The call to the C function runtime.findnull() requires
that we provide the argument at 0(SP).
R=rsc, rminnich, ality
CC=golang-dev
https://golang.org/cl/7559047
Otherwise the next goroutine run on the m
can get inadvertently locked if it executes a cgo call
that turns on the internal lock.
While we're here, fix the cgo panic unwind to
decrement m->ncgo like the non-panic unwind does.
Fixes#4971.
R=golang-dev, iant, dvyukov
CC=golang-dev
https://golang.org/cl/7627043
Now the default startup is that the program begins at _rt0_386_$GOOS,
which behaves as if calling main(argc, argv). Main jumps to _rt0_386.
This makes the _rt0_386 entry match the expected semantics for
the standard C "main" function, which we can now provide for use when
linking against a standard C library.
386 analogue of https://golang.org/cl/7525043
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/7551045
Change 231af8ac63aa (CL 7314062) made runtime.enteryscall()
set m->mcache = nil, which means that we can no longer use
syscall.errstr in syscall.Syscall and syscall.Syscall6, since it
requires a new buffer to be allocated for holding the error string.
Instead, we use pre-allocated per-M storage to hold error strings
from syscalls made while in entersyscall mode, and call
runtime.findnull to calculate the lengths.
Fixes#4994.
R=rsc, rminnich, ality, dvyukov, rminnich, r
CC=golang-dev
https://golang.org/cl/7567043
The deadlock episodically occurs on misc/cgo/test/TestCthread.
The problem is that starttheworld() leaves some P's with local work
without M's. Then all active M's enter into syscalls, but reject to
wake another M's due to the following check (both in entersyscallblock() and in retake()):
if(p->runqhead == p->runqtail &&
runtime·atomicload(&runtime·sched.nmspinning) +
runtime·atomicload(&runtime·sched.npidle) > 0)
continue;
R=rsc
CC=golang-dev
https://golang.org/cl/7424054
Still to do: non-linux and non-amd64.
It may work on other ELF-based amd64 systems too, but untested.
"go test -ldflags -hostobj $GOROOT/misc/cgo/test" passes.
Much may yet change, but this seems a reasonable checkpoint.
R=iant
CC=golang-dev
https://golang.org/cl/7369057
Now the default startup is that the program begins at _rt0_amd64_$GOOS,
which sets DI = argc, SI = argv and jumps to _rt0_amd64.
This makes the _rt0_amd64 entry match the expected semantics for
the standard C "main" function, which we can now provide for use when
linking against a standard C library.
R=golang-dev, devon.odell, minux.ma
CC=golang-dev
https://golang.org/cl/7525043
broke arm garbage collector
traceback_arm fails with a missing pc. It needs CL 7494043.
But that only makes the build break later, this time with
"invalid freelist". Roll back until it can be fixed correctly.
««« original CL description
runtime: restrict stack root scan to locals and arguments
R=rsc
CC=golang-dev
https://golang.org/cl/7301062
»»»
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/7493044
If the constant CollectStats is non-zero and GOGCTRACE=1
the garbage collector will print basic statistics about executed
GC instructions.
R=golang-dev, dvyukov
CC=golang-dev, rsc
https://golang.org/cl/7413049
Fixes#4904.
The problem was that when the test runs the heap had grown to ~100MB,
so GC allows it to grow to 200MB, and so the test fails.
Moving the test to a separate process makes it much more isolated and stable.
R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/7441046
Also make the crossover point an architecture-dependent constant,
although it's the same everywhere for now.
BenchmarkAppendStr1Byte 416 145 -65.14%
BenchmarkAppendStr4Bytes 743 217 -70.79%
BenchmarkAppendStr8Bytes 421 270 -35.87%
BenchmarkAppendStr16Bytes 415 403 -2.89%
BenchmarkAppendStr32Bytes 415 391 -5.78%
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/7459044
Putting the M initialization in multiple places will not scale.
Various code assumes mstart is the start already. Make it so.
R=golang-dev, devon.odell
CC=golang-dev
https://golang.org/cl/7420048
There is a #pragma dynexport crosscall2, to help SWIG,
and 6l cannot export the symbol if it doesn't get to see it.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/7448044
There are some function pointers declared by 6c in
package runtime without initialization and then also
declared in package runtime/cgo with initialization,
so that if runtime/cgo is linked in, the function pointers
are non-nil, and otherwise they are nil. We depend on
this property for implementing non-essential cgo hooks
in package runtime.
The declarations in package runtime are 6c-compiled
and end up in .6 files. The declarations in package runtime/cgo
are gcc-compiled and end up in .o files. Since 6l links the .6
and .o files together, this all works.
However, when we switch to "external linking" mode,
6l will not see the .o files, and it would be up to the host linker
to resolve the two into a single initialized symbol.
