unix: merge Linux readv/writev implementation with Darwin/OpenBSD This reduces some code duplication. Change-Id: Ib648f90a26960d0bc25d2fe27e9b3fb1419ac02d Reviewed-on: https://go-review.googlesource.com/c/sys/+/777161 Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com> LUCI-TryBot-Result: golang-scoped@luci-project-accounts.iam.gserviceaccount.com <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Cherry Mui <cherryyz@google.com> Auto-Submit: Ian Lance Taylor <iant@golang.org>
diff --git a/unix/readv_unix.go b/unix/readv_unix.go index 7725ec8..38a2be9 100644 --- a/unix/readv_unix.go +++ b/unix/readv_unix.go
@@ -2,17 +2,21 @@ // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. -//go:build darwin || openbsd +//go:build darwin || linux || openbsd package unix import "unsafe" +// minIovec is the size of the small initial allocation used by +// Readv, Writev, etc. +// // This small allocation gets stack allocated, which lets the // common use case of len(iovs) <= minIovec avoid more expensive // heap allocations. const minIovec = 8 +// appendBytes converts bs to Iovecs and appends them to vecs. func appendBytes(vecs []Iovec, bs [][]byte) []Iovec { for _, b := range bs { var v Iovec @@ -27,7 +31,9 @@ return vecs } -func writevRacedetect(iovecs []Iovec, n int) { +// writevRaceDetect tells the race detector that the program +// has read the first n bytes stored in iovecs. +func writevRaceDetect(iovecs []Iovec, n int) { if !raceenabled { return } @@ -40,7 +46,9 @@ } } -func readvRacedetect(iovecs []Iovec, n int, err error) { +// readvRaceDetect tells the race detector that the program +// has written to the first n bytes stored in iovecs. +func readvRaceDetect(iovecs []Iovec, n int, err error) { if !raceenabled { return } @@ -60,7 +68,7 @@ iovecs := make([]Iovec, 0, minIovec) iovecs = appendBytes(iovecs, iovs) n, err = readv(fd, iovecs) - readvRacedetect(iovecs, n, err) + readvRaceDetect(iovecs, n, err) return n, err } @@ -68,7 +76,7 @@ iovecs := make([]Iovec, 0, minIovec) iovecs = appendBytes(iovecs, iovs) n, err = preadv(fd, iovecs, offset) - readvRacedetect(iovecs, n, err) + readvRaceDetect(iovecs, n, err) return n, err } @@ -79,7 +87,7 @@ raceReleaseMerge(unsafe.Pointer(&ioSync)) } n, err = writev(fd, iovecs) - writevRacedetect(iovecs, n) + writevRaceDetect(iovecs, n) return n, err } @@ -90,6 +98,6 @@ raceReleaseMerge(unsafe.Pointer(&ioSync)) } n, err = pwritev(fd, iovecs, offset) - writevRacedetect(iovecs, n) + writevRaceDetect(iovecs, n) return n, err }
diff --git a/unix/readv_unix_test.go b/unix/readv_unix_test.go index f753e61..2193c42 100644 --- a/unix/readv_unix_test.go +++ b/unix/readv_unix_test.go
@@ -2,7 +2,7 @@ // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. -//go:build darwin || openbsd +//go:build darwin || linux || openbsd package unix_test
diff --git a/unix/syscall_linux.go b/unix/syscall_linux.go index f7b82bc..ce4d7ab 100644 --- a/unix/syscall_linux.go +++ b/unix/syscall_linux.go
@@ -2150,33 +2150,10 @@ //sys exitThread(code int) (err error) = SYS_EXIT //sys readv(fd int, iovs []Iovec) (n int, err error) = SYS_READV //sys writev(fd int, iovs []Iovec) (n int, err error) = SYS_WRITEV -//sys preadv(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr) (n int, err error) = SYS_PREADV -//sys pwritev(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr) (n int, err error) = SYS_PWRITEV -//sys preadv2(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr, flags int) (n int, err error) = SYS_PREADV2 -//sys pwritev2(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr, flags int) (n int, err error) = SYS_PWRITEV2 - -// minIovec is the size of the small initial allocation used by -// Readv, Writev, etc. -// -// This small allocation gets stack allocated, which lets the -// common use case of len(iovs) <= minIovs avoid more expensive -// heap allocations. -const minIovec = 8 - -// appendBytes converts bs to Iovecs and appends them to vecs. -func appendBytes(vecs []Iovec, bs [][]byte) []Iovec { - for _, b := range bs { - var v Iovec - v.SetLen(len(b)) - if len(b) > 0 { - v.Base = &b[0] - } else { - v.Base = (*byte)(unsafe.Pointer(&_zero)) - } - vecs = append(vecs, v) - } - return vecs -} +//sys preadvSyscall(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr) (n int, err error) = SYS_PREADV +//sys pwritevSyscall(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr) (n int, err error) = SYS_PWRITEV +//sys preadv2Syscall(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr, flags int) (n int, err error) = SYS_PREADV2 +//sys pwritev2Syscall(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr, flags int) (n int, err error) = SYS_PWRITEV2 // offs2lohi splits offs into its low and high order bits. func offs2lohi(offs int64) (lo, hi uintptr) { @@ -2184,69 +2161,23 @@ return uintptr(offs), uintptr(uint64(offs) >> (longBits - 1) >> 1) // two shifts to avoid false positive in vet } -func Readv(fd int, iovs [][]byte) (n int, err error) { - iovecs := make([]Iovec, 0, minIovec) - iovecs = appendBytes(iovecs, iovs) - n, err = readv(fd, iovecs) - readvRacedetect(iovecs, n, err) - return n, err -} - -func Preadv(fd int, iovs [][]byte, offset int64) (n int, err error) { - iovecs := make([]Iovec, 0, minIovec) - iovecs = appendBytes(iovecs, iovs) +func preadv(fd int, iovecs []Iovec, offset int64) (n int, err error) { lo, hi := offs2lohi(offset) - n, err = preadv(fd, iovecs, lo, hi) - readvRacedetect(iovecs, n, err) - return n, err + return preadvSyscall(fd, iovecs, lo, hi) } func Preadv2(fd int, iovs [][]byte, offset int64, flags int) (n int, err error) { iovecs := make([]Iovec, 0, minIovec) iovecs = appendBytes(iovecs, iovs) lo, hi := offs2lohi(offset) - n, err = preadv2(fd, iovecs, lo, hi, flags) - readvRacedetect(iovecs, n, err) + n, err = preadv2Syscall(fd, iovecs, lo, hi, flags) + readvRaceDetect(iovecs, n, err) return n, err } -func readvRacedetect(iovecs []Iovec, n int, err error) { - if !raceenabled { - return - } - for i := 0; n > 0 && i < len(iovecs); i++ { - m := min(int(iovecs[i].Len), n) - n -= m - if m > 0 { - raceWriteRange(unsafe.Pointer(iovecs[i].Base), m) - } - } - if err == nil { - raceAcquire(unsafe.Pointer(&ioSync)) - } -} - -func Writev(fd int, iovs [][]byte) (n int, err error) { - iovecs := make([]Iovec, 0, minIovec) - iovecs = appendBytes(iovecs, iovs) - if raceenabled { - raceReleaseMerge(unsafe.Pointer(&ioSync)) - } - n, err = writev(fd, iovecs) - writevRacedetect(iovecs, n) - return n, err -} - -func Pwritev(fd int, iovs [][]byte, offset int64) (n int, err error) { - iovecs := make([]Iovec, 0, minIovec) - iovecs = appendBytes(iovecs, iovs) - if raceenabled { - raceReleaseMerge(unsafe.Pointer(&ioSync)) - } +func pwritev(fd int, iovecs []Iovec, offset int64) (n int, err error) { lo, hi := offs2lohi(offset) - n, err = pwritev(fd, iovecs, lo, hi) - writevRacedetect(iovecs, n) - return n, err + return pwritevSyscall(fd, iovecs, lo, hi) } func Pwritev2(fd int, iovs [][]byte, offset int64, flags int) (n int, err error) { @@ -2256,24 +2187,11 @@ raceReleaseMerge(unsafe.Pointer(&ioSync)) } lo, hi := offs2lohi(offset) - n, err = pwritev2(fd, iovecs, lo, hi, flags) - writevRacedetect(iovecs, n) + n, err = pwritev2Syscall(fd, iovecs, lo, hi, flags) + writevRaceDetect(iovecs, n) return n, err } -func writevRacedetect(iovecs []Iovec, n int) { - if !raceenabled { - return - } - for i := 0; n > 0 && i < len(iovecs); i++ { - m := min(int(iovecs[i].Len), n) - n -= m - if m > 0 { - raceReadRange(unsafe.Pointer(iovecs[i].Base), m) - } - } -} - // mmap varies by architecture; see syscall_linux_*.go. //sys munmap(addr uintptr, length uintptr) (err error) //sys mremap(oldaddr uintptr, oldlength uintptr, newlength uintptr, flags int, newaddr uintptr) (xaddr uintptr, err error)
diff --git a/unix/zsyscall_linux.go b/unix/zsyscall_linux.go index 886f5de..80f40e4 100644 --- a/unix/zsyscall_linux.go +++ b/unix/zsyscall_linux.go
@@ -1785,7 +1785,7 @@ // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT -func preadv(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr) (n int, err error) { +func preadvSyscall(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr) (n int, err error) { var _p0 unsafe.Pointer if len(iovs) > 0 { _p0 = unsafe.Pointer(&iovs[0]) @@ -1802,7 +1802,7 @@ // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT -func pwritev(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr) (n int, err error) { +func pwritevSyscall(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr) (n int, err error) { var _p0 unsafe.Pointer if len(iovs) > 0 { _p0 = unsafe.Pointer(&iovs[0]) @@ -1819,7 +1819,7 @@ // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT -func preadv2(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr, flags int) (n int, err error) { +func preadv2Syscall(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr, flags int) (n int, err error) { var _p0 unsafe.Pointer if len(iovs) > 0 { _p0 = unsafe.Pointer(&iovs[0]) @@ -1836,7 +1836,7 @@ // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT -func pwritev2(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr, flags int) (n int, err error) { +func pwritev2Syscall(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr, flags int) (n int, err error) { var _p0 unsafe.Pointer if len(iovs) > 0 { _p0 = unsafe.Pointer(&iovs[0])