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2021-08-12[dev.typeparams] all: merge master (46fd547) into dev.typeparamsMatthew Dempsky
Conflicts: - src/go/types/check_test.go CL 324730 on dev.typeparams changed the directory paths in TestCheck, TestExamples, and TestFixedbugs and renamed checkFiles to testFiles; whereas CL 337529 on master added a new test case just above them and that used checkFiles. Merge List: + 2021-08-12 46fd547d89 internal/goversion: update Version to 1.18 + 2021-08-12 5805efc78e doc/go1.17: remove draft notice + 2021-08-12 39634e7dae CONTRIBUTORS: update for the Go 1.17 release + 2021-08-12 095bb790e1 os/exec: re-enable LookPathTest/16 + 2021-08-11 dea23e9ca8 src/make.*: make --no-clean flag a no-op that prints a warning + 2021-08-11 d4c0ed26ac doc/go1.17: linker passes -I to extld as -Wl,--dynamic-linker + 2021-08-10 1f9c9d8530 doc: use "high address/low address" instead of "top/bottom" + 2021-08-09 f1dce319ff cmd/go: with -mod=vendor, don't panic if there are duplicate requirements + 2021-08-09 7aeaad5c86 runtime/cgo: when using msan explicitly unpoison cgoCallers + 2021-08-08 507cc341ec doc: add example for conversion from slice expressions to array ptr + 2021-08-07 891547e2d4 doc/go1.17: fix a typo introduced in CL 335135 + 2021-08-06 8eaf4d16bc make.bash: do not overwrite GO_LDSO if already set + 2021-08-06 63b968f4f8 doc/go1.17: clarify Modules changes + 2021-08-06 70546f6404 runtime: allow arm64 SEH to be called if illegal instruction + 2021-08-05 fd45e267c2 runtime: warn that KeepAlive is not an unsafe.Pointer workaround + 2021-08-04 6e738868a7 net/http: speed up and deflake TestCancelRequestWhenSharingConnection + 2021-08-02 8a7ee4c51e io/fs: don't use absolute path in DirEntry.Name doc + 2021-07-31 b8ca6e59ed all: gofmt + 2021-07-30 b7a85e0003 net/http/httputil: close incoming ReverseProxy request body + 2021-07-29 70fd4e47d7 runtime: avoid possible preemption when returning from Go to C + 2021-07-28 9eee0ed439 cmd/go: fix go.mod file name printed in error messages for replacements + 2021-07-28 b39e0f461c runtime: don't crash on nil pointers in checkptrAlignment + 2021-07-27 7cd10c1149 cmd/go: use .mod instead of .zip to determine if version has go.mod file + 2021-07-27 c8cf0f74e4 cmd/go: add missing flag in UsageLine + 2021-07-27 7ba8e796c9 testing: clarify T.Name returns a distinct name of the running test + 2021-07-27 33ff155970 go/types: preserve untyped constants on the RHS of a shift expression + 2021-07-26 840e583ff3 runtime: correct variable name in comment + 2021-07-26 bfbb288574 runtime: remove adjustTimers counter + 2021-07-26 9c81fd53b3 cmd/vet: add missing copyright header Change-Id: Ia80604d24c6f4205265683024e3100769cf32065
2021-07-29runtime: avoid possible preemption when returning from Go to CIan Lance Taylor
When returning from Go to C, it was possible for the goroutine to be preempted after calling unlockOSThread. This could happen when there a context function installed by SetCgoTraceback set a non-zero context, leading to a defer call in cgocallbackg1. The defer function wrapper, introduced in 1.17 as part of the regabi support, was not nosplit, and hence was a potential preemption point. If it did get preempted, the G would move to a new M. It would then attempt to return to C code on a different stack, typically leading to a SIGSEGV. Fix this in a simple way by postponing the unlockOSThread until after the other defer. Also check for the failure condition and fail early, rather than waiting for a SIGSEGV. Without the fix to cgocall.go, the test case fails about 50% of the time on my laptop. Fixes #47441 Change-Id: Ib8ca13215bd36cddc2a49e86698824a29c6a68ba Reviewed-on: https://go-review.googlesource.com/c/go/+/338197 Trust: Ian Lance Taylor <iant@golang.org> Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com>
2021-06-30[dev.typeparams] all: merge master (4711bf3) into dev.typeparamsMatthew Dempsky
Conflicts: - src/cmd/compile/internal/walk/builtin.go On dev.typeparams, CL 330194 changed OCHECKNIL to not require manual SetTypecheck(1) anymore; while on master, CL 331070 got rid of the OCHECKNIL altogether by moving the check into the runtime support functions. - src/internal/buildcfg/exp.go On master, CL 331109 refactored the logic for parsing the GOEXPERIMENT string, so that it could be more easily reused by cmd/go; while on dev.typeparams, several CLs tweaked the regabi experiment defaults. Merge List: + 2021-06-30 4711bf30e5 doc/go1.17: linkify "language changes" in the runtime section + 2021-06-30 ed56ea73e8 path/filepath: deflake TestEvalSymlinksAboveRoot on darwin + 2021-06-30 c080d0323b cmd/dist: pass -Wno-unknown-warning-option in swig_callback_lto + 2021-06-30 7d0e9e6e74 image/gif: fix typo in the comment (io.ReadByte -> io.ByteReader) + 2021-06-30 0fa3265fe1 os: change example to avoid deprecated function + 2021-06-30 d19a53338f image: add Uniform.RGBA64At and Rectangle.RGBA64At + 2021-06-30 c45e800e0c crypto/x509: don't fail on optional auth key id fields + 2021-06-29 f9d50953b9 net: fix failure of TestCVE202133195 + 2021-06-29 e294b8a49e doc/go1.17: fix typo "MacOS" -> "macOS" + 2021-06-29 3463852b76 math/big: fix typo of comment (`BytesScanner` to `ByteScanner`) + 2021-06-29 fd4b587da3 cmd/compile: suppress details error for invalid variadic argument type + 2021-06-29 e2e05af6e1 cmd/internal/obj/arm64: fix an encoding error of CMPW instruction + 2021-06-28 4bb0847b08 cmd/compile,runtime: change unsafe.Slice((*T)(nil), 0) to return []T(nil) + 2021-06-28 1519271a93 spec: change unsafe.Slice((*T)(nil), 0) to return []T(nil) + 2021-06-28 5385e2386b runtime/internal/atomic: drop Cas64 pointer indirection in comments + 2021-06-28 956c81bfe6 cmd/go: add GOEXPERIMENT to `go env` output + 2021-06-28 a1d27269d6 cmd/go: prep for 'go env' refactoring + 2021-06-28 901510ed4e cmd/link/internal/ld: skip the windows ASLR test when CGO_ENABLED=0 + 2021-06-28 361159c055 cmd/cgo: fix 'see gmp.go' to 'see doc.go' + 2021-06-27 c95464f0ea internal/buildcfg: refactor GOEXPERIMENT parsing code somewhat + 2021-06-25 ed01ceaf48 runtime/race: use race build tag on syso_test.go + 2021-06-25 d1916e5e84 go/types: in TestCheck/issues.src, import regexp/syntax instead of cmd/compile/internal/syntax + 2021-06-25 5160896c69 go/types: in TestStdlib, import from source instead of export data + 2021-06-25 d01bc571f7 runtime: make ncgocall a global counter Change-Id: I1ce4a3b3ff7c824c67ad66dd27d9d5f1d25c0023
2021-06-25runtime: make ncgocall a global counterTao Qingyun
ncgocall was stored per M, runtime.NumCgoCall lost the counter when a M die. Fixes #46789 Change-Id: I85831fbb2713f4c30d1800d07e1f47aa0031970e GitHub-Last-Rev: cbc15fa870de776d3fbf3b62fc9a5e01792e6a26 GitHub-Pull-Request: golang/go#46842 Reviewed-on: https://go-review.googlesource.com/c/go/+/329729 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> Trust: Alexander Rakoczy <alex@golang.org>
2021-06-17[dev.typeparams] runtime: fix import sort order [generated]Michael Anthony Knyszek
