August 2018 - tor-commits - lists.torproject.org

[tor/release-0.3.4] Merge branch 'maint-0.3.4' into release-0.3.4
by nickm＠torproject.org 15 Aug '18

15 Aug '18

commit 0cc4152b05ae7b5a77721c36409c1229ea2f85d4 Merge: 00dc2f7ee 6c1d2549d Author: Nick Mathewson <nickm(a)torproject.org> Date: Wed Aug 15 02:18:54 2018 -0400 Merge branch 'maint-0.3.4' into release-0.3.4 changes/bug26779 | 4 ++++ configure.ac | 20 ++++++++++++++++++++ src/common/compat_threads.c | 5 ++--- src/common/compat_threads.h | 19 +++++++++++-------- 4 files changed, 37 insertions(+), 11 deletions(-)

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[tor/maint-0.3.3] Detect broken stdatomic.h, and pretend that it isn't there at all
by nickm＠torproject.org 15 Aug '18

15 Aug '18

commit b66386865e68d8df0f228187781fcd5bc2dbf184 Author: Nick Mathewson <nickm(a)torproject.org> Date: Wed Aug 8 15:41:40 2018 -0400 Detect broken stdatomic.h, and pretend that it isn't there at all I hope that the debian clang maintainers will look at debian bug 903709 soon. But until they do, this should keep our users and our CI happy on sid with clang. Closes ticket 26779. --- changes/bug26779 | 4 ++++ configure.ac | 20 ++++++++++++++++++++ src/common/compat_threads.c | 5 ++--- src/common/compat_threads.h | 19 +++++++++++-------- 4 files changed, 37 insertions(+), 11 deletions(-) diff --git a/changes/bug26779 b/changes/bug26779 new file mode 100644 index 000000000..fb7f6160e --- /dev/null +++ b/changes/bug26779 @@ -0,0 +1,4 @@ + o Minor features (bug workaround): + - Compile correctly on systems that provide the C11 stdatomic.h header, + but where C11 atomic functions don't actually compile. + Closes ticket 26779; workaround for Debian issue 903709. diff --git a/configure.ac b/configure.ac index cd591c785..8e6683bb7 100644 --- a/configure.ac +++ b/configure.ac @@ -1557,6 +1557,26 @@ AC_CHECK_SIZEOF(socklen_t, , [AC_INCLUDES_DEFAULT() AC_CHECK_SIZEOF(cell_t) +# Let's see if stdatomic works. (There are some debian clangs that screw it +# up; see Tor bug #26779 and debian bug 903709.) +AC_CACHE_CHECK([whether C11 stdatomic.h actually works], + tor_cv_stdatomic_works, +[AC_COMPILE_IFELSE([AC_LANG_SOURCE([[ +#include <stdatomic.h> +struct x { atomic_size_t y; }; +void try_atomic_init(struct x *xx) +{ + atomic_init(&xx->y, 99); + atomic_fetch_add(&xx->y, 1); +} +]])], [tor_cv_stdatomic_works=yes], [tor_cv_stdatomic_works=no])]) + +if test "$tor_cv_stdatomic_works" = "yes"; then + AC_DEFINE(STDATOMIC_WORKS, 1, [Set to 1 if we can compile a simple stdatomic example.]) +elif test "$ac_cv_header_stdatomic_h" = "yes"; then + AC_MSG_WARN([Your compiler provides the stdatomic.h header, but it doesn't seem to work. I'll pretend it isn't there. If you are using Clang on Debian, maybe this is because of https://bugs.debian.org/903709 ]) +fi + # Now make sure that NULL can be represented as zero bytes. AC_CACHE_CHECK([whether memset(0) sets pointers to NULL], tor_cv_null_is_zero, [AC_RUN_IFELSE([AC_LANG_SOURCE( diff --git a/src/common/compat_threads.c b/src/common/compat_threads.c index 3171c4b2f..9f64c0634 100644 --- a/src/common/compat_threads.c +++ b/src/common/compat_threads.c @@ -352,7 +352,7 @@ alert_sockets_close(alert_sockets_t *socks) socks->read_fd = socks->write_fd = -1; } -#ifndef HAVE_STDATOMIC_H +#ifndef HAVE_WORKING_STDATOMIC /** Initialize a new atomic counter with the value 0 */ void atomic_counter_init(atomic_counter_t *counter) @@ -403,5 +403,4 @@ atomic_counter_exchange(atomic_counter_t *counter, size_t newval) tor_mutex_release(&counter->mutex); return oldval; } -#endif /* !defined(HAVE_STDATOMIC_H) */ - +#endif /* !defined(HAVE_WORKING_STDATOMIC) */ diff --git a/src/common/compat_threads.h b/src/common/compat_threads.h index c93e601ec..8bf822568 100644 --- a/src/common/compat_threads.h +++ b/src/common/compat_threads.h @@ -14,7 +14,11 @@ #include <pthread.h> #endif -#ifdef HAVE_STDATOMIC_H +#if defined(HAVE_STDATOMIC_H) && defined(STDATOMIC_WORKS) +#define HAVE_WORKING_STDATOMIC +#endif + +#ifdef HAVE_WORKING_STDATOMIC #include <stdatomic.h> #endif @@ -156,18 +160,18 @@ void tor_threadlocal_set(tor_threadlocal_t *threadlocal, void *value); /** * Atomic counter type; holds a size_t value. */ -#ifdef HAVE_STDATOMIC_H +#ifdef HAVE_WORKING_STDATOMIC typedef struct atomic_counter_t { atomic_size_t val; } atomic_counter_t; #define ATOMIC_LINKAGE static -#else /* !(defined(HAVE_STDATOMIC_H)) */ +#else /* !(defined(HAVE_WORKING_STDATOMIC)) */ typedef struct atomic_counter_t { tor_mutex_t mutex; size_t val; } atomic_counter_t; #define ATOMIC_LINKAGE -#endif /* defined(HAVE_STDATOMIC_H) */ +#endif /* defined(HAVE_WORKING_STDATOMIC) */ ATOMIC_LINKAGE void atomic_counter_init(atomic_counter_t *counter); ATOMIC_LINKAGE void atomic_counter_destroy(atomic_counter_t *counter); @@ -178,7 +182,7 @@ ATOMIC_LINKAGE size_t atomic_counter_exchange(atomic_counter_t *counter, size_t newval); #undef ATOMIC_LINKAGE -#ifdef HAVE_STDATOMIC_H +#ifdef HAVE_WORKING_STDATOMIC /** Initialize a new atomic counter with the value 0 */ static inline void atomic_counter_init(atomic_counter_t *counter) @@ -216,8 +220,7 @@ atomic_counter_exchange(atomic_counter_t *counter, size_t newval) return atomic_exchange(&counter->val, newval); } -#else /* !(defined(HAVE_STDATOMIC_H)) */ -#endif /* defined(HAVE_STDATOMIC_H) */ +#else /* !(defined(HAVE_WORKING_STDATOMIC)) */ +#endif /* defined(HAVE_WORKING_STDATOMIC) */ #endif /* !defined(TOR_COMPAT_THREADS_H) */ -

