Commit Graph

14 Commits

Author SHA1 Message Date
Paul Eggert
2b778ceb40 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
2021-01-02 12:17:34 -08:00
Joseph Myers
d614a75396 Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
Paul Eggert
5a82c74822 Prefer https to http for gnu.org and fsf.org URLs
Also, change sources.redhat.com to sourceware.org.
This patch was automatically generated by running the following shell
script, which uses GNU sed, and which avoids modifying files imported
from upstream:

sed -ri '
  s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g
  s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g
' \
  $(find $(git ls-files) -prune -type f \
      ! -name '*.po' \
      ! -name 'ChangeLog*' \
      ! -path COPYING ! -path COPYING.LIB \
      ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \
      ! -path manual/texinfo.tex ! -path scripts/config.guess \
      ! -path scripts/config.sub ! -path scripts/install-sh \
      ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \
      ! -path INSTALL ! -path  locale/programs/charmap-kw.h \
      ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \
      ! '(' -name configure \
            -execdir test -f configure.ac -o -f configure.in ';' ')' \
      ! '(' -name preconfigure \
            -execdir test -f preconfigure.ac ';' ')' \
      -print)

and then by running 'make dist-prepare' to regenerate files built
from the altered files, and then executing the following to cleanup:

  chmod a+x sysdeps/unix/sysv/linux/riscv/configure
  # Omit irrelevant whitespace and comment-only changes,
  # perhaps from a slightly-different Autoconf version.
  git checkout -f \
    sysdeps/csky/configure \
    sysdeps/hppa/configure \
    sysdeps/riscv/configure \
    sysdeps/unix/sysv/linux/csky/configure
  # Omit changes that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines
  git checkout -f \
    sysdeps/powerpc/powerpc64/ppc-mcount.S \
    sysdeps/unix/sysv/linux/s390/s390-64/syscall.S
  # Omit change that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline
  git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-09-07 02:43:31 -07:00
Joseph Myers
04277e02d7 Update copyright dates with scripts/update-copyrights.
* All files with FSF copyright notices: Update copyright dates
	using scripts/update-copyrights.
	* locale/programs/charmap-kw.h: Regenerated.
	* locale/programs/locfile-kw.h: Likewise.
2019-01-01 00:11:28 +00:00
Joseph Myers
cb7be1590e Use gen-as-const.py to process .pysym files.
This patch eliminates the gen-py-const.awk variant of gen-as-const,
switching to use of gnu-as-const.py (with a new --python option) to
process .pysym files (i.e., to generate nptl_lock_constants.py), as
the syntax of those files is identical to that of .sym files.

Note that the generated nptl_lock_constants.py is *not* identical to
the version generated by the awk script.  Apart from the trivial
changes (comment referencing the new script, and output being sorted),
the constant FUTEX_WAITERS, PTHREAD_MUTEXATTR_FLAG_BITS,
PTHREAD_MUTEXATTR_FLAG_PSHARED and PTHREAD_MUTEX_PRIO_CEILING_MASK are
now output as positive rather than negative constants (on x86_64
anyway; maybe not necessarily on 32-bit systems):

< FUTEX_WAITERS = -2147483648
---
> FUTEX_WAITERS = 2147483648

< PTHREAD_MUTEXATTR_FLAG_BITS = -251662336
< PTHREAD_MUTEXATTR_FLAG_PSHARED = -2147483648
---
> PTHREAD_MUTEXATTR_FLAG_BITS = 4043304960
> PTHREAD_MUTEXATTR_FLAG_PSHARED = 2147483648

< PTHREAD_MUTEX_PRIO_CEILING_MASK = -524288
---
> PTHREAD_MUTEX_PRIO_CEILING_MASK = 4294443008

This is because gen-as-const has a cast of the constant value to long
int, which gen-py-const lacks.

I think the positive values are more logically correct, since the
constants in question are in fact unsigned in C.  But to reliably
produce gen-as-const.py output for constants that always (in C and
Python) reflects the signedness of values with the high bit of "long
int" set would mean more complicated logic needs to be used in
computing values.

The more correct positive values by themselves produce a failure of
nptl/test-mutexattr-printers, because masking with
~PTHREAD_MUTEXATTR_FLAG_BITS & ~PTHREAD_MUTEX_NO_ELISION_NP now leaves
a bit -1 << 32 in the Python value, resulting in a KeyError exception.
To avoid that, places masking with ~ of one of the constants in
question are changed to mask with 0xffffffff as well (this reflects
how ~ in Python applies to an infinite-precision integer whereas ~ in
C does not do any promotions beyond the width of int).