Not all host linkers will do this (in particular OS X gcc will not).
To fix this, move the cgo declarations into 6c-compiled code,
so that they end up in .6 files, so that 6l gets them no matter what.
R=golang-dev
CC=golang-dev
https://golang.org/cl/7440045
The naming in this package is a disaster.
Make it all consistent.
Remove some 'static' from functions that will
be referred to from other files soon.
This CL is purely renames using global search and replace.
Submitting separately so that real changes will not
be drowned out by these renames in future CLs.
TBR=iant
CC=golang-dev
https://golang.org/cl/7416046
runtime: double-check that symbol table is sorted
If the symbol table is unsorted, the binary search in findfunc
will not find its func, which will make stack traces stop early.
When the garbage collector starts using the stack tracer,
that would be a serious problem.
The unsorted symbol addresses came from from two things:
1. The symbols in an ELF object are not necessarily sorted,
so sort them before adding them to the symbol list.
2. The __i686.get_pc_thunk.bx symbol is present in multiple
object files and was having its address adjusted multiple
times, producing an incorrect address in the symbol table.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/7440044
Revision 6a88e1893941 corrupts the argument to
racefuncenter by pushing the data block pointer
to the stack.
Fixes#4885.
R=dvyukov, rsc
CC=golang-dev
https://golang.org/cl/7381053
add per-P cache of dead G's
add global runnable queue (not used for now)
add list of idle P's (not used for now)
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7397061
The current code uses 64-bit pc-relative on 64-bit systems,
but in ELF linkers there is no such thing, so we cannot
express this in a .o file. Change to 32-bit.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/7383055
This CL changes the encoding used for the Go symbol table,
stored in the binary and used at run time. It does not change
any of the semantics or structure: the bits are just packed
a little differently.
The comment at the top of runtime/symtab.c describes the new format.
Compared to the Go 1.0 format, the main changes are:
* Store symbol addresses as full-pointer-sized host-endian values.
(For 6g, this means addresses are 64-bit little-endian.)
* Store other values (frame sizes and so on) varint-encoded.
The second change more than compensates for the first:
for the godoc binary on OS X/amd64, the new symbol table
is 8% smaller than the old symbol table (1,425,668 down from 1,546,276).
This is a required step for allowing the host linker (gcc) to write
the final Go binary, since it will have to fill in the symbol address slots
(so the slots must be host-endian) and on 64-bit systems it may
choose addresses above 4 GB.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/7403054
Separates the implementation of nanotime on 64-bit
version of Plan 9 from that on the 32-bit version.
The former uses a syscall.
R=rsc, rminnich, ality
CC=golang-dev
https://golang.org/cl/7379051
sigprocmask() is process-wide on darwin, so two concurrent
libcgo_sys_thread_start() can result in all signals permanently
blocked, which in particular blocks handling of nil derefs.
Fixes#4833.
R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/7324058
For now, all the callbacks from C use top-level Go functions,
so they use the equivalent C function pointer, and will continue
to do so. But perhaps some day this will be useful for calling
a Go func value (at least if the type is already known).
More importantly, the Windows callback code needs to be able
to use cgocallback_gofunc to call a Go func value.
Should fix the Windows build.
R=ken2
CC=golang-dev
https://golang.org/cl/7388049
Change ARM context register to R7, to get out of the way
of the register allocator during the compilation of the
prologue statements (it wants to use R0 as a temporary).
Step 2 of http://golang.org/s/go11func.
R=ken2
CC=golang-dev
https://golang.org/cl/7369048
runtime: add context argument to gogocall
Too many other things use AX, and at least one
(stack zeroing) cannot be moved onto a different
register. Use the less special DX instead.
Preparation for step 2 of http://golang.org/s/go11func.
Nothing interesting here, just split out so that we can
see it's correct before moving on.
R=ken2
CC=golang-dev
https://golang.org/cl/7395050
Previously, the func structure contained an inaccurate value for
the args member and a 0 value for the locals member.
This change populates the func structure with args and locals
values computed by the compiler. The number of args was
already available in the ATEXT instruction. The number of
locals is now passed through in the new ALOCALS instruction.
This change also switches the unit of args and locals to be
bytes, just like the frame member, instead of 32-bit words.
R=golang-dev, bradfitz, cshapiro, dave, rsc
CC=golang-dev
https://golang.org/cl/7399045
mpreinit() is called on the parent thread and with mcache (can allocate memory),
minit() is called on the child thread and can not allocate memory.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7389043
The removed code leads to the situation when M executes the same locked G again
and again.
This is https://golang.org/cl/7310096 but with return instead of break
in the nested switch.
Fixes#4820.