[git-generate] cd src/runtime goimports -w *.go Change-Id: I1387af0f2fd1a213dc2f4c122e83a8db0fcb15f0 Reviewed-on: https://go-review.googlesource.com/c/go/+/329189 Trust: Michael Knyszek <mknyszek@google.com> Run-TryBot: Michael Knyszek <mknyszek@google.com> Reviewed-by: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Go Bot <gobot@golang.org>
2021-06-17[dev.typeparams] runtime: replace uses of runtime/internal/sys.PtrSize with ↵Michael Anthony Knyszek
internal/goarch.PtrSize [generated] [git-generate] cd src/runtime/internal/math gofmt -w -r "sys.PtrSize -> goarch.PtrSize" . goimports -w *.go cd ../.. gofmt -w -r "sys.PtrSize -> goarch.PtrSize" . goimports -w *.go Change-Id: I43491cdd54d2e06d4d04152b3d213851b7d6d423 Reviewed-on: https://go-review.googlesource.com/c/go/+/328337 Trust: Michael Knyszek <mknyszek@google.com> Run-TryBot: Michael Knyszek <mknyszek@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2021-04-01runtime: fix uses of ABIInternal PCs in assemblyAustin Clements
The covers three kinds of uses: 1. Calls of closures from assembly. These are always ABIInternal calls without wrappers. I went through every indirect call in the runtime and I think mcall is the only case of assembly calling a Go closure in a way that's affected by ABIInternal. systemstack also calls a closure, but it takes no arguments. 2. Calls of Go functions that expect raw ABIInternal pointers. I also only found one of these: callbackasm1 -> cgocallback on Windows. These are trickier to find, though. 3. Finally, I found one case on NetBSD where new OS threads were directly calling the Go runtime entry-point from assembly via a PC, rather than going through a wrapper. This meant new threads may not have special registers set up. In this case, a change on all other OSes had already forced new thread entry to go through an ABI wrapper, so I just caught NetBSD up with that change. With this change, I'm able to run a "hello world" with GOEXPERIMENT=regabi,regabiargs. For #40724. Change-Id: I2a6d0e530c4fd4edf13484d923891c6160d683aa Reviewed-on: https://go-review.googlesource.com/c/go/+/305669 Trust: Austin Clements <austin@google.com> Run-TryBot: Austin Clements <austin@google.com> Reviewed-by: Cherry Zhang <cherryyz@google.com> Reviewed-by: Michael Knyszek <mknyszek@google.com> TryBot-Result: Go Bot <gobot@golang.org>
2021-02-19runtime: document, clean up internal/sysRuss Cox
Document what the values in internal/sys mean. Remove various special cases for arm64 in the code using StackAlign. Delete Uintreg - it was for GOARCH=amd64p32, which was specific to GOOS=nacl and has been retired. This CL is part of a stack adding windows/arm64 support (#36439), intended to land in the Go 1.17 cycle. This CL is, however, not windows/arm64-specific. It is cleanup meant to make the port (and future ports) easier. Change-Id: I40e8fa07b4e192298b6536b98a72a751951a4383 Reviewed-on: https://go-review.googlesource.com/c/go/+/288795 Trust: Russ Cox <rsc@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-11-03cmd/dist,cmd/go,runtime: add support for cgo on linux/riscv64Joel Sing
Fixes #36641 Change-Id: I51868d83ce341d78d33b221d184c5a5110c60d14 Reviewed-on: https://go-review.googlesource.com/c/go/+/263598 Trust: Joel Sing <joel@sing.id.au> Run-TryBot: Joel Sing <joel@sing.id.au> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-10-26runtime,cmd/cgo: simplify C -> Go call pathAustin Clements
This redesigns the way calls work from C to exported Go functions. It removes several steps from the call path, makes cmd/cgo no longer sensitive to the Go calling convention, and eliminates the use of reflectcall from cgo. In order to avoid generating a large amount of FFI glue between the C and Go ABIs, the cgo tool has long depended on generating a C function that marshals the arguments into a struct, and then the actual ABI switch happens in functions with fixed signatures that simply take a pointer to this struct. In a way, this CL simply pushes this idea further. Currently, the cgo tool generates this argument struct in the exact layout of the Go stack frame and depends on reflectcall to unpack it into the appropriate Go call (even though it's actually reflectcall'ing a function generated by cgo). In this CL, we decouple this struct from the Go stack layout. Instead, cgo generates a Go function that takes the struct, unpacks it, and calls the exported function. Since this generated function has a generic signature (like the rest of the call path), we don't need reflectcall and can instead depend on the Go compiler itself to implement the call to the exported Go function. One complication is that syscall.NewCallback on Windows, which converts a Go function into a C function pointer, depends on cgocallback's current dynamic calling approach since the signatures of the callbacks aren't known statically. For this specific case, we continue to depend on reflectcall. Really, the current approach makes some overly simplistic assumptions about translating the C ABI to the Go ABI. Now we're at least in a much better position to do a proper ABI translation. For comparison, the current cgo call path looks like: GoF (generated C function) -> crosscall2 (in cgo/asm_*.s) -> _cgoexp_GoF (generated Go function) -> cgocallback (in asm_*.s) -> cgocallback_gofunc (in asm_*.s) -> cgocallbackg (in cgocall.go) -> cgocallbackg1 (in cgocall.go) -> reflectcall (in asm_*.s) -> _cgoexpwrap_GoF (generated Go function) -> p.GoF Now the call path looks like: GoF (generated C function) -> crosscall2 (in cgo/asm_*.s) -> cgocallback (in asm_*.s) -> cgocallbackg (in cgocall.go) -> cgocallbackg1 (in cgocall.go) -> _cgoexp_GoF (generated Go function) -> p.GoF Notably: 1. We combine _cgoexp_GoF and _cgoexpwrap_GoF and move the combined operation to the end of the sequence. This combined function also handles reflectcall's previous role. 2. We combined cgocallback and cgocallback_gofunc since the only purpose of having both was to convert a raw PC into a Go function value. We instead construct the Go function value in cgocallbackg1. 3. cgocallbackg1 no longer reaches backwards through the stack to get the arguments to cgocallback_gofunc. Instead, we just pass the arguments down. 4. Currently, we need an explicit msanwrite to mark the results struct as written because reflectcall doesn't do this. Now, the results are written by regular Go assignments, so the Go compiler generates the necessary MSAN annotations. This also means we no longer need to track the size of the arguments frame. Updates #40724, since now we don't need to teach cgo about the register ABI or change how it uses reflectcall. Change-Id: I7840489a2597962aeb670e0c1798a16a7359c94f Reviewed-on: https://go-review.googlesource.com/c/go/+/258938 Trust: Austin Clements <austin@google.com> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-10-23syscall: support POSIX semantics for Linux syscallsAndrew G. Morgan