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[tor/maint-0.3.4] Merge branch 'maint-0.3.3' into maint-0.3.4
by nickm＠torproject.org 15 Aug '18

15 Aug '18

commit 6c1d2549df546b6d2628582c9b078753eecd16f4 Merge: b4362b99c 1868982de Author: Nick Mathewson <nickm(a)torproject.org> Date: Wed Aug 15 02:16:23 2018 -0400 Merge branch 'maint-0.3.3' into maint-0.3.4 changes/bug26779 | 4 ++++ configure.ac | 20 ++++++++++++++++++++ src/common/compat_threads.c | 5 ++--- src/common/compat_threads.h | 19 +++++++++++-------- 4 files changed, 37 insertions(+), 11 deletions(-)

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[tor/maint-0.3.3] Merge remote-tracking branch 'public/bug26779_033' into maint-0.3.3
by nickm＠torproject.org 15 Aug '18

15 Aug '18

commit 1868982de6c538b75ab599b332fa896492608620 Merge: fde551a38 b66386865 Author: Nick Mathewson <nickm(a)torproject.org> Date: Wed Aug 15 02:16:19 2018 -0400 Merge remote-tracking branch 'public/bug26779_033' into maint-0.3.3 changes/bug26779 | 4 ++++ configure.ac | 20 ++++++++++++++++++++ src/common/compat_threads.c | 5 ++--- src/common/compat_threads.h | 19 +++++++++++-------- 4 files changed, 37 insertions(+), 11 deletions(-)

