- 13 Jan, 2017 4 commits
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Michael Munday authored
mkpost.go replaces all variables prefixed with 'X_' with '_' on s390x because most of them do not need to be exposed. X__val is being used by a third party library so it turns out we do need to expose it on s390x (it is already exposed on all other Linux architectures). Fixes #17298 and updates #18632. Change-Id: Ic03463229a5f75ca41a4a4b50300da4b4d892d45 Reviewed-on: https://go-review.googlesource.com/30130Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
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Alberto Donizetti authored
Also fix a couple of other errors. Fixes #6877 Change-Id: I94c81c5847cc7b0adab19418e71687bc2ee7fe94 Reviewed-on: https://go-review.googlesource.com/34960Reviewed-by: Ian Lance Taylor <iant@golang.org>
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Keith Randall authored
Make sure that the same type and itab generated in two different plugins are actually the same thing. See also CL 35115 Change-Id: I0c1ecb039d7e2bf5a601d58dfa162a435ae4ef76 Reviewed-on: https://go-review.googlesource.com/35116 Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: David Crawshaw <crawshaw@golang.org>
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Austin Clements authored
When traceback sees reflect.makeFuncStub (or reflect.methodValueCall) on the stack, it expects to be able to get the *reflect.makeFuncImpl (or *reflect.methodValue) for that call from the first outgoing argument slot of makeFuncStub/methodValueCall. However, currently this object isn't necessarily kept live across makeFuncStub. This means it may get garbage collected while in a reflect call and reused for something else. If we then try to traceback, the runtime will see a corrupted makeFuncImpl object and panic. This was not a problem in previous releases because we always kept arguments live across the whole function. This became a problem when we stopped doing this. Fix this by using reflect.KeepAlive to keep the makeFuncImpl/methodValue live across all of callReflect/callMethod, which in turn keeps it live as long as makeFuncStub/methodValueCall are on the stack. Fixes #18635. Change-Id: I91853efcf17912390fddedfb0230648391c33936 Reviewed-on: https://go-review.googlesource.com/35151 Run-TryBot: Austin Clements <austin@google.com> Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Russ Cox <rsc@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
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- 12 Jan, 2017 7 commits
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David Crawshaw authored
C-only symbols are excluded from pclntab because of a quirk of darwin, where functions are referred to by an exported symbol so dynamic relocations de-duplicate to the host binary module and break unwinding. This doesn't happen on ELF systems because the linker always refers to unexported module-local symbols, so we don't need this condition. And the current logic for excluding some functions breaks the module verification code in moduledataverify1. So disable this for plugins on linux. (In 1.9, it will probably be necessary to introduce a module-local symbol reference system on darwin to fix a different bug, so all of this onlycsymbol code made be short-lived.) With this CL, the tests in CL 35116 pass. Change-Id: I517d7ca4427241fa0a91276c462827efb9383be9 Reviewed-on: https://go-review.googlesource.com/35190Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com> Run-TryBot: David Crawshaw <crawshaw@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
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Joe Tsai authored
Ranging over an array causes the array to be copied over to the stack, which cause large re-growths. Instead, we should iterate over slices of the array. Also, assigning a large struct literal uses the stack even though the actual fields being populated are small in comparison to the entirety of the struct (see #18636). Fixing the stack growth does not alter CPU-time performance much since the stack-growth and copying was such a tiny portion of the compression work: name old time/op new time/op delta Encode/Digits/Default/1e4-8 332µs ± 1% 332µs ± 1% ~ (p=0.796 n=10+10) Encode/Digits/Default/1e5-8 5.07ms ± 2% 5.05ms ± 1% ~ (p=0.815 n=9+8) Encode/Digits/Default/1e6-8 53.7ms ± 1% 53.9ms ± 1% ~ (p=0.075 n=10+10) Encode/Twain/Default/1e4-8 380µs ± 1% 380µs ± 1% ~ (p=0.684 n=10+10) Encode/Twain/Default/1e5-8 5.79ms ± 2% 5.79ms ± 1% ~ (p=0.497 n=9+10) Encode/Twain/Default/1e6-8 61.5ms ± 1% 61.8ms ± 1% ~ (p=0.247 n=10+10) name old speed new speed delta Encode/Digits/Default/1e4-8 30.1MB/s ± 1% 30.1MB/s ± 1% ~ (p=0.753 n=10+10) Encode/Digits/Default/1e5-8 19.7MB/s ± 2% 19.8MB/s ± 1% ~ (p=0.795 n=9+8) Encode/Digits/Default/1e6-8 18.6MB/s ± 1% 18.5MB/s ± 1% ~ (p=0.072 n=10+10) Encode/Twain/Default/1e4-8 26.3MB/s ± 1% 26.3MB/s ± 1% ~ (p=0.616 n=10+10) Encode/Twain/Default/1e5-8 17.3MB/s ± 2% 17.3MB/s ± 1% ~ (p=0.484 n=9+10) Encode/Twain/Default/1e6-8 16.3MB/s ± 1% 16.2MB/s ± 1% ~ (p=0.238 n=10+10) Updates #18636 Fixes #18625 Change-Id: I471b20339bf675f63dc56d38b3acdd824fe23328 Reviewed-on: https://go-review.googlesource.com/35122Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