This change adds two new methods for invoking system calls under Linux: syscall.AllThreadsSyscall() and syscall.AllThreadsSyscall6(). These system call wrappers ensure that all OSThreads mirror a common system call. The wrappers serialize execution of the runtime to ensure no race conditions where any Go code observes a non-atomic OS state change. As such, the syscalls have higher runtime overhead than regular system calls, and only need to be used where such thread (or 'm' in the parlance of the runtime sources) consistency is required. The new support is used to enable these functions under Linux: syscall.Setegid(), syscall.Seteuid(), syscall.Setgroups(), syscall.Setgid(), syscall.Setregid(), syscall.Setreuid(), syscall.Setresgid(), syscall.Setresuid() and syscall.Setuid(). They work identically to their glibc counterparts. Extensive discussion of the background issue addressed in this patch can be found here: https://github.com/golang/go/issues/1435 In the case where cgo is used, the C runtime can launch pthreads that are not managed by the Go runtime. As such, the added syscall.AllThreadsSyscall*() return ENOTSUP when cgo is enabled. However, for the 9 syscall.Set*() functions listed above, when cgo is active, these functions redirect to invoke their C.set*() equivalents in glibc, which wraps the raw system calls with a nptl:setxid fixup mechanism. This achieves POSIX semantics for these functions in the combined Go and C runtime. As a side note, the glibc/nptl:setxid support (2019-11-30) does not extend to all security related system calls under Linux so using native Go (CGO_ENABLED=0) and these AllThreadsSyscall*()s, where needed, will yield more well defined/consistent behavior over all threads of a Go program. That is, using the syscall.AllThreadsSyscall*() wrappers for things like setting state through SYS_PRCTL and SYS_CAPSET etc. Fixes #1435 Change-Id: Ib1a3e16b9180f64223196a32fc0f9dce14d9105c Reviewed-on: https://go-review.googlesource.com/c/go/+/210639 Trust: Emmanuel Odeke <emm.odeke@gmail.com> Trust: Ian Lance Taylor <iant@golang.org> Trust: Michael Pratt <mpratt@google.com> Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com> Reviewed-by: Michael Pratt <mpratt@google.com> Reviewed-by: Austin Clements <austin@google.com>
2020-10-02runtime: update and tidy cgo callback descriptionAustin Clements
The documentation on how cgo callbacks (C -> Go calls) works internally has gotten somewhat stale. This CL refreshes it. Change-Id: I1ab66225c9da52d698d97ebeb4f3c7b9b5ee97db Reviewed-on: https://go-review.googlesource.com/c/go/+/258937 Trust: Austin Clements <austin@google.com> Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-08-27runtime: framepointers are no longer an experiment - hard code themKeith Randall
I think they are no longer experimental status. Might as well promote them to permanent. Change-Id: Id1259601b3dd2061dd60df86ee48080bfb575d2f Reviewed-on: https://go-review.googlesource.com/c/go/+/249857 Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: David Chase <drchase@google.com>
2020-08-17runtime: move checkmarks to a separate bitmapAustin Clements
Currently, the GC stores the object marks for checkmarks mode in the heap bitmap using a rather complex encoding: for one word objects, the checkmark is stored in the pointer/scalar bit since one word objects must be pointers; for larger objects, the checkmark is stored in what would be the scan/dead bit for the second word of the object. This encoding made more sense when the runtime used the first scan/dead bit as the regular mark bit, but we moved away from that long ago. This encoding and overloading of the heap bitmap bits causes a great deal of complexity in many parts of the allocator and garbage collector and leads to some subtle bugs like #15903. This CL moves the checkmarks mark bits into their own per-arena bitmap and reclaims the second scan/dead bit as a regular scan/dead bit. I tested this by enabling doubleCheck mode in heapBitsSetType and running in both regular and GODEBUG=gccheckmark=1 mode. Fixes #15903. No performance degradation. (Very slight improvement on a few benchmarks, but it's probably just noise.) name old time/op new time/op delta BiogoIgor 16.6s ± 1% 16.4s ± 1% -0.94% (p=0.000 n=25+24) BiogoKrishna 19.2s ± 3% 19.2s ± 3% ~ (p=0.638 n=23+25) BleveIndexBatch100 6.12s ± 5% 6.17s ± 4% ~ (p=0.170 n=25+25) CompileTemplate 206ms ± 1% 205ms ± 1% -0.43% (p=0.005 n=24+24) CompileUnicode 82.2ms ± 2% 81.5ms ± 2% -0.95% (p=0.001 n=22+22) CompileGoTypes 755ms ± 3% 754ms ± 4% ~ (p=0.715 n=25+25) CompileCompiler 3.73s ± 1% 3.73s ± 1% ~ (p=0.445 n=25+24) CompileSSA 8.67s ± 1% 8.66s ± 1% ~ (p=0.836 n=24+22) CompileFlate 134ms ± 2% 133ms ± 1% -0.66% (p=0.001 n=24+23) CompileGoParser 164ms ± 1% 163ms ± 1% -0.85% (p=0.000 n=24+24) CompileReflect 466ms ± 5% 466ms ± 3% ~ (p=0.863 n=25+25) CompileTar 182ms ± 1% 182ms ± 1% -0.31% (p=0.048 n=24+24) CompileXML 249ms ± 1% 248ms ± 1% -0.32% (p=0.031 n=21+25) CompileStdCmd 10.3s ± 1% 10.3s ± 1% ~ (p=0.459 n=23+23) FoglemanFauxGLRenderRotateBoat 8.66s ± 1% 8.62s ± 1% -0.47% (p=0.000 n=23+24) FoglemanPathTraceRenderGopherIter1 20.3s ± 3% 20.2s ± 2% ~ (p=0.893 n=25+25) GopherLuaKNucleotide 29.7s ± 1% 29.8s ± 2% ~ (p=0.421 n=24+25) MarkdownRenderXHTML 246ms ± 1% 247ms ± 1% ~ (p=0.558 n=25+24) Tile38WithinCircle100kmRequest 779µs ± 4% 779µs ± 3% ~ (p=0.954 n=25+25) Tile38IntersectsCircle100kmRequest 1.02ms ± 3% 1.01ms ± 4% ~ (p=0.658 n=25+25) Tile38KNearestLimit100Request 984µs ± 4% 986µs ± 4% ~ (p=0.627 n=24+25) [Geo mean] 552ms 551ms -0.19% https://perf.golang.org/search?q=upload:20200723.6 Change-Id: Ic703f26a83fb034941dc6f4788fc997d56890dec Reviewed-on: https://go-review.googlesource.com/c/go/+/244539 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: Martin Möhrmann <moehrmann@google.com>
2020-01-09runtime: protect against external code calling ExitProcessAustin Clements
On Windows, we implement asynchronous preemption using SuspendThread to suspend other threads in our process. However, SuspendThread is itself actually asynchronous (it enqueues a kernel "asynchronous procedure call" and returns). Unfortunately, Windows' ExitProcess API kills all threads except the calling one and then runs APCs. As a result, if SuspendThread and ExitProcess are called simultaneously, the exiting thread can be suspended and the suspending thread can be exited, leaving behind a ghost process consisting of a single thread that's suspended. We've already protected against the runtime's own calls to ExitProcess, but if Go code calls external code, there's nothing stopping that code from calling ExitProcess. For example, in #35775, our own call to racefini leads to C code calling ExitProcess and occasionally causing a deadlock. This CL fixes this by introducing synchronization between calling external code on Windows and preemption. It adds an atomic field to the M that participates in a simple CAS-based synchronization protocol to prevent suspending a thread running external code. We use this to protect cgocall (which is used for both cgo calls and system calls on Windows) and racefini. Tested by running the flag package's TestParse test compiled in race mode in a loop. Before this change, this would reliably deadlock after a few minutes. Fixes #35775. Updates #10958, #24543. Change-Id: I50d847abcdc2688b4f71eee6a75eca0f2fee892c Reviewed-on: https://go-review.googlesource.com/c/go/+/213837 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com> Reviewed-by: David Chase <drchase@google.com>
