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runtime·cbctxts has been unused since CL 258938, but it was left over.
Change-Id: I374ad26e668a36994e41f5d17593b33090bdc644
Reviewed-on: https://go-review.googlesource.com/c/go/+/463119
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
Run-TryBot: Quim Muntal <quimmuntal@gmail.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
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This CL removes badsignal2 function, as it is unused on Windows.
badsignal2 was originally intended to abort the process when
an exception was raised on a non-Go thread, following the same approach
as Linux and others.
Since it was added, back on https://golang.org/cl/5797068, it has caused
several issues on Windows, see #8224 and #50877. That's because we can't
know wether the signal is bad or not, as our trap might not be at the
end of the exception handler chain.
To fix those issues, https://golang.org/cl/104200046 and CL 442896
stopped calling badsignal2, and CL 458135 removed one last incorrect
call on amd64 and 386.
Change-Id: I5bd31ee2672118ae0f1a2c8b46a1bb0f4893a011
Reviewed-on: https://go-review.googlesource.com/c/go/+/463116
Reviewed-by: Bryan Mills <bcmills@google.com>
Run-TryBot: Quim Muntal <quimmuntal@gmail.com>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
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This CL factors out part of the Windows sigtramp implementation, which
was duplicated in all four architectures. The new common code is
implemented in Go rather than in assembly, which will make Windows
error handling easier to reason and maintain.
While here, implement the control flow guard workaround on
windows/386, which almost comes for free.
Change-Id: I0bf38c28c54793225126e161bd95527a62de05e0
Reviewed-on: https://go-review.googlesource.com/c/go/+/458135
Run-TryBot: Quim Muntal <quimmuntal@gmail.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
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If there is no current G while handling an exception it means
the exception was originated in a non-Go thread.
The best we can do is ignore the exception and let it flow
through other vectored and structured error handlers.
I've removed badsignal2 from sigtramp because we can't really know
if the signal is bad or not, it might be handled later in the chain.
Fixes #50877
Updates #56082
Change-Id: Ica159eb843629986d1fb5482f0b59a9c1ed91698
Reviewed-on: https://go-review.googlesource.com/c/go/+/442896
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Auto-Submit: Michael Pratt <mpratt@google.com>
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Reviewed-by: Michael Pratt <mpratt@google.com>
Run-TryBot: Quim Muntal <quimmuntal@gmail.com>
Reviewed-by: David Chase <drchase@google.com>
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Change-Id: I63eb42f3ce5ca452279120a5b33518f4ce16be45
GitHub-Last-Rev: a88f2f72bef402344582ae997a4907457002b5df
GitHub-Pull-Request: golang/go#52951
Reviewed-on: https://go-review.googlesource.com/c/go/+/406843
Run-TryBot: Robert Griesemer <gri@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
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On 64-bit, this is more efficient, and on ARM64, this prevents the time
from moving backwards due to the weaker memory model. On ARM32 due to
the weaker memory model, we issue a memory barrier.
Updates #48072.
Change-Id: If4695716c3039d8af14e14808af217f5c99fc93a
Reviewed-on: https://go-review.googlesource.com/c/go/+/361057
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
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assembly functions
There are a few assembly functions in the runtime that are marked
as ABIInternal, solely because funcPC can get the right address.
The functions themselves do not actually follow ABIInternal (or
irrelevant). Now we have internal/abi.FuncPCABI0, use that, and
un-mark the functions.
Also un-mark assembly functions that are only called in assembly.
For them, it only matters if the caller and callee are consistent.
Change-Id: I240e126ac13cb362f61ff8482057ee9f53c24097
Reviewed-on: https://go-review.googlesource.com/c/go/+/321950
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
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Reviewed-by: Michael Knyszek <mknyszek@google.com>
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Currently if a signal lands on a non-Go thread that's handled by the Go
handler, Go will emit a message. However, unlike everywhere else in the
runtime, Go will not abort the process after, and the signal handler
will try to continue executing.
This leads to cascading failures and possibly even memory corruption.