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David Crawshaw authored
Missing from CL 34926. Change-Id: I4a046440c30811f26da53bee0e853dae3b0ac57a Reviewed-on: https://go-review.googlesource.com/35123Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
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David Crawshaw authored
The iOS test harness has set a breakpoint early in the life of Go programs so that it can change the current working directory using information only available from the host debugger. Somewhere in the upgrade to iOS 10 / XCode 8.2, breakpoints stopped working. This may be an LLDB bug, or a bug in the ios-deploy LLDB scripts, it's not clear. Work around the problem by giving up on breakpoints. Instead, early in the life of every test binary built for iOS, send (and ignore) a SIGUSR2 signal. The debugger will catch this, giving the script go_darwin_arm_exec a chance to change the working directory. For the iOS builders. Change-Id: I7476531985217d0c76bc176904c48379210576c2 Reviewed-on: https://go-review.googlesource.com/34926Reviewed-by: Ian Lance Taylor <iant@golang.org> Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
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Shenghou Ma authored
Fixes #18623. Change-Id: Ic965f5f7088c3270adbca7162226be486d1b9b4e Reviewed-on: https://go-review.googlesource.com/35130Reviewed-by: Ian Lance Taylor <iant@golang.org>
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Keith Randall authored
Make sure that the same type and itab generated in two different shared library are actually the same thing. Change-Id: Ica45862d65ff8bc7ad04d59a41f57223f71224cd Reviewed-on: https://go-review.googlesource.com/35115 Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
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Bryan C. Mills authored
Use R11 (a caller-saved temp register) instead of RBX (a callee-saved register). I believe this only affects linux/amd64, since it is the only platform with a non-trivial cgoSigtramp implementation. Updates #18328. Change-Id: I3d35c4512624184d5a8ece653fa09ddf50e079a2 Reviewed-on: https://go-review.googlesource.com/35068Reviewed-by: Ian Lance Taylor <iant@golang.org> Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
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- 11 Jan, 2017 4 commits
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Josh Bleecher Snyder authored
This reduces compilation time for the program in #18602 from 7 hours to 30 min. Updates #14781 Updates #18602 Change-Id: I3c4af878a08920e6373d3b3b0c4453ee002e32eb Reviewed-on: https://go-review.googlesource.com/35113 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> Reviewed-by: Robert Griesemer <gri@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
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Joe Tsai authored
Fixes #18604 Change-Id: I89221d5e632042167dfced068e1dc14e932cd618 Reviewed-on: https://go-review.googlesource.com/35111 Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
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Austin Clements authored
Somehow this file didn't get gofmted after the last change, which interferes with merges. Change-Id: I965cfdbf27a01124a6ed300be9687ff84f68f9a1 Reviewed-on: https://go-review.googlesource.com/35064Reviewed-by: Matt Layher <mdlayher@gmail.com> Reviewed-by: Adam Langley <agl@chromium.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Run-TryBot: Matt Layher <mdlayher@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
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Brad Fitzpatrick authored
The test was previously an integration test, relying on luck and many goroutines and lots of time to hit the path to be tested. Instead, rewrite the test to exactly hit the path to be tested, in one try, in one goroutine. Fixes #18205 Change-Id: I63cd513316344bfd7375dcc452c1c396dec0e49f Reviewed-on: https://go-review.googlesource.com/35107 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
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- 10 Jan, 2017 3 commits
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Jaana Burcu Dogan authored
Change-Id: I7ca7e9a2d4cf97cf33c60a9a4d0ba5fb0ca6e44c Reviewed-on: https://go-review.googlesource.com/35098Reviewed-by: Chris Broadfoot <cbro@golang.org>
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David Chase authored
The test is inherently racy and vulnerable to starvation, and within all.bash on some platforms that means it flakes. Test is kept because it can be useful standalone to verify behavior of GOEXPERIMENT=preeemptibleloops, and there is likely to be further development of this feature in the future. There's also some question as to why it is flaking, because though technically this is permitted, it's very odd in this simple case. Fixes #18589. Change-Id: Ia0dd9037285c4a03122da4012c96981c9cc43b60 Reviewed-on: https://go-review.googlesource.com/35051 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Russ Cox <rsc@golang.org>
