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author | David Monniaux <david.monniaux@univ-grenoble-alpes.fr> | 2020-03-03 08:17:40 +0100 |
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committer | David Monniaux <david.monniaux@univ-grenoble-alpes.fr> | 2020-03-03 08:17:40 +0100 |
commit | 1ab7b51c30e1b10ac45b0bd64cefdc01da0f7f68 (patch) | |
tree | 210ffc156c83f04fb0c61a40b4f9037d7ba8a7e1 /test/monniaux/ocaml/byterun/memory.c | |
parent | 222c9047d61961db9c6b19fed5ca49829223fd33 (diff) | |
parent | 12be46d59a2483a10d77fa8ee67f7e0ca1bd702f (diff) | |
download | compcert-kvx-1ab7b51c30e1b10ac45b0bd64cefdc01da0f7f68.tar.gz compcert-kvx-1ab7b51c30e1b10ac45b0bd64cefdc01da0f7f68.zip |
Merge branch 'mppa-cse2' of gricad-gitlab.univ-grenoble-alpes.fr:sixcy/CompCert into mppa-work
Diffstat (limited to 'test/monniaux/ocaml/byterun/memory.c')
-rw-r--r-- | test/monniaux/ocaml/byterun/memory.c | 1016 |
1 files changed, 1016 insertions, 0 deletions
diff --git a/test/monniaux/ocaml/byterun/memory.c b/test/monniaux/ocaml/byterun/memory.c new file mode 100644 index 00000000..f92b23c4 --- /dev/null +++ b/test/monniaux/ocaml/byterun/memory.c @@ -0,0 +1,1016 @@ +/**************************************************************************/ +/* */ +/* OCaml */ +/* */ +/* Damien Doligez, projet Para, INRIA Rocquencourt */ +/* */ +/* Copyright 1996 Institut National de Recherche en Informatique et */ +/* en Automatique. */ +/* */ +/* All rights reserved. This file is distributed under the terms of */ +/* the GNU Lesser General Public License version 2.1, with the */ +/* special exception on linking described in the file LICENSE. */ +/* */ +/**************************************************************************/ + +#define CAML_INTERNALS + +#include <stdlib.h> +#include <string.h> +#include <stdarg.h> +#include <stddef.h> +#include "caml/address_class.h" +#include "caml/config.h" +#include "caml/fail.h" +#include "caml/freelist.h" +#include "caml/gc.h" +#include "caml/gc_ctrl.h" +#include "caml/major_gc.h" +#include "caml/memory.h" +#include "caml/major_gc.h" +#include "caml/minor_gc.h" +#include "caml/misc.h" +#include "caml/mlvalues.h" +#include "caml/signals.h" + +int caml_huge_fallback_count = 0; +/* Number of times that mmapping big pages fails and we fell back to small + pages. This counter is available to the program through + [Gc.huge_fallback_count]. +*/ + +uintnat caml_use_huge_pages = 0; +/* True iff the program allocates heap chunks by mmapping huge pages. + This is set when parsing [OCAMLRUNPARAM] and must stay constant + after that. +*/ + +extern uintnat caml_percent_free; /* major_gc.c */ + +/* Page table management */ + +#define Page(p) ((uintnat) (p) >> Page_log) +#define Page_mask ((uintnat) -1 << Page_log) + +#ifdef ARCH_SIXTYFOUR + +/* 64-bit implementation: + The page table is represented sparsely as a hash table + with linear probing */ + +struct page_table { + mlsize_t size; /* size == 1 << (wordsize - shift) */ + int shift; + mlsize_t mask; /* mask == size - 1 */ + mlsize_t occupancy; + uintnat * entries; /* [size] */ +}; + +static struct page_table caml_page_table; + +/* Page table entries are the logical 'or' of + - the key: address of a page (low Page_log bits = 0) + - the data: a 8-bit integer */ + +#define Page_entry_matches(entry,addr) \ + ((((entry) ^ (addr)) & Page_mask) == 0) + +/* Multiplicative Fibonacci hashing + (Knuth, TAOCP vol 3, section 6.4, page 518). + HASH_FACTOR is (sqrt(5) - 1) / 2 * 2^wordsize. */ +#ifdef ARCH_SIXTYFOUR +#define HASH_FACTOR 11400714819323198486UL +#else +#define HASH_FACTOR 2654435769UL +#endif +#define Hash(v) (((v) * HASH_FACTOR) >> caml_page_table.shift) + +int caml_page_table_lookup(void * addr) +{ + uintnat h, e; + + h = Hash(Page(addr)); + /* The first hit is almost always successful, so optimize for this case */ + e = caml_page_table.entries[h]; + if (Page_entry_matches(e, (uintnat)addr)) return e & 0xFF; + while(1) { + if (e == 0) return 0; + h = (h + 1) & caml_page_table.mask; + e = caml_page_table.entries[h]; + if (Page_entry_matches(e, (uintnat)addr)) return e & 0xFF; + } +} + +int caml_page_table_initialize(mlsize_t bytesize) +{ + uintnat pagesize = Page(bytesize); + + caml_page_table.size = 1; + caml_page_table.shift = 8 * sizeof(uintnat); + /* Aim for initial load factor between 1/4 and 1/2 */ + while (caml_page_table.size < 2 * pagesize) { + caml_page_table.size <<= 1; + caml_page_table.shift -= 1; + } + caml_page_table.mask = caml_page_table.size - 1; + caml_page_table.occupancy = 0; + caml_page_table.entries = + caml_stat_calloc_noexc(caml_page_table.size, sizeof(uintnat)); + if (caml_page_table.entries == NULL) + return -1; + else + return 0; +} + +static int caml_page_table_resize(void) +{ + struct page_table old = caml_page_table; + uintnat * new_entries; + uintnat i, h; + + caml_gc_message (0x08, "Growing page table to %" + ARCH_INTNAT_PRINTF_FORMAT "u entries\n", + caml_page_table.size); + + new_entries = caml_stat_calloc_noexc(2 * old.size, sizeof(uintnat)); + if (new_entries == NULL) { + caml_gc_message (0x08, "No room for growing page table\n"); + return -1; + } + + caml_page_table.size = 2 * old.size; + caml_page_table.shift = old.shift - 1; + caml_page_table.mask = caml_page_table.size - 1; + caml_page_table.occupancy = old.occupancy; + caml_page_table.entries = new_entries; + + for (i = 0; i < old.size; i++) { + uintnat e = old.entries[i]; + if (e == 0) continue; + h = Hash(Page(e)); + while (caml_page_table.entries[h] != 0) + h = (h + 1) & caml_page_table.mask; + caml_page_table.entries[h] = e; + } + + caml_stat_free(old.entries); + return 0; +} + +static int caml_page_table_modify(uintnat page, int toclear, int toset) +{ + uintnat h; + + CAMLassert ((page & ~Page_mask) == 0); + + /* Resize to keep load factor below 1/2 */ + if (caml_page_table.occupancy * 2 >= caml_page_table.size) { + if (caml_page_table_resize() != 0) return -1; + } + h = Hash(Page(page)); + while (1) { + if (caml_page_table.entries[h] == 0) { + caml_page_table.entries[h] = page | toset; + caml_page_table.occupancy++; + break; + } + if (Page_entry_matches(caml_page_table.entries[h], page)) { + caml_page_table.entries[h] = + (caml_page_table.entries[h] & ~toclear) | toset; + break; + } + h = (h + 1) & caml_page_table.mask; + } + return 0; +} + +#else + +/* 32-bit implementation: + The page table is represented as a 2-level array of unsigned char */ + +CAMLexport unsigned char * caml_page_table[Pagetable1_size]; +static unsigned char caml_page_table_empty[Pagetable2_size] = { 0, }; + +int caml_page_table_initialize(mlsize_t bytesize) +{ + int i; + for (i = 0; i < Pagetable1_size; i++) + caml_page_table[i] = caml_page_table_empty; + return 0; +} + +static int caml_page_table_modify(uintnat page, int toclear, int toset) +{ + uintnat i = Pagetable_index1(page); + uintnat j = Pagetable_index2(page); + + if (caml_page_table[i] == caml_page_table_empty) { + unsigned char * new_tbl = caml_stat_calloc_noexc(Pagetable2_size, 1); + if (new_tbl == 0) return -1; + caml_page_table[i] = new_tbl; + } + caml_page_table[i][j] = (caml_page_table[i][j] & ~toclear) | toset; + return 0; +} + +#endif + +int caml_page_table_add(int kind, void * start, void * end) +{ + uintnat pstart = (uintnat) start & Page_mask; + uintnat pend = ((uintnat) end - 1) & Page_mask; + uintnat p; + + for (p = pstart; p <= pend; p += Page_size) + if (caml_page_table_modify(p, 0, kind) != 