For #45638.
Change-Id: I546f4e82f339d555bed295528d819ac883b92bc6
Reviewed-on: https://go-review.googlesource.com/c/go/+/316809
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
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This is a step toward separating whether time.now is implemented in
assembly from whether we are using faketime.
Change-Id: I8bf059b44a103b034835e3d3b799319cc05e9552
Reviewed-on: https://go-review.googlesource.com/c/go/+/314273
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
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Change-Id: I1a583d3da9cca4ac51f3fec9b508b7638b452d60
Reviewed-on: https://go-review.googlesource.com/c/go/+/314270
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
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This code is needed for use with cgo proper
(as opposed to hand-written DLL calls, which
we always use but only exercise cgo execution,
not cgo linking).
Change-Id: Iddc31d9c1c924d83d032b80dca65ddfda6624046
Reviewed-on: https://go-review.googlesource.com/c/go/+/312041
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
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This function is no longer used.
Eliminating this actually fixes several problems:
- It made assumptions about what registers memclrNoHeapPointers would
preserve. Besides being an abstraction violation and lurking
maintenance issue, this actively became a problem for regabi because
the call to memclrNoHeapPointers now happens through an ABI wrapper,
which is generated by the compiler and hence we can't easily control
what registers it clobbers.
- The amd64 implementation (at least), does not interact with the host
ABI correctly. Notably, it doesn't save many of the registers that
are callee-save in the host ABI but caller-save in the Go ABI.
- It interacts strangely with the NOSPLIT checker because it allocates
an entire M and G on its stack. It worked around this on arm64, and
happened to do things the NOSPLIT checker couldn't track on 386 and
amd64, and happened to be *4 bytes* below the limit on arm (so any
addition to the m or g structs would cause a NOSPLIT failure). See
CL 309031 for a more complete explanation.
Fixes #45530.
Updates #40724.
Change-Id: Ic70d4d7e1c17f1d796575b3377b8529449e93576
Reviewed-on: https://go-review.googlesource.com/c/go/+/309634
Trust: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
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This replaces the externalthreadhandler-based implementation of
profileloop with one that uses newm to start a new thread. This is a
step toward eliminating externalthreadhandler.
For #45530.
Change-Id: Id8e5540423fe2d2004024b649afec6998f77b092
Reviewed-on: https://go-review.googlesource.com/c/go/+/309633
Trust: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
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This replaces the externalthreadhandler-based implementation of
ctrlhandler with one based on compileCallback. This is a step toward
eliminating externalthreadhandler.
For #45530.
Change-Id: I2de2f2f37777af292db67ccf8057b7566aab81f8
Reviewed-on: https://go-review.googlesource.com/c/go/+/309632
Trust: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
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Fixes #45498
Change-Id: I89365f3517bc84376f0f580c64a57f38aaba0cbb
Reviewed-on: https://go-review.googlesource.com/c/go/+/308997
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Alex Brainman <alex.brainman@gmail.com>
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Change-Id: I31f2081eb7c30a9583f479f9194e636fe721b9b3
GitHub-Last-Rev: d09f5fbdc5785dc3963b22ad75309740e0de258e
GitHub-Pull-Request: golang/go#45278
Reviewed-on: https://go-review.googlesource.com/c/go/+/305231
Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Emmanuel Odeke <emmanuel@orijtech.com>
TryBot-Result: Go Bot <gobot@golang.org>
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In the runtime there are Windows-specific assembly routines that are
address-taken via funcPC and are not intended to be called through a
wrapper. Mark them as ABIInternal so that we don't grab the wrapper,
because that will break in all sorts of contexts.
For #40724.
For #44065.
Change-Id: I12a728786786f423e5b229f8622e4a80ec27a31c
Reviewed-on: https://go-review.googlesource.com/c/go/+/302109
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
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Changed calling convention to pre-multiply the argument by -100,
and then deleted the * 100 but not the negation in the windows/arm assembly.
Delete the negation.
Fixes the current all.bash breakage on windows/arm builder.
