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https://github.com/golang/go
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ef0dedce87
In a C thread, it's necessary to acquire an extra M by using needm while invoking a Go function from C. But, needm and dropm are heavy costs due to the signal-related syscalls.
So, we change to not dropm while returning back to C, which means binding the extra M to the C thread until it exits, to avoid needm and dropm on each C to Go call.
Instead, we only dropm while the C thread exits, so the extra M won't leak.
When invoking a Go function from C:
Allocate a pthread variable using pthread_key_create, only once per shared object, and register a thread-exit-time destructor.
And store the g0 of the current m into the thread-specified value of the pthread key, only once per C thread, so that the destructor will put the extra M back onto the extra M list while the C thread exits.
When returning back to C:
Skip dropm in cgocallback, when the pthread variable has been created, so that the extra M will be reused the next time invoke a Go function from C.
This is purely a performance optimization. The old version, in which needm & dropm happen on each cgo call, is still correct too, and we have to keep the old version on systems with cgo but without pthreads, like Windows.
This optimization is significant, and the specific value depends on the OS system and CPU, but in general, it can be considered as 10x faster, for a simple Go function call from a C thread.
For the newly added BenchmarkCGoInCThread, some benchmark results:
1. it's 28x faster, from 3395 ns/op to 121 ns/op, in darwin OS & Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
2. it's 6.5x faster, from 1495 ns/op to 230 ns/op, in Linux OS & Intel(R) Xeon(R) CPU E5-2630 0 @ 2.30GHz
Fixes #51676
Change-Id: I380702fe2f9b6b401b2d6f04b0aba990f4b9ee6c
GitHub-Last-Rev: 93dc64ad98
GitHub-Pull-Request: golang/go#51679
Reviewed-on: https://go-review.googlesource.com/c/go/+/392854
Reviewed-by: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: thepudds <thepudds1460@gmail.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
111 lines
6.4 KiB
Go
111 lines
6.4 KiB
Go
// Copyright 2011 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package cgotest
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import "testing"
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// The actual test functions are in non-_test.go files
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// so that they can use cgo (import "C").
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// These wrappers are here for gotest to find.
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func Test1328(t *testing.T) { test1328(t) }
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func Test1560(t *testing.T) { test1560(t) }
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func Test1635(t *testing.T) { test1635(t) }
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func Test3250(t *testing.T) { test3250(t) }
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func Test3729(t *testing.T) { test3729(t) }
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func Test3775(t *testing.T) { test3775(t) }
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func Test4029(t *testing.T) { test4029(t) }
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func Test4339(t *testing.T) { test4339(t) }
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func Test5227(t *testing.T) { test5227(t) }
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func Test5242(t *testing.T) { test5242(t) }
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func Test5337(t *testing.T) { test5337(t) }
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func Test5548(t *testing.T) { test5548(t) }
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func Test5603(t *testing.T) { test5603(t) }
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func Test5986(t *testing.T) { test5986(t) }
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func Test6390(t *testing.T) { test6390(t) }
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func Test6833(t *testing.T) { test6833(t) }
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func Test6907(t *testing.T) { test6907(t) }
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func Test6907Go(t *testing.T) { test6907Go(t) }
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func Test7560(t *testing.T) { test7560(t) }
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func Test7665(t *testing.T) { test7665(t) }
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func Test7978(t *testing.T) { test7978(t) }
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func Test8092(t *testing.T) { test8092(t) }
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func Test8517(t *testing.T) { test8517(t) }
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func Test8694(t *testing.T) { test8694(t) }
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func Test8756(t *testing.T) { test8756(t) }
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func Test8811(t *testing.T) { test8811(t) }
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func Test9026(t *testing.T) { test9026(t) }
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func Test9510(t *testing.T) { test9510(t) }
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func Test9557(t *testing.T) { test9557(t) }
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func Test10303(t *testing.T) { test10303(t, 10) }
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func Test11925(t *testing.T) { test11925(t) }
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func Test12030(t *testing.T) { test12030(t) }
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func Test14838(t *testing.T) { test14838(t) }
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func Test17065(t *testing.T) { test17065(t) }
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func Test17537(t *testing.T) { test17537(t) }
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func Test18126(t *testing.T) { test18126(t) }
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func Test18720(t *testing.T) { test18720(t) }
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func Test20129(t *testing.T) { test20129(t) }