0) return -1; + return 0; +} + +int caml_page_table_remove(int kind, void * start, void * end) +{ + uintnat pstart = (uintnat) start & Page_mask; + uintnat pend = ((uintnat) end - 1) & Page_mask; + uintnat p; + + for (p = pstart; p <= pend; p += Page_size) + if (caml_page_table_modify(p, kind, 0) != 0) return -1; + return 0; +} + + +/* Initialize the [alloc_for_heap] system. + This function must be called exactly once, and it must be called + before the first call to [alloc_for_heap]. + It returns 0 on success and -1 on failure. +*/ +int caml_init_alloc_for_heap (void) +{ + return 0; +} + +/* Allocate a block of the requested size, to be passed to + [caml_add_to_heap] later. + [request] will be rounded up to some implementation-dependent size. + The caller must use [Chunk_size] on the result to recover the actual + size. + Return NULL if the request cannot be satisfied. The returned pointer + is a hp, but the header (and the contents) must be initialized by the + caller. +*/ +char *caml_alloc_for_heap (asize_t request) +{ + if (caml_use_huge_pages){ +#ifdef HAS_HUGE_PAGES + uintnat size = Round_mmap_size (sizeof (heap_chunk_head) + request); + void *block; + char *mem; + block = mmap (NULL, size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, -1, 0); + if (block == MAP_FAILED) return NULL; + mem = (char *) block + sizeof (heap_chunk_head); + Chunk_size (mem) = size - sizeof (heap_chunk_head); + Chunk_block (mem) = block; + return mem; +#else + return NULL; +#endif + }else{ + char *mem; + void *block; + + request = ((request + Page_size - 1) >> Page_log) << Page_log; + mem = caml_stat_alloc_aligned_noexc (request + sizeof (heap_chunk_head), + sizeof (heap_chunk_head), &block); + if (mem == NULL) return NULL; + mem += sizeof (heap_chunk_head); + Chunk_size (mem) = request; + Chunk_block (mem) = block; + return mem; + } +} + +/* Use this function if a block allocated with [caml_alloc_for_heap] is + not actually going to be added to the heap. The caller is responsible + for freeing it. */ +void caml_disown_for_heap (char* mem) +{ + /* Currently a no-op. */ + (void)mem; /* can CAMLunused_{start,end} be used here? */ +} + +/* Use this function to free a block allocated with [caml_alloc_for_heap] + if you don't add it with [caml_add_to_heap]. +*/ +void caml_free_for_heap (char *mem) +{ + if (caml_use_huge_pages){ +#ifdef HAS_HUGE_PAGES + munmap (Chunk_block (mem), Chunk_size (mem) + sizeof (heap_chunk_head)); +#else + CAMLassert (0); +#endif + }else{ + caml_stat_free (Chunk_block (mem)); + } +} + +/* Take a chunk of memory as argument, which must be the result of a + call to [caml_alloc_for_heap], and insert it into the heap chaining. + The contents of the chunk must be a sequence of valid blocks and + fragments: no space between blocks and no trailing garbage. If + some blocks are blue, they must be added to the free list by the + caller. All other blocks must have the color [caml_allocation_color(m)]. + The caller must update [caml_allocated_words] if applicable. + Return value: 0 if no error; -1 in case of error. + + See also: caml_compact_heap, which duplicates most of this function. +*/ +int caml_add_to_heap (char *m) +{ +#ifdef DEBUG + /* Should check the contents of the block. */ +#endif /* DEBUG */ + + caml_gc_message (0x04, "Growing heap to %" + ARCH_INTNAT_PRINTF_FORMAT "uk bytes\n", + (Bsize_wsize (caml_stat_heap_wsz) + Chunk_size (m)) / 1024); + + /* Register block in page table */ + if (caml_page_table_add(In_heap, m, m + Chunk_size(m)) != 0) + return -1; + + /* Chain this heap chunk. */ + { + char **last = &caml_heap_start; + char *cur = *last; + + while (cur != NULL && cur < m){ + last = &(Chunk_next (cur)); + cur = *last; + } + Chunk_next (m) = cur; + *last = m; + + ++ caml_stat_heap_chunks; + } + + caml_stat_heap_wsz += Wsize_bsize (Chunk_size (m)); + if (caml_stat_heap_wsz > caml_stat_top_heap_wsz){ + caml_stat_top_heap_wsz = caml_stat_heap_wsz; + } + return 0; +} + +/* Allocate more memory from malloc for the heap. + Return a blue block of at least the requested size. + The blue block is chained to a sequence of blue blocks (through their + field 0); the last block of the chain is pointed by field 1 of the + first. There may be a fragment after the last block. + The caller must insert the blocks into the free list. + [request] is a number of words and must be less than or equal + to [Max_wosize]. + Return NULL when out of memory. +*/ +static value *expand_heap (mlsize_t request) +{ + /* these point to headers, but we do arithmetic on them, hence [value *]. */ + value *mem, *hp, *prev; + asize_t over_request, malloc_request, remain; + + CAMLassert (request <= Max_wosize); + over_request = request + request / 100 * caml_percent_free; + malloc_request = caml_clip_heap_chunk_wsz (over_request); + mem = (value *) caml_alloc_for_heap (Bsize_wsize (malloc_request)); + if (mem == NULL){ + caml_gc_message (0x04, "No room for growing heap\n"); + return NULL; + } + remain = Wsize_bsize (Chunk_size (mem)); + prev = hp = mem; + /* FIXME find a way to do this with a call to caml_make_free_blocks */ + while (Wosize_whsize (remain) > Max_wosize){ + Hd_hp (hp) = Make_header (Max_wosize, 0, Caml_blue); +#ifdef DEBUG + caml_set_fields (Val_hp (hp), 0, Debug_free_major); +#endif + hp += Whsize_wosize (Max_wosize); + remain -= Whsize_wosize (Max_wosize); + Field (Val_hp (mem), 1) = Field (Val_hp (prev), 0) = Val_hp (hp); + prev = hp; + } + if (remain > 1){ + Hd_hp (hp) = Make_header (Wosize_whsize (remain), 0, Caml_blue); +#ifdef DEBUG + caml_set_fields (Val_hp (hp), 0, Debug_free_major); +#endif + Field (Val_hp (mem), 1) = Field (Val_hp (prev), 0) = Val_hp (hp); + Field (Val_hp (hp), 0) = (value) NULL; + }else{ + Field (Val_hp (prev), 0) = (value) NULL; + if (remain == 1) { + Hd_hp (hp) = Make_header_allocated_here (0, 0, Caml_white); + } + } + CAMLassert (Wosize_hp (mem) >= request); + if (caml_add_to_heap ((char *) mem) != 0){ + caml_free_for_heap ((char *) mem); + return NULL; + } + return Op_hp (mem); +} + +/* Remove the heap chunk [chunk] from the heap and give the memory back + to [free]. +*/ +void caml_shrink_heap (char *chunk) +{ + char **cp; + + /* Never deallocate the first chunk, because caml_heap_start is both the + first block and the base address for page numbers, and we don't + want to shift the page table, it's too messy (see above). + It will never happen anyway, because of the way compaction works. + (see compact.c) + XXX FIXME this has become false with the fix to PR#5389 (see compact.c) + */ + if (chunk == caml_heap_start) return; + + caml_stat_heap_wsz -= Wsize_bsize (Chunk_size (chunk)); + caml_gc_message (0x04, "Shrinking heap to %" + ARCH_INTNAT_PRINTF_FORMAT "uk words\n", + caml_stat_heap_wsz / 1024); + +#ifdef DEBUG + { + mlsize_t i; + for (i = 0; i < Wsize_bsize (Chunk_size (chunk)); i++){ + ((value *) chunk) [i] = Debug_free_shrink; + } + } +#endif + + -- caml_stat_heap_chunks; + + /* Remove [chunk] from the list of chunks. */ + cp = &caml_heap_start; + while (*cp != chunk) cp = &(Chunk_next (*cp)); + *cp = Chunk_next (chunk); + + /* Remove the pages of [chunk] from the page table. */ + caml_page_table_remove(In_heap, chunk, chunk + Chunk_size (chunk)); + + /* Free the [malloc] block that contains [chunk]. */ + caml_free_for_heap (chunk); +} + +color_t caml_allocation_color (void *hp) +{ + if (caml_gc_phase == Phase_mark || caml_gc_phase == Phase_clean + || (caml_gc_phase == Phase_sweep && (addr)hp >= (addr)caml_gc_sweep_hp)){ + return Caml_black; + }else{ + CAMLassert (caml_gc_phase == Phase_idle + || (caml_gc_phase == Phase_sweep + && (addr)hp < (addr)caml_gc_sweep_hp)); + return Caml_white; + } +} + +static inline value caml_alloc_shr_aux (mlsize_t wosize, tag_t tag, + int raise_oom, uintnat profinfo) +{ + header_t *hp; + value *new_block; + + if (wosize > Max_wosize) { + if (raise_oom) + caml_raise_out_of_memory (); + else + return 0; + } + hp = caml_fl_allocate (wosize); + if (hp == NULL){ + new_block = expand_heap (wosize); + if (new_block == NULL) { + if (!raise_oom) + return 0; + else if (caml_in_minor_collection) + caml_fatal_error ("Fatal error: out of memory.\n"); + else + caml_raise_out_of_memory (); + } + caml_fl_add_blocks ((value) new_block); + hp = caml_fl_allocate (wosize); + } + + CAMLassert (Is_in_heap (Val_hp (hp))); + + /* Inline expansion of caml_allocation_color. */ + if (caml_gc_phase == Phase_mark || caml_gc_phase == Phase_clean + || (caml_gc_phase == Phase_sweep && (addr)hp >= (addr)caml_gc_sweep_hp)){ + Hd_hp (hp) = Make_header_with_profinfo (wosize, tag, Caml_black, profinfo); + }else{ + CAMLassert (caml_gc_phase == Phase_idle + || (caml_gc_phase == Phase_sweep + && (addr)hp < (addr)caml_gc_sweep_hp)); + Hd_hp (hp) = Make_header_with_profinfo (wosize, tag, Caml_white, profinfo); + } + CAMLassert (Hd_hp (hp) + == Make_header_with_profinfo (wosize, tag, caml_allocation_color (hp), + profinfo)); + caml_allocated_words += Whsize_wosize (wosize); + if (caml_allocated_words > caml_minor_heap_wsz){ + CAML_INSTR_INT ("request_major/alloc_shr@", 1); + caml_request_major_slice (); + } +#ifdef DEBUG + { + uintnat i; + for (i = 0; i < wosize; i++){ + Field (Val_hp (hp), i) = Debug_uninit_major; + } + } +#endif + return Val_hp (hp); +} + +CAMLexport value caml_alloc_shr_no_raise (mlsize_t wosize, tag_t tag) +{ + return caml_alloc_shr_aux(wosize, tag, 0, 0); +} + +#ifdef WITH_PROFINFO + +/* Use this to debug problems with macros... */ +#define NO_PROFINFO 0xff + +CAMLexport value caml_alloc_shr_with_profinfo (mlsize_t wosize, tag_t tag, + intnat profinfo) +{ + return caml_alloc_shr_aux(wosize, tag, 1, profinfo); +} + +CAMLexport value caml_alloc_shr_preserving_profinfo (mlsize_t wosize, + tag_t tag, header_t old_header) +{ + return caml_alloc_shr_with_profinfo (wosize, tag, Profinfo_hd(old_header)); +} + +#else +#define NO_PROFINFO 0 +#endif /* WITH_PROFINFO */ + +#if defined(NATIVE_CODE) && defined(WITH_SPACETIME) +#include "caml/spacetime.h" + +CAMLexport value caml_alloc_shr (mlsize_t wosize, tag_t tag) +{ + return caml_alloc_shr_with_profinfo (wosize, tag, + caml_spacetime_my_profinfo (NULL, wosize)); +} +#else +CAMLexport value caml_alloc_shr (mlsize_t wosize, tag_t tag) +{ + return caml_alloc_shr_aux (wosize, tag, 1, NO_PROFINFO); +} +#endif + +/* Dependent memory is all memory blocks allocated out of the heap + that depend on the GC (and finalizers) for deallocation. + For the GC to take dependent memory into account when computing + its automatic speed setting, + you must call [caml_alloc_dependent_memory] when you alloate some + dependent memory, and [caml_free_dependent_memory] when you + free it. In both cases, you pass as argument the size (in bytes) + of the block being allocated or freed. +*/ +CAMLexport void caml_alloc_dependent_memory (mlsize_t nbytes) +{ + caml_dependent_size += nbytes / sizeof (value); + caml_dependent_allocated += nbytes / sizeof (value); +} + +CAMLexport void caml_free_dependent_memory (mlsize_t nbytes) +{ + if (caml_dependent_size < nbytes / sizeof (value)){ + caml_dependent_size = 0; + }else{ + caml_dependent_size -= nbytes / sizeof (value); + } +} + +/* Use this