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[tor/maint-0.3.4] Detect broken stdatomic.h, and pretend that it isn't there at all
by nickm＠torproject.org 15 Aug '18

15 Aug '18

commit b66386865e68d8df0f228187781fcd5bc2dbf184 Author: Nick Mathewson <nickm(a)torproject.org> Date: Wed Aug 8 15:41:40 2018 -0400 Detect broken stdatomic.h, and pretend that it isn't there at all I hope that the debian clang maintainers will look at debian bug 903709 soon. But until they do, this should keep our users and our CI happy on sid with clang. Closes ticket 26779. --- changes/bug26779 | 4 ++++ configure.ac | 20 ++++++++++++++++++++ src/common/compat_threads.c | 5 ++--- src/common/compat_threads.h | 19 +++++++++++-------- 4 files changed, 37 insertions(+), 11 deletions(-) diff --git a/changes/bug26779 b/changes/bug26779 new file mode 100644 index 000000000..fb7f6160e --- /dev/null +++ b/changes/bug26779 @@ -0,0 +1,4 @@ + o Minor features (bug workaround): + - Compile correctly on systems that provide the C11 stdatomic.h header, + but where C11 atomic functions don't actually compile. + Closes ticket 26779; workaround for Debian issue 903709. diff --git a/configure.ac b/configure.ac index cd591c785..8e6683bb7 100644 --- a/configure.ac +++ b/configure.ac @@ -1557,6 +1557,26 @@ AC_CHECK_SIZEOF(socklen_t, , [AC_INCLUDES_DEFAULT() AC_CHECK_SIZEOF(cell_t) +# Let's see if stdatomic works. (There are some debian clangs that screw it +# up; see Tor bug #26779 and debian bug 903709.) +AC_CACHE_CHECK([whether C11 stdatomic.h actually works], + tor_cv_stdatomic_works, +[AC_COMPILE_IFELSE([AC_LANG_SOURCE([[ +#include <stdatomic.h> +struct x { atomic_size_t y; }; +void try_atomic_init(struct x *xx) +{ + atomic_init(&xx->y, 99); + atomic_fetch_add(&xx->y, 1); +} +]])], [tor_cv_stdatomic_works=yes], [tor_cv_stdatomic_works=no])]) + +if test "$tor_cv_stdatomic_works" = "yes"; then + AC_DEFINE(STDATOMIC_WORKS, 1, [Set to 1 if we can compile a simple stdatomic example.]) +elif test "$ac_cv_header_stdatomic_h" = "yes"; then + AC_MSG_WARN([Your compiler provides the stdatomic.h header, but it doesn't seem to work. I'll pretend it isn't there. If you are using Clang on Debian, maybe this is because of https://bugs.debian.org/903709 ]) +fi + # Now make sure that NULL can be represented as zero bytes. AC_CACHE_CHECK([whether memset(0) sets pointers to NULL], tor_cv_null_is_zero, [AC_RUN_IFELSE([AC_LANG_SOURCE( diff --git a/src/common/compat_threads.c b/src/common/compat_threads.c index 3171c4b2f..9f64c0634 100644 --- a/src/common/compat_threads.c +++ b/src/common/compat_threads.c @@ -352,7 +352,7 @@ alert_sockets_close(alert_sockets_t *socks) socks->read_fd = socks->write_fd = -1; } -#ifndef HAVE_STDATOMIC_H +#ifndef HAVE_WORKING_STDATOMIC /** Initialize a new atomic counter with the value 0 */ void atomic_counter_init(atomic_counter_t *counter) @@ -403,5 +403,4 @@ atomic_counter_exchange(atomic_counter_t *counter, size_t newval) tor_mutex_release(&counter->mutex); return oldval; } -#endif /* !defined(HAVE_STDATOMIC_H) */ - +#endif /* !defined(HAVE_WORKING_STDATOMIC) */ diff --git a/src/common/compat_threads.h b/src/common/compat_threads.h index c93e601ec..8bf822568 100644 --- a/src/common/compat_threads.h +++ b/src/common/compat_threads.h @@ -14,7 +14,11 @@ #include <pthread.h> #endif -#ifdef HAVE_STDATOMIC_H +#if defined(HAVE_STDATOMIC_H) && defined(STDATOMIC_WORKS) +#define HAVE_WORKING_STDATOMIC +#endif + +#ifdef HAVE_WORKING_STDATOMIC #include <stdatomic.h> #endif @@ -156,18 +160,18 @@ void tor_threadlocal_set(tor_threadlocal_t *threadlocal, void *value); /** * Atomic counter type; holds a size_t value. */ -#ifdef HAVE_STDATOMIC_H +#ifdef HAVE_WORKING_STDATOMIC typedef struct atomic_counter_t { atomic_size_t val; } atomic_counter_t; #define ATOMIC_LINKAGE static -#else /* !(defined(HAVE_STDATOMIC_H)) */ +#else /* !(defined(HAVE_WORKING_STDATOMIC)) */ typedef struct atomic_counter_t { tor_mutex_t mutex; size_t val; } atomic_counter_t; #define ATOMIC_LINKAGE -#endif /* defined(HAVE_STDATOMIC_H) */ +#endif /* defined(HAVE_WORKING_STDATOMIC) */ ATOMIC_LINKAGE void atomic_counter_init(atomic_counter_t *counter); ATOMIC_LINKAGE void atomic_counter_destroy(atomic_counter_t *counter); @@ -178,7 +182,7 @@ ATOMIC_LINKAGE size_t atomic_counter_exchange(atomic_counter_t *counter, size_t newval); #undef ATOMIC_LINKAGE -#ifdef HAVE_STDATOMIC_H +#ifdef HAVE_WORKING_STDATOMIC /** Initialize a new atomic counter with the value 0 */ static inline void atomic_counter_init(atomic_counter_t *counter) @@ -216,8 +220,7 @@ atomic_counter_exchange(atomic_counter_t *counter, size_t newval) return atomic_exchange(&counter->val, newval); } -#else /* !(defined(HAVE_STDATOMIC_H)) */ -#endif /* defined(HAVE_STDATOMIC_H) */ +#else /* !(defined(HAVE_WORKING_STDATOMIC)) */ +#endif /* defined(HAVE_WORKING_STDATOMIC) */ #endif /* !defined(TOR_COMPAT_THREADS_H) */ -