R=golang-dev, alex.brainman, rsc
CC=golang-dev
https://golang.org/cl/7304102
If a test can be placed in the same package ("internal"), it is placed
there. This facilitates testing of package-private details. Because of
dependency cycles some packages cannot be tested by internal tests.
R=golang-dev, rsc, mikioh.mikioh
CC=golang-dev, r
https://golang.org/cl/7323044
* Handle p==nil in signalstack by setting SS_DISABLE flag.
* Make minit only allocate a signal g if there's not one already.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/7323072
Fix the sa_mask member of the sigaction struct - on FreeBSD this is
declared as a sigset_t, which is an array of four unsigned ints.
Replace the current int64 with Sigset from defs_freebsd_GOARCH, which
has the correct definition.
Unbreaks the FreeBSD builds.
R=golang-dev, dave, minux.ma
CC=golang-dev
https://golang.org/cl/7333047
broke windows build
««« original CL description
runtime: ensure forward progress of runtime.Gosched() for locked goroutines
The removed code leads to the situation when M executes the same locked G again and again.
Fixes#4820.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7310096
»»»
TBR=dvyukov
CC=golang-dev
https://golang.org/cl/7343050
Arguably if this happens the program is buggy anyway,
but letting the panic continue looks better than interrupting it.
Otherwise things like this are possible, and confusing:
$ go run x.go
panic: $ echo $?
0
$
Fixes#3934.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/7322083
This is the same logic used in the standard tracebacks.
The caller pc is the pc after the call, so except in the
fake "call" caused by a panic, back up the pc enough
that the lookup will use the previous instruction.
Fixes#4150.
Fixes#4151.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/7317047
Before, the mheap structure was in the bss,
but it's quite large (today, 256 MB, much of
which is never actually paged in), and it makes
Go binaries run afoul of exec-time bss size
limits on some BSD systems.
Fixes#4447.
R=golang-dev, dave, minux.ma, remyoudompheng, iant
CC=golang-dev
https://golang.org/cl/7307122
The removed code leads to the situation when M executes the same locked G again and again.
Fixes#4820.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7310096
In addition to the compile failure fixed in signal*.c,
preserving the signal mask led to very strange crashes.
Testing shows that looking for SIG_IGN is all that
matters to get along with nohup, so reintroduce
sigset_zero instead of trying to preserve the signal mask.
TBR=iant
CC=golang-dev
https://golang.org/cl/7323067
There are two ways nohup(1) might be implemented:
it might mask away the signal, or it might set the handler
to SIG_IGN, both of which are inherited across fork+exec.
So two fixes:
* Make sure to preserve the inherited signal mask at
minit instead of clearing it.
* If the SIGHUP handler is SIG_IGN, leave it that way.
Fixes#4491.
R=golang-dev, mikioh.mikioh, iant
CC=golang-dev
https://golang.org/cl/7308102
No code changes.
This is mainly in preparation to scheduler changes,
oldstack/newstack are not related to scheduling.
R=golang-dev, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/7311085
With the new scheduler races in the tests are reported during execution of other tests.
The change joins goroutines started during the tests.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/7310066
The problem happens when end=0, then end-1 is very big number.
Observed with the new scheduler.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/7307073
Removes limit on maximum number of goroutines ever existed.
code.google.com/p/goexecutor tests now pass successfully.
Also slightly improves performance.
Before: $ time ./flate.test -test.short
real 0m9.314s
After: $ time ./flate.test -test.short
real 0m8.958s
Fixes#4286.
The runtime is built from llvm rev 174312.
R=rsc
CC=golang-dev
https://golang.org/cl/7218044
Change the stack unwinding code to compensate for the dynamic
relocation of symbols.
Change the gc instruction GC_CALL to use a relative offset instead of
an absolute address.
R=golang-dev
CC=golang-dev
https://golang.org/cl/7248048
* Separate internal and external LockOSThread, for cgo safety.
* Show goroutine that made faulting cgo call.
* Never start a panic due to a signal caused by a cgo call.
Fixes#3774.
Fixes#3775.
Fixes#3797.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/7228081
Binary data in mprof.goc may prevent the garbage collector from freeing
memory blocks. This patch replaces all calls to runtime·mallocgc() with
calls to an allocator private to mprof.goc, thus making the private
memory invisible to the garbage collector. The addrhash variable is
moved outside of the .bss section.
R=golang-dev, dvyukov, rsc, minux.ma
CC=dave, golang-dev, remyoudompheng
https://golang.org/cl/7135063
This change also resolves some issues with note handling: we now make
sure that there is enough room at the bottom of every goroutine to
execute the note handler, and the `exitstatus' is no longer a global
entity, which resolves some race conditions.
R=rminnich, npe, rsc, ality
CC=golang-dev
https://golang.org/cl/6569068
Range access functions are already available in TSan library
but were not yet used.
