diff options
Diffstat (limited to 'erts/emulator/beam/erl_nif.c')
| -rw-r--r-- | erts/emulator/beam/erl_nif.c | 365 |
1 files changed, 365 insertions, 0 deletions
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c index 05bcf73451..c440ae287f 100644 --- a/erts/emulator/beam/erl_nif.c +++ b/erts/emulator/beam/erl_nif.c @@ -56,6 +56,7 @@ #include "erl_process.h" #include "erl_bif_unique.h" #include "erl_utils.h" +#include "erl_io_queue.h" #undef ERTS_WANT_NFUNC_SCHED_INTERNALS__ #define ERTS_WANT_NFUNC_SCHED_INTERNALS__ #include "erl_nfunc_sched.h" @@ -66,6 +67,13 @@ #include <limits.h> #include <stddef.h> /* offsetof */ +#ifndef MAX +#define MAX(X, Y) ((X) > (Y) ? (X) : (Y)) +#endif + +#ifndef MIN +#define MIN(X, Y) ((X) < (Y) ? (X) : (Y)) +#endif /* Information about a loaded nif library. * Each successful call to erlang:load_nif will allocate an instance of @@ -3259,6 +3267,363 @@ int enif_compare_monitors(const ErlNifMonitor *monitor1, ERTS_REF_THING_SIZE*sizeof(Eterm)); } +ErlNifIOQueue *enif_ioq_create(ErlNifIOQueueOpts opts) +{ + ErlNifIOQueue *q; + + if (opts != ERL_NIF_IOQ_NORMAL) + return NULL; + + q = enif_alloc(sizeof(ErlNifIOQueue)); + if (!q) return NULL; + erts_ioq_init(q, ERTS_ALC_T_NIF, 0); + + return q; +} + +void enif_ioq_destroy(ErlNifIOQueue *q) +{ + erts_ioq_clear(q); + enif_free(q); +} + +/* If the iovec was preallocated (Stack or otherwise) it needs to be marked as + * such to perform a proper free. */ +#define ERL_NIF_IOVEC_FLAGS_PREALLOC (1 << 0) + +void enif_free_iovec(ErlNifIOVec *iov) +{ + int i; + /* Decrement the refc of all the binaries */ + for (i = 0; i < iov->iovcnt; i++) { + Binary *bptr = ((Binary**)iov->ref_bins)[i]; + /* bptr can be null if enq_binary was used */ + if (bptr && erts_refc_dectest(&bptr->intern.refc, 0) == 0) { + erts_bin_free(bptr); + } + } + + if (!(iov->flags & ERL_NIF_IOVEC_FLAGS_PREALLOC)) { + enif_free(iov); + } +} + +typedef struct { + UWord sublist_length; + Eterm sublist_start; + Eterm sublist_end; + + UWord offheap_size; + UWord onheap_size; + + UWord iovec_len; +} iovec_slice_t; + +static int examine_iovec_term(Eterm list, UWord max_length, iovec_slice_t *result) { + Eterm lookahead; + + result->sublist_start = list; + result->sublist_length = 0; + result->offheap_size = 0; + result->onheap_size = 0; + result->iovec_len = 0; + + lookahead = result->sublist_start; + + while (is_list(lookahead)) { + Eterm *binary_header, binary; + Eterm *cell; + UWord size; + + cell = list_val(lookahead); + binary = CAR(cell); + + if (!is_binary(binary)) { + return 0; + } + + size = binary_size(binary); + binary_header = binary_val(binary); + + /* If we're a sub-binary we'll need to check our underlying binary to + * determine whether we're on-heap or not. */ + if(thing_subtag(*binary_header) == SUB_BINARY_SUBTAG) { + ErlSubBin *sb = (ErlSubBin*)binary_header; + + /* Reject bitstrings */ + if((sb->bitoffs + sb->bitsize) > 0) { + return 0; + } + + ASSERT(size <= binary_size(sb->orig)); + binary_header = binary_val(sb->orig); + } + + if(thing_subtag(*binary_header) == HEAP_BINARY_SUBTAG) { + ASSERT(size <= ERL_ONHEAP_BIN_LIMIT); + + result->iovec_len += 1; + result->onheap_size += size; + } else { + ASSERT(thing_subtag(*binary_header) == REFC_BINARY_SUBTAG); + + result->iovec_len += 1 + size / MAX_SYSIOVEC_IOVLEN; + result->offheap_size += size; + } + + result->sublist_length += 1; + lookahead = CDR(cell); + + if(result->sublist_length >= max_length) { + break; + } + } + + if (!is_nil(lookahead) && !is_list(lookahead)) { + return 0; + } + + result->sublist_end = lookahead; + + return 1; +} + +static void inspect_raw_binary_data(Eterm binary, ErlNifBinary *result) { + Eterm *parent_header; + Eterm parent_binary; + + int bit_offset, bit_size; + Uint byte_offset; + + ASSERT(is_binary(binary)); + + ERTS_GET_REAL_BIN(binary, parent_binary, byte_offset, bit_offset, bit_size); + + parent_header = binary_val(parent_binary); + + result->size = binary_size(binary); + result->bin_term = binary; + + if (thing_subtag(*parent_header) == REFC_BINARY_SUBTAG) { + ProcBin *pb = (ProcBin*)parent_header; + + ASSERT(pb->val != NULL); + ASSERT(byte_offset < pb->size); + ASSERT(&pb->bytes[byte_offset] >= (byte*)(pb->val)->orig_bytes); + + result->data = (unsigned char*)&pb->bytes[byte_offset]; + result->ref_bin = (void*)pb->val; + } else { + ErlHeapBin *hb = (ErlHeapBin*)parent_header; + + ASSERT(thing_subtag(*parent_header) == HEAP_BINARY_SUBTAG); + + result->data = &((unsigned char*)&hb->data)[byte_offset]; + result->ref_bin = NULL; + } +} + +static int fill_iovec_with_slice(ErlNifEnv *env, + iovec_slice_t *slice, + ErlNifIOVec *iovec) { + UWord onheap_offset, iovec_idx; + ErlNifBinary onheap_data; + Eterm sublist_iterator; + + /* Set up a common refc binary for all on-heap binaries. */ + if (slice->onheap_size > 0) { + if (!enif_alloc_binary(slice->onheap_size, &onheap_data)) { + return 0; + } + } + + sublist_iterator = slice->sublist_start; + onheap_offset = 0; + iovec_idx = 0; + + while (sublist_iterator != slice->sublist_end) { + ErlNifBinary raw_data; + Eterm *cell; + + cell = list_val(sublist_iterator); + inspect_raw_binary_data(CAR(cell), &raw_data); + + /* If this isn't a refc binary, copy its contents to the onheap buffer + * and reference that instead. */ + if (raw_data.ref_bin == NULL) { + ASSERT(onheap_offset < onheap_data.size); + ASSERT(slice->onheap_size > 0); + + sys_memcpy(&onheap_data.data[onheap_offset], + raw_data.data, raw_data.size); + + raw_data.data = &onheap_data.data[onheap_offset]; + raw_data.ref_bin = onheap_data.ref_bin; + } + + ASSERT(raw_data.ref_bin != NULL); + + while (raw_data.size > 0) { + UWord chunk_len = MIN(raw_data.size, MAX_SYSIOVEC_IOVLEN); + + ASSERT(iovec_idx < iovec->iovcnt); + + iovec->iov[iovec_idx].iov_base = raw_data.data; + iovec->iov[iovec_idx].iov_len = chunk_len; + + iovec->ref_bins[iovec_idx] = raw_data.ref_bin; + + raw_data.data += chunk_len; + raw_data.size -= chunk_len; + + iovec_idx += 1; + } + + sublist_iterator = CDR(cell); + } + + ASSERT(iovec_idx == iovec->iovcnt); + + if (env == NULL) { + int i; + for (i = 0; i < iovec->iovcnt; i++) { + Binary *refc_binary = (Binary*)(iovec->ref_bins[i]); + erts_refc_inc(&refc_binary->intern.refc, 1); + } + + if (slice->onheap_size > 0) { + /* Transfer ownership to the iovec; we've taken references to it in + * the above loop. */ + enif_release_binary(&onheap_data); + } + } else { + if (slice->onheap_size > 0) { + /* Attach the binary to our environment and let the GC take care of + * it after returning. */ + enif_make_binary(env, &onheap_data); + } + } + + return 1; +} + +static int create_iovec_from_slice(ErlNifEnv *env, + iovec_slice_t *slice, + ErlNifIOVec **result) { + ErlNifIOVec *iovec = *result; + + if (iovec && slice->iovec_len < ERL_NIF_IOVEC_SIZE) { + iovec->iov = iovec->small_iov; + iovec->ref_bins = iovec->small_ref_bin; + iovec->flags = ERL_NIF_IOVEC_FLAGS_PREALLOC; + } else { + UWord iov_offset, binv_offset, alloc_size; + char *alloc_base; + + iov_offset = ERTS_ALC_DATA_ALIGN_SIZE(sizeof(ErlNifIOVec)); + binv_offset = iov_offset; + binv_offset += ERTS_ALC_DATA_ALIGN_SIZE(slice->iovec_len * sizeof(SysIOVec)); + alloc_size = binv_offset; + alloc_size += slice->iovec_len * sizeof(Binary*); + + /* If we have an environment we'll attach the allocated data to it. The + * GC will take care of releasing it later on. */ + if (env != NULL) { + ErlNifBinary gc_bin; + + if (!enif_alloc_binary(alloc_size, &gc_bin)) { + return 0; + } + + alloc_base = (char*)gc_bin.data; + enif_make_binary(env, &gc_bin); + } else { + alloc_base = enif_alloc(alloc_size); + } + + iovec = (ErlNifIOVec*)alloc_base; + iovec->iov = (SysIOVec*)(alloc_base + iov_offset); + iovec->ref_bins = (void**)(alloc_base + binv_offset); + iovec->flags = 0; + } + + iovec->size = slice->offheap_size + slice->onheap_size; + iovec->iovcnt = slice->iovec_len; + + if(!fill_iovec_with_slice(env, slice, iovec)) { + if (env == NULL && !(iovec->flags & ERL_NIF_IOVEC_FLAGS_PREALLOC)) { + enif_free(iovec); + } + + return 0; + } + + *result = iovec; + + return 1; +} + +int enif_inspect_iovec(ErlNifEnv *env, size_t max_elements, + ERL_NIF_TERM list, ERL_NIF_TERM *tail, + ErlNifIOVec **iov) { + iovec_slice_t slice; + + if(!examine_iovec_term(list, max_elements, &slice)) { + return 0; + } else if(!create_iovec_from_slice(env, &slice, iov)) { + return 0; + } + + (*tail) = slice.sublist_end; + + return 1; +} + +/* */ +int enif_ioq_enqv(ErlNifIOQueue *q, ErlNifIOVec *iov, size_t skip) +{ + if(skip <= iov->size) { + return !erts_ioq_enqv(q, (ErtsIOVec*)iov, skip); + } + + return 0; +} + +int enif_ioq_enq_binary(ErlNifIOQueue *q, ErlNifBinary *bin, size_t skip) +{ + ErlNifIOVec vec = {1, bin->size, NULL, NULL, ERL_NIF_IOVEC_FLAGS_PREALLOC }; + Binary *ref_bin = (Binary*)bin->ref_bin; + int res; + vec.iov = vec.small_iov; + vec.ref_bins = vec.small_ref_bin; + vec.iov[0].iov_base = bin->data; + vec.iov[0].iov_len = bin->size; + ((Binary**)(vec.ref_bins))[0] = ref_bin; + + res = enif_ioq_enqv(q, &vec, skip); + enif_release_binary(bin); + return res; +} + +size_t enif_ioq_size(ErlNifIOQueue *q) +{ + return erts_ioq_size(q); +} + +int enif_ioq_deq(ErlNifIOQueue *q, size_t elems, size_t *size) +{ + if (erts_ioq_deq(q, elems) == -1) + return 0; + if (size) + *size = erts_ioq_size(q); + return 1; +} + +SysIOVec *enif_ioq_peek(ErlNifIOQueue *q, int *iovlen) +{ + return erts_ioq_peekq(q, iovlen); +} + /*************************************************************************** ** load_nif/2 ** ***************************************************************************/ |