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-rwxr-xr-xvendor/gopkg.in/olebedev/go-duktape.v3/duk_alloc_pool.c612
1 files changed, 612 insertions, 0 deletions
diff --git a/vendor/gopkg.in/olebedev/go-duktape.v3/duk_alloc_pool.c b/vendor/gopkg.in/olebedev/go-duktape.v3/duk_alloc_pool.c
new file mode 100755
index 000000000..750fa71df
--- /dev/null
+++ b/vendor/gopkg.in/olebedev/go-duktape.v3/duk_alloc_pool.c
@@ -0,0 +1,612 @@
+/*
+ * Pool allocator for low memory targets.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+#include <stdarg.h>
+#include "duktape.h"
+#include "duk_alloc_pool.h"
+
+/* Define to enable some debug printfs. */
+/* #define DUK_ALLOC_POOL_DEBUG */
+
+/* Define to enable approximate waste tracking. */
+/* #define DUK_ALLOC_POOL_TRACK_WASTE */
+
+/* Define to track global highwater for used and waste bytes. VERY SLOW, only
+ * useful for manual testing.
+ */
+/* #define DUK_ALLOC_POOL_TRACK_HIGHWATER */
+
+#if defined(DUK_ALLOC_POOL_ROMPTR_COMPRESSION)
+#if 0 /* This extern declaration is provided by duktape.h, array provided by duktape.c. */
+extern const void * const duk_rom_compressed_pointers[];
+#endif
+const void *duk_alloc_pool_romptr_low = NULL;
+const void *duk_alloc_pool_romptr_high = NULL;
+static void duk__alloc_pool_romptr_init(void);
+#endif
+
+#if defined(DUK_USE_HEAPPTR16)
+void *duk_alloc_pool_ptrcomp_base = NULL;
+#endif
+
+#if defined(DUK_ALLOC_POOL_DEBUG)
+static void duk__alloc_pool_dprintf(const char *fmt, ...) {
+ va_list ap;
+ va_start(ap, fmt);
+ vfprintf(stderr, fmt, ap);
+ va_end(ap);
+}
+#endif
+
+/*
+ * Pool initialization
+ */
+
+void *duk_alloc_pool_init(char *buffer,
+ size_t size,
+ const duk_pool_config *configs,
+ duk_pool_state *states,
+ int num_pools,
+ duk_pool_global *global) {
+ double t_min, t_max, t_curr, x;
+ int step, i, j, n;
+ size_t total;
+ char *p;
+
+ /* XXX: check that 'size' is not too large when using pointer
+ * compression.
+ */
+
+ /* To optimize pool counts first come up with a 't' which still allows
+ * total pool size to fit within user provided region. After that
+ * sprinkle any remaining bytes to the counts. Binary search with a
+ * fixed step count; last round uses 't_min' as 't_curr' to ensure it
+ * succeeds.
+ */
+
+ t_min = 0.0; /* Unless config is insane, this should always be "good". */
+ t_max = 1e6;
+
+ for (step = 0; ; step++) {
+ if (step >= 100) {
+ /* Force "known good", rerun config, and break out.
+ * Deals with rounding corner cases where t_curr is
+ * persistently "bad" even though t_min is a valid
+ * solution.
+ */
+ t_curr = t_min;
+ } else {
+ t_curr = (t_min + t_max) / 2.0;
+ }
+
+ for (i = 0, total = 0; i < num_pools; i++) {
+ states[i].size = configs[i].size;
+
+ /* Target bytes = A*t + B ==> target count = (A*t + B) / block_size.
+ * Rely on A and B being small enough so that 'x' won't wrap.