function to tell the major GC to speed up when you use + finalized blocks to automatically deallocate resources (other + than memory). The GC will do at least one cycle every [max] + allocated resources; [res] is the number of resources allocated + this time. + Note that only [res/max] is relevant. The units (and kind of + resource) can change between calls to [caml_adjust_gc_speed]. +*/ +CAMLexport void caml_adjust_gc_speed (mlsize_t res, mlsize_t max) +{ + if (max == 0) max = 1; + if (res > max) res = max; + caml_extra_heap_resources += (double) res / (double) max; + if (caml_extra_heap_resources > 1.0){ + CAML_INSTR_INT ("request_major/adjust_gc_speed_1@", 1); + caml_extra_heap_resources = 1.0; + caml_request_major_slice (); + } + if (caml_extra_heap_resources + > (double) caml_minor_heap_wsz / 2.0 + / (double) caml_stat_heap_wsz) { + CAML_INSTR_INT ("request_major/adjust_gc_speed_2@", 1); + caml_request_major_slice (); + } +} + +/* You must use [caml_initialize] to store the initial value in a field of + a shared block, unless you are sure the value is not a young block. + A block value [v] is a shared block if and only if [Is_in_heap (v)] + is true. +*/ +/* [caml_initialize] never calls the GC, so you may call it while a block is + unfinished (i.e. just after a call to [caml_alloc_shr].) */ +/* PR#6084 workaround: define it as a weak symbol */ +CAMLexport CAMLweakdef void caml_initialize (value *fp, value val) +{ + CAMLassert(Is_in_heap_or_young(fp)); + *fp = val; + if (!Is_young((value)fp) && Is_block (val) && Is_young (val)) { + add_to_ref_table (&caml_ref_table, fp); + } +} + +/* You must use [caml_modify] to change a field of an existing shared block, + unless you are sure the value being overwritten is not a shared block and + the value being written is not a young block. */ +/* [caml_modify] never calls the GC. */ +/* [caml_modify] can also be used to do assignment on data structures that are + in the minor heap instead of in the major heap. In this case, it + is a bit slower than simple assignment. + In particular, you can use [caml_modify] when you don't know whether the + block being changed is in the minor heap or the major heap. */ +/* PR#6084 workaround: define it as a weak symbol */ + +CAMLexport CAMLweakdef void caml_modify (value *fp, value val) +{ + /* The write barrier implemented by [caml_modify] checks for the + following two conditions and takes appropriate action: + 1- a pointer from the major heap to the minor heap is created + --> add [fp] to the remembered set + 2- a pointer from the major heap to the major heap is overwritten, + while the GC is in the marking phase + --> call [caml_darken] on the overwritten pointer so that the + major GC treats it as an additional root. + */ + value old; + + if (Is_young((value)fp)) { + /* The modified object resides in the minor heap. + Conditions 1 and 2 cannot occur. */ + *fp = val; + } else { + /* The modified object resides in the major heap. */ + CAMLassert(Is_in_heap(fp)); + old = *fp; + *fp = val; + if (Is_block(old)) { + /* If [old] is a pointer within the minor heap, we already + have a major->minor pointer and [fp] is already in the + remembered set. Conditions 1 and 2 cannot occur. */ + if (Is_young(old)) return; + /* Here, [old] can be a pointer within the major heap. + Check for condition 2. */ + if (caml_gc_phase == Phase_mark) caml_darken(old, NULL); + } + /* Check for condition 1. */ + if (Is_block(val) && Is_young(val)) { + add_to_ref_table (&caml_ref_table, fp); + } + } +} + + +/* Global memory pool. + + The pool is structured as a ring of blocks, where each block's header + contains two links: to the previous and to the next block. The data + structure allows for insertions