2019-10-03runtime: use efaceOf where applicableMatthew Dempsky
Prepared with gofmt -r. Change-Id: Ifea325c209d800b5692d318955930b10debb548b Reviewed-on: https://go-review.googlesource.com/c/go/+/198494 Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-10-02cmd/cgo: optimize cgoCheckPointer callEgon Elbre
Currently cgoCheckPointer is only used with one optional argument. Using a slice for the optional arguments is quite expensive, hence replace it with a single interface{}. This results in ~30% improvement. When checking struct fields, they quite often end up being without pointers. Check this before calling cgoCheckPointer, which results in additional ~20% improvement. Inline some p == nil checks from cgoIsGoPointer which gives additional ~15% improvement. All of this translates to: name old time/op new time/op delta CgoCall/add-int-32 46.9ns ± 1% 46.6ns ± 1% -0.75% (p=0.000 n=18+20) CgoCall/one-pointer-32 143ns ± 1% 87ns ± 1% -38.96% (p=0.000 n=20+20) CgoCall/eight-pointers-32 767ns ± 0% 327ns ± 1% -57.30% (p=0.000 n=18+16) CgoCall/eight-pointers-nil-32 110ns ± 1% 89ns ± 2% -19.10% (p=0.000 n=19+19) CgoCall/eight-pointers-array-32 5.09µs ± 1% 3.56µs ± 2% -30.09% (p=0.000 n=19+19) CgoCall/eight-pointers-slice-32 3.92µs ± 0% 2.57µs ± 2% -34.48% (p=0.000 n=20+20) Change-Id: I2aa9f5ae8962a9a41a7fb1db0c300893109d0d75 Reviewed-on: https://go-review.googlesource.com/c/go/+/198081 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-04-30all: add new GOOS=illumos, split out of GOOS=solarisJoshua M. Clulow
Like GOOS=android which implies the "linux" build tag, GOOS=illumos implies the "solaris" build tag. This lets the existing ecosystem of packages still work on illumos, but still permits packages to start differentiating between solaris and illumos. Fixes #20603 Change-Id: I8f4eabf1a66060538dca15d7658c1fbc6c826622 Reviewed-on: https://go-review.googlesource.com/c/go/+/174457 Run-TryBot: Benny Siegert <bsiegert@gmail.com> Reviewed-by: Benny Siegert <bsiegert@gmail.com> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-03-25runtime: remove kindNoPointersKeith Randall
We already have the ptrdata field in a type, which encodes exactly the same information that kindNoPointers does. My problem with kindNoPointers is that it often leads to double-negative code like: t.kind & kindNoPointers != 0 Much clearer is: t.ptrdata == 0 Update #27167 Change-Id: I92307d7f018a6bbe3daca4a4abb4225e359349b1 Reviewed-on: https://go-review.googlesource.com/c/go/+/169157 Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-12-02all: use "reports whether" consistently instead of "returns whether"Tobias Klauser
Follow-up for CL 147037 and after Brad noticed the "returns whether" pattern during the review of CL 150621. Go documentation style for boolean funcs is to say: // Foo reports whether ... func Foo() bool (rather than "returns whether") Created with: $ perl -i -npe 's/returns whether/reports whether/' $(git grep -l "returns whether" | grep -v vendor) Change-Id: I15fe9ff99180ad97750cd05a10eceafdb12dc0b4 Reviewed-on: https://go-review.googlesource.com/c/150918 Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-11-09runtime: never call into race detector with retaken PNikhil Benesch
cgocall could previously invoke the race detector on an M whose P had been retaken. The race detector would attempt to use the P-local state from this stale P, racing with the thread that was actually wired to that P. The result was memory corruption of ThreadSanitizer's internal data structures that presented as hard-to-understand assertion failures and segfaults. Reorder cgocall so that it always acquires a P before invoking the race detector, and add a test that stresses the interaction between cgo and the race detector to protect against future bugs of this kind. Fixes #27660. Change-Id: Ide93f96a23490314d6647547140e0a412a97f0d4 Reviewed-on: https://go-review.googlesource.com/c/148717 Run-TryBot: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
2018-08-29build: support frame-pointer for arm64Zheng Xu
Supporting frame-pointer makes Linux's perf and other profilers much more useful because it lets them gather a stack trace efficiently on profiling events. Major changes include: 1. save FP on the word below where RSP is pointing to (proposed by Cherry and Austin) 2. adjust some specific offsets in runtime assembly and wrapper code 3. add support to FP in goroutine scheduler 4. adjust link stack overflow check to take the extra word into account 5. adjust nosplit test cases to enable frame sizes which are 16 bytes aligned Performance impacts on go1 benchmarks: Enable frame-pointer (by default) name old time/op new time/op delta BinaryTree17-46 5.94s ± 0% 6.00s ± 0% +1.03% (p=0.029 n=4+4) Fannkuch11-46 2.84s ± 1% 2.77s ± 0% -2.58% (p=0.008 n=5+5) FmtFprintfEmpty-46 55.0ns ± 1% 58.9ns ± 1% +7.06% (p=0.008 n=5+5) FmtFprintfString-46 102ns ± 0% 105ns ± 0% +2.94% (p=0.008 n=5+5) FmtFprintfInt-46 118ns ± 0% 117ns ± 1% -1.19% (p=0.000 n=4+5) FmtFprintfIntInt-46 181ns ± 0% 182ns ± 1% ~ (p=0.444 n=5+5) FmtFprintfPrefixedInt-46 215ns ± 1% 214ns ± 0% ~ (p=0.254 n=5+4) FmtFprintfFloat-46 292ns ± 0% 296ns ± 0% +1.46% (p=0.029 n=4+4) FmtManyArgs-46 720ns ± 0% 732ns ± 0% +1.72% (p=0.008 n=5+5) GobDecode-46 9.82ms ± 1% 10.03ms ± 2% +2.10% (p=0.008 n=5+5) GobEncode-46 8.14ms ± 0% 8.72ms ± 1% +7.14% (p=0.008 n=5+5) Gzip-46 420ms ± 0% 424ms ± 0% +0.92% (p=0.008 n=5+5) Gunzip-46 48.2ms ± 0% 48.4ms ± 0% +0.41% (p=0.008 n=5+5) HTTPClientServer-46 201µs ± 4% 201µs ± 0% ~ (p=0.730 n=5+4) JSONEncode-46 17.1ms ± 0% 17.7ms ± 1% +3.80% (p=0.008 n=5+5) JSONDecode-46 88.0ms ± 0% 90.1ms ± 0% +2.42% (p=0.008 n=5+5) Mandelbrot200-46 5.06ms ± 0% 5.07ms ± 0% ~ (p=0.310 n=5+5) GoParse-46 5.04ms ± 0% 5.12ms ± 0% +1.53% (p=0.008 n=5+5) RegexpMatchEasy0_32-46 117ns ± 0% 117ns ± 0% ~ (all equal) RegexpMatchEasy0_1K-46 332ns ± 0% 329ns ± 0% -0.78% (p=0.008 n=5+5) RegexpMatchEasy1_32-46 104ns ± 0% 113ns ± 0% +8.65% (p=0.029 n=4+4) RegexpMatchEasy1_1K-46 563ns ± 0% 569ns ± 0% +1.10% (p=0.008 n=5+5) RegexpMatchMedium_32-46 167ns ± 2% 177ns ± 1% +5.74% (p=0.008 n=5+5) RegexpMatchMedium_1K-46 49.5µs ± 0% 53.4µs ± 0% +7.81% (p=0.008 n=5+5) RegexpMatchHard_32-46 2.56µs ± 1% 2.72µs ± 0% +6.01% (p=0.008 n=5+5) RegexpMatchHard_1K-46 77.0µs ± 0% 81.8µs ± 0% +6.24% (p=0.016 n=5+4) Revcomp-46 631ms ± 1% 627ms ± 1% ~ (p=0.095 n=5+5) Template-46 81.8ms ± 0% 86.3ms ± 0% +5.55% (p=0.008 n=5+5) TimeParse-46 423ns ± 0% 432ns ± 0% +2.32% (p=0.008 n=5+5) TimeFormat-46 478ns ± 2% 497ns ± 1% +3.89% (p=0.008 n=5+5) [Geo mean] 71.6µs 73.3µs +2.45% name old speed new speed delta GobDecode-46 78.1MB/s ± 1% 76.6MB/s ± 2% -2.04% (p=0.008 n=5+5) GobEncode-46 94.3MB/s ± 0% 88.0MB/s ± 1% -6.67% (p=0.008 n=5+5) Gzip-46 46.2MB/s ± 0% 45.8MB/s ± 0% -0.91% (p=0.008 n=5+5) Gunzip-46 403MB/s ± 0% 401MB/s ± 0% -0.41% (p=0.008 n=5+5) JSONEncode-46 114MB/s ± 0% 109MB/s ± 1% -3.66% (p=0.008 n=5+5) JSONDecode-46 22.0MB/s ± 0% 21.5MB/s ± 0% -2.35% (p=0.008 n=5+5) GoParse-46 11.5MB/s ± 0% 11.3MB/s ± 0% -1.51% (p=0.008 n=5+5) RegexpMatchEasy0_32-46 272MB/s ± 0% 272MB/s ± 1% ~ (p=0.190 n=4+5) RegexpMatchEasy0_1K-46 3.08GB/s ± 0% 3.11GB/s ± 0% +0.77% (p=0.008 