Tested for x86_64.

	* scripts/gen-as-const.py (main): Handle --python option.
	* scripts/gen-py-const.awk: Remove.
	* Makerules (py-const-script): Use gen-as-const.py.
	($(py-const)): Likewise.
	* nptl/nptl-printers.py (MutexPrinter.read_status_no_robust): Mask
	with 0xffffffff together with ~(PTHREAD_MUTEX_PRIO_CEILING_MASK).
	(MutexAttributesPrinter.read_values): Mask with 0xffffffff
	together with ~PTHREAD_MUTEXATTR_FLAG_BITS and
	~PTHREAD_MUTEX_NO_ELISION_NP.
	* manual/README.pretty-printers: Update reference to
	gen-py-const.awk.
2018-12-10 22:56:59 +00:00
Joseph Myers
688903eb3e Update copyright dates with scripts/update-copyrights.
* All files with FSF copyright notices: Update copyright dates
	using scripts/update-copyrights.
	* locale/programs/charmap-kw.h: Regenerated.
	* locale/programs/locfile-kw.h: Likewise.
2018-01-01 00:32:25 +00:00
Torvald Riegel
6d523660e9 Fix mutex pretty printer test and pretty printer output.
This fixes the mutex pretty printer so that, if the owner ID isn't recorded
(such as in the current lock elision implementation), "Owner ID" will be shown
as "Unknown" instead of 0. It also changes the mutex printer output so that it
says "Acquired" instead of "Locked". The mutex tests are updated accordingly.

In addition, this adds a paragraph to the "Known issues" section of the
printers README explaining that the printer output isn't guaranteed to cover
every detail.

2017-01-14  Martin Galvan  <martingalvan@sourceware.org>

        * README.pretty-printers (Known issues): Warn about printers not
        always covering everything.
        * nptl/nptl-printers.py (MutexPrinter): Change output.
        * nptl/test-mutex-printers.py: Fix test and adapt to changed output.
2017-01-20 14:56:39 +01:00
Torvald Riegel
cc25c8b4c1 New pthread rwlock that is more scalable.
This replaces the pthread rwlock with a new implementation that uses a
more scalable algorithm (primarily through not using a critical section
anymore to make state changes).  The fast path for rdlock acquisition and
release is now basically a single atomic read-modify write or CAS and a few
branches.  See nptl/pthread_rwlock_common.c for details.

	* nptl/DESIGN-rwlock.txt: Remove.
	* nptl/lowlevelrwlock.sym: Remove.
	* nptl/Makefile: Add new tests.
	* nptl/pthread_rwlock_common.c: New file.  Contains the new rwlock.
	* nptl/pthreadP.h (PTHREAD_RWLOCK_PREFER_READER_P): Remove.
	(PTHREAD_RWLOCK_WRPHASE, PTHREAD_RWLOCK_WRLOCKED,
	PTHREAD_RWLOCK_RWAITING, PTHREAD_RWLOCK_READER_SHIFT,
	PTHREAD_RWLOCK_READER_OVERFLOW, PTHREAD_RWLOCK_WRHANDOVER,
	PTHREAD_RWLOCK_FUTEX_USED): New.
	* nptl/pthread_rwlock_init.c (__pthread_rwlock_init): Adapt to new
	implementation.
	* nptl/pthread_rwlock_rdlock.c (__pthread_rwlock_rdlock_slow): Remove.
	(__pthread_rwlock_rdlock): Adapt.
	* nptl/pthread_rwlock_timedrdlock.c
	(pthread_rwlock_timedrdlock): Adapt.
	* nptl/pthread_rwlock_timedwrlock.c
	(pthread_rwlock_timedwrlock): Adapt.
	* nptl/pthread_rwlock_trywrlock.c (pthread_rwlock_trywrlock): Adapt.
	* nptl/pthread_rwlock_tryrdlock.c (pthread_rwlock_tryrdlock): Adapt.
	* nptl/pthread_rwlock_unlock.c (pthread_rwlock_unlock): Adapt.
	* nptl/pthread_rwlock_wrlock.c (__pthread_rwlock_wrlock_slow): Remove.
	(__pthread_rwlock_wrlock): Adapt.
	* nptl/tst-rwlock10.c: Adapt.
	* nptl/tst-rwlock11.c: Adapt.
	* nptl/tst-rwlock17.c: New file.
	* nptl/tst-rwlock18.c: New file.
	* nptl/tst-rwlock19.c: New file.
	* nptl/tst-rwlock2b.c: New file.
	* nptl/tst-rwlock8.c: Adapt.
	* nptl/tst-rwlock9.c: Adapt.
	* sysdeps/aarch64/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/arm/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/hppa/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/ia64/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/m68k/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/microblaze/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/mips/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/nios2/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/s390/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/sh/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/sparc/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/tile/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/unix/sysv/linux/alpha/bits/pthreadtypes.h
	(pthread_rwlock_t): Adapt.
	* sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h
	(pthread_rwlock_t): Adapt.
	* sysdeps/x86/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* nptl/nptl-printers.py (): Adapt.
	* nptl/nptl_lock_constants.pysym: Adapt.
	* nptl/test-rwlock-printers.py: Adapt.
	* nptl/test-rwlockattr-printers.c: Adapt.
	* nptl/test-rwlockattr-printers.py: Adapt.
2017-01-10 11:50:17 +01:00
Martin Galvan
26e21ad35d Fix up tabs/spaces mismatches
Mixing them up breaks the gdb pretty printer tests.

