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authorLukas Larsson <[email protected]>2017-02-24 19:38:37 +0100
committerLukas Larsson <[email protected]>2017-09-05 14:35:26 +0200
commit314702f86c9199957e40edfb73bcdbddb422f9d7 (patch)
tree08421d1740b23964f62eaefa74321528897bb06a /erts/emulator/beam/erl_nif.c
parent520310feef0d76c0f99447187f3574408b219ae5 (diff)
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erts: Add nif ioq
Diffstat (limited to 'erts/emulator/beam/erl_nif.c')
-rw-r--r--erts/emulator/beam/erl_nif.c365
1 files changed, 365 insertions, 0 deletions
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index d3c5af3a83..0ebb2b6db0 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
@@ -3344,6 +3352,363 @@ 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 **
***************************************************************************/