go/test
Dan Scales 0a820007e7 runtime: static lock ranking for the runtime (enabled by GOEXPERIMENT)
I took some of the infrastructure from Austin's lock logging CR
https://go-review.googlesource.com/c/go/+/192704 (with deadlock
detection from the logs), and developed a setup to give static lock
ranking for runtime locks.

Static lock ranking establishes a documented total ordering among locks,
and then reports an error if the total order is violated. This can
happen if a deadlock happens (by acquiring a sequence of locks in
different orders), or if just one side of a possible deadlock happens.
Lock ordering deadlocks cannot happen as long as the lock ordering is
followed.

Along the way, I found a deadlock involving the new timer code, which Ian fixed
via https://go-review.googlesource.com/c/go/+/207348, as well as two other
potential deadlocks.

See the constants at the top of runtime/lockrank.go to show the static
lock ranking that I ended up with, along with some comments. This is
great documentation of the current intended lock ordering when acquiring
multiple locks in the runtime.

I also added an array lockPartialOrder[] which shows and enforces the
current partial ordering among locks (which is embedded within the total
ordering). This is more specific about the dependencies among locks.

I don't try to check the ranking within a lock class with multiple locks
that can be acquired at the same time (i.e. check the ranking when
multiple hchan locks are acquired).

Currently, I am doing a lockInit() call to set the lock rank of most
locks. Any lock that is not otherwise initialized is assumed to be a
leaf lock (a very high rank lock), so that eliminates the need to do
anything for a bunch of locks (including all architecture-dependent
locks). For two locks, root.lock and notifyList.lock (only in the
runtime/sema.go file), it is not as easy to do lock initialization, so
instead, I am passing the lock rank with the lock calls.

For Windows compilation, I needed to increase the StackGuard size from
896 to 928 because of the new lock-rank checking functions.

Checking of the static lock ranking is enabled by setting
GOEXPERIMENT=staticlockranking before doing a run.

To make sure that the static lock ranking code has no overhead in memory
or CPU when not enabled by GOEXPERIMENT, I changed 'go build/install' so
that it defines a build tag (with the same name) whenever any experiment
has been baked into the toolchain (by checking Expstring()). This allows
me to avoid increasing the size of the 'mutex' type when static lock
ranking is not enabled.