ChangeLog:

2017-01-02  Martin Galvan  <martingalvan@sourceware.org>

	* nptl/nptl-printers.py: Fix tabs/spaces mismatches.
2017-01-03 12:56:23 +05:30
Joseph Myers
bfff8b1bec Update copyright dates with scripts/update-copyrights. 2017-01-01 00:14:16 +00:00
Torvald Riegel
ed19993b5b New condvar implementation that provides stronger ordering guarantees.
This is a new implementation for condition variables, required
after http://austingroupbugs.net/view.php?id=609 to fix bug 13165.  In
essence, we need to be stricter in which waiters a signal or broadcast
is required to wake up; this couldn't be solved using the old algorithm.
ISO C++ made a similar clarification, so this also fixes a bug in
current libstdc++, for example.

We can't use the old algorithm anymore because futexes do not guarantee
to wake in FIFO order.  Thus, when we wake, we can't simply let any
waiter grab a signal, but we need to ensure that one of the waiters
happening before the signal is woken up.  This is something the previous
algorithm violated (see bug 13165).

There's another issue specific to condvars: ABA issues on the underlying
futexes.  Unlike mutexes that have just three states, or semaphores that
have no tokens or a limited number of them, the state of a condvar is
the *order* of the waiters.  A waiter on a semaphore can grab a token
whenever one is available; a condvar waiter must only consume a signal
if it is eligible to do so as determined by the relative order of the
waiter and the signal.
Therefore, this new algorithm maintains two groups of waiters: Those
eligible to consume signals (G1), and those that have to wait until
previous waiters have consumed signals (G2).  Once G1 is empty, G2
becomes the new G1.  64b counters are used to avoid ABA issues.

This condvar doesn't yet use a requeue optimization (ie, on a broadcast,
waking just one thread and requeueing all others on the futex of the
mutex supplied by the program).  I don't think doing the requeue is
necessarily the right approach (but I haven't done real measurements
yet):
* If a program expects to wake many threads at the same time and make
that scalable, a condvar isn't great anyway because of how it requires
waiters to operate mutually exclusive (due to the mutex usage).  Thus, a
thundering herd problem is a scalability problem with or without the
optimization.  Using something like a semaphore might be more
appropriate in such a case.
* The scalability problem is actually at the mutex side; the condvar
could help (and it tries to with the requeue optimization), but it
should be the mutex who decides how that is done, and whether it is done
at all.
* Forcing all but one waiter into the kernel-side wait queue of the
mutex prevents/avoids the use of lock elision on the mutex.  Thus, it
prevents the only cure against the underlying scalability problem
inherent to condvars.
* If condvars use short critical sections (ie, hold the mutex just to
check a binary flag or such), which they should do ideally, then forcing
all those waiter to proceed serially with kernel-based hand-off (ie,
futex ops in the mutex' contended state, via the futex wait queues) will
be less efficient than just letting a scalable mutex implementation take
care of it.  Our current mutex impl doesn't employ spinning at all, but
if critical sections are short, spinning can be much better.
* Doing the requeue stuff requires all waiters to always drive the mutex
into the contended state.  This leads to each waiter having to call
futex_wake after lock release, even if this wouldn't be necessary.

