#include "test/jemalloc_test.h"

#include "jemalloc/internal/sec.h"

typedef struct pai_test_allocator_s pai_test_allocator_t;
struct pai_test_allocator_s {
       pai_t pai;
       bool alloc_fail;
       size_t alloc_count;
       size_t alloc_batch_count;
       size_t dalloc_count;
       size_t dalloc_batch_count;
       /*
        * We use a simple bump allocator as the implementation.  This isn't
        * *really* correct, since we may allow expansion into a subsequent
        * allocation, but it's not like the SEC is really examining the
        * pointers it gets back; this is mostly just helpful for debugging.
        */
       uintptr_t next_ptr;
       size_t expand_count;
       bool expand_return_value;
       size_t shrink_count;
       bool shrink_return_value;
};

static void
test_sec_init(sec_t *sec, pai_t *fallback, size_t nshards, size_t max_alloc,
   size_t max_bytes) {
       sec_opts_t opts;
       opts.nshards = 1;
       opts.max_alloc = max_alloc;
       opts.max_bytes = max_bytes;
       /*
        * Just choose reasonable defaults for these; most tests don't care so
        * long as they're something reasonable.
        */
       opts.bytes_after_flush = max_bytes / 2;
       opts.batch_fill_extra = 4;

       /*
        * We end up leaking this base, but that's fine; this test is
        * short-running, and SECs are arena-scoped in reality.
        */
       base_t *base = base_new(TSDN_NULL, /* ind */ 123,
           &ehooks_default_extent_hooks, /* metadata_use_hooks */ true);

       bool err = sec_init(TSDN_NULL, sec, base, fallback, &opts);
       assert_false(err, "Unexpected initialization failure");
       assert_u_ge(sec->npsizes, 0, "Zero size classes allowed for caching");
}

static inline edata_t *
pai_test_allocator_alloc(tsdn_t *tsdn, pai_t *self, size_t size,
   size_t alignment, bool zero, bool guarded, bool frequent_reuse,
   bool *deferred_work_generated) {
       assert(!guarded);
       pai_test_allocator_t *ta = (pai_test_allocator_t *)self;
       if (ta->alloc_fail) {
               return NULL;
       }
       edata_t *edata = malloc(sizeof(edata_t));
       assert_ptr_not_null(edata, "");
       ta->next_ptr += alignment - 1;
       edata_init(edata, /* arena_ind */ 0,
           (void *)(ta->next_ptr & ~(alignment - 1)), size,
           /* slab */ false,
           /* szind */ 0, /* sn */ 1, extent_state_active, /* zero */ zero,
           /* comitted */ true, /* ranged */ false, EXTENT_NOT_HEAD);
       ta->next_ptr += size;
       ta->alloc_count++;
       return edata;
}

static inline size_t
pai_test_allocator_alloc_batch(tsdn_t *tsdn, pai_t *self, size_t size,
   size_t nallocs, edata_list_active_t *results,
   bool *deferred_work_generated) {
       pai_test_allocator_t *ta = (pai_test_allocator_t *)self;
       if (ta->alloc_fail) {
               return 0;
       }
       for (size_t i = 0; i < nallocs; i++) {
               edata_t *edata = malloc(sizeof(edata_t));
               assert_ptr_not_null(edata, "");
               edata_init(edata, /* arena_ind */ 0,
                   (void *)ta->next_ptr, size,
                   /* slab */ false, /* szind */ 0, /* sn */ 1,
                   extent_state_active, /* zero */ false, /* comitted */ true,
                   /* ranged */ false, EXTENT_NOT_HEAD);
               ta->next_ptr += size;
               ta->alloc_batch_count++;
               edata_list_active_append(results, edata);
       }
       return nallocs;
}

