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Diffstat (limited to 'erts/emulator/beam/erl_io_queue.h')
| -rw-r--r-- | erts/emulator/beam/erl_io_queue.h | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/erts/emulator/beam/erl_io_queue.h b/erts/emulator/beam/erl_io_queue.h new file mode 100644 index 0000000000..51abe99510 --- /dev/null +++ b/erts/emulator/beam/erl_io_queue.h @@ -0,0 +1,201 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson AB 2017. All Rights Reserved. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * %CopyrightEnd% + */ + +/* + * Description: A queue used for storing binary data that should be + * passed to writev or similar functions. Used by both + * the nif and driver api. + * + * Author: Lukas Larsson + */ + +#ifndef ERL_IO_QUEUE_H__TYPES__ +#define ERL_IO_QUEUE_H__TYPES__ + +#define ERTS_BINARY_TYPES_ONLY__ +#include "erl_binary.h" +#undef ERTS_BINARY_TYPES_ONLY__ +#include "erl_nif.h" + +#ifdef DEBUG +#define MAX_SYSIOVEC_IOVLEN (1ull << (32 - 1)) +#else +#define MAX_SYSIOVEC_IOVLEN (1ull << (sizeof(((SysIOVec*)0)->iov_len) * 8 - 1)) +#endif + +#define ERTS_SMALL_IO_QUEUE 5 + +typedef union { + ErlDrvBinary driver; + Binary nif; +} ErtsIOQBinary; + +typedef struct { + int vsize; /* length of vectors */ + Uint size; /* total size in bytes */ + SysIOVec* iov; + ErtsIOQBinary** binv; +} ErtsIOVecCommon; + +typedef union { + ErtsIOVecCommon common; + ErlIOVec driver; + ErlNifIOVec nif; +} ErtsIOVec; + +/* head/tail represent the data in the queue + * start/end represent the edges of the allocated queue + * small is used when the number of iovec elements is < SMALL_IO_QUEUE + */ +typedef struct erts_io_queue { + ErtsAlcType_t alct; + int driver; + Uint size; /* total size in bytes */ + + SysIOVec* v_start; + SysIOVec* v_end; + SysIOVec* v_head; + SysIOVec* v_tail; + SysIOVec v_small[ERTS_SMALL_IO_QUEUE]; + + ErtsIOQBinary **b_start; + ErtsIOQBinary **b_end; + ErtsIOQBinary **b_head; + ErtsIOQBinary **b_tail; + ErtsIOQBinary *b_small[ERTS_SMALL_IO_QUEUE]; + +} ErtsIOQueue; + +#endif /* ERL_IO_QUEUE_H__TYPES__ */ + +#if !defined(ERL_IO_QUEUE_H) && !defined(ERTS_IO_QUEUE_TYPES_ONLY__) +#define ERL_IO_QUEUE_H + +#include "erl_binary.h" +#include "erl_bits.h" + +void erts_ioq_init(ErtsIOQueue *q, ErtsAlcType_t alct, int driver); +void erts_ioq_clear(ErtsIOQueue *q); +Uint erts_ioq_size(ErtsIOQueue *q); +int erts_ioq_enqv(ErtsIOQueue *q, ErtsIOVec *vec, Uint skip); +int erts_ioq_pushqv(ErtsIOQueue *q, ErtsIOVec *vec, Uint skip); +int erts_ioq_deq(ErtsIOQueue *q, Uint Uint); +Uint erts_ioq_peekqv(ErtsIOQueue *q, ErtsIOVec *ev); +SysIOVec *erts_ioq_peekq(ErtsIOQueue *q, int *vlenp); +Uint erts_ioq_sizeq(ErtsIOQueue *q); + +int erts_ioq_iolist_vec_len(Eterm obj, int* vsize, Uint* csize, + Uint* pvsize, Uint* pcsize, + Uint* total_size, Uint blimit); +int erts_ioq_iolist_to_vec(Eterm obj, SysIOVec* iov, + ErtsIOQBinary** binv, ErtsIOQBinary* cbin, + Uint bin_limit, int driver_binary); + +ERTS_GLB_INLINE +int erts_ioq_iodata_vec_len(Eterm obj, int* vsize, Uint* csize, + Uint* pvsize, Uint* pcsize, + Uint* total_size, Uint blimit); +ERTS_GLB_INLINE +int erts_ioq_iodata_to_vec(Eterm obj, SysIOVec* iov, + ErtsIOQBinary** binv, ErtsIOQBinary* cbin, + Uint bin_limit, int driver_binary); + + +#if ERTS_GLB_INLINE_INCL_FUNC_DEF + +ERTS_GLB_INLINE +int erts_ioq_iodata_vec_len(Eterm obj, int* vsize, Uint* csize, + Uint* pvsize, Uint* pcsize, + Uint* total_size, Uint blimit) { + if (is_binary(obj)) { + /* We optimize for when we get a procbin without a bit-offset + * that fits in one iov slot + */ + Eterm real_bin; + byte bitoffs; + byte bitsize; + ERTS_DECLARE_DUMMY(Uint offset); + Uint size = binary_size(obj); + ERTS_GET_REAL_BIN(obj, real_bin, offset, bitoffs, bitsize); + if (size < MAX_SYSIOVEC_IOVLEN && bitoffs == 0 && bitsize == 0) { + *vsize = 1; + *pvsize = 1; + if (thing_subtag(*binary_val(real_bin)) == REFC_BINARY_SUBTAG) { + *csize = 0; + *pcsize = 0; + } else { + *csize = size; + *pcsize = size; + } + *total_size = size; + return 0; + } + } + + return erts_ioq_iolist_vec_len(obj, vsize, csize, + pvsize, pcsize, total_size, blimit); +} + +ERTS_GLB_INLINE +int erts_ioq_iodata_to_vec(Eterm obj, + SysIOVec *iov, + ErtsIOQBinary **binv, + ErtsIOQBinary *cbin, + Uint bin_limit, + int driver) +{ + if (is_binary(obj)) { + Eterm real_bin; + byte bitoffs; + byte bitsize; + Uint offset; + Uint size = binary_size(obj); + ERTS_GET_REAL_BIN(obj, real_bin, offset, bitoffs, bitsize); + if (size < MAX_SYSIOVEC_IOVLEN && bitoffs == 0 && bitsize == 0) { + Eterm *bptr = binary_val(real_bin); + if (thing_subtag(*bptr) == REFC_BINARY_SUBTAG) { + ProcBin *pb = (ProcBin *)bptr; + if (pb->flags) + erts_emasculate_writable_binary(pb); + iov[0].iov_base = pb->bytes+offset; + iov[0].iov_len = size; + if (driver) + binv[0] = (ErtsIOQBinary*)Binary2ErlDrvBinary(pb->val); + else + binv[0] = (ErtsIOQBinary*)pb->val; + return 1; + } else { + ErlHeapBin* hb = (ErlHeapBin *)bptr; + byte *buf = driver ? (byte*)cbin->driver.orig_bytes : + (byte*)cbin->nif.orig_bytes; + copy_binary_to_buffer(buf, 0, ((byte *) hb->data)+offset, 0, 8*size); + iov[0].iov_base = buf; + iov[0].iov_len = size; + binv[0] = cbin; + return 1; + } + } + } + return erts_ioq_iolist_to_vec(obj, iov, binv, cbin, bin_limit, driver); +} + +#endif + +#endif /* ERL_IO_QUEUE_H */ |