+ */
+ x = ((double) configs[i].a * t_curr + (double) configs[i].b) / (double) configs[i].size;
+
+ states[i].count = (unsigned int) x;
+ total += (size_t) states[i].size * (size_t) states[i].count;
+ if (total > size) {
+ goto bad;
+ }
+ }
+
+ /* t_curr is good. */
+#if defined(DUK_ALLOC_POOL_DEBUG)
+ duk__alloc_pool_dprintf("duk_alloc_pool_init: step=%d, t=[%lf %lf %lf] -> total %ld/%ld (good)\n",
+ step, t_min, t_curr, t_max, (long) total, (long) size);
+#endif
+ if (step >= 100) {
+ /* Keep state[] initialization state. The state was
+ * created using the highest 't_min'.
+ */
+ break;
+ }
+ t_min = t_curr;
+ continue;
+
+ bad:
+ /* t_curr is bad. */
+#if defined(DUK_ALLOC_POOL_DEBUG)
+ duk__alloc_pool_dprintf("duk_alloc_pool_init: step=%d, t=[%lf %lf %lf] -> total %ld/%ld (bad)\n",
+ step, t_min, t_curr, t_max, (long) total, (long) size);
+#endif
+
+ if (step >= 1000) {
+ /* Cannot find any good solution; shouldn't happen
+ * unless config is bad or 'size' is so small that
+ * even a baseline allocation won't fit.
+ */
+ return NULL;
+ }
+ t_max = t_curr;
+ /* continue */
+ }
+
+ /* The base configuration is now good; sprinkle any leftovers to
+ * pools in descending order. Note that for good t_curr, 'total'
+ * indicates allocated bytes so far and 'size - total' indicates
+ * leftovers.
+ */
+ for (i = num_pools - 1; i >= 0; i--) {
+ while (size - total >= states[i].size) {
+ /* Ignore potential wrapping of states[i].count as the count
+ * is 32 bits and shouldn't wrap in practice.
+ */
+ states[i].count++;
+ total += states[i].size;
+#if defined(DUK_ALLOC_POOL_DEBUG)
+ duk__alloc_pool_dprintf("duk_alloc_pool_init: sprinkle %ld bytes (%ld left after) to pool index %ld, new count %ld\n",
+ (long) states[i].size, (long) (size - total), (long) i, (long) states[i].count);
+#endif
+ }
+ }
+
+ /* Pool counts are final. Allocate the user supplied region based
+ * on the final counts, initialize free lists for each block size,
+ * and otherwise finalize 'state' for use.
+ */
+ p = buffer;
+ global->num_pools = num_pools;
+ global->states = states;
+#if defined(DUK_ALLOC_POOL_TRACK_HIGHWATER)
+#if defined(DUK_ALLOC_POOL_DEBUG)
+ duk__alloc_pool_dprintf("duk_alloc_pool_init: global highwater mark tracking enabled, THIS IS VERY SLOW!\n");
+#endif
+ global->hwm_used_bytes = 0U;
+ global->hwm_waste_bytes = 0U;
+#endif
+#if defined(DUK_ALLOC_POOL_TRACK_WASTE)
+#if defined(DUK_ALLOC_POOL_DEBUG)
+ duk__alloc_pool_dprintf("duk_alloc_pool_init: approximate waste tracking enabled\n");
+#endif
+#endif
+
+#if defined(DUK_USE_HEAPPTR16)
+ /* Register global base value for pointer compression, assumes
+ * a single active pool -4 allows a single subtract to be used and
+ * still ensures no non-NULL pointer encodes to zero.
+ */
+ duk_alloc_pool_ptrcomp_base = (void *) (p - 4);
+#endif
+
+ for (i = 0; i < num_pools; i++) {
+ n = (int) states[i].count;
+ if (n > 0) {
+ states[i].first = (duk_pool_free *) p;
+ for (j = 0; j < n; j++) {
+ char *p_next = p + states[i].size;
+ ((duk_pool_free *) p)->next =
+ (j == n - 1) ? (duk_pool_free *) NULL : (duk_pool_free *) p_next;
+ p = p_next;
+ }
+ } else {
+ states[i].first = (duk_pool_free *) NULL;
+ }
+ states[i].alloc_end = p;
+#if defined(DUK_ALLOC_POOL_TRACK_HIGHWATER)
+ states[i].hwm_used_count = 0;
+#endif
+ /* All members of 'state' now initialized. */
+
+#if defined(DUK_ALLOC_POOL_DEBUG)
+ duk__alloc_pool_dprintf("duk_alloc_pool_init: block size %5ld, count %5ld, %8ld total bytes, "
+ "end %p\n",
+ (long) states[i].size, (long) states[i].count,
+ (long) states[i].size * (long) states[i].count,
+ (void *) states[i].alloc_end);
+#endif
+ }
+
+#if defined(DUK_ALLOC_POOL_ROMPTR_COMPRESSION)
+ /* ROM pointer compression precomputation. Assumes a single active
+ * pool.