n=5+5) RegexpMatchEasy1_32-46 306MB/s ± 0% 283MB/s ± 0% -7.63% (p=0.029 n=4+4) RegexpMatchEasy1_1K-46 1.82GB/s ± 0% 1.80GB/s ± 0% -1.07% (p=0.008 n=5+5) RegexpMatchMedium_32-46 5.99MB/s ± 0% 5.64MB/s ± 1% -5.77% (p=0.016 n=4+5) RegexpMatchMedium_1K-46 20.7MB/s ± 0% 19.2MB/s ± 0% -7.25% (p=0.008 n=5+5) RegexpMatchHard_32-46 12.5MB/s ± 1% 11.8MB/s ± 0% -5.66% (p=0.008 n=5+5) RegexpMatchHard_1K-46 13.3MB/s ± 0% 12.5MB/s ± 1% -6.01% (p=0.008 n=5+5) Revcomp-46 402MB/s ± 1% 405MB/s ± 1% ~ (p=0.095 n=5+5) Template-46 23.7MB/s ± 0% 22.5MB/s ± 0% -5.25% (p=0.008 n=5+5) [Geo mean] 82.2MB/s 79.6MB/s -3.26% Disable frame-pointer (GOEXPERIMENT=noframepointer) name old time/op new time/op delta BinaryTree17-46 5.94s ± 0% 5.96s ± 0% +0.39% (p=0.029 n=4+4) Fannkuch11-46 2.84s ± 1% 2.79s ± 1% -1.68% (p=0.008 n=5+5) FmtFprintfEmpty-46 55.0ns ± 1% 55.2ns ± 3% ~ (p=0.794 n=5+5) FmtFprintfString-46 102ns ± 0% 103ns ± 0% +0.98% (p=0.016 n=5+4) FmtFprintfInt-46 118ns ± 0% 115ns ± 0% -2.54% (p=0.029 n=4+4) FmtFprintfIntInt-46 181ns ± 0% 179ns ± 0% -1.10% (p=0.000 n=5+4) FmtFprintfPrefixedInt-46 215ns ± 1% 213ns ± 0% ~ (p=0.143 n=5+4) FmtFprintfFloat-46 292ns ± 0% 300ns ± 0% +2.83% (p=0.029 n=4+4) FmtManyArgs-46 720ns ± 0% 739ns ± 0% +2.64% (p=0.008 n=5+5) GobDecode-46 9.82ms ± 1% 9.78ms ± 1% ~ (p=0.151 n=5+5) GobEncode-46 8.14ms ± 0% 8.12ms ± 1% ~ (p=0.690 n=5+5) Gzip-46 420ms ± 0% 420ms ± 0% ~ (p=0.548 n=5+5) Gunzip-46 48.2ms ± 0% 48.0ms ± 0% -0.33% (p=0.032 n=5+5) HTTPClientServer-46 201µs ± 4% 199µs ± 3% ~ (p=0.548 n=5+5) JSONEncode-46 17.1ms ± 0% 17.2ms ± 0% ~ (p=0.056 n=5+5) JSONDecode-46 88.0ms ± 0% 88.6ms ± 0% +0.64% (p=0.008 n=5+5) Mandelbrot200-46 5.06ms ± 0% 5.07ms ± 0% ~ (p=0.548 n=5+5) GoParse-46 5.04ms ± 0% 5.07ms ± 0% +0.65% (p=0.008 n=5+5) RegexpMatchEasy0_32-46 117ns ± 0% 112ns ± 4% -4.27% (p=0.016 n=4+5) RegexpMatchEasy0_1K-46 332ns ± 0% 330ns ± 1% ~ (p=0.095 n=5+5) RegexpMatchEasy1_32-46 104ns ± 0% 110ns ± 1% +5.29% (p=0.029 n=4+4) RegexpMatchEasy1_1K-46 563ns ± 0% 567ns ± 2% ~ (p=0.151 n=5+5) RegexpMatchMedium_32-46 167ns ± 2% 166ns ± 0% ~ (p=0.333 n=5+4) RegexpMatchMedium_1K-46 49.5µs ± 0% 49.6µs ± 0% ~ (p=0.841 n=5+5) RegexpMatchHard_32-46 2.56µs ± 1% 2.49µs ± 0% -2.81% (p=0.008 n=5+5) RegexpMatchHard_1K-46 77.0µs ± 0% 75.8µs ± 0% -1.55% (p=0.008 n=5+5) Revcomp-46 631ms ± 1% 628ms ± 0% ~ (p=0.095 n=5+5) Template-46 81.8ms ± 0% 84.3ms ± 1% +3.05% (p=0.008 n=5+5) TimeParse-46 423ns ± 0% 425ns ± 0% +0.52% (p=0.008 n=5+5) TimeFormat-46 478ns ± 2% 478ns ± 1% ~ (p=1.000 n=5+5) [Geo mean] 71.6µs 71.6µs -0.01% name old speed new speed delta GobDecode-46 78.1MB/s ± 1% 78.5MB/s ± 1% ~ (p=0.151 n=5+5) GobEncode-46 94.3MB/s ± 0% 94.5MB/s ± 1% ~ (p=0.690 n=5+5) Gzip-46 46.2MB/s ± 0% 46.2MB/s ± 0% ~ (p=0.571 n=5+5) Gunzip-46 403MB/s ± 0% 404MB/s ± 0% +0.33% (p=0.032 n=5+5) JSONEncode-46 114MB/s ± 0% 113MB/s ± 0% ~ (p=0.056 n=5+5) JSONDecode-46 22.0MB/s ± 0% 21.9MB/s ± 0% -0.64% (p=0.008 n=5+5) GoParse-46 11.5MB/s ± 0% 11.4MB/s ± 0% -0.64% (p=0.008 n=5+5) RegexpMatchEasy0_32-46 272MB/s ± 0% 285MB/s ± 4% +4.74% (p=0.016 n=4+5) RegexpMatchEasy0_1K-46 3.08GB/s ± 0% 3.10GB/s ± 1% ~ (p=0.151 n=5+5) RegexpMatchEasy1_32-46 306MB/s ± 0% 290MB/s ± 1% -5.21% (p=0.029 n=4+4) RegexpMatchEasy1_1K-46 1.82GB/s ± 0% 1.81GB/s ± 2% ~ (p=0.151 n=5+5) RegexpMatchMedium_32-46 5.99MB/s ± 0% 6.02MB/s ± 1% ~ (p=0.063 n=4+5) RegexpMatchMedium_1K-46 20.7MB/s ± 0% 20.7MB/s ± 0% ~ (p=0.659 n=5+5) RegexpMatchHard_32-46 12.5MB/s ± 1% 12.8MB/s ± 0% +2.88% (p=0.008 n=5+5) RegexpMatchHard_1K-46 13.3MB/s ± 0% 13.5MB/s ± 0% +1.58% (p=0.008 n=5+5) Revcomp-46 402MB/s ± 1% 405MB/s ± 0% ~ (p=0.095 n=5+5) Template-46 23.7MB/s ± 0% 23.0MB/s ± 1% -2.95% (p=0.008 n=5+5) [Geo mean] 82.2MB/s 82.3MB/s +0.04% Frame-pointer is enabled on Linux by default but can be disabled by setting: GOEXPERIMENT=noframepointer. Fixes #10110 Change-Id: I1bfaca6dba29a63009d7c6ab04ed7a1413d9479e Reviewed-on: https://go-review.googlesource.com/61511 Reviewed-by: Cherry Zhang <cherryyz@google.com> Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-04-26runtime: remove the dummy arg of getcallerspCherry Zhang
getcallersp is intrinsified, and so the dummy arg is no longer needed. Remove it, as well as a few dummy args that are solely to feed getcallersp. Change-Id: Ibb6c948ff9c56537042b380ac3be3a91b247aaa6 Reviewed-on: https://go-review.googlesource.com/109596 Run-TryBot: Cherry Zhang <cherryyz@google.com> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-02-15runtime: eliminate most uses of mheap_.arena_*Austin Clements
This replaces all uses of the mheap_.arena_* fields outside of mallocinit and sysAlloc. These fields fundamentally assume a contiguous heap between two bounds, so eliminating these is necessary for a sparse heap. Many of these are replaced with checks for non-nil spans at the test address (which in turn checks for a non-nil entry in the heap arena array). Some of them are just for debugging and somewhat meaningless with a sparse heap, so those we just delete. Updates #10460. Change-Id: I8345b95ffc610aed694f08f74633b3c63506a41f Reviewed-on: https://go-review.googlesource.com/85886 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Rick Hudson <rlh@golang.org>
2018-02-15runtime: split object finding out of heapBitsForObjectAustin Clements
heapBitsForObject does two things: it finds the base of the object and it creates the heapBits for the base of the object. There are several places where we just care about the base of the object. Furthermore, greyobject only needs the heapBits in the checkmark path and can easily compute them only when needed. Once we eliminate passing the heap bits to grayobject, almost all uses of heapBitsForObject don't need the heap bits. Hence, this splits heapBitsForObject into findObject and heapBitsForAddr (the latter already exists), removes the hbits argument to grayobject, and replaces all heapBitsForObject calls with calls to findObject. In addition to making things cleaner overall, heapBitsForAddr is going to get more expensive shortly, so it's important that we don't do it needlessly. Note that there's an interesting performance pitfall here. I had originally moved findObject to mheap.go, since it made more sense there. However, that leads to a ~2% slow down and a whopping 11% increase in L1 icache misses on both the x/garbage and compilebench benchmarks. This suggests we may want to be more principled about this, but, for now, let's just leave findObject in mbitmap.go. (I tried to make findObject small enough to inline by splitting out the error case, but, sadly, wasn't quite able to get it under the inlining budget.) Change-Id: I7bcb92f383ade565d22a9f2494e4c66fd513fb10 Reviewed-on: https://go-review.googlesource.com/85878 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Rick Hudson <rlh@golang.org>
2017-09-22runtime: don't call lockOSThread for every cgo callIan Lance Taylor