	[BZ #13165]
	* nptl/pthread_cond_broadcast.c (__pthread_cond_broadcast): Rewrite to
	use new algorithm.
	* nptl/pthread_cond_destroy.c (__pthread_cond_destroy): Likewise.
	* nptl/pthread_cond_init.c (__pthread_cond_init): Likewise.
	* nptl/pthread_cond_signal.c (__pthread_cond_signal): Likewise.
	* nptl/pthread_cond_wait.c (__pthread_cond_wait): Likewise.
	(__pthread_cond_timedwait): Move here from pthread_cond_timedwait.c.
	(__condvar_confirm_wakeup, __condvar_cancel_waiting,
	__condvar_cleanup_waiting, __condvar_dec_grefs,
	__pthread_cond_wait_common): New.
	(__condvar_cleanup): Remove.
	* npt/pthread_condattr_getclock.c (pthread_condattr_getclock): Adapt.
	* npt/pthread_condattr_setclock.c (pthread_condattr_setclock):
	Likewise.
	* npt/pthread_condattr_getpshared.c (pthread_condattr_getpshared):
	Likewise.
	* npt/pthread_condattr_init.c (pthread_condattr_init): Likewise.
	* nptl/tst-cond1.c: Add comment.
	* nptl/tst-cond20.c (do_test): Adapt.
	* nptl/tst-cond22.c (do_test): Likewise.
	* sysdeps/aarch64/nptl/bits/pthreadtypes.h (pthread_cond_t): Adapt
	structure.
	* sysdeps/arm/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
	* sysdeps/ia64/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
	* sysdeps/m68k/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
	* sysdeps/microblaze/nptl/bits/pthreadtypes.h (pthread_cond_t):
	Likewise.
	* sysdeps/mips/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
	* sysdeps/nios2/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
	* sysdeps/s390/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
	* sysdeps/sh/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
	* sysdeps/tile/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
	* sysdeps/unix/sysv/linux/alpha/bits/pthreadtypes.h (pthread_cond_t):
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h (pthread_cond_t):
	Likewise.
	* sysdeps/x86/bits/pthreadtypes.h (pthread_cond_t): Likewise.
	* sysdeps/nptl/internaltypes.h (COND_NWAITERS_SHIFT): Remove.
	(COND_CLOCK_BITS): Adapt.
	* sysdeps/nptl/pthread.h (PTHREAD_COND_INITIALIZER): Adapt.
	* nptl/pthreadP.h (__PTHREAD_COND_CLOCK_MONOTONIC_MASK,
	__PTHREAD_COND_SHARED_MASK): New.
	* nptl/nptl-printers.py (CLOCK_IDS): Remove.
	(ConditionVariablePrinter, ConditionVariableAttributesPrinter): Adapt.
	* nptl/nptl_lock_constants.pysym: Adapt.
	* nptl/test-cond-printers.py: Adapt.
	* sysdeps/unix/sysv/linux/hppa/internaltypes.h (cond_compat_clear,
	cond_compat_check_and_clear): Adapt.
	* sysdeps/unix/sysv/linux/hppa/pthread_cond_timedwait.c: Remove file ...
	* sysdeps/unix/sysv/linux/hppa/pthread_cond_wait.c
	(__pthread_cond_timedwait): ... and move here.
	* nptl/DESIGN-condvar.txt: Remove file.
	* nptl/lowlevelcond.sym: Likewise.
	* nptl/pthread_cond_timedwait.c: Likewise.
	* sysdeps/unix/sysv/linux/i386/i486/pthread_cond_broadcast.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i486/pthread_cond_signal.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i486/pthread_cond_timedwait.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i486/pthread_cond_wait.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i586/pthread_cond_broadcast.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i586/pthread_cond_signal.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i586/pthread_cond_timedwait.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i586/pthread_cond_wait.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i686/pthread_cond_broadcast.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i686/pthread_cond_signal.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i686/pthread_cond_timedwait.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i686/pthread_cond_wait.S: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/pthread_cond_broadcast.S: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/pthread_cond_signal.S: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S: Likewise.
2016-12-31 14:56:47 +01:00
Martin Galvan
23b5cae1af Add pretty printers for the NPTL lock types
This patch adds pretty printers for the following NPTL types:

- pthread_mutex_t
- pthread_mutexattr_t
- pthread_cond_t
- pthread_condattr_t
- pthread_rwlock_t
- pthread_rwlockattr_t

To load the pretty printers into your gdb session, do the following:

python
import sys
sys.path.insert(0, '/path/to/glibc/build/nptl/pretty-printers')
end

source /path/to/glibc/source/pretty-printers/nptl-printers.py

You can check which printers are registered and enabled by issuing the
'info pretty-printer' gdb command. Printers should trigger automatically when
trying to print a variable of one of the types mentioned above.