+ */
+ duk__alloc_pool_romptr_init();
+#endif
+
+ /* Use 'global' as udata. */
+ return (void *) global;
+}
+
+/*
+ * Misc helpers
+ */
+
+#if defined(DUK_ALLOC_POOL_TRACK_WASTE)
+static void duk__alloc_pool_set_waste_marker(void *ptr, size_t used, size_t size) {
+ /* Rely on the base pointer and size being divisible by 4 and thus
+ * aligned. Use 32-bit markers: a 4-byte resolution is good enough,
+ * and comparing 32 bits at a time makes false waste estimates less
+ * likely than when comparing as bytes.
+ */
+ duk_uint32_t *p, *p_start, *p_end;
+ size_t used_round;
+
+ used_round = (used + 3U) & ~0x03U; /* round up to 4 */
+ p_end = (duk_uint32_t *) ((duk_uint8_t *) ptr + size);
+ p_start = (duk_uint32_t *) ((duk_uint8_t *) ptr + used_round);
+ p = (duk_uint32_t *) p_start;
+ while (p != p_end) {
+ *p++ = DUK_ALLOC_POOL_WASTE_MARKER;
+ }
+}
+#else /* DUK_ALLOC_POOL_TRACK_WASTE */
+static void duk__alloc_pool_set_waste_marker(void *ptr, size_t used, size_t size) {
+ (void) ptr; (void) used; (void) size;
+}
+#endif /* DUK_ALLOC_POOL_TRACK_WASTE */
+
+#if defined(DUK_ALLOC_POOL_TRACK_WASTE)
+static size_t duk__alloc_pool_get_waste_estimate(void *ptr, size_t size) {
+ duk_uint32_t *p, *p_end, *p_start;
+
+ /* Assumes size is >= 4. */
+ p_start = (duk_uint32_t *) ptr;
+ p_end = (duk_uint32_t *) ((duk_uint8_t *) ptr + size);
+ p = p_end;
+
+ /* This scan may cause harmless valgrind complaints: there may be
+ * uninitialized bytes within the legitimate allocation or between
+ * the start of the waste marker and the end of the allocation.