(Maybe that will uncover more.)
Change-Id: I13006a44866ecc007586deb180a49c038d70aa99
Reviewed-on: https://go-review.googlesource.com/c/go/+/295529
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
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Bug introduced in CL 288799: R12 is used but not set.
Fixes windows/arm builder.
Change-Id: I015a5a83cfa3bdd23da1ffb73713623764f2f817
Reviewed-on: https://go-review.googlesource.com/c/go/+/295109
Trust: Russ Cox <rsc@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
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The assembly is mostly a straightforward conversion of the
equivalent arm assembly.
This CL is part of a stack adding windows/arm64
support (#36439), intended to land in the Go 1.17 cycle.
Change-Id: I61b15d712ade4d3a7285c7680de8e0987aacba10
Reviewed-on: https://go-review.googlesource.com/c/go/+/288828
Trust: Russ Cox <rsc@golang.org>
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
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Externalthreadhandler was not handling its own stack correctly.
It incorrectly referred to the saved LR slot (uninitialized, it turned out)
as holding the return value from the called function.
Externalthreadhandler is used to call two different functions:
profileloop1 and ctrlhandler1.
Profileloop1 does not return, so no harm done.
Ctrlhandler1 returns a boolean indicating whether the handler
took care of the control event (if true, no other handlers run).
It's hard to say exactly what uninitialized values are likely to
have been returned instead of ctrlhandler1's result, but it
probably wasn't helping matters.
Change-Id: Ia02f1c033df618cb82c2193b3a8241ed048a8b18
Reviewed-on: https://go-review.googlesource.com/c/go/+/288812
Trust: Russ Cox <rsc@golang.org>
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
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This code has clearly never run successfully,
since one of the “tail calls" calls the wrong function,
and both of them appear in functions with stack frames
that are never going to be properly unwound.
Probably there is no windows/arm under WINE at all.
But might as well fix the code.
Change-Id: I5fa62274b3661bc6bce098657b5bcf11d59655eb
Reviewed-on: https://go-review.googlesource.com/c/go/+/288811
Trust: Russ Cox <rsc@golang.org>
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
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The architecture-specific interpretation of m->tls[0]
is unnecessary and fragile. Delete it.
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: I927345e52fa2f1741d4914478a29d1fb8acb0dc3
Reviewed-on: https://go-review.googlesource.com/c/go/+/288806
Trust: Russ Cox <rsc@golang.org>
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
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No change to actual runtime, but helps reduce the laundry list
of functions.
mcall, morestack, and asmcgocall are not actually top-of-frame,
so those need more attention in follow-up CLs.
mstart moved to assembly so that it can be marked TOPFRAME.
Since TOPFRAME also tells DWARF consumers not to unwind
this way, this change should also improve debuggers a
marginal amount.
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: If1e0d46ca973de5e46b62948d076f675f285b5d9
Reviewed-on: https://go-review.googlesource.com/c/go/+/288802
Trust: Russ Cox <rsc@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
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Both asmcgocall and systemstack need to save the calling Go code's
context for use by traceback, but they do it differently.
Systemstack's appraoch is better, because it doesn't require a
special case in traceback.
So make them both use that.
While we are here, the fake mstart caller in systemstack is
no longer needed and can be removed.
(traceback knows to stop in systemstack because of the writes to SP.)
Also remove the fake mstarts in sys_windows_*.s.
And while we are there, fix the control flow guard code in sys_windows_arm.s.
The current code is using pointers to a stack frame that technically is gone
once we hit the RET instruction. Clearly it's working OK, but better not to depend
on data below SP being preserved, even for just a few instructions.
Store the value we need in other registers instead.
(This code is only used for pushing a sigpanic call, which does not
actually return to the site of the fault and therefore doesn't need to
preserve any of the registers.)
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: Id1e3ef5e54f7ad786e4b87043f2626eba7c3bbd9
Reviewed-on: https://go-review.googlesource.com/c/go/+/288799
Trust: Russ Cox <rsc@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
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This is dead code and need not be ported to each architecture.