static bool
pai_test_allocator_expand(tsdn_t *tsdn, pai_t *self, edata_t *edata,
   size_t old_size, size_t new_size, bool zero,
   bool *deferred_work_generated) {
       pai_test_allocator_t *ta = (pai_test_allocator_t *)self;
       ta->expand_count++;
       return ta->expand_return_value;
}

static bool
pai_test_allocator_shrink(tsdn_t *tsdn, pai_t *self, edata_t *edata,
   size_t old_size, size_t new_size, bool *deferred_work_generated) {
       pai_test_allocator_t *ta = (pai_test_allocator_t *)self;
       ta->shrink_count++;
       return ta->shrink_return_value;
}

static void
pai_test_allocator_dalloc(tsdn_t *tsdn, pai_t *self, edata_t *edata,
   bool *deferred_work_generated) {
       pai_test_allocator_t *ta = (pai_test_allocator_t *)self;
       ta->dalloc_count++;
       free(edata);
}

static void
pai_test_allocator_dalloc_batch(tsdn_t *tsdn, pai_t *self,
   edata_list_active_t *list, bool *deferred_work_generated) {
       pai_test_allocator_t *ta = (pai_test_allocator_t *)self;

       edata_t *edata;
       while ((edata = edata_list_active_first(list)) != NULL) {
               edata_list_active_remove(list, edata);
               ta->dalloc_batch_count++;
               free(edata);
       }
}

static inline void
pai_test_allocator_init(pai_test_allocator_t *ta) {
       ta->alloc_fail = false;
       ta->alloc_count = 0;
       ta->alloc_batch_count = 0;
       ta->dalloc_count = 0;
       ta->dalloc_batch_count = 0;
       /* Just don't start the edata at 0. */
       ta->next_ptr = 10 * PAGE;
       ta->expand_count = 0;
       ta->expand_return_value = false;
       ta->shrink_count = 0;
       ta->shrink_return_value = false;
       ta->pai.alloc = &pai_test_allocator_alloc;
       ta->pai.alloc_batch = &pai_test_allocator_alloc_batch;
       ta->pai.expand = &pai_test_allocator_expand;
       ta->pai.shrink = &pai_test_allocator_shrink;
       ta->pai.dalloc = &pai_test_allocator_dalloc;
       ta->pai.dalloc_batch = &pai_test_allocator_dalloc_batch;
}