+ */
+ do {
+ p--;
+ if (*p == DUK_ALLOC_POOL_WASTE_MARKER) {
+ ;
+ } else {
+ return (size_t) (p_end - p - 1) * 4U;
+ }
+ } while (p != p_start);
+
+ return size;
+}
+#else /* DUK_ALLOC_POOL_TRACK_WASTE */
+static size_t duk__alloc_pool_get_waste_estimate(void *ptr, size_t size) {
+ (void) ptr; (void) size;
+ return 0;
+}
+#endif /* DUK_ALLOC_POOL_TRACK_WASTE */
+
+static int duk__alloc_pool_ptr_in_freelist(duk_pool_state *s, void *ptr) {
+ duk_pool_free *curr;
+
+ for (curr = s->first; curr != NULL; curr = curr->next) {
+ if ((void *) curr == ptr) {
+ return 1;
+ }
+ }
+ return 0;
+}
+
+void duk_alloc_pool_get_pool_stats(duk_pool_state *s, duk_pool_stats *res) {
+ void *curr;
+ size_t free_count;
+ size_t used_count;
+ size_t waste_bytes;
+
+ curr = s->alloc_end - (s->size * s->count);
+ free_count = 0U;
+ waste_bytes = 0U;
+ while (curr != s->alloc_end) {
+ if (duk__alloc_pool_ptr_in_freelist(s, curr)) {
+ free_count++;
+ } else {
+ waste_bytes += duk__alloc_pool_get_waste_estimate(curr, s->size);
+ }
+ curr = curr + s->size;
+ }
+ used_count = (size_t) (s->count - free_count);
+
+ res->used_count = used_count;
+ res->used_bytes = (size_t) (used_count * s->size);
+ res->free_count = free_count;
+ res->free_bytes = (size_t) (free_count * s->size);
+ res->waste_bytes = waste_bytes;
+#if defined(DUK_ALLOC_POOL_TRACK_HIGHWATER)
+ res->hwm_used_count = s->hwm_used_count;
+#else
+ res->hwm_used_count = 0U;
+#endif
+}
+
+void duk_alloc_pool_get_global_stats(duk_pool_global *g, duk_pool_global_stats *res) {
+ int i;
+ size_t total_used = 0U;
+ size_t total_free = 0U;
+ size_t total_waste = 0U;
+
+ for (i = 0; i < g->num_pools; i++) {
+ duk_pool_state *s = &g->states[i];
+ duk_pool_stats stats;
+
+ duk_alloc_pool_get_pool_stats(s, &stats);
+
+ total_used += stats.used_bytes;
+ total_free += stats.free_bytes;
+ total_waste += stats.waste_bytes;
+ }
+
+ res->used_bytes = total_used;
+ res->free_bytes = total_free;
+ res->waste_bytes = total_waste;
+#if defined(DUK_ALLOC_POOL_TRACK_HIGHWATER)
+ res->hwm_used_bytes = g->hwm_used_bytes;
+ res->hwm_waste_bytes = g->hwm_waste_bytes;
+#else
+ res->hwm_used_bytes = 0U;
+ res->hwm_waste_bytes = 0U;
+#endif
+}
+
+#if defined(DUK_ALLOC_POOL_TRACK_HIGHWATER)
+static void duk__alloc_pool_update_highwater(duk_pool_global *g) {
+ int i;
+ size_t total_used = 0U;
+ size_t total_free = 0U;
+ size_t total_waste = 0U;
+
+ /* Per pool highwater used count, useful to checking if a pool is
+ * too small.
+ */
+ for (i = 0; i < g->num_pools; i++) {
+ duk_pool_state *s = &g->states[i];
+ duk_pool_stats stats;
+
+ duk_alloc_pool_get_pool_stats(s, &stats);
+ if (stats.used_count > s->hwm_used_count) {
+#if defined(DUK_ALLOC_POOL_DEBUG)
+ duk__alloc_pool_dprintf("duk__alloc_pool_update_highwater: pool %ld (%ld bytes) highwater updated: count %ld -> %ld\n",
+ (long) i, (long) s->size,
+ (long) s->hwm_used_count, (long) stats.used_count);
+#endif
+ s->hwm_used_count = stats.used_count;
+ }
+
+ total_used += stats.used_bytes;
+ total_free += stats.free_bytes;
+ total_waste += stats.waste_bytes;
+ }
+
+ /* Global highwater mark for used and waste bytes. Both fields are
+ * updated from the same snapshot based on highest used count.
+ * This is VERY, VERY slow and only useful for development.
+ * (Note that updating HWM states for pools individually and then
+ * summing them won't create a consistent global snapshot. There
+ * are still easy ways to make this much, much faster.)