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[tor/maint-0.3.4] Merge remote-tracking branch 'public/bug26779_033' into maint-0.3.3
by nickm＠torproject.org 15 Aug '18

15 Aug '18

commit 1868982de6c538b75ab599b332fa896492608620 Merge: fde551a38 b66386865 Author: Nick Mathewson <nickm(a)torproject.org> Date: Wed Aug 15 02:16:19 2018 -0400 Merge remote-tracking branch 'public/bug26779_033' into maint-0.3.3 changes/bug26779 | 4 ++++ configure.ac | 20 ++++++++++++++++++++ src/common/compat_threads.c | 5 ++--- src/common/compat_threads.h | 19 +++++++++++-------- 4 files changed, 37 insertions(+), 11 deletions(-)

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[tor/master] Merge branch 'bug26779_033' into bug26779_035
by nickm＠torproject.org 15 Aug '18

15 Aug '18

commit 26f1167e7151791a04a2c8584360f37602320779 Merge: 778715052 b66386865 Author: Nick Mathewson <nickm(a)torproject.org> Date: Wed Aug 8 15:50:29 2018 -0400 Merge branch 'bug26779_033' into bug26779_035 changes/bug26779 | 4 ++++ configure.ac | 20 ++++++++++++++++++++ src/lib/thread/compat_threads.c | 4 ++-- src/lib/thread/threads.h | 18 +++++++++++------- 4 files changed, 37 insertions(+), 9 deletions(-) diff --cc src/lib/thread/compat_threads.c index 24129946b,000000000..7f1970af4 mode 100644,000000..100644 --- a/src/lib/thread/compat_threads.c +++ b/src/lib/thread/compat_threads.c @@@ -1,111 -1,0 +1,111 @@@ +/* Copyright (c) 2003-2004, Roger Dingledine + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2018, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file compat_threads.c + * + * \brief Cross-platform threading and inter-thread communication logic. + * (Platform-specific parts are written in the other compat_*threads + * modules.) + */ + +#include "orconfig.h" +#include <stdlib.h> +#include "lib/thread/threads.h" + +#include "lib/log/log.h" +#include "lib/log/util_bug.h" + +#include <string.h> + +/** Allocate and return a new condition variable. */ +tor_cond_t * +tor_cond_new(void) +{ + tor_cond_t *cond = tor_malloc(sizeof(tor_cond_t)); + if (BUG(tor_cond_init(cond)<0)) + tor_free(cond); // LCOV_EXCL_LINE + return cond; +} + +/** Free all storage held in <b>c</b>. */ +void +tor_cond_free_(tor_cond_t *c) +{ + if (!c) + return; + tor_cond_uninit(c); + tor_free(c); +} + +/** Identity of the "main" thread */ +static unsigned long main_thread_id = -1; + +/** Start considering the current thread to be the 'main thread'. This has + * no effect on anything besides in_main_thread(). */ +void +set_main_thread(void) +{ + main_thread_id = tor_get_thread_id(); +} +/** Return true iff called from the main thread. */ +int +in_main_thread(void) +{ + return main_thread_id == tor_get_thread_id(); +} + - #ifndef HAVE_STDATOMIC_H ++#ifndef HAVE_WORKING_STDATOMIC +/** Initialize a new atomic counter with the value 0 */ +void +atomic_counter_init(atomic_counter_t *counter) +{ + memset(counter, 0, sizeof(*counter)); + tor_mutex_init_nonrecursive(&counter->mutex); +} +/** Clean up all resources held by an atomic counter. */ +void +atomic_counter_destroy(atomic_counter_t *counter) +{ + tor_mutex_uninit(&counter->mutex); + memset(counter, 0, sizeof(*counter)); +} +/** Add a value to an atomic counter. */ +void +atomic_counter_add(atomic_counter_t *counter, size_t add) +{ + tor_mutex_acquire(&counter->mutex); + counter->val += add; + tor_mutex_release(&counter->mutex); +} +/** Subtract a value from an atomic counter. */ +void +atomic_counter_sub(atomic_counter_t *counter, size_t sub) +{ + // this relies on unsigned overflow, but that's fine. + atomic_counter_add(counter, -sub); +} +/** Return the current value of an atomic counter */ +size_t +atomic_counter_get(atomic_counter_t *counter) +{ + size_t val; + tor_mutex_acquire(&counter->mutex); + val = counter->val; + tor_mutex_release(&counter->mutex); + return val; +} +/** Replace the value of an atomic counter; return the old one. */ +size_t +atomic_counter_exchange(atomic_counter_t *counter, size_t newval) +{ + size_t oldval; + tor_mutex_acquire(&counter->mutex); + oldval = counter->val; + counter->val = newval; + tor_mutex_release(&counter->mutex); + return oldval; +} - #endif /* !defined(HAVE_STDATOMIC_H) */ ++#endif /* !defined(HAVE_WORKING_STDATOMIC) */ diff --cc src/lib/thread/threads.h index 89d2a9d93,000000000..4d5191124 mode 100644,000000..100644 --- a/src/lib/thread/threads.h +++ b/src/lib/thread/threads.h @@@ -1,164 -1,0 +1,168 @@@ +/* Copyright (c) 2003-2004, Roger Dingledine + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2018, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file threads.h + * \brief Header for threads.c + **/ + +#ifndef TOR_COMPAT_THREADS_H +#define TOR_COMPAT_THREADS_H + +#include "orconfig.h" +#include "lib/cc/torint.h" +#include "lib/testsupport/testsupport.h" +#include "lib/lock/compat_mutex.h" + - #ifdef HAVE_STDATOMIC_H ++#if defined(HAVE_STDATOMIC_H) && defined(STDATOMIC_WORKS) ++#define HAVE_WORKING_STDATOMIC ++#endif ++ ++#ifdef HAVE_WORKING_STDATOMIC +#include <stdatomic.h> +#endif + +struct timeval; + +int spawn_func(void (*func)(void *), void *data); +void spawn_exit(void) ATTR_NORETURN; + +unsigned long tor_get_thread_id(void); +void tor_threads_init(void); + +/** Conditions need nonrecursive mutexes with pthreads. */ +#define tor_mutex_init_for_cond(m) tor_mutex_init_nonrecursive(m) + +void set_main_thread(void); +int in_main_thread(void); + +typedef struct tor_cond_t { +#ifdef USE_PTHREADS + pthread_cond_t cond; +#elif defined(USE_WIN32_THREADS) + HANDLE event; + + CRITICAL_SECTION lock; + int n_waiting; + int n_to_wake; + int generation; +#else +#error no known condition implementation. +#endif /* defined(USE_PTHREADS) || ... */ +} tor_cond_t; + +tor_cond_t *tor_cond_new(void); +void tor_cond_free_(tor_cond_t *cond); +#define tor_cond_free(c) FREE_AND_NULL(tor_cond_t, tor_cond_free_, (c)) +int tor_cond_init(tor_cond_t *cond); +void tor_cond_uninit(tor_cond_t *cond); +int tor_cond_wait(tor_cond_t *cond, tor_mutex_t *mutex, + const struct timeval *tv); +void tor_cond_signal_one(tor_cond_t *cond); +void tor_cond_signal_all(tor_cond_t *cond); + +typedef struct tor_threadlocal_s { +#ifdef _WIN32 + DWORD index; +#else + pthread_key_t key; +#endif +} tor_threadlocal_t; + +/** Initialize a thread-local variable. + * + * After you call this function on a tor_threadlocal_t, you can call + * tor_threadlocal_set to change the current value of this variable for the + * current thread, and