TEST_BEGIN(test_reuse) {
       pai_test_allocator_t ta;
       pai_test_allocator_init(&ta);
       sec_t sec;
       /*
        * We can't use the "real" tsd, since we malloc within the test
        * allocator hooks; we'd get lock inversion crashes.  Eventually, we
        * should have a way to mock tsds, but for now just don't do any
        * lock-order checking.
        */
       tsdn_t *tsdn = TSDN_NULL;
       /*
        * 11 allocs apiece of 1-PAGE and 2-PAGE objects means that we should be
        * able to get to 33 pages in the cache before triggering a flush.  We
        * set the flush liimt to twice this amount, to avoid accidentally
        * triggering a flush caused by the batch-allocation down the cache fill
        * pathway disrupting ordering.
        */
       enum { NALLOCS = 11 };
       edata_t *one_page[NALLOCS];
       edata_t *two_page[NALLOCS];
       bool deferred_work_generated = false;
       test_sec_init(&sec, &ta.pai, /* nshards */ 1, /* max_alloc */ 2 * PAGE,
           /* max_bytes */ 2 * (NALLOCS * PAGE + NALLOCS * 2 * PAGE));
       for (int i = 0; i < NALLOCS; i++) {
               one_page[i] = pai_alloc(tsdn, &sec.pai, PAGE, PAGE,
                   /* zero */ false, /* guarded */ false, /* frequent_reuse */
                   false, &deferred_work_generated);
               expect_ptr_not_null(one_page[i], "Unexpected alloc failure");
               two_page[i] = pai_alloc(tsdn, &sec.pai, 2 * PAGE, PAGE,
                   /* zero */ false, /* guarded */ false, /* frequent_reuse */
                   false, &deferred_work_generated);
               expect_ptr_not_null(one_page[i], "Unexpected alloc failure");
       }
       expect_zu_eq(0, ta.alloc_count, "Should be using batch allocs");
       size_t max_allocs = ta.alloc_count + ta.alloc_batch_count;
       expect_zu_le(2 * NALLOCS, max_allocs,
           "Incorrect number of allocations");
       expect_zu_eq(0, ta.dalloc_count,
           "Incorrect number of allocations");
       /*
        * Free in a different order than we allocated, to make sure free-list
        * separation works correctly.
        */
       for (int i = NALLOCS - 1; i >= 0; i--) {
               pai_dalloc(tsdn, &sec.pai, one_page[i],
                   &deferred_work_generated);
       }
       for (int i = NALLOCS - 1; i >= 0; i--) {
               pai_dalloc(tsdn, &sec.pai, two_page[i],
                   &deferred_work_generated);
       }
       expect_zu_eq(max_allocs, ta.alloc_count + ta.alloc_batch_count,
           "Incorrect number of allocations");
       expect_zu_eq(0, ta.dalloc_count,
           "Incorrect number of allocations");
       /*
        * Check that the n'th most recent deallocated extent is returned for
        * the n'th alloc request of a given size.
        */
       for (int i = 0; i < NALLOCS; i++) {
               edata_t *alloc1 = pai_alloc(tsdn, &sec.pai, PAGE, PAGE,
                   /* zero */ false, /* guarded */ false, /* frequent_reuse */
                   false, &deferred_work_generated);
               edata_t *alloc2 = pai_alloc(tsdn, &sec.pai, 2 * PAGE, PAGE,
                   /* zero */ false, /* guarded */ false, /* frequent_reuse */
                   false, &deferred_work_generated);
               expect_ptr_eq(one_page[i], alloc1,
                   "Got unexpected allocation");
               expect_ptr_eq(two_page[i], alloc2,
                   "Got unexpected allocation");
       }
       expect_zu_eq(max_allocs, ta.alloc_count + ta.alloc_batch_count,
           "Incorrect number of allocations");
       expect_zu_eq(0, ta.dalloc_count,
           "Incorrect number of allocations");
}
TEST_END


TEST_BEGIN(test_auto_flush) {
       pai_test_allocator_t ta;
       pai_test_allocator_init(&ta);
       sec_t sec;
       /* See the note above -- we can't use the real tsd. */
       tsdn_t *tsdn = TSDN_NULL;
       /*
        * 10-allocs apiece of 1-PAGE and 2-PAGE objects means that we should be
        * able to get to 30 pages in the cache before triggering a flush.  The
        * choice of NALLOCS here is chosen to match the batch allocation
        * default (4 extra + 1 == 5; so 10 allocations leaves the cache exactly
        * empty, even in the presence of batch allocation on fill).
        * Eventually, once our allocation batching strategies become smarter,
        * this should change.
        */
       enum { NALLOCS = 10 };
       edata_t *extra_alloc;
       edata_t *allocs[NALLOCS];
       bool deferred_work_generated = false;
       test_sec_init(&sec, &ta.pai, /* nshards */ 1, /* max_alloc */ PAGE,
           /* max_bytes */ NALLOCS * PAGE);
       for (int i = 0; i < NALLOCS; i++) {
               allocs[i] = pai_alloc(tsdn, &sec.pai, PAGE, PAGE,
                   /* zero */ false, /* guarded */ false, /* frequent_reuse */
                   false, &deferred_work_generated);
               expect_ptr_not_null(allocs[i], "Unexpected alloc failure");
       }
       extra_alloc = pai_alloc(tsdn, &sec.pai, PAGE, PAGE, /* zero */ false,
           /* guarded */ false, /* frequent_reuse */ false,
           &deferred_work_generated);
       expect_ptr_not_null(extra_alloc, "Unexpected alloc failure");
       size_t max_allocs = ta.alloc_count + ta.alloc_batch_count;
       expect_zu_le(NALLOCS + 1, max_allocs,
           "Incorrect number of allocations");
       expect_zu_eq(0, ta.dalloc_count,
           "Incorrect number of allocations");
       /* Free until the SEC is full, but should not have flushed yet. */
       for (int i = 0; i < NALLOCS; i++) {
               pai_dalloc(tsdn, &sec.pai, allocs[i], &deferred_work_generated);
       }
       expect_zu_le(NALLOCS + 1, max_allocs,
           "Incorrect number of allocations");
       expect_zu_eq(0, ta.dalloc_count,
           "Incorrect number of allocations");
       /*
        * Free the extra allocation; this should trigger a flush.  The internal
        * flushing logic is allowed to get complicated; for now, we rely on our
        * whitebox knowledge of the fact that the SEC flushes bins in their
        * entirety when it decides to do so, and it has only one bin active
        * right now.
        */
       pai_dalloc(tsdn, &sec.pai, extra_alloc, &deferred_work_generated);
       expect_zu_eq(max_allocs, ta.alloc_count + ta.alloc_batch_count,
           "Incorrect number of allocations");
       expect_zu_eq(0, ta.dalloc_count,
           "Incorrect number of (non-batch) deallocations");
       expect_zu_eq(NALLOCS + 1, ta.dalloc_batch_count,
           "Incorrect number of batch deallocations");
}
TEST_END