+ */
+ if (total_used > g->hwm_used_bytes) {
+#if defined(DUK_ALLOC_POOL_DEBUG)
+ duk__alloc_pool_dprintf("duk__alloc_pool_update_highwater: global highwater updated: used=%ld, bytes=%ld -> "
+ "used=%ld, bytes=%ld\n",
+ (long) g->hwm_used_bytes, (long) g->hwm_waste_bytes,
+ (long) total_used, (long) total_waste);
+#endif
+ g->hwm_used_bytes = total_used;
+ g->hwm_waste_bytes = total_waste;
+ }
+}
+#else /* DUK_ALLOC_POOL_TRACK_HIGHWATER */
+static void duk__alloc_pool_update_highwater(duk_pool_global *g) {
+ (void) g;
+}
+#endif /* DUK_ALLOC_POOL_TRACK_HIGHWATER */
+
+/*
+ * Allocation providers
+ */
+
+void *duk_alloc_pool(void *udata, duk_size_t size) {
+ duk_pool_global *g = (duk_pool_global *) udata;
+ int i, n;
+
+#if defined(DUK_ALLOC_POOL_DEBUG)
+ duk__alloc_pool_dprintf("duk_alloc_pool: %p %ld\n", udata, (long) size);
+#endif
+
+ if (size == 0) {
+ return NULL;
+ }
+
+ for (i = 0, n = g->num_pools; i < n; i++) {
+ duk_pool_state *st = g->states + i;
+
+ if (size <= st->size) {
+ duk_pool_free *res = st->first;
+ if (res != NULL) {
+ st->first = res->next;
+ duk__alloc_pool_set_waste_marker((void *) res, size, st->size);
+ duk__alloc_pool_update_highwater(g);
+ return (void *) res;
+ }
+ }
+
+ /* Allocation doesn't fit or no free entries, try to borrow
+ * from the next block size. There's no support for preventing
+ * a borrow at present.
+ */
+ }
+
+ return NULL;
+}
+
+void *duk_realloc_pool(void *udata, void *ptr, duk_size_t size) {
+ duk_pool_global *g = (duk_pool_global *) udata;
+ int i, j, n;
+
+#if defined(DUK_ALLOC_POOL_DEBUG)
+ duk__alloc_pool_dprintf("duk_realloc_pool: %p %p %ld\n", udata, ptr, (long) size);
+#endif
+
+ if (ptr == NULL) {
+ return duk_alloc_pool(udata, size);
+ }
+ if (size == 0) {
+ duk_free_pool(udata, ptr);
+ return NULL;
+ }
+
+ /* Non-NULL pointers are necessarily from the pool so we should
+ * always be able to find the allocation.
+ */
+
+ for (i = 0, n = g->num_pools; i < n; i++) {
+ duk_pool_state *st = g->states + i;
+ char *new_ptr;
+
+ /* Because 'ptr' is assumed to be in the pool and pools are
+ * allocated in sequence, it suffices to check for end pointer
+ * only.
+ */
+ if ((char *) ptr >= st->alloc_end) {
+ continue;
+ }
+
+ if (size <= st->size) {
+ /* Allocation still fits existing allocation. Check if
+ * we can shrink the allocation to a smaller block size
+ * (smallest possible).
+ */
+ for (j = 0; j < i; j++) {
+ duk_pool_state *st2 = g->states + j;
+
+ if (size <= st2->size) {
+ new_ptr = (char *) st2->first;
+ if (new_ptr != NULL) {
+#if defined(DUK_ALLOC_POOL_DEBUG)
+ duk__alloc_pool_dprintf("duk_realloc_pool: shrink, block size %ld -> %ld\n",
+ (long) st->size, (long) st2->size);
+#endif
+ st2->first = ((duk_pool_free *) new_ptr)->next;
+ memcpy((void *) new_ptr, (const void *) ptr, (size_t) size);
+ ((duk_pool_free *) ptr)->next = st->first;
+ st->first = (duk_pool_free *) ptr;
+ duk__alloc_pool_set_waste_marker((void *) new_ptr, size, st2->size);
+ duk__alloc_pool_update_highwater(g);
+ return (void *) new_ptr;
+ }
+ }
+ }
+
+ /* Failed to shrink; return existing pointer. */
+ duk__alloc_pool_set_waste_marker((void *) ptr, size, st->size);
+ return ptr;
+ }
+
+ /* Find first free larger block. */
+ for (j = i + 1; j < n; j++) {
+ duk_pool_state *st2 = g->states + j;
+
+ if (size <= st2->size) {
+ new_ptr = (char *) st2->first;
+ if (new_ptr != NULL) {
+ st2->first = ((duk_pool_free *) new_ptr)->next;
+ memcpy((void *) new_ptr, (const void *) ptr, (size_t) st->size);
+ ((duk_pool_free *) ptr)->next = st->first;
+ st->first = (duk_pool_free *) ptr;
+ duk__alloc_pool_set_waste_marker((void *) new_ptr, size, st2->size);
+ duk__alloc_pool_update_highwater(g);
+ return (void *) new_ptr;
+ }
+ }
+ }
+
+ /* Failed to resize. */
+ return NULL;
+ }
+
+ /* We should never be here because 'ptr' should be a valid pool
+ * entry and thus always found above.