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Austin Clements authored
Updates #18043. Change-Id: I24e687fdd5521c48b672987f15f0d5de9f308884 Reviewed-on: https://go-review.googlesource.com/34612 Run-TryBot: Austin Clements <austin@google.com> Reviewed-by: Rick Hudson <rlh@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
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- 09 Jan, 2017 3 commits
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David Chase authored
Loop breaking with a counter. Benchmarked (see comments), eyeball checked for sanity on popular loops. This code ought to handle loops in general, and properly inserts phi functions in cases where the earlier version might not have. Includes test, plus modifications to test/run.go to deal with timeout and killing looping test. Tests broken by the addition of extra code (branch frequency and live vars) for added checks turn the check insertion off. If GOEXPERIMENT=preemptibleloops, the compiler inserts reschedule checks on every backedge of every reducible loop. Alternately, specifying GO_GCFLAGS=-d=ssa/insert_resched_checks/on will enable it for a single compilation, but because the core Go libraries contain some loops that may run long, this is less likely to have the desired effect. This is intended as a tool to help in the study and diagnosis of GC and other latency problems, now that goal STW GC latency is on the order of 100 microseconds or less. Updates #17831. Updates #10958. Change-Id: I6206c163a5b0248e3f21eb4fc65f73a179e1f639 Reviewed-on: https://go-review.googlesource.com/33910 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
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Robert Griesemer authored
Minimally invasive; fixes a regression from 1.7. Fixes #18459. Change-Id: I93b3b5c05706eaff8ae97a237f770838c1f8778c Reviewed-on: https://go-review.googlesource.com/34721Reviewed-by: David Chase <drchase@google.com> Reviewed-by: Russ Cox <rsc@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
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Joe Tsai authored
In Go1.7, a 301, 302, or 303 redirect on a HEAD method, would still cause the following redirects to still use a HEAD. In CL/29852 this behavior was changed such that those codes always caused a redirect with the GET method. Fix this such that both GET and HEAD will preserve the method. Fixes #18570 Change-Id: I4bfe69872a30799419e3fad9178f907fe439b449 Reviewed-on: https://go-review.googlesource.com/34981 Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com> Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
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- 08 Jan, 2017 1 commit
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Austin Clements authored
Change-Id: I52fae67c9aeceaa23e70f2ef0468745b354f8c75 Reviewed-on: https://go-review.googlesource.com/34932Reviewed-by: Minux Ma <minux@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
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- 07 Jan, 2017 6 commits
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gulyasm authored
Fixes #18562 Change-Id: Ic195a8606f09876e2667e4ef720b84a07d316f4a Reviewed-on: https://go-review.googlesource.com/34939Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
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Kevin Burke authored
Fixes #18261. Change-Id: I4bd7363aac4e62461f61fd95b3c7a18063412182 Reviewed-on: https://go-review.googlesource.com/34241Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
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shawnps authored
Change-Id: I429637ca91f7db4144f17621de851a548dc1ce76 Reviewed-on: https://go-review.googlesource.com/34923Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Daniel Martí <mvdan@mvdan.cc> Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
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Ian Lance Taylor authored
Fixes #18535 Change-Id: I9e49d33ce357a534529a6b0fcdbc09ff4fa98622 Reviewed-on: https://go-review.googlesource.com/34920 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
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Jaana Burcu Dogan authored
Also moves the GOPATH env variable guide to golang.org/wiki/SettingGOPATH. Fixes #18294. Change-Id: I88a2ce550df7466f8d2388d86bc8476dcf3c2ad6 Reviewed-on: https://go-review.googlesource.com/34918Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
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Mikio Hara authored
Updates golang.org/x/crypto/chacha20poly1305 to rev cb497ae for: - chacha20poly1305: fix detection of BMI on amd64 (https://golang.org/cl/34852) - chacha20poly1305: fix typos (https://golang.org/cl/34536) - chacha20poly1305: fix typos (https://golang.org/cl/33855) - chacha20poly1305: fix build constraints (https://golang.org/cl/32391) Change-Id: I3a608b5e21b3a72b5aaa5d0afe6c6cffbb1d6fc1 Reviewed-on: https://go-review.googlesource.com/34871Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