/*
* A disable and a flush are *almost* equivalent; the only difference is what
* happens afterwards; disabling disallows all future caching as well.
*/
static void
do_disable_flush_test(bool is_disable) {
       pai_test_allocator_t ta;
       pai_test_allocator_init(&ta);
       sec_t sec;
       /* See the note above -- we can't use the real tsd. */
       tsdn_t *tsdn = TSDN_NULL;

       enum { NALLOCS = 11 };
       edata_t *allocs[NALLOCS];
       bool deferred_work_generated = false;
       test_sec_init(&sec, &ta.pai, /* nshards */ 1, /* max_alloc */ PAGE,
           /* max_bytes */ NALLOCS * PAGE);
       for (int i = 0; i < NALLOCS; i++) {
               allocs[i] = pai_alloc(tsdn, &sec.pai, PAGE, PAGE,
                   /* zero */ false, /* guarded */ false, /* frequent_reuse */
                   false, &deferred_work_generated);
               expect_ptr_not_null(allocs[i], "Unexpected alloc failure");
       }
       /* Free all but the last aloc. */
       for (int i = 0; i < NALLOCS - 1; i++) {
               pai_dalloc(tsdn, &sec.pai, allocs[i], &deferred_work_generated);
       }
       size_t max_allocs = ta.alloc_count + ta.alloc_batch_count;

       expect_zu_le(NALLOCS, max_allocs, "Incorrect number of allocations");
       expect_zu_eq(0, ta.dalloc_count,
           "Incorrect number of allocations");

       if (is_disable) {
               sec_disable(tsdn, &sec);
       } else {
               sec_flush(tsdn, &sec);
       }

       expect_zu_eq(max_allocs, ta.alloc_count + ta.alloc_batch_count,
           "Incorrect number of allocations");
       expect_zu_eq(0, ta.dalloc_count,
           "Incorrect number of (non-batch) deallocations");
       expect_zu_le(NALLOCS - 1, ta.dalloc_batch_count,
           "Incorrect number of batch deallocations");
       size_t old_dalloc_batch_count = ta.dalloc_batch_count;