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: I2d0072b377f73e49d7158ea304670c26f5486c59
Reviewed-on: https://go-review.googlesource.com/c/go/+/288794
Trust: Russ Cox <rsc@golang.org>
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
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During a cgocallback, the runtime calls needm to get an m.
The calls made during needm cannot themselves assume that
there is an m or a g (which is attached to the m).
In the old days of making direct system calls, the only thing
you had to do for such functions was mark them //go:nosplit,
to avoid the use of g in the stack split prologue.
But now, on operating systems that make system calls through
shared libraries and use code that saves state in the g or m
before doing so, it's not safe to assume g exists. In fact, it is
not even safe to call getg(), because it might fault deferencing
the TLS storage to find the g pointer (that storage may not be
initialized yet, at least on Windows, and perhaps on other systems
in the future).
The specific routines that are problematic are usleep and osyield,
which are called during lock contention in lockextra, called
from needm.
All this is rather subtle and hidden, so in addition to fixing the
problem on Windows, this CL makes the fact of not running on
a g much clearer by introducing variants usleep_no_g and
osyield_no_g whose names should make clear that there is no g.
And then we can remove the various sketchy getg() == nil checks
in the existing routines.
As part of this cleanup, this CL also deletes onosstack on Windows.
onosstack is from back when the runtime was implemented in C.
It predates systemstack but does essentially the same thing.
Instead of having two different copies of this code, we can use
systemstack consistently. This way we need not port onosstack
to each architecture.
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: I3352de1fd0a3c26267c6e209063e6e86abd26187
Reviewed-on: https://go-review.googlesource.com/c/go/+/288793
Trust: Russ Cox <rsc@golang.org>
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
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This updates the callbacks implementation on windows/arm for the
changes made in CL 258938. At the time, that was left as a TODO.
At the same time, it also extends the previous support for only 4
arguments to also support additional arguments on the stack. This is
required for functions like SetWinEventHook, which take 7 arguments. It
does this by pushing r0-r3 onto the stack before the normal prologue,
and then pointing the args struct to that location.
This is derived from CL 270077 and CL 270078.
Updates #40724.
Fixes #42591.
Change-Id: Icc199e7f2c24205e41be4e00015283c7e2a9b797
Reviewed-on: https://go-review.googlesource.com/c/go/+/271178
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Austin Clements <austin@google.com>
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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>
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@jstarks suggested that recent versions of Windows provide access to high resolution timers. See
https://github.com/golang/go/issues/8687#issuecomment-656259353
for details.
I tried to run this C program on my Windows 10 computer
```
#include <stdio.h>
#include <Windows.h>
#pragma comment(lib, "Winmm.lib")
// Apparently this is already defined when I use msvc cl.
//#define CREATE_WAITABLE_TIMER_HIGH_RESOLUTION = 0x00000002;
int usleep(HANDLE timer, LONGLONG d) {
LARGE_INTEGER liDueTime;
DWORD ret;
LARGE_INTEGER StartingTime, EndingTime, ElapsedMicroseconds;
LARGE_INTEGER Frequency;
QueryPerformanceFrequency(&Frequency);
QueryPerformanceCounter(&StartingTime);
liDueTime.QuadPart = d;
liDueTime.QuadPart = liDueTime.QuadPart * 10; // us into 100 of ns units
liDueTime.QuadPart = -liDueTime.QuadPart; // negative for relative dure time
if (!SetWaitableTimer(timer, &liDueTime, 0, NULL, NULL, 0)) {
printf("SetWaitableTimer failed: errno=%d\n", GetLastError());