For a trivial benchmark with a do-nothing cgo call: name old time/op new time/op delta Call-4 64.5ns ± 7% 63.0ns ± 6% -2.25% (p=0.027 n=20+16) Because Windows uses the cgocall mechanism to make system calls, and passes arguments in a struct held in the m, we need to do the lockOSThread/unlockOSThread in that code. Because deferreturn was getting a nosplit stack overflow error, change it to avoid calling typedmemmove. Updates #21827. Change-Id: I9b1d61434c44faeb29805b46b409c812c9acadc2 Reviewed-on: https://go-review.googlesource.com/64070 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com> Reviewed-by: David Crawshaw <crawshaw@golang.org>
2017-09-15all: fix article typosKunpei Sakai
a -> an Change-Id: I7362bdc199e83073a712be657f5d9ba16df3077e Reviewed-on: https://go-review.googlesource.com/63850 Reviewed-by: Rob Pike <r@golang.org>
2017-08-29all: join some chained ifs to unindent codeDaniel Martí
Found with mvdan.cc/unindent. It skipped the cases where parentheses would need to be added, where comments would have to be moved elsewhere, or where actions and simple logic would mix. One of them was of the form "err != nil && err == io.EOF", so the first part was removed. Change-Id: Ie504c2b03a2c87d10ecbca1b9270069be1171b91 Reviewed-on: https://go-review.googlesource.com/57690 Run-TryBot: Daniel Martí <mvdan@mvdan.cc> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-02-03runtime: handle SIGPIPE in c-archive and c-shared programsElias Naur
Before this CL, Go programs in c-archive or c-shared buildmodes would not handle SIGPIPE. That leads to surprising behaviour where writes on a closed pipe or socket would raise SIGPIPE and terminate the program. This CL changes the Go runtime to handle SIGPIPE regardless of buildmode. In addition, SIGPIPE from non-Go code is forwarded. This is a refinement of CL 32796 that fixes the case where a non-default handler for SIGPIPE is installed by the host C program. Fixes #17393 Change-Id: Ia41186e52c1ac209d0a594bae9904166ae7df7de Reviewed-on: https://go-review.googlesource.com/35960 Run-TryBot: Elias Naur <elias.naur@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-01-25[dev.typealias] cmd/compile, reflect: fix struct field names for embedded ↵Russ Cox
byte, rune Will also fix type aliases. Fixes #17766. For #18130. Change-Id: I9e1584d47128782152e06abd0a30ef423d5c30d2 Reviewed-on: https://go-review.googlesource.com/35732 Run-TryBot: Russ Cox <rsc@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
2016-12-14runtime: add cgo support for GOARCH=mips{,le}Vladimir Stefanovic
Change-Id: Ib425ead7b340672837d3cb983bd785488706bd6d Reviewed-on: https://go-review.googlesource.com/34314 Reviewed-by: Cherry Zhang <cherryyz@google.com> Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-11-30runtime: fix undead arguments in cgocallAustin Clements
From the garbage collector's perspective, time can move backwards in cgocall. However, in the midst of this time warp, the pointer arguments to cgocall can go from dead back to live. If a stack growth happens while they're dead and then a GC happens when they become live again, GC can crash with a bad heap pointer. Specifically, the sequence that leads to a panic is: 1. cgocall calls entersyscall, which saves the PC and SP of its call site in cgocall. Call this PC/SP "X". At "X" both pointer arguments are live. 2. cgocall calls asmcgocall. Call the PC/SP of this call "Y". At "Y" neither pointer argument is live. 3. asmcgocall calls the C code, which eventually calls back into the Go code. 4. cgocallbackg remembers the saved PC/SP "X" in some local variables, calls exitsyscall, and then calls cgocallbackg1. 5. The Go code causes a stack growth. This stack unwind sees PC/SP "Y" in the cgocall frame. Since the arguments are dead at "Y", they are not adjusted. 6. The Go code returns to cgocallbackg1, which calls reentersyscall with the recorded saved PC/SP "X", so "X" gets stashed back into gp.syscallpc/sp. 7. GC scans the stack. It sees there's a saved syscall PC/SP, so it starts the traceback at PC/SP "X". At "X" the arguments are considered live, so it scans them, but since they weren't adjusted, the pointers are bad, so it panics. This issue started as of commit ca4089ad, when the compiler stopped marking arguments as live for the whole function. Since this is a variable liveness issue, fix it by adding KeepAlive calls that keep the arguments live across this whole time warp. The existing issue7978 test has all of the infrastructure for testing this except that it's currently up to chance whether a stack growth happens in the callback (it currently only happens on the linux-amd64-noopt builder, for example). Update this test to force a stack growth, which causes it to fail reliably without this fix. Fixes #17785. Change-Id: If706963819ee7814e6705693247bcb97a6f7adb8 Reviewed-on: https://go-review.googlesource.com/33710 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2016-11-30runtime: use standard comment style in cgocallAustin Clements
Change-Id: I9f2c2da4aa512729ae40562b06601da95ba50d6f Reviewed-on: https://go-review.googlesource.com/33689 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2016-11-01runtime: access modules via a sliceDavid Crawshaw
The introduction of -buildmode=plugin means modules can be added to a Go program while it is running. This means there exists some time while the program is running with the module is on the moduledata linked list, but it has not been initialized to the satisfaction of other parts of the runtime. Notably, the GC. This CL adds a new way of access modules, an activeModules function. It returns a slice of modules that is built in the background and atomically swapped in. The parts of the runtime that need to wait on module initialization can use this slice instead of the linked list. Fixes #17455 Change-Id: I04790fd07e40c7295beb47cea202eb439206d33d Reviewed-on: https://go-review.googlesource.com/32357 Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-10-19cmd/cgo: always use a function literal for pointer checkingIan Lance Taylor
The pointer checking code needs to know the exact type of the parameter expected by the C function, so that it can use a type assertion to convert the empty interface returned by cgoCheckPointer to the correct type. Previously this was done by using a type conversion, but that meant that the code accepted arguments that were convertible to the parameter type, rather than arguments that were assignable as in a normal function call. In other words, some code that should not have passed type checking was accepted. This CL changes cgo to always use a function literal for pointer checking. Now the argument is passed to the function literal, which has the correct argument type, so type checking is performed just as for a function call as it should be. Since we now always use a function literal, simplify the checking code to run as a statement by itself. It now no longer needs to return a value, and we no longer need a type assertion. This does have the cost of introducing another function call into any call to a C function that requires pointer checking, but the cost of the additional call should be minimal compared to the cost of pointer checking. Fixes #16591. Change-Id: I220165564cf69db9fd5f746532d7f977a5b2c989 Reviewed-on: https://go-review.googlesource.com/31233 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-09-30runtime: remove defer from standard cgo callDavid Crawshaw