       /*
        * If we free into a disabled SEC, it should forward to the fallback.
        * Otherwise, the SEC should accept the allocation.
        */
       pai_dalloc(tsdn, &sec.pai, allocs[NALLOCS - 1],
           &deferred_work_generated);

       expect_zu_eq(max_allocs, ta.alloc_count + ta.alloc_batch_count,
           "Incorrect number of allocations");
       expect_zu_eq(is_disable ? 1 : 0, ta.dalloc_count,
           "Incorrect number of (non-batch) deallocations");
       expect_zu_eq(old_dalloc_batch_count, ta.dalloc_batch_count,
           "Incorrect number of batch deallocations");
}

TEST_BEGIN(test_disable) {
       do_disable_flush_test(/* is_disable */ true);
}
TEST_END

TEST_BEGIN(test_flush) {
       do_disable_flush_test(/* is_disable */ false);
}
TEST_END

TEST_BEGIN(test_max_alloc_respected) {
       pai_test_allocator_t ta;
       pai_test_allocator_init(&ta);
       sec_t sec;
       /* See the note above -- we can't use the real tsd. */
       tsdn_t *tsdn = TSDN_NULL;

       size_t max_alloc = 2 * PAGE;
       size_t attempted_alloc = 3 * PAGE;

       bool deferred_work_generated = false;

       test_sec_init(&sec, &ta.pai, /* nshards */ 1, max_alloc,
           /* max_bytes */ 1000 * PAGE);

       for (size_t i = 0; i < 100; i++) {
               expect_zu_eq(i, ta.alloc_count,
                   "Incorrect number of allocations");
               expect_zu_eq(i, ta.dalloc_count,
                   "Incorrect number of deallocations");
               edata_t *edata = pai_alloc(tsdn, &sec.pai, attempted_alloc,
                   PAGE, /* zero */ false, /* guarded */ false,
                   /* frequent_reuse */ false, &deferred_work_generated);
               expect_ptr_not_null(edata, "Unexpected alloc failure");
               expect_zu_eq(i + 1, ta.alloc_count,
                   "Incorrect number of allocations");
               expect_zu_eq(i, ta.dalloc_count,
                   "Incorrect number of deallocations");
               pai_dalloc(tsdn, &sec.pai, edata, &deferred_work_generated);
       }
}
TEST_END

TEST_BEGIN(test_expand_shrink_delegate) {
       /*
        * Expand and shrink shouldn't affect sec state; they should just
        * delegate to the fallback PAI.
        */
       pai_test_allocator_t ta;
       pai_test_allocator_init(&ta);
       sec_t sec;
       /* See the note above -- we can't use the real tsd. */
       tsdn_t *tsdn = TSDN_NULL;

       bool deferred_work_generated = false;

       test_sec_init(&sec, &ta.pai, /* nshards */ 1, /* max_alloc */ 10 * PAGE,
           /* max_bytes */ 1000 * PAGE);
       edata_t *edata = pai_alloc(tsdn, &sec.pai, PAGE, PAGE,
           /* zero */ false, /* guarded */ false, /* frequent_reuse */ false,
           &deferred_work_generated);
       expect_ptr_not_null(edata, "Unexpected alloc failure");

       bool err = pai_expand(tsdn, &sec.pai, edata, PAGE, 4 * PAGE,
           /* zero */ false, &deferred_work_generated);
       expect_false(err, "Unexpected expand failure");
       expect_zu_eq(1, ta.expand_count, "");
       ta.expand_return_value = true;
       err = pai_expand(tsdn, &sec.pai, edata, 4 * PAGE, 3 * PAGE,
           /* zero */ false, &deferred_work_generated);
       expect_true(err, "Unexpected expand success");
       expect_zu_eq(2, ta.expand_count, "");

       err = pai_shrink(tsdn, &sec.pai, edata, 4 * PAGE, 2 * PAGE,
           &deferred_work_generated);
       expect_false(err, "Unexpected shrink failure");
       expect_zu_eq(1, ta.shrink_count, "");
       ta.shrink_return_value = true;
       err = pai_shrink(tsdn, &sec.pai, edata, 2 * PAGE, PAGE,
           &deferred_work_generated);
       expect_true(err, "Unexpected shrink success");
       expect_zu_eq(2, ta.shrink_count, "");
}
TEST_END