The printers are architecture-independent, and were tested on an AMD64 running
Ubuntu 14.04 and an x86 VM running Fedora 24.

In order to work, the printers need to know the values of various flags that
are scattered throughout pthread.h and pthreadP.h as enums and #defines. Since
replicating these constants in the printers file itself would create a
maintenance burden, I wrote a script called gen-py-const.awk that Makerules uses
to extract the constants. This script is pretty much the same as gen-as-const.awk,
except it doesn't cast the constant values to 'long' and is thorougly documented.
The constants need only to be enumerated in a .pysym file, which is then referenced
by a Make variable called gen-py-const-headers.

As for the install directory, I discussed this with Mike Frysinger and Siddhesh
Poyarekar, and we agreed that it can be handled in a separate patch, and shouldn't
block merging of this one.

In addition, I've written a series of test cases for the pretty printers.
Each lock type (mutex, condvar and rwlock) has two test programs, one for itself
and other for its related 'attributes' object. Each test program in turn has a
PExpect-based Python script that drives gdb and compares its output to the
expected printer's. The tests run on the glibc host, which is assumed to have
both gdb and PExpect; if either is absent the tests will fail with code 77
(UNSUPPORTED). For cross-testing you should use cross-test-ssh.sh as test-wrapper.
I've tested the printers on both native builds and a cross build using a Beaglebone
Black running Debian, with the build system's filesystem shared with the board
through NFS.

Finally, I've written a README that explains all this and more.

	* INSTALL: Regenerated.
	* Makeconfig: Add comments and whitespace to make the control flow
	clearer.
	(+link-printers-tests, +link-pie-printers-tests, CFLAGS-printers-tests,
	installed-rtld-LDFLAGS, built-rtld-LDFLAGS, link-libc-rpath,
	link-libc-tests-after-rpath-link, link-libc-printers-tests): New.
	(rtld-LDFLAGS, rtld-tests-LDFLAGS, link-libc-tests-rpath-link,
	link-libc-tests): Use the new variables as required.
	* Makerules ($(py-const)): New rule.
	generated: Add $(py-const).
	* README.pretty-printers: New file.
	* Rules (tests-printers-programs, tests-printers-out, py-env): New.
	(others): Depend on $(py-const).
	(tests): Depend on $(tests-printers-programs) or $(tests-printers-out),
	as required.  Pass $(tests-printers) to merge-test-results.sh.
	* manual/install.texi: Add requirements for testing the pretty printers.
	* nptl/Makefile (gen-py-const-headers, pretty-printers, tests-printers,
	CFLAGS-test-mutexattr-printers.c CFLAGS-test-mutex-printers.c,
	CFLAGS-test-condattr-printers.c, CFLAGS-test-cond-printers.c,
	CFLAGS-test-rwlockattr-printers.c CFLAGS-test-rwlock-printers.c,
	tests-printers-libs): Define.
	* nptl/nptl-printers.py: New file.
	* nptl/nptl_lock_constants.pysym: Likewise.
	* nptl/test-cond-printers.c: Likewise.
	* nptl/test-cond-printers.py: Likewise.
	* nptl/test-condattr-printers.c: Likewise.
	* nptl/test-condattr-printers.py: Likewise.
	* nptl/test-mutex-printers.c: Likewise.
	* nptl/test-mutex-printers.py: Likewise.
	* nptl/test-mutexattr-printers.c: Likewise.
	* nptl/test-mutexattr-printers.py: Likewise.
	* nptl/test-rwlock-printers.c: Likewise.
	* nptl/test-rwlock-printers.py: Likewise.
	* nptl/test-rwlockattr-printers.c: Likewise.
	* nptl/test-rwlockattr-printers.py: Likewise.
	* scripts/gen-py-const.awk: Likewise.
	* scripts/test_printers_common.py: Likewise.
	* scripts/test_printers_exceptions.py: Likewise.
2016-12-08 18:59:02 +05:30
Siddhesh Poyarekar
c10f90dcef Revert "Add pretty printers for the NPTL lock types"
This reverts commit 62ce266b0b.