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func Test20266(t *testing.T) { test20266(t) }
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func Test20369(t *testing.T) { test20369(t) }
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func Test20910(t *testing.T) { test20910(t) }
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func Test21708(t *testing.T) { test21708(t) }
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func Test21809(t *testing.T) { test21809(t) }
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func Test21897(t *testing.T) { test21897(t) }
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func Test22906(t *testing.T) { test22906(t) }
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func Test23356(t *testing.T) { test23356(t) }
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func Test24206(t *testing.T) { test24206(t) }
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func Test25143(t *testing.T) { test25143(t) }
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func Test26066(t *testing.T) { test26066(t) }
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func Test26213(t *testing.T) { test26213(t) }
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func Test27660(t *testing.T) { test27660(t) }
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func Test28896(t *testing.T) { test28896(t) }
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func Test30065(t *testing.T) { test30065(t) }
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func Test32579(t *testing.T) { test32579(t) }
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func Test31891(t *testing.T) { test31891(t) }
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func Test42018(t *testing.T) { test42018(t) }
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func Test45451(t *testing.T) { test45451(t) }
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func Test49633(t *testing.T) { test49633(t) }
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func TestAlign(t *testing.T) { testAlign(t) }
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func TestAtol(t *testing.T) { testAtol(t) }
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func TestBlocking(t *testing.T) { testBlocking(t) }
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func TestBoolAlign(t *testing.T) { testBoolAlign(t) }
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func TestCallGoWithString(t *testing.T) { testCallGoWithString(t) }
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func TestCallback(t *testing.T) { testCallback(t) }
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func TestCallbackCallers(t *testing.T) { testCallbackCallers(t) }
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func TestCallbackGC(t *testing.T) { testCallbackGC(t) }
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func TestCallbackPanic(t *testing.T) { testCallbackPanic(t) }
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func TestCallbackPanicLocked(t *testing.T) { testCallbackPanicLocked(t) }
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func TestCallbackPanicLoop(t *testing.T) { testCallbackPanicLoop(t) }
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func TestCallbackStack(t *testing.T) { testCallbackStack(t) }
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func TestCflags(t *testing.T) { testCflags(t) }
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func TestCheckConst(t *testing.T) { testCheckConst(t) }
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func TestConst(t *testing.T) { testConst(t) }
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func TestCthread(t *testing.T) { testCthread(t) }
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func TestEnum(t *testing.T) { testEnum(t) }
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func TestNamedEnum(t *testing.T) { testNamedEnum(t) }
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func TestCastToEnum(t *testing.T) { testCastToEnum(t) }
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func TestErrno(t *testing.T) { testErrno(t) }
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func TestFpVar(t *testing.T) { testFpVar(t) }
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func TestGCC68255(t *testing.T) { testGCC68255(t) }
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func TestHandle(t *testing.T) { testHandle(t) }
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func TestHelpers(t *testing.T) { testHelpers(t) }
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func TestLibgcc(t *testing.T) { testLibgcc(t) }
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func TestMultipleAssign(t *testing.T) { testMultipleAssign(t) }
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func TestNaming(t *testing.T) { testNaming(t) }
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func TestPanicFromC(t *testing.T) { testPanicFromC(t) }
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func TestPrintf(t *testing.T) { testPrintf(t) }
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func TestReturnAfterGrow(t *testing.T) { testReturnAfterGrow(t) }
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func TestReturnAfterGrowFromGo(t *testing.T) { testReturnAfterGrowFromGo(t) }
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func TestSetEnv(t *testing.T) { testSetEnv(t) }
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func TestThreadLock(t *testing.T) { testThreadLockFunc(t) }
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func TestUnsignedInt(t *testing.T) { testUnsignedInt(t) }
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func TestZeroArgCallback(t *testing.T) { testZeroArgCallback(t) }
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func BenchmarkCgoCall(b *testing.B) { benchCgoCall(b) }
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func BenchmarkGoString(b *testing.B) { benchGoString(b) }
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func BenchmarkCGoCallback(b *testing.B) { benchCallback(b) }
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func BenchmarkCGoInCThread(b *testing.B) { benchCGoInCthread(b) }
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