TEST_BEGIN(test_nshards_0) {
       pai_test_allocator_t ta;
       pai_test_allocator_init(&ta);
       sec_t sec;
       /* See the note above -- we can't use the real tsd. */
       tsdn_t *tsdn = TSDN_NULL;
       base_t *base = base_new(TSDN_NULL, /* ind */ 123,
           &ehooks_default_extent_hooks, /* metadata_use_hooks */ true);

       sec_opts_t opts = SEC_OPTS_DEFAULT;
       opts.nshards = 0;
       sec_init(TSDN_NULL, &sec, base, &ta.pai, &opts);

       bool deferred_work_generated = false;
       edata_t *edata = pai_alloc(tsdn, &sec.pai, PAGE, PAGE,
           /* zero */ false, /* guarded */ false, /* frequent_reuse */ false,
           &deferred_work_generated);
       pai_dalloc(tsdn, &sec.pai, edata, &deferred_work_generated);

       /* Both operations should have gone directly to the fallback. */
       expect_zu_eq(1, ta.alloc_count, "");
       expect_zu_eq(1, ta.dalloc_count, "");
}
TEST_END

static void
expect_stats_pages(tsdn_t *tsdn, sec_t *sec, size_t npages) {
       sec_stats_t stats;
       /*
        * Check that the stats merging accumulates rather than overwrites by
        * putting some (made up) data there to begin with.
        */
       stats.bytes = 123;
       sec_stats_merge(tsdn, sec, &stats);
       assert_zu_le(npages * PAGE + 123, stats.bytes, "");
}

TEST_BEGIN(test_stats_simple) {
       pai_test_allocator_t ta;
       pai_test_allocator_init(&ta);
       sec_t sec;

       /* See the note above -- we can't use the real tsd. */
       tsdn_t *tsdn = TSDN_NULL;

       enum {
               NITERS = 100,
               FLUSH_PAGES = 20,
       };

       bool deferred_work_generated = false;

       test_sec_init(&sec, &ta.pai, /* nshards */ 1, /* max_alloc */ PAGE,
           /* max_bytes */ FLUSH_PAGES * PAGE);

       edata_t *allocs[FLUSH_PAGES];
       for (size_t i = 0; i < FLUSH_PAGES; i++) {
               allocs[i] = pai_alloc(tsdn, &sec.pai, PAGE, PAGE,
                   /* zero */ false, /* guarded */ false, /* frequent_reuse */
                   false, &deferred_work_generated);
               expect_stats_pages(tsdn, &sec, 0);
       }

       /* Increase and decrease, without flushing. */
       for (size_t i = 0; i < NITERS; i++) {
               for (size_t j = 0; j < FLUSH_PAGES / 2; j++) {
                       pai_dalloc(tsdn, &sec.pai, allocs[j],
                           &deferred_work_generated);
                       expect_stats_pages(tsdn, &sec, j + 1);
               }
               for (size_t j = 0; j < FLUSH_PAGES / 2; j++) {
                       allocs[j] = pai_alloc(tsdn, &sec.pai, PAGE, PAGE,
                           /* zero */ false, /* guarded */ false,
                           /* frequent_reuse */ false,
                           &deferred_work_generated);
                       expect_stats_pages(tsdn, &sec, FLUSH_PAGES / 2 - j - 1);
               }
       }
}
TEST_END

TEST_BEGIN(test_stats_auto_flush) {
       pai_test_allocator_t ta;
       pai_test_allocator_init(&ta);
       sec_t sec;