Time for go test -race -short:
Before:
compress/flate 24.244s
exp/norm >200s
go/printer 78.268s
After:
compress/flate 17.760s
exp/norm 5.537s
go/printer 5.738s
Fixes#4250.
R=dvyukov, golang-dev, fullung
CC=golang-dev
https://golang.org/cl/7229044
Useful for debugging of runtime bugs.
+ Do not print "stack segment boundary" unless GOTRACEBACK>1.
+ Do not traceback system goroutines unless GOTRACEBACK>1.
R=rsc, minux.ma
CC=golang-dev
https://golang.org/cl/7098050
Mark candidate spans one GC pass earlier.
Move scavenger's code out from mgc0 and constrain it into mheap (where it belongs).
R=rsc, dvyukov, minux.ma
CC=golang-dev
https://golang.org/cl/7002049
This is for SPARC64, a 64-bit processor that uses all 64-bits
of virtual addresses. The idea is to use the low order 3 bits
to at least get a small ABA counter. That should work since
pointers are aligned. The idea is for SPARC64 to set CNT_MASK
== 7, PTR_BITS == 0, PTR_MASK == 0xffffffffffffff8.
Also add uintptr casts to avoid GCC warnings. The gccgo
runtime code is compiled with GCC, and GCC warns when casting
between a pointer and a type of a different size.
R=dvyukov
CC=golang-dev
https://golang.org/cl/7225043
Currently it's summed to mark phase.
The change makes it easier to diagnose long stop-the-world phases.
R=golang-dev, bradfitz, dave
CC=golang-dev
https://golang.org/cl/7182043
If the scanned block has no typeinfo the garbage collector will attempt
to get the actual type of the block.
R=golang-dev, bradfitz, rsc
CC=golang-dev
https://golang.org/cl/7093045
Also undo revision a5b96b602690 used to workaround the bug.
Fixes#4643.
R=rsc, golang-dev, dave, minux.ma, lucio.dere, bradfitz
CC=golang-dev
https://golang.org/cl/7090043
The Plan 9 symbol table format defines big-endian symbol values
for portability, but we want to be able to generate an ELF object file
and let the host linker link it, as part of the solution to issue 4069.
The symbol table itself, since it is loaded into memory at run time,
must be filled in by the final host linker, using relocation directives
to set the symbol values. On a little-endian machine, the linker will
only fill in little-endian values during relocation, so we are forced
to use little-endian symbol values.
To preserve most of the original portability of the symbol table
format, we make the table itself say whether it uses big- or
little-endian values. If the table begins with the magic sequence
fe ff ff ff 00 00
then the actual table begins after those six bytes and contains
little-endian symbol values. Otherwise, the table is in the original
format and contains big-endian symbol values. The magic sequence
looks like an "end of table" entry (the fifth byte is zero), so legacy
readers will see a little-endian table as an empty table.
All the gc architectures are little-endian today, so the practical
effect of this CL is to make all the generated tables little-endian,
but if a big-endian system comes along, ld will not generate
the magic sequence, and the various readers will fall back to the
original big-endian interpretation.
R=ken2
CC=golang-dev
https://golang.org/cl/7066043
sysarch requires arguments to be passed on the stack, not in registers.
Credit to Shenghou Ma (minux) for the fix.
R=minux.ma, devon.odell
CC=golang-dev
https://golang.org/cl/7037043
Used to then die on a nil pointer situation. Most Linux standard setups are rather
restrictive regarding the default amount of lockable memory.
R=minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6997049
Currently it silently "succeeds" saying that it run 0 tests
if there are compilations errors.
With this change it fails and outputs the compilation error.
R=golang-dev, remyoudompheng
CC=golang-dev
https://golang.org/cl/7002058
When we release memory to the OS, if the OS doesn't want us
to release it (for example, because the program executed
mlockall(MCL_FUTURE)), madvise will fail. Ignore the failure
instead of crashing.
Fixes#3435.
R=ken2
CC=golang-dev
https://golang.org/cl/6998052
This disables checks for limited address space
and unlimited stack. They are not required for Go.
Fixes#4577.
R=golang-dev, iant
CC=golang-dev, kamil.kisiel, minux.ma
https://golang.org/cl/7003045
Enable cgo on OpenBSD.
The OpenBSD ld.so(1) does not currently support PT_TLS sections. Work
around this by fixing up the TCB that has been provided by librthread
and reallocating a TCB with additional space for TLS. Also provide a
wrapper for pthread_create, allowing zeroed TLS to be allocated for
threads created externally to Go.
Joint work with Shenghou Ma (minux).
Requires change 6846064.
Fixes#3205.
R=golang-dev, minux.ma, iant, rsc, iant
CC=golang-dev
https://golang.org/cl/6853059