return 1;
}
ret = WaitForSingleObject(timer, INFINITE);
if (ret != WAIT_OBJECT_0) {
printf("WaitForSingleObject failed: ret=%d errno=%d\n", ret, GetLastError());
return 1;
}
QueryPerformanceCounter(&EndingTime);
ElapsedMicroseconds.QuadPart = EndingTime.QuadPart - StartingTime.QuadPart;
ElapsedMicroseconds.QuadPart *= 1000000;
ElapsedMicroseconds.QuadPart /= Frequency.QuadPart;
printf("delay is %lld us - slept for %lld us\n", d, ElapsedMicroseconds.QuadPart);
return 0;
}
int testTimer(DWORD createFlag)
{
HANDLE timer;
timer = CreateWaitableTimerEx(NULL, NULL, createFlag, TIMER_ALL_ACCESS);
if (timer == NULL) {
printf("CreateWaitableTimerEx failed: errno=%d\n", GetLastError());
return 1;
}
usleep(timer, 1000LL);
usleep(timer, 100LL);
usleep(timer, 10LL);
usleep(timer, 1LL);
CloseHandle(timer);
return 0;
}
int main()
{
printf("\n1. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is off - timeBeginPeriod is off\n");
testTimer(0);
printf("\n2. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is on - timeBeginPeriod is off\n");
testTimer(CREATE_WAITABLE_TIMER_HIGH_RESOLUTION);
timeBeginPeriod(1);
printf("\n3. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is off - timeBeginPeriod is on\n");
testTimer(0);
printf("\n4. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is on - timeBeginPeriod is on\n");
testTimer(CREATE_WAITABLE_TIMER_HIGH_RESOLUTION);
}
```
and I see this output
```
1. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is off - timeBeginPeriod is off
delay is 1000 us - slept for 4045 us
delay is 100 us - slept for 3915 us
delay is 10 us - slept for 3291 us
delay is 1 us - slept for 2234 us
2. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is on - timeBeginPeriod is off
delay is 1000 us - slept for 1076 us
delay is 100 us - slept for 569 us
delay is 10 us - slept for 585 us
delay is 1 us - slept for 17 us
3. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is off - timeBeginPeriod is on
delay is 1000 us - slept for 742 us
delay is 100 us - slept for 893 us
delay is 10 us - slept for 414 us
delay is 1 us - slept for 920 us
4. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is on - timeBeginPeriod is on
delay is 1000 us - slept for 1466 us
delay is 100 us - slept for 559 us
delay is 10 us - slept for 535 us
delay is 1 us - slept for 5 us
```
That shows, that indeed using CREATE_WAITABLE_TIMER_HIGH_RESOLUTION
will provide sleeps as low as about 500 microseconds, while our
current approach provides about 1 millisecond sleep.
New approach also does not require for timeBeginPeriod to be on,
so this change solves long standing problem with go programs draining
laptop battery, because it calls timeBeginPeriod.
This change will only run on systems where
CREATE_WAITABLE_TIMER_HIGH_RESOLUTION flag is available. If not
available, the runtime will fallback to original code that uses
timeBeginPeriod.
This is how this change affects benchmark reported in issue #14790
name old time/op new time/op delta
ChanToSyscallPing 1.05ms ± 2% 0.68ms ±11% -35.43% (p=0.000 n=10+10)
The benchmark was run with GOMAXPROCS set to 1.
Fixes #8687
Updates #14790
Change-Id: I5b97ba58289c088c17c05292e12e45285c467eae
Reviewed-on: https://go-review.googlesource.com/c/go/+/248699
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Austin Clements <austin@google.com>
|
|
In preparation for general faketime support, this renames the existing
nanotime, walltime, and write functions to nanotime1, walltime1, and
write1 and wraps them with trivial Go functions. This will let us
inject different implementations on all platforms when faketime is
enabled.
Updates #30439.
Change-Id: Ice5ccc513a32a6d89ea051638676d3ee05b00418
Reviewed-on: https://go-review.googlesource.com/c/go/+/192738
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
|
|
This reverts CL 191759.
Reason for revert: broke most Go programs using the time package on Wine,
including on 4.15, the latest stable version. Only wine-staging (with
experimental patches) contains an upstream fix we could rely on.