       /* See the note above -- we can't use the real tsd. */
       tsdn_t *tsdn = TSDN_NULL;

       enum {
               FLUSH_PAGES = 10,
       };

       test_sec_init(&sec, &ta.pai, /* nshards */ 1, /* max_alloc */ PAGE,
           /* max_bytes */ FLUSH_PAGES * PAGE);

       edata_t *extra_alloc0;
       edata_t *extra_alloc1;
       edata_t *allocs[2 * FLUSH_PAGES];

       bool deferred_work_generated = false;

       extra_alloc0 = pai_alloc(tsdn, &sec.pai, PAGE, PAGE, /* zero */ false,
           /* guarded */ false, /* frequent_reuse */ false,
           &deferred_work_generated);
       extra_alloc1 = pai_alloc(tsdn, &sec.pai, PAGE, PAGE, /* zero */ false,
           /* guarded */ false, /* frequent_reuse */ false,
           &deferred_work_generated);

       for (size_t i = 0; i < 2 * FLUSH_PAGES; i++) {
               allocs[i] = pai_alloc(tsdn, &sec.pai, PAGE, PAGE,
                   /* zero */ false, /* guarded */ false, /* frequent_reuse */
                   false, &deferred_work_generated);
       }

       for (size_t i = 0; i < FLUSH_PAGES; i++) {
               pai_dalloc(tsdn, &sec.pai, allocs[i], &deferred_work_generated);
       }
       pai_dalloc(tsdn, &sec.pai, extra_alloc0, &deferred_work_generated);

       /* Flush the remaining pages; stats should still work. */
       for (size_t i = 0; i < FLUSH_PAGES; i++) {
               pai_dalloc(tsdn, &sec.pai, allocs[FLUSH_PAGES + i],
                   &deferred_work_generated);
       }

       pai_dalloc(tsdn, &sec.pai, extra_alloc1, &deferred_work_generated);

       expect_stats_pages(tsdn, &sec, ta.alloc_count + ta.alloc_batch_count
           - ta.dalloc_count - ta.dalloc_batch_count);
}
TEST_END

TEST_BEGIN(test_stats_manual_flush) {
       pai_test_allocator_t ta;
       pai_test_allocator_init(&ta);
       sec_t sec;

       /* See the note above -- we can't use the real tsd. */
       tsdn_t *tsdn = TSDN_NULL;

       enum {
               FLUSH_PAGES = 10,
       };

       test_sec_init(&sec, &ta.pai, /* nshards */ 1, /* max_alloc */ PAGE,
           /* max_bytes */ FLUSH_PAGES * PAGE);

       bool deferred_work_generated = false;
       edata_t *allocs[FLUSH_PAGES];
       for (size_t i = 0; i < FLUSH_PAGES; i++) {
               allocs[i] = pai_alloc(tsdn, &sec.pai, PAGE, PAGE,
                   /* zero */ false, /* guarded */ false, /* frequent_reuse */
                   false, &deferred_work_generated);
               expect_stats_pages(tsdn, &sec, 0);
       }

       /* Dalloc the first half of the allocations. */
       for (size_t i = 0; i < FLUSH_PAGES / 2; i++) {
               pai_dalloc(tsdn, &sec.pai, allocs[i], &deferred_work_generated);
               expect_stats_pages(tsdn, &sec, i + 1);
       }

       sec_flush(tsdn, &sec);
       expect_stats_pages(tsdn, &sec, 0);

       /* Flush the remaining pages. */
       for (size_t i = 0; i < FLUSH_PAGES / 2; i++) {
               pai_dalloc(tsdn, &sec.pai, allocs[FLUSH_PAGES / 2 + i],
                   &deferred_work_generated);
               expect_stats_pages(tsdn, &sec, i + 1);
       }
       sec_disable(tsdn, &sec);
       expect_stats_pages(tsdn, &sec, 0);
}
TEST_END

int
main(void) {
       return test(
           test_reuse,
           test_auto_flush,
           test_disable,
           test_flush,
           test_max_alloc_respected,
           test_expand_shrink_delegate,
           test_nshards_0,
           test_stats_simple,
           test_stats_auto_flush,
           test_stats_manual_flush);
}