and removals of blocks in constant time, + given that a pointer to the operated block is provided. + + Initially, the pool contains a single block -- a pivot with no data, the + guaranteed existence of which makes for a more concise implementation. + + The API functions that operate on the pool receive not pointers to the + block's header, but rather pointers to the block's "data" field. This + behaviour is required to maintain compatibility with the interfaces of + [malloc], [realloc], and [free] family of functions, as well as to hide + the implementation from the user. +*/ + +/* A type with the most strict alignment requirements */ +union max_align { + char c; + short s; + long l; + int i; + float f; + double d; + void *v; + void (*q)(void); +}; + +struct pool_block { +#ifdef DEBUG + long magic; +#endif + struct pool_block *next; + struct pool_block *prev; + /* Use C99's flexible array types if possible */ +#if (__STDC_VERSION__ >= 199901L) + union max_align data[]; /* not allocated, used for alignment purposes */ +#else + union max_align data[1]; +#endif +}; + +#if (__STDC_VERSION__ >= 199901L) +#define SIZEOF_POOL_BLOCK sizeof(struct pool_block) +#else +#define SIZEOF_POOL_BLOCK offsetof(struct pool_block, data) +#endif + +static struct pool_block *pool = NULL; + + +/* Returns a pointer to the block header, given a pointer to "data" */ +static struct pool_block* get_pool_block(caml_stat_block b) +{ + if (b == NULL) + return NULL; + + else { + struct pool_block *pb = + (struct pool_block*)(((char*)b) - SIZEOF_POOL_BLOCK); +#ifdef DEBUG + CAMLassert(pb->magic == Debug_pool_magic); +#endif + return pb; + } +} + +CAMLexport void caml_stat_create_pool(void) +{ + if (pool == NULL) { + pool = malloc(SIZEOF_POOL_BLOCK); + if (pool == NULL) + caml_fatal_error("Fatal error: out of memory.\n"); +#ifdef DEBUG + pool->magic = Debug_pool_magic; +#endif + pool->next = pool; + pool->prev = pool; + } +} + +CAMLexport void caml_stat_destroy_pool(void) +{ + if (pool != NULL) { + pool->prev->next = NULL; + while (pool != NULL) { + struct pool_block *next = pool->next; + free(pool); + pool = next; + } + pool = NULL; + } +} + +/* [sz] and [modulo] are numbers of bytes */ +CAMLexport void* caml_stat_alloc_aligned_noexc(asize_t sz, int modulo, + caml_stat_block *b) +{ + char *raw_mem; + uintnat aligned_mem; + CAMLassert (modulo < Page_size); + raw_mem = (char *) caml_stat_alloc_noexc(sz + Page_size); + if (raw_mem == NULL) return NULL; + *b = raw_mem; + raw_mem += modulo; /* Address to be aligned */ + aligned_mem = (((uintnat) raw_mem / Page_size + 1) * Page_size); +#ifdef DEBUG + { + uintnat *p; + uintnat *p0 = (void *) *b; + uintnat *p1 = (void *) (aligned_mem - modulo); + uintnat *p2 = (void *) (aligned_mem - modulo + sz); + uintnat *p3 = (void *) ((char *) *b + sz + Page_size); + for (p = p0; p < p1; p++) *p = Debug_filler_align; + for (p = p1; p < p2; p++) *p = Debug_uninit_align; + for (p = p2; p < p3; p++) *p = Debug_filler_align; + } +#endif + return (char *) (aligned_mem - modulo); +} + +/* [sz] and [modulo] are numbers of bytes */ +CAMLexport void* caml_stat_alloc_aligned(asize_t sz, int modulo, + caml_stat_block *b) +{ + void *result = caml_stat_alloc_aligned_noexc(sz, modulo, b); + /* malloc() may return NULL if size is 0 */ + if ((result == NULL) && (sz != 0)) + caml_raise_out_of_memory(); + return result; +} + +/* [sz] is a number of bytes */ +CAMLexport caml_stat_block caml_stat_alloc_noexc(asize_t sz) +{ + /* Backward compatibility mode */ + if (pool == NULL) + return malloc(sz); + else { + struct pool_block *pb = malloc(sz + SIZEOF_POOL_BLOCK); + if (pb == NULL) return NULL; +#ifdef DEBUG + memset(&(pb->data), Debug_uninit_stat, sz); + pb->magic = Debug_pool_magic; +#endif + + /* Linking the block into the ring */ + pb->next = pool->next; + pb->prev = pool; + pool->next->prev = pb; + pool->next = pb; + + return &(pb->data); + } +} + +/* [sz] is a number of bytes */ +CAMLexport caml_stat_block caml_stat_alloc(asize_t sz) +{ + void *result = caml_stat_alloc_noexc(sz); + /* malloc() may return NULL if size is 0 */ + if ((result == NULL) && (sz != 0)) + caml_raise_out_of_memory(); + return result; +} + +CAMLexport void caml_stat_free(caml_stat_block b) +{ + /* Backward compatibility mode */ + if (pool == NULL) + free(b); + else { + struct pool_block *pb = get_pool_block(b); + if (pb == NULL) return; + + /* Unlinking the block from the ring */ + pb->prev->next = pb->next; + pb->next->prev = pb->prev; + + free(pb); + } +} + +/* [sz] is a number of bytes */ +CAMLexport caml_stat_block caml_stat_resize_noexc(caml_stat_block b, asize_t sz) +{ + /* Backward compatibility mode */ + if (pool == NULL) + return realloc(b, sz); + else { + struct pool_block *pb = get_pool_block(b); + struct pool_block *pb_new = realloc(pb, sz + SIZEOF_POOL_BLOCK); + if (pb_new == NULL) return NULL; + + /* Relinking the new block into the ring in place of the old one */ + pb_new->prev->next = pb_new; + pb_new->next->prev = pb_new; + + return &(pb_new->data); + } +} + +/* [sz] is a number of bytes */ +CAMLexport caml_stat_block caml_stat_resize(caml_stat_block b, asize_t sz) +{ + void *result = caml_stat_resize_noexc(b, sz); + if (result == NULL) + caml_raise_out_of_memory(); + return result; +} + +/* [sz] is a number of bytes */ +CAMLexport caml_stat_block caml_stat_calloc_noexc(asize_t num, asize_t sz) +{ + uintnat total; + if (caml_umul_overflow(sz, num, &total)) + return NULL; + else { + caml_stat_block result = caml_stat_alloc_noexc(total); + if (result != NULL) + memset(result, 0, total); + return result; + } +} + +CAMLexport caml_stat_string caml_stat_strdup_noexc(const char *s) +{ + size_t slen = strlen(s); + caml_stat_block result = caml_stat_alloc_noexc(slen + 1); + if (result == NULL) + return NULL; + memcpy(result, s, slen + 1); + return result; +} + +CAMLexport caml_stat_string caml_stat_strdup(const char *s) +{ + caml_stat_string result = caml_stat_strdup_noexc(s); + if (result == NULL) + caml_raise_out_of_memory(); + return result; +} + +#ifdef _WIN32 + +CAMLexport wchar_t * caml_stat_wcsdup(const wchar_t *s) +{ + int slen = wcslen(s); + wchar_t* result = caml_stat_alloc((slen + 1)*sizeof(wchar_t)); + if (result == NULL) + caml_raise_out_of_memory(); + memcpy(result, s, (slen + 1)*sizeof(wchar_t)); + return result; +} + +#endif + +CAMLexport caml_stat_string caml_stat_strconcat(int n, ...) +{ + va_list args; + char *result, *p; + size_t len = 0; + int i; + + va_start(args, n); + for (i = 0; i < n; i++) { + const char *s = va_arg(args, const char*); + len += strlen(s); + } + va_end(args); + + result = caml_stat_alloc(len + 1); + + va_start(args, n); + p = result; + for (i = 0; i < n; i++) { + const char *s = va_arg(args, const char*); + size_t l = strlen(s); + memcpy(p, s, l); + p += l; + } + va_end(args); + + *p = 0; + return result; +} + +#ifdef _WIN32 + +CAMLexport wchar_t* caml_stat_wcsconcat(int n, ...) +{ + va_list args; + wchar_t *result, *p; + size_t len = 0; + int i; + + va_start(args, n); + for (i = 0; i < n; i++) { + const wchar_t *s = va_arg(args, const wchar_t*); + len += wcslen(s); + } + va_end(args); + + result = caml_stat_alloc((len + 1)*sizeof(wchar_t)); + + va_start(args, n); + p = result; + for (i = 0; i < n; i++) { + const wchar_t *s = va_arg(args, const wchar_t*); + size_t l = wcslen(s); + memcpy(p, s, l*sizeof(wchar_t)); + p += l; + } + va_end(args); + + *p = 0; + return result; +} + +#endif |