+ */
+ return NULL;
+}
+
+void duk_free_pool(void *udata, void *ptr) {
+ duk_pool_global *g = (duk_pool_global *) udata;
+ int i, n;
+
+#if defined(DUK_ALLOC_POOL_DEBUG)
+ duk__alloc_pool_dprintf("duk_free_pool: %p %p\n", udata, ptr);
+#endif
+
+ if (ptr == NULL) {
+ return;
+ }
+
+ for (i = 0, n = g->num_pools; i < n; i++) {
+ duk_pool_state *st = g->states + i;
+
+ /* Enough to check end address only. */
+ if ((char *) ptr >= st->alloc_end) {
+ continue;
+ }
+
+ ((duk_pool_free *) ptr)->next = st->first;
+ st->first = (duk_pool_free *) ptr;
+#if 0 /* never necessary when freeing */
+ duk__alloc_pool_update_highwater(g);
+#endif
+ return;
+ }
+
+ /* We should never be here because 'ptr' should be a valid pool
+ * entry and thus always found above.
+ */
+}
+
+/*
+ * Pointer compression
+ */
+
+#if defined(DUK_ALLOC_POOL_ROMPTR_COMPRESSION)
+static void duk__alloc_pool_romptr_init(void) {
+ /* Scan ROM pointer range for faster detection of "is 'p' a ROM pointer"
+ * later on.
+ */
+ const void * const * ptrs = (const void * const *) duk_rom_compressed_pointers;
+ duk_alloc_pool_romptr_low = duk_alloc_pool_romptr_high = (const void *) *ptrs;
+ while (*ptrs) {
+ if (*ptrs > duk_alloc_pool_romptr_high) {
+ duk_alloc_pool_romptr_high = (const void *) *ptrs;
+ }
+ if (*ptrs < duk_alloc_pool_romptr_low) {
+ duk_alloc_pool_romptr_low = (const void *) *ptrs;
+ }
+ ptrs++;
+ }
+}
+#endif
+
+/* Encode/decode functions are defined in the header to allow inlining. */
+
+#if defined(DUK_ALLOC_POOL_ROMPTR_COMPRESSION)
+duk_uint16_t duk_alloc_pool_enc16_rom(void *ptr) {
+ /* The if-condition should be the fastest possible check
+ * for "is 'ptr' in ROM?". If pointer is in ROM, we'd like
+ * to compress it quickly. Here we just scan a ~1K array
+ * which is very bad for performance.
+ */
+ const void * const * ptrs = duk_rom_compressed_pointers;
+ while (*ptrs) {
+ if (*ptrs == ptr) {
+ return DUK_ALLOC_POOL_ROMPTR_FIRST + (duk_uint16_t) (ptrs - duk_rom_compressed_pointers);
+ }
+ ptrs++;
+ }
+
+ /* We should really never be here: Duktape should only be
+ * compressing pointers which are in the ROM compressed
+ * pointers list, which are known at 'make dist' time.
+ * We go on, causing a pointer compression error.
+ */
+ return 0;
+}
+#endif