tor_threadlocal_get to retrieve the current value for + * the current thread. Each thread has its own value. + **/ +int tor_threadlocal_init(tor_threadlocal_t *threadlocal); +/** + * Release all resource associated with a thread-local variable. + */ +void tor_threadlocal_destroy(tor_threadlocal_t *threadlocal); +/** + * Return the current value of a thread-local variable for this thread. + * + * It's undefined behavior to use this function if the threadlocal hasn't + * been initialized, or has been destroyed. + */ +void *tor_threadlocal_get(tor_threadlocal_t *threadlocal); +/** + * Change the current value of a thread-local variable for this thread to + * <b>value</b>. + * + * It's undefined behavior to use this function if the threadlocal hasn't + * been initialized, or has been destroyed. + */ +void tor_threadlocal_set(tor_threadlocal_t *threadlocal, void *value); + +/** + * Atomic counter type; holds a size_t value. + */ - #ifdef HAVE_STDATOMIC_H ++#ifdef HAVE_WORKING_STDATOMIC +typedef struct atomic_counter_t { + atomic_size_t val; +} atomic_counter_t; +#define ATOMIC_LINKAGE static - #else /* !(defined(HAVE_STDATOMIC_H)) */ ++#else /* !(defined(HAVE_WORKING_STDATOMIC)) */ +typedef struct atomic_counter_t { + tor_mutex_t mutex; + size_t val; +} atomic_counter_t; +#define ATOMIC_LINKAGE - #endif /* defined(HAVE_STDATOMIC_H) */ ++#endif /* defined(HAVE_WORKING_STDATOMIC) */ + +ATOMIC_LINKAGE void atomic_counter_init(atomic_counter_t *counter); +ATOMIC_LINKAGE void atomic_counter_destroy(atomic_counter_t *counter); +ATOMIC_LINKAGE void atomic_counter_add(atomic_counter_t *counter, size_t add); +ATOMIC_LINKAGE void atomic_counter_sub(atomic_counter_t *counter, size_t sub); +ATOMIC_LINKAGE size_t atomic_counter_get(atomic_counter_t *counter); +ATOMIC_LINKAGE size_t atomic_counter_exchange(atomic_counter_t *counter, + size_t newval); +#undef ATOMIC_LINKAGE + - #ifdef HAVE_STDATOMIC_H ++#ifdef HAVE_WORKING_STDATOMIC +/** Initialize a new atomic counter with the value 0 */ +static inline void +atomic_counter_init(atomic_counter_t *counter) +{ + atomic_init(&counter->val, 0); +} +/** Clean up all resources held by an atomic counter. */ +static inline void +atomic_counter_destroy(atomic_counter_t *counter) +{ + (void)counter; +} +/** Add a value to an atomic counter. */ +static inline void +atomic_counter_add(atomic_counter_t *counter, size_t add) +{ + (void) atomic_fetch_add(&counter->val, add); +} +/** Subtract a value from an atomic counter. */ +static inline void +atomic_counter_sub(atomic_counter_t *counter, size_t sub) +{ + (void) atomic_fetch_sub(&counter->val, sub); +} +/** Return the current value of an atomic counter */ +static inline size_t +atomic_counter_get(atomic_counter_t *counter) +{ + return atomic_load(&counter->val); +} +/** Replace the value of an atomic counter; return the old one. */ +static inline size_t +atomic_counter_exchange(atomic_counter_t *counter, size_t newval) +{ + return atomic_exchange(&counter->val, newval); +} + - #else /* !(defined(HAVE_STDATOMIC_H)) */ - #endif /* defined(HAVE_STDATOMIC_H) */ ++#else /* !(defined(HAVE_WORKING_STDATOMIC)) */ ++#endif /* defined(HAVE_WORKING_STDATOMIC) */ + +#endif /* !defined(TOR_COMPAT_THREADS_H) */