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- 06 Jan, 2017 11 commits
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Brad Fitzpatrick authored
Fixes #18550 Change-Id: Ia08d0ef6964216fcc14fa63c2ba378d68daa2c02 Reviewed-on: https://go-review.googlesource.com/34917Reviewed-by: Chris Broadfoot <cbro@golang.org>
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Matthew Dempsky authored
Rule 9 arguably doesn't make sense for IPv4 addresses, and so far it has only caused problems (#13283, #18518). Disable it until we hear from users that actually want/need it. Fixes #18518. Change-Id: I7b0dd75d03819cab8e0cd4c29f0c1dc8d2e9c179 Reviewed-on: https://go-review.googlesource.com/34914Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
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David Chase authored
CALLPART of STRUCTLIT did not check for incomplete initialization of struct; modify PTRLIT treatment to force zeroing. Test for structlit, believe this might have also failed for arraylit. Fixes #18410. Change-Id: I511abf8ef850e300996d40568944665714efe1fc Reviewed-on: https://go-review.googlesource.com/34622 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
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Jaana Burcu Dogan authored
Updates #18294. Change-Id: Ib6b84243a15ed921cc8960e5fa355fd7594181e6 Reviewed-on: https://go-review.googlesource.com/34821Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
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Russ Cox authored
To implement the blocking of a select, a goroutine builds a list of offers to communicate (pseudo-g's, aka sudog), one for each case, queues them on the corresponding channels, and waits for another goroutine to complete one of those cases and wake it up. Obviously it is not OK for two other goroutines to complete multiple cases and both wake the goroutine blocked in select. To make sure that only one branch of the select is chosen, all the sudogs contain a pointer to a shared (single) 'done uint32', which is atomically cas'ed by any interested goroutines. The goroutine that wins the cas race gets to wake up the select. A complication is that 'done uint32' is stored on the stack of the goroutine running the select, and that stack can move during the select due to stack growth or stack shrinking. The relevant ordering to block and unblock in select is: 1. Lock all channels. 2. Create list of sudogs and queue sudogs on all channels. 3. Switch to system stack, mark goroutine as asleep, unlock all channels. 4. Sleep until woken. 5. Wake up on goroutine stack. 6. Lock all channels. 7. Dequeue sudogs from all channels. 8. Free list of sudogs. 9. Unlock all channels. There are two kinds of stack moves: stack growth and stack shrinking. Stack growth happens while the original goroutine is running. Stack shrinking happens asynchronously, during garbage collection. While a channel listing a sudog is locked by select in this process, no other goroutine can attempt to complete communication on that channel, because that other goroutine doesn't hold the lock and can't find the sudog. If the stack moves while all the channel locks are held or when the sudogs are not yet or no longer queued in the channels, no problem, because no goroutine can get to the sudogs and therefore to selectdone. We only need to worry about the stack (and 'done uint32') moving with the sudogs queued in unlocked channels. Stack shrinking can happen any time the goroutine is stopped. That code already acquires all the channel locks before doing the stack move, so it avoids this problem. Stack growth can happen essentially any time the original goroutine is running on its own stack (not the system stack). In the first half of the select, all the channels are locked before any sudogs are queued, and the channels are not unlocked until the goroutine has stopped executing on its own stack and is asleep, so that part is OK. In the second half of the select, the goroutine wakes up on its own goroutine stack and immediately locks all channels. But the actual call to lock might grow the stack, before acquiring any locks. In that case, the stack is moving with the sudogs queued in unlocked channels. Not good. One goroutine has already won a cas on the old stack (that goroutine woke up the selecting goroutine, moving it out of step 4), and the fact that done = 1 now should prevent any other goroutines from completing any other select cases. During the stack move, however, sudog.selectdone is moved from pointing to the old done variable on the old stack to a new memory location on the new stack. Another goroutine might observe the moved pointer before the new memory location has been initialized. If the new memory word happens to be zero, that goroutine might win a cas on the new location, thinking it can now complete the select (again). It will then complete a second communication (reading from or writing to the