Change-Id: Ic8ba126022e54f412174042fbb9abed82d5eb318
Reviewed-on: https://go-review.googlesource.com/c/go/+/192622
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
|
|
A few years ago, Wine-specific detection was added as an ugly hack to
work around shortcomings in the emulation layer. Probably it's best to
not special case this emulator versus that emulator versus the real
deal, but there were two arguments presented in the hack's favor:
1. Wine is useful and developers will appreciate being able to debug
stuff with it.
2. The existing KUSER_SHARED_DATA technique for gathering time is
undocumented, and we shouldn't be relying on it anyway, since
Microsoft might remove it without notice.
As it turns out, neither one of these are, at the time of writing, true.
(1) has been handled for some time by Wine with the introduction of the
commit entitled "ntdll: Create thread to update user_shared_data time
values when necessary". And (2) is in fact documented:
https://docs.microsoft.com/en-us/windows-hardware/drivers/ddi/content/ntddk/ns-ntddk-kuser_shared_data
https://docs.microsoft.com/en-us/windows-hardware/drivers/debugger/-kuser
It's in use so widely by both third-party software (such as games, a
massive market segment) and by Microsoft binaries that removing it from
the operating system will basically never happen.
So with both issues taken care of, this commit simply gets rid of the
old hack.
Change-Id: I80093f50e0d10d53648128d0f9dd76b1b92a119e
Reviewed-on: https://go-review.googlesource.com/c/go/+/191759
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
|
|
Working toward making the tree vet-safe instead of having
so many exceptions in cmd/vet/all/whitelist.
This CL makes "go vet -unsafeptr=false runtime" happy for windows/*,
while keeping "GO_BUILDER_NAME=misc-vetall go tool dist test" happy too.
For #31916.
Change-Id: If37ab2b3f6fca4696b8a6afb2ef11ba6c4fb42e0
Reviewed-on: https://go-review.googlesource.com/c/go/+/176106
Reviewed-by: Austin Clements <austin@google.com>
|
|
This reverts change https://golang.org/cl/154758.
Restore the previous implementations of nanotime and time.now, which
are sufficiently high resolution and more efficient than
QueryPerformanceCounter. The intent of the change was to improve
resolution of tracing timestamps, but the change was overly broad
as it was only necessary to fix cputicks(). cputicks() is fixed in
a subsequent change.
Updates #26148
Change-Id: Ib9883d02fe1af2cc4940e866d8f6dc7622d47781
Reviewed-on: https://go-review.googlesource.com/c/154761
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
|
|
The previous implementation of nanotime and time.now used a time source
that was updated on the system clock tick, which has a maximum
resolution of about 1ms. On 386 and amd64, this time source maps to
the system performance counter, so has much higher resolution.
On ARM, use QueryPerformanceCounter() to get a high resolution timestamp.
Updates #26148
Change-Id: I1abc99baf927a95b472ac05020a7788626c71d08
Reviewed-on: https://go-review.googlesource.com/c/154758
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
|
|
Fix profiling handler to get the correct g for the m being profiled.
Store a pointer to the TLS slot holding g in the thread's m. This
enables the profiling handler to get the current g for the thread,
even if the thread is executing external code or system code.
Updates #26148
Signed-off-by: Jordan Rhee <jordanrh@microsoft.com>
Change-Id: Ie061284c12341c76c7d96cc0c2d5bac969230829
Reviewed-on: https://go-review.googlesource.com/c/153718
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
|
|
Move startNano from runtime to time package.
In preparation for a subsequent change that speeds up Since and Until.
This also makes code simpler as we have less assembly as the result,
monotonic time handling is better localized in time package.
This changes values returned from nanotime on windows
(it does not account for startNano anymore), current comments state
that it's important, but it's unclear how it can be important
since no other OS does this.
Update #25729
Change-Id: I2275d57b7b5ed8fd0d53eb0f19d55a86136cc555
Reviewed-on: https://go-review.googlesource.com/c/146340
Reviewed-by: Ian Lance Taylor <iant@golang.org>
|
|
Updates #26148
Change-Id: I8f68b2c926c7b11dc86c9664ed7ff2d2f78b64b4
Reviewed-on: https://go-review.googlesource.com/128715
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
|
