = SPIN_INITIALIZER;
+        while (true) {
+                bool expected = false;
+                if (atomic_compare_exchange_weak_b(&dss_extending, &expected,
+                    true, ATOMIC_ACQ_REL, ATOMIC_RELAXED)) {
+                        break;
+                }
+                spin_adaptive(&spinner);
+        }
+}
+
+static void
+extent_dss_extending_finish(void) {
+        assert(atomic_load_b(&dss_extending, ATOMIC_RELAXED));
+
+        atomic_store_b(&dss_extending, false, ATOMIC_RELEASE);
+}
+
+static void *
+extent_dss_max_update(void *new_addr) {
+        /*
+         * Get the current end of the DSS as max_cur and assure that dss_max is
+         * up to date.
+         */
+        void *max_cur = extent_dss_sbrk(0);
+        if (max_cur == (void *)-1) {
+                return NULL;
+        }
+        atomic_store_p(&dss_max, max_cur, ATOMIC_RELEASE);
+        /* Fixed new_addr can only be supported if it is at the edge of DSS. */
+        if (new_addr != NULL && max_cur != new_addr) {
+                return NULL;
+        }
+        return max_cur;
+}
+
+void *
+extent_alloc_dss(tsdn_t *tsdn, arena_t *arena, void *new_addr, size_t size,
+    size_t alignment, bool *zero, bool *commit) {
+        edata_t *gap;
+
+        cassert(have_dss);
+        assert(size > 0);
+        assert(alignment == ALIGNMENT_CEILING(alignment, PAGE));
+
+        /*
+         * sbrk() uses a signed increment argument, so take care not to
+         * interpret a large allocation request as a negative increment.
+         */
+        if ((intptr_t)size < 0) {
+                return NULL;
+        }
+
+        gap = edata_cache_get(tsdn, &arena->pa_shard.edata_cache);
+        if (gap == NULL) {
+                return NULL;
+        }
+
+        extent_dss_extending_start();
+        if (!atomic_load_b(&dss_exhausted, ATOMIC_ACQUIRE)) {
+                /*
+                 * The loop is necessary to recover from races with other
+                 * threads that are using the DSS for something other than
+                 * malloc.
+                 */
+                while (true) {
+                        void *max_cur = extent_dss_max_update(new_addr);
+                        if (max_cur == NULL) {
+                                goto label_oom;
+                        }
+
+                        bool head_state = opt_retain ? EXTENT_IS_HEAD :
+                            EXTENT_NOT_HEAD;
+                        /*
+                         * Compute how much page-aligned gap space (if any) is
+                         * necessary to satisfy alignment.  This space can be
+                         * recycled for later use.
+                         */
+                        void *gap_addr_page = (void *)(PAGE_CEILING(
+                            (uintptr_t)max_cur));
+                        void *ret = (void *)ALIGNMENT_CEILING(
+                            (uintptr_t)gap_addr_page, alignment);
+                        size_t gap_size_page = (uintptr_t)ret -
+                            (uintptr_t)gap_addr_page;
+                        if (gap_size_page != 0) {
+                                edata_init(gap, arena_ind_get(arena),
+                                    gap_addr_page, gap_size_page, false,
+                                    SC_NSIZES, extent_sn_next(
+                                        &arena->pa_shard.pac),
+                                    extent_state_active, false, true,
+                                    EXTENT_PAI_PAC, head_state);
+                        }
+                        /*
+                         * Compute the address just past the end of the desired
+                         * allocation space.
+                         */
+                        void *dss_next = (void *)((uintptr_t)ret + size);
+                        if ((uintptr_t)ret < (uintptr_t)max_cur ||
+                            (uintptr_t)dss_next < (uintptr_t)max_cur) {
+                                goto label_oom; /* Wrap-around. */
+                        }
+                        /* Compute the increment, including subpage bytes. */
+                        void *gap_addr_subpage = max_cur;
+                        size_t gap_size_subpage = (uintptr_t)ret -
+                            (uintptr_t)gap_addr_subpage;
+                        intptr_t incr = gap_size_subpage + size;
+
+                        assert((uintptr_t)max_cur + incr == (uintptr_t)ret +
+                            size);
+
+                        /* Try to allocate. */
+                        void *dss_prev = extent_dss_sbrk(incr);
+                        if (dss_prev == max_cur) {
+                                /* Success. */
+                                atomic_store_p(&dss_max, dss_next,
+                                    ATOMIC_RELEASE);
+                                extent_dss_extending_finish();
+
+                                if (gap_size_page != 0) {
+                                        ehooks_t *ehooks = arena_get_ehooks(
+                                            arena);
+                                        extent_dalloc_gap(tsdn,
+                                            &arena->pa_shard.pac, ehooks, gap);
+                                } else {
+                                        edata_cache_put(tsdn,
+                                            &arena->pa_shard.edata_cache, gap);
+                                }
+                                if (!*commit) {
+                                        *commit = pages_decommit(ret, size);
+                                }
+                                if (*zero && *commit) {
+                                        edata_t edata = {0};
+                                        ehooks_t *ehooks = arena_get_ehooks(
+                                            arena);
+
+                                        edata_init(&edata,
+                                            arena_ind_get(arena), ret, size,
+                                            size, false, SC_NSIZES,
+                                            extent_state_active, false, true,
+                                            EXTENT_PAI_PAC, head_state);
+                                        if (extent_purge_forced_wrapper(tsdn,
+                                            ehooks, &edata, 0, size)) {
+                                                memset(ret, 0, size);
+                                        }
+                                }
+                                return ret;
+                        }
+                        /*
+                         * Failure, whether due to OOM or a race with a raw
+                         * sbrk() call from outside the allocator.
+                         */
+                        if (dss_prev == (void *)-1) {
+                                /* OOM. */
+                                atomic_store_b(&dss_exhausted, true,
+                                    ATOMIC_RELEASE);
+                                goto label_oom;
+                        }
+                }
+        }
+label_oom:
+        extent_dss_extending_finish();
+        edata_cache_put(tsdn, &arena->pa_shard.edata_cache, gap);
+        return NULL;
+}
+
+static bool
+extent_in_dss_helper(void *addr, void *max) {
+        return ((uintptr_t)addr >= (uintptr_t)dss_base && (uintptr_t)addr <
+            (uintptr_t)max);
+}
+
+bool
+extent_in_dss(void *addr) {
+        cassert(have_dss);
+
+        return extent_in_dss_helper(addr, atomic_load_p(&dss_max,
+            ATOMIC_ACQUIRE));
+}
+
+bool
+extent_dss_mergeable(void *addr_a, void *addr_b) {
+        void *max;
+
+        cassert(have_dss);
+
+        if ((uintptr_t)addr_a < (uintptr_t)dss_base && (uintptr_t)addr_b <
+            (uintptr_t)dss_base) {
+                return true;
+        }
+
+        max = atomic_load_p(&dss_max, ATOMIC_ACQUIRE);
+        return (extent_in_dss_helper(addr_a, max) ==
+            extent_in_dss_helper(addr_b, max));
+}
+
+void
+extent_dss_boot(void) {
+        cassert(have_dss);
+
+        dss_base = extent_dss_sbrk(0);
+        atomic_store_b(&dss_extending, false, ATOMIC_RELAXED);
+        atomic_store_b(&dss_exhausted, dss_base == (void *)-1, ATOMIC_RELAXED);
+        atomic_store_p(&dss_max, dss_base, ATOMIC_RELAXED);
+}
+
+/******************************************************************************/