The change is not mature enough because it needs the following fixes:

1. Redirect test output to a file like other tests

2. Eliminate the need to use a .gdbinit because distributions will
   break without it.  I should have caught that but I was in too much
   of a hurry to get the patch in :/

3. Feature checking during configure to determine things like minimum
   required gdb version, python-pexpect version, etc. to make sure
   that tests work correctly.
2016-07-11 20:32:12 +05:30
Martin Galvan
62ce266b0b Add pretty printers for the NPTL lock types
This patch adds pretty printers for the following NPTL types:

- pthread_mutex_t
- pthread_mutexattr_t
- pthread_cond_t
- pthread_condattr_t
- pthread_rwlock_t
- pthread_rwlockattr_t

To load the pretty printers into your gdb session, do the following:

python
import sys
sys.path.insert(0, '/path/to/glibc/build/nptl/pretty-printers')
end

source /path/to/glibc/source/pretty-printers/nptl-printers.py

You can check which printers are registered and enabled by issuing the
'info pretty-printer' gdb command. Printers should trigger automatically when
trying to print a variable of one of the types mentioned above.

The printers are architecture-independent, and were manually tested on both
the gdb CLI and Eclipse CDT.

In order to work, the printers need to know the values of various flags that
are scattered throughout pthread.h and pthreadP.h as enums and #defines. Since
replicating these constants in the printers file itself would create a
maintenance burden, I wrote a script called gen-py-const.awk that Makerules uses
to extract the constants. This script is pretty much the same as gen-as-const.awk,
except it doesn't cast the constant values to 'long' and is thorougly documented.
The constants need only to be enumerated in a .pysym file, which is then referenced
by a Make variable called gen-py-const-headers.

As for the install directory, I discussed this with Mike Frysinger and Siddhesh
Poyarekar, and we agreed that it can be handled in a separate patch, and it shouldn't
block merging of this one.

In addition, I've written a series of test cases for the pretty printers.
Each lock type (mutex, condvar and rwlock) has two test programs, one for itself
and other for its related 'attributes' object. Each test program in turn has a
PExpect-based Python script that drives gdb and compares its output to the
expected printer's. The tests run on the glibc host, which is assumed to have
both gdb and PExpect; if either is absent the tests will fail with code 77
(UNSUPPORTED). For cross-testing you should use cross-test-ssh.sh as test-wrapper.
I've tested the printers on both a native build and a cross build using a Beaglebone
Black, with the build system's filesystem shared with the board through NFS.

Finally, I've written a README that explains all this and more.

Hopefully this should be good to go in now. Thanks.

ChangeLog:

2016-07-04  Martin Galvan  <martin.galvan@tallertechnologies.com>

	* Makeconfig (build-hardcoded-path-in-tests): Set to 'yes' for shared builds
	if tests-need-hardcoded-path is defined.
	(all-subdirs): Add pretty-printers.
	* Makerules ($(py-const)): New rule.
	* Rules (others): Add $(py-const), if defined.
	* nptl/Makefile (gen-py-const-headers): Define.
	* nptl/nptl-printers.py: New file.
	* nptl/nptl_lock_constants.pysym: Likewise.
	* pretty-printers/Makefile: Likewise.
	* pretty-printers/README: Likewise.
	* pretty-printers/test-condvar-attributes.c: Likewise.
	* pretty-printers/test-condvar-attributes.p: Likewise.
	* pretty-printers/test-condvar-printer.c: Likewise.
	* pretty-printers/test-condvar-printer.py: Likewise.
	* pretty-printers/test-mutex-attributes.c: Likewise.
	* pretty-printers/test-mutex-attributes.py: Likewise.
	* pretty-printers/test-mutex-printer.c: Likewise.
	* pretty-printers/test-mutex-printer.py: Likewise.
	* pretty-printers/test-rwlock-attributes.c: Likewise.
	* pretty-printers/test-rwlock-attributes.py: Likewise.
	* pretty-printers/test-rwlock-printer.c: Likewise.
	* pretty-printers/test-rwlock-printer.py: Likewise.
	* pretty-printers/test_common.py: Likewise.
	* scripts/gen-py-const.awk: Likewise.
2016-07-08 20:03:05 +05:30