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[tor/master] Detect broken stdatomic.h, and pretend that it isn't there at all
by nickm＠torproject.org 15 Aug '18

15 Aug '18

commit b66386865e68d8df0f228187781fcd5bc2dbf184 Author: Nick Mathewson <nickm(a)torproject.org> Date: Wed Aug 8 15:41:40 2018 -0400 Detect broken stdatomic.h, and pretend that it isn't there at all I hope that the debian clang maintainers will look at debian bug 903709 soon. But until they do, this should keep our users and our CI happy on sid with clang. Closes ticket 26779. --- changes/bug26779 | 4 ++++ configure.ac | 20 ++++++++++++++++++++ src/common/compat_threads.c | 5 ++--- src/common/compat_threads.h | 19 +++++++++++-------- 4 files changed, 37 insertions(+), 11 deletions(-) diff --git a/changes/bug26779 b/changes/bug26779 new file mode 100644 index 000000000..fb7f6160e --- /dev/null +++ b/changes/bug26779 @@ -0,0 +1,4 @@ + o Minor features (bug workaround): + - Compile correctly on systems that provide the C11 stdatomic.h header, + but where C11 atomic functions don't actually compile. + Closes ticket 26779; workaround for Debian issue 903709. diff --git a/configure.ac b/configure.ac index cd591c785..8e6683bb7 100644 --- a/configure.ac +++ b/configure.ac @@ -1557,6 +1557,26 @@ AC_CHECK_SIZEOF(socklen_t, , [AC_INCLUDES_DEFAULT() AC_CHECK_SIZEOF(cell_t) +# Let's see if stdatomic works. (There are some debian clangs that screw it +# up; see Tor bug #26779 and debian bug 903709.) +AC_CACHE_CHECK([whether C11 stdatomic.h actually works], + tor_cv_stdatomic_works, +[AC_COMPILE_IFELSE([AC_LANG_SOURCE([[ +#include <stdatomic.h> +struct x { atomic_size_t y; }; +void try_atomic_init(struct x *xx) +{ + atomic_init(&xx->y, 99); + atomic_fetch_add(&xx->y, 1); +} +]])], [tor_cv_stdatomic_works=yes], [tor_cv_stdatomic_works=no])]) + +if test "$tor_cv_stdatomic_works" = "yes"; then + AC_DEFINE(STDATOMIC_WORKS, 1, [Set to 1 if we can compile a simple stdatomic example.]) +elif test "$ac_cv_header_stdatomic_h" = "yes"; then + AC_MSG_WARN([Your compiler provides the stdatomic.h header, but it doesn't seem to work. I'll pretend it isn't there. If you are using Clang on Debian, maybe this is because of https://bugs.debian.org/903709 ]) +fi + # Now make sure that NULL can be represented as zero bytes. AC_CACHE_CHECK([whether memset(0) sets pointers to NULL], tor_cv_null_is_zero, [AC_RUN_IFELSE([AC_LANG_SOURCE( diff --git a/src/common/compat_threads.c b/src/common/compat_threads.c index 3171c4b2f..9f64c0634 100644 --- a/src/common/compat_threads.c +++ b/src/common/compat_threads.c @@ -352,7 +352,7 @@ alert_sockets_close(alert_sockets_t *socks) socks->read_fd = socks->write_fd = -1; } -#ifndef HAVE_STDATOMIC_H +#ifndef HAVE_WORKING_STDATOMIC /** Initialize a new atomic counter with the value 0 */ void atomic_counter_init(atomic_counter_t *counter) @@ -403,5 +403,4 @@ atomic_counter_exchange(atomic_counter_t *counter, size_t newval) tor_mutex_release(&counter->mutex); return oldval; } -#endif /* !defined(HAVE_STDATOMIC_H) */ - +#endif /* !defined(HAVE_WORKING_STDATOMIC) */ diff --git a/src/common/compat_threads.h b/src/common/compat_threads.h index c93e601ec..8bf822568 100644 --- a/src/common/compat_threads.h +++ b/src/common/compat_threads.h @@ -14,7 +14,11 @@ #include <pthread.h> #endif -#ifdef HAVE_STDATOMIC_H +#if defined(HAVE_STDATOMIC_H) && defined(STDATOMIC_WORKS) +#define HAVE_WORKING_STDATOMIC +#endif + +#ifdef HAVE_WORKING_STDATOMIC #include <stdatomic.h> #endif @@ -156,18 +160,18 @@ void tor_threadlocal_set(tor_threadlocal_t *threadlocal, void *value); /** * Atomic counter type; holds a size_t value. */ -#ifdef HAVE_STDATOMIC_H +#ifdef HAVE_WORKING_STDATOMIC typedef struct atomic_counter_t { atomic_size_t val; } atomic_counter_t; #define ATOMIC_LINKAGE static -#else /* !(defined(HAVE_STDATOMIC_H)) */ +#else /* !(defined(HAVE_WORKING_STDATOMIC)) */ typedef struct atomic_counter_t { tor_mutex_t mutex; size_t val; } atomic_counter_t; #define ATOMIC_LINKAGE -#endif /* defined(HAVE_STDATOMIC_H) */ +#endif /* defined(HAVE_WORKING_STDATOMIC) */ ATOMIC_LINKAGE void atomic_counter_init(atomic_counter_t *counter); ATOMIC_LINKAGE void atomic_counter_destroy(atomic_counter_t *counter); @@ -178,7 +182,7 @@ ATOMIC_LINKAGE size_t atomic_counter_exchange(atomic_counter_t *counter, size_t newval); #undef ATOMIC_LINKAGE -#ifdef HAVE_STDATOMIC_H +#ifdef HAVE_WORKING_STDATOMIC /** Initialize a new atomic counter with the value 0 */ static inline void atomic_counter_init(atomic_counter_t *counter) @@ -216,8 +220,7 @@ atomic_counter_exchange(atomic_counter_t *counter, size_t newval) return atomic_exchange(&counter->val, newval); } -#else /* !(defined(HAVE_STDATOMIC_H)) */ -#endif /* defined(HAVE_STDATOMIC_H) */ +#else /* !(defined(HAVE_WORKING_STDATOMIC)) */ +#endif /* defined(HAVE_WORKING_STDATOMIC) */ #endif /* !defined(TOR_COMPAT_THREADS_H) */ -