The endcgo function call is currently deferred in case a cgo callback into Go panics and unwinds through cgocall. Typical cgo calls do not have callbacks into Go, and even fewer panic, so we pay the cost of this defer for no typical benefit. Amazingly, there is another defer on the cgocallback path also used to cleanup in case the Go code called by cgo panics. This CL folds the first defer into the second, to reduce the cost of typical cgo calls. This reduces the overhead for a no-op cgo call significantly: name old time/op new time/op delta CgoNoop-8 93.5ns ± 0% 51.1ns ± 1% -45.34% (p=0.016 n=4+5) The total effect between Go 1.7 and 1.8 is even greater, as CL 29656 reduced the cost of defer recently. Hopefully a future Go release will drop the cost of defer to nothing, making this optimization unnecessary. But until then, this is nice. Change-Id: Id1a5648f687a87001d95bec6842e4054bd20ee4f Reviewed-on: https://go-review.googlesource.com/30080 Run-TryBot: David Crawshaw <crawshaw@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-07-20runtime: add as many extra M's as neededIan Lance Taylor
When a non-Go thread calls into Go, the runtime needs an M to run the Go code. The runtime keeps a list of extra M's available. When the last extra M is allocated, the needextram field is set to tell it to allocate a new extra M as soon as it is running in Go. This ensures that an extra M will always be available for the next thread. However, if many threads need an extra M at the same time, this serializes them all. One thread will get an extra M with the needextram field set. All the other threads will see that there is no M available and will go to sleep. The one thread that succeeded will create a new extra M. One lucky thread will get it. All the other threads will see that there is no M available and will go to sleep. The effect is thundering herd, as all the threads looking for an extra M go through the process one by one. This seems to have a particularly bad effect on the FreeBSD scheduler for some reason. With this change, we track the number of threads waiting for an M, and create all of them as soon as one thread gets through. This still means that all the threads will fight for the lock to pick up the next M. But at least each thread that gets the lock will succeed, instead of going to sleep only to fight again. This smooths out the performance greatly on FreeBSD, reducing the average wall time of `testprogcgo CgoCallbackGC` by 74%. On GNU/Linux the average wall time goes down by 9%. Fixes #13926 Fixes #16396 Change-Id: I6dc42a4156085a7ed4e5334c60b39db8f8ef8fea Reviewed-on: https://go-review.googlesource.com/25047 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
2016-07-12runtime: add ctxt parameter to cgocallback called from GoIan Lance Taylor
The cgocallback function picked up a ctxt parameter in CL 22508. That CL updated the assembler implementation, but there are a few mentions in Go code that were not updated. This CL fixes that. Fixes #16326 Change-Id: I5f68e23565c6a0b11057aff476d13990bff54a66 Reviewed-on: https://go-review.googlesource.com/24848 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Minux Ma <minux@golang.org>
2016-05-25cmd/cgo, runtime, runtime/cgo: TSAN support for mallocIan Lance Taylor
Acquire and release the TSAN synchronization point when calling malloc, just as we do when calling any other C function. If we don't do this, TSAN will report false positive errors about races calling malloc and free. We used to have a special code path for malloc and free, going through the runtime functions cmalloc and cfree. The special code path for cfree was no longer used even before this CL. This CL stops using the special code path for malloc, because there is no place along that path where we could conditionally insert the TSAN synchronization. This CL removes the support for the special code path for both functions. Instead, cgo now automatically generates the malloc function as though it were referenced as C.malloc. We need to automatically generate it even if C.malloc is not called, even if malloc and size_t are not declared, to support cgo-provided functions like C.CString. Change-Id: I829854ec0787a80f33fa0a8a0dc2ee1d617830e2 Reviewed-on: https://go-review.googlesource.com/23260 Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com>
2016-05-07runtime: use entire address space on 32 bitElias Naur
In issue #13992, Russ mentioned that the heap bitmap footprint was halved but that the bitmap size calculation hadn't been updated. This presents the opportunity to either halve the bitmap size or double the addressable virtual space. This CL doubles the addressable virtual space. On 32 bit this can be tweaked further to allow the bitmap to cover the entire 4GB virtual address space, removing a failure mode if the kernel hands out memory with a too low address. First, fix the calculation and double _MaxArena32 to cover 4GB virtual memory space with the same bitmap size (256 MB). Then, allow the fallback mode for the initial memory reservation on 32 bit (or 64 bit with too little available virtual memory) to not include space for the arena. mheap.sysAlloc will automatically reserve additional space when the existing arena is full. Finally, set arena_start to 0 in 32 bit mode, so that any address is acceptable for subsequent (additional) reservations. Before, the bitmap was always located just before arena_start, so fix the two places relying on that assumption: Point the otherwise unused mheap.bitmap to one byte after the end of the bitmap, and use it for bitmap addressing instead of arena_start. With arena_start set to 0 on 32 bit, the cgoInRange check is no longer a sufficient check for Go pointers. Introduce and call inHeapOrStack to check whether a pointer is to the Go heap or stack. While we're here, remove sysReserveHigh which seems to be unused. Fixes #13992 Change-Id: I592b513148a50b9d3967b5c5d94b86b3ec39acc2 Reviewed-on: https://go-review.googlesource.com/20471 Reviewed-by: Austin Clements <austin@google.com> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-04runtime: add linux/mips64x cgo supportCherry Zhang
Change-Id: Id40dd05b7b264f3b779fdf9ccc2421ba4bc70589 Reviewed-on: https://go-review.googlesource.com/19806 Reviewed-by: Minux Ma <minux@golang.org>
2016-04-30runtime: reclaim scan/dead bit in first wordAustin Clements