goroutine stack incorrectly) and then attempt to wake up the selecting goroutine, which is already awake. The scribbling over the goroutine stack unexpectedly is already bad, but likely to go unnoticed, at least immediately. As for the second wakeup, there are a variety of ways it might play out. * The goroutine might not be asleep. That will produce a runtime crash (throw) like in #17007: runtime: gp: gp=0xc0422dcb60, goid=2299, gp->atomicstatus=8 runtime: g: g=0xa5cfe0, goid=0, g->atomicstatus=0 fatal error: bad g->status in ready Here, atomicstatus=8 is copystack; the second, incorrect wakeup is observing that the selecting goroutine is in state "Gcopystack" instead of "Gwaiting". * The goroutine might be sleeping in a send on a nil chan. If it wakes up, it will crash with 'fatal error: unreachable'. * The goroutine might be sleeping in a send on a non-nil chan. If it wakes up, it will crash with 'fatal error: chansend: spurious wakeup'. * The goroutine might be sleeping in a receive on a nil chan. If it wakes up, it will crash with 'fatal error: unreachable'. * The goroutine might be sleeping in a receive on a non-nil chan. If it wakes up, it will silently (incorrectly!) continue as if it received a zero value from a closed channel, leaving a sudog queued on the channel pointing at that zero vaue on the goroutine's stack; that space will be reused as the goroutine executes, and when some other goroutine finally completes the receive, it will do a stray write into the goroutine's stack memory, which may cause problems. Then it will attempt the real wakeup of the goroutine, leading recursively to any of the cases in this list. * The goroutine might have been running a select in a finalizer (I hope not!) and might now be sleeping waiting for more things to finalize. If it wakes up, as long as it goes back to sleep quickly (before the real GC code tries to wake it), the spurious wakeup does no harm (but the stack was still scribbled on). * The goroutine might be sleeping in gcParkAssist. If it wakes up, that will let the goroutine continue executing a bit earlier than we would have liked. Eventually the GC will attempt the real wakeup of the goroutine, leading recursively to any of the cases in this list. * The goroutine cannot be sleeping in bgsweep, because the background sweepers never use select. * The goroutine might be sleeping in netpollblock. If it wakes up, it will crash with 'fatal error: netpollblock: corrupted state'. * The goroutine might be sleeping in main as another thread crashes. If it wakes up, it will exit(0) instead of letting the other thread crash with a non-zero exit status. * The goroutine cannot be sleeping in forcegchelper, because forcegchelper never uses select. * The goroutine might be sleeping in an empty select - select {}. If it wakes up, it will return to the next line in the program! * The goroutine might be sleeping in a non-empty select (again). In this case, it will wake up spuriously, with gp.param == nil (no reason for wakeup), but that was fortuitously overloaded for handling wakeup due to a closing channel and the way it is handled is to rerun the select, which (accidentally) handles the spurious wakeup correctly: if cas == nil { // This can happen if we were woken up by a close(). // TODO: figure that out explicitly so we don't need this loop. goto loop } Before looping, it will dequeue all the sudogs on all the channels involved, so that no other goroutine will attempt to wake it. Since the goroutine was blocked in select before, being blocked in select again when the spurious wakeup arrives may be quite likely. In this case, the spurious wakeup does no harm (but the stack was still scribbled on). * The goroutine might be sleeping in semacquire (mutex slow path). If it wakes up, that is taken as a signal to try for the semaphore again, not a signal that the semaphore is now held, but the next iteration around the loop will queue the sudog a second time, causing a cycle in the wakeup list for the given address. If that sudog is the only one in the list, when it is eventually dequeued, it will (due to the precise way the code is written) leave the sudog on the queue inactive with the sudog broken. But the sudog will also be in the free list, and that will eventually cause confusion. * The goroutine might be sleeping in notifyListWait, for sync.Cond. If it wakes up, (*Cond).Wait returns. The docs say "Unlike in other systems, Wait cannot return unless awoken by Broadcast or Signal," so the spurious wakeup is incorrect behavior, but most callers do not depend on that fact. Eventually the condition will happen, attempting the real wakeup of the goroutine and leading recursively to any of the cases in this list. * The goroutine might be sleeping in timeSleep aka time.Sleep. If it wakes up, it will continue running, leaving a timer ticking. When that time bomb goes off, it will try to ready the goroutine again, leading to any one of the cases in this list. * The goroutine cannot be sleeping in timerproc, because timerproc never