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[tor/master] Merge remote-tracking branch 'public/bug26779_035'
by nickm＠torproject.org 15 Aug '18

15 Aug '18

commit b329cdf768e9bb67bc11eb9306b0e330d6522670 Merge: 57d0b8c3c 26f1167e7 Author: Nick Mathewson <nickm(a)torproject.org> Date: Wed Aug 15 02:14:17 2018 -0400 Merge remote-tracking branch 'public/bug26779_035' changes/bug26779 | 4 ++++ configure.ac | 20 ++++++++++++++++++++ src/lib/thread/compat_threads.c | 4 ++-- src/lib/thread/threads.h | 18 +++++++++++------- 4 files changed, 37 insertions(+), 9 deletions(-)

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[tor/master] Merge remote-tracking branch 'public/bug26779_033' into maint-0.3.3
by nickm＠torproject.org 15 Aug '18

15 Aug '18

commit 1868982de6c538b75ab599b332fa896492608620 Merge: fde551a38 b66386865 Author: Nick Mathewson <nickm(a)torproject.org> Date: Wed Aug 15 02:16:19 2018 -0400 Merge remote-tracking branch 'public/bug26779_033' into maint-0.3.3 changes/bug26779 | 4 ++++ configure.ac | 20 ++++++++++++++++++++ src/common/compat_threads.c | 5 ++--- src/common/compat_threads.h | 19 +++++++++++-------- 4 files changed, 37 insertions(+), 11 deletions(-)

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