Fixes #38029

Change-Id: I154217ff307c47051f8dae9c2a03b53081acd83a
Reviewed-on: https://go-review.googlesource.com/c/go/+/207619
Reviewed-by: Dan Scales <danscales@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-07 21:51:03 +00:00
..
alias3.dir
bench
chan test/chan: fix trivial typos 2020-03-25 22:22:20 +00:00
closure3.dir
codegen cmd/compile: delete the floating point Greater and Geq ops 2020-04-07 19:55:05 +00:00
ddd2.dir
dwarf
fixedbugs cmd/compile: don't inline reflect.Value.UnsafeAddr/Pointer if enable checkptr 2020-04-01 06:12:05 +00:00
import2.dir
import4.dir
interface
intrinsic.dir
ken
linkname.dir
method4.dir
oldescape_linkname.dir
retjmp.dir
runtime
stress
syntax
uintptrescapes.dir
64bit.go
235.go
README.md
alg.go
alias.go
alias1.go
alias2.go
alias3.go
align.go
append.go
append1.go
args.go
armimm.go
assign.go
assign1.go
atomicload.go
bigalg.go
bigmap.go
blank.go
blank1.go test, test/fixedbugs, crypto/x509, go/internal/gccgoimporter: fix typos 2020-03-29 17:12:56 +00:00
bom.go
bombad.go
bounds.go
chancap.go
chanlinear.go test, test/fixedbugs, crypto/x509, go/internal/gccgoimporter: fix typos 2020-03-29 17:12:56 +00:00
char_lit.go
char_lit1.go
checkbce.go
clearfat.go
closedchan.go
closure.go
closure1.go
closure2.go
closure3.go
closure4.go
cmp.go
cmp6.go
cmplx.go
cmplxdivide.c
cmplxdivide.go
cmplxdivide1.go
complit.go
complit1.go
compos.go
const.go
const1.go
const2.go
const3.go
const4.go
const5.go
const6.go
convT2X.go
convert.go
convert1.go
convert2.go
convert3.go
convlit.go
convlit1.go
copy.go
copy1.go
crlf.go
ddd.go
ddd1.go
ddd2.go
decl.go
declbad.go
defer.go
defererrcheck.go
deferfin.go
defernil.go
deferprint.go
deferprint.out
devirt.go
divide.go
divmod.go
empty.go
env.go
eof.go
eof1.go
escape.go
escape2.go
escape2n.go
escape3.go
escape4.go
escape5.go
escape_array.go
escape_calls.go
escape_closure.go
escape_field.go
escape_goto.go
escape_hash_maphash.go
escape_iface.go
escape_indir.go
escape_level.go
escape_map.go
escape_param.go
escape_runtime_atomic.go
escape_selfassign.go
escape_slice.go cmd/compile: make isSmallMakeSlice checks slice cap only 2020-03-31 21:51:51 +00:00
escape_struct_param1.go
escape_struct_param2.go
escape_struct_return.go
escape_sync_atomic.go
escape_unsafe.go
fibo.go
finprofiled.go
float_lit.go
float_lit2.go
float_lit3.go
floatcmp.go
for.go
func.go
func1.go
func2.go
func3.go
func4.go
func5.go
func6.go
func7.go
func8.go
funcdup.go
funcdup2.go
gc.go
gc1.go
gc2.go
gcgort.go
gcstring.go
goprint.go
goprint.out
goto.go
heapsampling.go
helloworld.go
helloworld.out
if.go
import.go
import1.go
import2.go
import4.go
import5.go
import6.go
index.go
index0.go
index1.go
index2.go
indirect.go
indirect1.go
init.go
init1.go
initcomma.go
initempty.go
initialize.go
initializerr.go
initloop.go
inline.go cmd/compile: allow mid-stack inlining when there is a cycle of recursion 2020-04-03 21:43:52 +00:00
inline_big.go
inline_caller.go
inline_callers.go
inline_literal.go
inline_math_bits_rotate.go
inline_sync.go test: re-enable atomic intrinsic related tests on riscv64 2020-03-25 01:11:15 +00:00
inline_variadic.go
int_lit.go
intcvt.go
intrinsic.go
intrinsic_atomic.go test: re-enable atomic intrinsic related tests on riscv64 2020-03-25 01:11:15 +00:00
iota.go
label.go
label1.go
linkmain.go
linkmain_run.go
linkname.go
linkobj.go
linkx.go
linkx_run.go
literal.go
literal2.go
live.go
live1.go
live2.go
live_syscall.go
locklinear.go
loopbce.go
makechan.go
makemap.go
makenew.go
mallocfin.go
map.go
map1.go
mapclear.go
maplinear.go
mergemul.go
method.go
method1.go
method2.go
method3.go
method4.go
method5.go
method6.go
method7.go
named.go
named1.go
nil.go
nilcheck.go
nilptr.go
nilptr2.go
nilptr3.go
nilptr4.go
nilptr5.go
nilptr5_aix.go
nilptr5_wasm.go
nilptr_aix.go
nosplit.go runtime: static lock ranking for the runtime (enabled by GOEXPERIMENT) 2020-04-07 21:51:03 +00:00
notinheap.go
notinheap2.go
notinheap3.go
nowritebarrier.go cmd/compile: allow mid-stack inlining when there is a cycle of recursion 2020-04-03 21:43:52 +00:00
nul1.go
opt_branchlikely.go
parentype.go
peano.go
phiopt.go
print.go
print.out
printbig.go
printbig.out
prove.go
range.go
recover.go
recover1.go
recover2.go
recover3.go
recover4.go
recover5.go
reflectmethod1.go
reflectmethod2.go
reflectmethod3.go
reflectmethod4.go
rename.go
rename1.go
reorder.go
reorder2.go
retjmp.go
return.go
rotate.go
rotate0.go
rotate1.go
rotate2.go
rotate3.go
run.go test: make runindir tests pass regardless of whether module mode is in use 2020-03-25 14:19:25 +00:00
rune.go
runtime.go
shift1.go
shift2.go
sieve.go
sigchld.go
sigchld.out
simassign.go
sinit.go
sinit_run.go
sizeof.go
slice3.go
slice3err.go
slicecap.go
sliceopt.go
solitaire.go
stack.go
stackobj.go
stackobj2.go
stackobj3.go
strcopy.go
strength.go
string_lit.go
stringrange.go
struct0.go
switch.go
switch2.go
switch3.go
switch4.go
switch5.go
switch6.go
switch7.go
tinyfin.go
torture.go
turing.go
typecheck.go
typecheckloop.go
typeswitch.go
typeswitch1.go
typeswitch2.go
typeswitch2b.go
typeswitch3.go
uintptrescapes.go
uintptrescapes2.go
uintptrescapes3.go
undef.go
utf.go
varerr.go
varinit.go
winbatch.go build: force all Windows batch files to CRLF 2020-03-22 08:42:38 +00:00
writebarrier.go
zerodivide.go

README.md

The test directory contains tests of the Go tool chain and runtime. It includes black box tests, regression tests, and error output tests. They are run as part of all.bash.

To run just these tests, execute:

../bin/go run run.go

Standard library tests should be written as regular Go tests in the appropriate package.

The tool chain and runtime also have regular Go tests in their packages. The main reasons to add a new test to this directory are:

  • it is most naturally expressed using the test runner; or
  • it is also applicable to gccgo and other Go tool chains.