uses select. * The goroutine might be sleeping in ReadTrace. If it wakes up, it will print 'runtime: spurious wakeup of trace reader' and return nil. All future calls to ReadTrace will print 'runtime: ReadTrace called from multiple goroutines simultaneously'. Eventually, when trace data is available, a true wakeup will be attempted, leading to any one of the cases in this list. None of these fatal errors appear in any of the trybot or dashboard logs. The 'bad g->status in ready' that happens if the goroutine is running (the most likely scenario anyway) has happened once on the dashboard and eight times in trybot logs. Of the eight, five were atomicstatus=8 during net/http tests, so almost certainly this bug. The other three were atomicstatus=2, all near code in select, but in a draft CL by Dmitry that was rewriting select and may or may not have had its own bugs. This bug has existed since Go 1.4. Until then the select code was implemented in C, 'done uint32' was a C stack variable 'uint32 done', and C stacks never moved. I believe it has become more common recently because of Brad's work to run more and more tests in net/http in parallel, which lengthens race windows. The fix is to run step 6 on the system stack, avoiding possibility of stack growth. Fixes #17007 and possibly other mysterious failures. Change-Id: I9d6575a51ac96ae9d67ec24da670426a4a45a317 Reviewed-on: https://go-review.googlesource.com/34835 Run-TryBot: Russ Cox <rsc@golang.org> Reviewed-by: Austin Clements <austin@google.com>
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Austin Clements authored
This adds high-level descriptions of the scheduler structures, the user and system stacks, error handling, and synchronization. Change-Id: I1eed97c6dd4a6e3d351279e967b11c6e64898356 Reviewed-on: https://go-review.googlesource.com/34290Reviewed-by: Rick Hudson <rlh@golang.org>
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Austin Clements authored
The comment describing the overall GC algorithm at the top of mgc.go has gotten woefully out-of-date (and was possibly never correct/complete). Update it to reflect the current workings of the GC and the set of phases that we now divide it into. Change-Id: I02143c0ebefe9d4cd7753349dab8045f0973bf95 Reviewed-on: https://go-review.googlesource.com/34711Reviewed-by: Rick Hudson <rlh@golang.org>
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Russ Cox authored
If one of the c.Get(ts.URL) results in an error, the child goroutine calls t.Errorf, but the test goroutine gets stuck waiting for <-gotReqCh, so the test hangs and the program is eventually killed (after 10 minutes!). Whatever might have been printed to t.Errorf is never seen. Adjust test so that the test fails cleanly in this case. Still trying to debug why c.Get might fail. It seems to have something to do with occasional connection failures on macOS Sierra. Change-Id: Ia797787bd51ea7cd6deb1192aec89c331c4f2c48 Reviewed-on: https://go-review.googlesource.com/34836 Run-TryBot: Russ Cox <rsc@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
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Austin Clements authored
Currently, the check for legal pointers in stack copying uses _PageSize (8K) as the minimum legal pointer. By default, Linux won't let you map under 64K, but 1) it's less clear what other OSes allow or will allow in the future; 2) while mapping the first page is a terrible idea, mapping anywhere above that is arguably more justifiable; 3) the compiler only assumes the first physical page (4K) is never mapped. Make the runtime consistent with the compiler and more robust by changing the bad pointer check to use 4K as the minimum legal pointer. This came out of discussions on CLs 34663 and 34719. Change-Id: Idf721a788bd9699fb348f47bdd083cf8fa8bd3e5 Reviewed-on: https://go-review.googlesource.com/34890 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Russ Cox <rsc@golang.org>
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Kevin Burke authored
Change-Id: I1c2e17b25ca91be37a18c47e70678c3753070fb8 Reviewed-on: https://go-review.googlesource.com/34827Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
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Mikio Hara authored
We cannot assume that the platform running documentation service is the target platform. Change-Id: I241ed6f8778169faac9ef49e11dcd40f7422cccc Reviewed-on: https://go-review.googlesource.com/34750 Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
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- 05 Jan, 2017 1 commit
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Emmanuel Odeke authored
Fixes #18392. Avoid nil dereferencing n.Right when dealing with non-existent self referenced interface methods e.g. type A interface{ Fn(A.Fn) } Instead, infer the symbol name from n.Sym itself. Change-Id: I60d5f8988e7318693e5c8da031285d8d7347b771 Reviewed-on: https://go-review.googlesource.com/34817 Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
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