With the switch to separate mark bitmaps, the scan/dead bit for the first word of each object is now unused. Reclaim this bit and use it as a scan/dead bit, just like words three and on. The second word is still used for checkmark. This dramatically simplifies heapBitsSetTypeNoScan and hasPointers, since they no longer need different cases for 1, 2, and 3+ word objects. They can instead just manipulate the heap bitmap for the first word and be done with it. In order to enable this, we change heapBitsSetType and runGCProg to always set the scan/dead bit to scan for the first word on every code path. Since these functions only apply to types that have pointers, there's no need to do this conditionally: it's *always* necessary to set the scan bit in the first word. We also change every place that scans an object and checks if there are more pointers. Rather than only checking morePointers if the word is >= 2, we now check morePointers if word != 1 (since that's the checkmark word). Looking forward, we should probably reclaim the checkmark bit, too, but that's going to be quite a bit more work. Tested by setting doubleCheck in heapBitsSetType and running all.bash on both linux/amd64 and linux/386, and by running GOGC=10 all.bash. This particularly improves the FmtFprintf* go1 benchmarks, since they do a large amount of noscan allocation. name old time/op new time/op delta BinaryTree17-12 2.34s ± 1% 2.38s ± 1% +1.70% (p=0.000 n=17+19) Fannkuch11-12 2.09s ± 0% 2.09s ± 1% ~ (p=0.276 n=17+16) FmtFprintfEmpty-12 44.9ns ± 2% 44.8ns ± 2% ~ (p=0.340 n=19+18) FmtFprintfString-12 127ns ± 0% 125ns ± 0% -1.57% (p=0.000 n=16+15) FmtFprintfInt-12 128ns ± 0% 122ns ± 1% -4.45% (p=0.000 n=15+20) FmtFprintfIntInt-12 207ns ± 1% 193ns ± 0% -6.55% (p=0.000 n=19+14) FmtFprintfPrefixedInt-12 197ns ± 1% 191ns ± 0% -2.93% (p=0.000 n=17+18) FmtFprintfFloat-12 263ns ± 0% 248ns ± 1% -5.88% (p=0.000 n=15+19) FmtManyArgs-12 794ns ± 0% 779ns ± 1% -1.90% (p=0.000 n=18+18) GobDecode-12 7.14ms ± 2% 7.11ms ± 1% ~ (p=0.072 n=20+20) GobEncode-12 5.85ms ± 1% 5.82ms ± 1% -0.49% (p=0.000 n=20+20) Gzip-12 218ms ± 1% 215ms ± 1% -1.22% (p=0.000 n=19+19) Gunzip-12 36.8ms ± 0% 36.7ms ± 0% -0.18% (p=0.006 n=18+20) HTTPClientServer-12 77.1µs ± 4% 77.1µs ± 3% ~ (p=0.945 n=19+20) JSONEncode-12 15.6ms ± 1% 15.9ms ± 1% +1.68% (p=0.000 n=18+20) JSONDecode-12 55.2ms ± 1% 53.6ms ± 1% -2.93% (p=0.000 n=17+19) Mandelbrot200-12 4.05ms ± 1% 4.05ms ± 0% ~ (p=0.306 n=17+17) GoParse-12 3.14ms ± 1% 3.10ms ± 1% -1.31% (p=0.000 n=19+18) RegexpMatchEasy0_32-12 69.3ns ± 1% 70.0ns ± 0% +0.89% (p=0.000 n=19+17) RegexpMatchEasy0_1K-12 237ns ± 1% 236ns ± 0% -0.62% (p=0.000 n=19+16) RegexpMatchEasy1_32-12 69.5ns ± 1% 70.3ns ± 1% +1.14% (p=0.000 n=18+17) RegexpMatchEasy1_1K-12 377ns ± 1% 366ns ± 1% -3.03% (p=0.000 n=15+19) RegexpMatchMedium_32-12 107ns ± 1% 107ns ± 2% ~ (p=0.318 n=20+19) RegexpMatchMedium_1K-12 33.8µs ± 3% 33.5µs ± 1% -1.04% (p=0.001 n=20+19) RegexpMatchHard_32-12 1.68µs ± 1% 1.73µs ± 0% +2.50% (p=0.000 n=20+18) RegexpMatchHard_1K-12 50.8µs ± 1% 52.0µs ± 1% +2.50% (p=0.000 n=19+18) Revcomp-12 381ms ± 1% 385ms ± 1% +1.00% (p=0.000 n=17+18) Template-12 64.9ms ± 3% 62.6ms ± 1% -3.55% (p=0.000 n=19+18) TimeParse-12 324ns ± 0% 328ns ± 1% +1.25% (p=0.000 n=18+18) TimeFormat-12 345ns ± 0% 334ns ± 0% -3.31% (p=0.000 n=15+17) [Geo mean] 52.1µs 51.5µs -1.00% Change-Id: I13e74da3193a7f80794c654f944d1f0d60817049 Reviewed-on: https://go-review.googlesource.com/22632 Reviewed-by: Rick Hudson <rlh@golang.org> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-30runtime: use morePointers and isPointer in more placesAustin Clements
This makes this code better self-documenting and makes it easier to find these places in the future. Change-Id: I31dc5598ae67f937fb9ef26df92fd41d01e983c3 Reviewed-on: https://go-review.googlesource.com/22631 Reviewed-by: Rick Hudson <rlh@golang.org> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-29cmd/cgo, runtime, runtime/cgo: use cgo context functionIan Lance Taylor
Add support for the context function set by runtime.SetCgoTraceback. The context function was added in CL 17761, without support. This CL is the support. This CL has not been tested for real C code, as a working context function for C code requires unwind support that does not seem to exist. I wanted to get the CL out before the freeze. I apologize for the length of this CL. It's mostly plumbing, but unfortunately the plumbing is processor-specific. Change-Id: I8ce11a0de9b3dafcc29efd2649d776e93bff0e90 Reviewed-on: https://go-review.googlesource.com/22508 Reviewed-by: Austin Clements <austin@google.com> Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-29[dev.garbage] runtime: restructure alloc and mark bitsRick Hudson
Two changes are included here that are dependent on the other. The first is that allocBits and gcamrkBits are changed to a *uint8 which points to the first byte of that span's mark and alloc bits. Several places were altered to perform pointer arithmetic to locate the byte corresponding to an object in the span. The actual bit corresponding to an object is indexed in the byte by using the lower three bits of the objects index. The second change avoids the redundant calculation of an object's index. The index is returned from heapBitsForObject and then used by the functions indexing allocBits and gcmarkBits. Finally we no longer allocate the gc bits in the span structures. Instead we use an arena based allocation scheme that allows for a more compact bit map as well as recycling and bulk clearing of the mark bits. Change-Id: If4d04b2021c092ec39a4caef5937a8182c64dfef Reviewed-on: https://go-review.googlesource.com/20705 Reviewed-by: Austin Clements <austin@google.com>
2016-04-06runtime: add s390x support (modified files only)Michael Munday
Change-Id: Ib79ad4a890994ad64edb1feb79bd242d26b5b08a Reviewed-on: https://go-review.googlesource.com/20945 Reviewed-by: Minux Ma <minux@golang.org> Run-TryBot: Michael Munday <munday@ca.ibm.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-01runtime: allocate mp.cgocallers earlierIan Lance Taylor
Fixes #15061. Change-Id: I71f69f398d1c5f3a884bbd044786f1a5600d0fae Reviewed-on: https://go-review.googlesource.com/21398 Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-01runtime: support symbolic backtrace of C code in a cgo crashIan Lance Taylor
The new function runtime.SetCgoTraceback may be used to register stack traceback and symbolizer functions, written in C, to do a stack traceback from cgo code. There is a sample implementation of runtime.SetCgoSymbolizer at github.com/ianlancetaylor/cgosymbolizer. Just importing that package is sufficient to get symbolic C backtraces. Currently only supported on linux/amd64. Change-Id: If96ee2eb41c6c7379d407b9561b87557bfe47341 Reviewed-on: https://go-review.googlesource.com/17761 Reviewed-by: Austin Clements <austin@google.com>
2016-03-07runtime: eliminate unnecessary type conversionsMatthew Dempsky
Automated refactoring produced using github.com/mdempsky/unconvert. Change-Id: Iacf871a4f221ef17f48999a464ab2858b2bbaa90 Reviewed-on: https://go-review.googlesource.com/20071 Reviewed-by: Austin Clements <austin@google.com> Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-02all: single space after period.Brad Fitzpatrick
The tree's pretty inconsistent about single space vs double space after a period in documentation. Make it consistently a single space, per earlier decisions. This means contributors won't be confused by misleading precedence. This CL doesn't use go/doc to parse. It only addresses // comments. It was generated with: $ perl -i -npe 's,^(\s*// .+[a-z]\.) +([A-Z]),$1 $2,' $(git grep -l -E '^\s*//(.+\.) +([A-Z])') $ go test go/doc -update Change-Id: Iccdb99c37c797ef1f804a94b22ba5ee4b500c4f7 Reviewed-on: https://go-review.googlesource.com/20022 Reviewed-by: Rob Pike <r@golang.org> Reviewed-by: Dave Day <djd@golang.org> Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>