On Thu, Jul 7, 2022 at 1:43 PM Martin Liška <mli...@suse.cz> wrote:
>
> For now, support locking only for linux targets that are different from
> riscv* where the target depends on libatomic (and fails during
> bootstrap).
>
> Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
>
> Ready to be installed?
OK - that also resolves the mingw issue, correct? I suppose we need
to be careful to not advertise v1 API (which includes threadsafeness)
when not HAVE_PTHREAD_LOCKING.
Thanks,
Richard.
> Thanks,
> Martin
>
> PR lto/106170
>
> lto-plugin/ChangeLog:
>
> * configure.ac: Configure HAVE_PTHREAD_LOCKING.
> * lto-plugin.c (LOCK_SECTION): New.
> (UNLOCK_SECTION): New.
> (claim_file_handler): Use the newly added macros.
> (onload): Likewise.
> * config.h.in: Regenerate.
> * configure: Regenerate.
> ---
> lto-plugin/config.h.in | 4 ++--
> lto-plugin/configure | 20 ++++++++++++++------
> lto-plugin/configure.ac | 17 +++++++++++++++--
> lto-plugin/lto-plugin.c | 30 ++++++++++++++++++++----------
> 4 files changed, 51 insertions(+), 20 deletions(-)
>
> diff --git a/lto-plugin/config.h.in b/lto-plugin/config.h.in
> index 029e782f1ee..bf269f000d2 100644
> --- a/lto-plugin/config.h.in
> +++ b/lto-plugin/config.h.in
> @@ -9,8 +9,8 @@
> /* Define to 1 if you have the <memory.h> header file. */
> #undef HAVE_MEMORY_H
>
> -/* Define to 1 if pthread.h is present. */
> -#undef HAVE_PTHREAD_H
> +/* Define if the system-provided pthread locking mechanism. */
> +#undef HAVE_PTHREAD_LOCKING
>
> /* Define to 1 if you have the <stdint.h> header file. */
> #undef HAVE_STDINT_H
> diff --git a/lto-plugin/configure b/lto-plugin/configure
> index aaa91a63623..7ea54e6008f 100755
> --- a/lto-plugin/configure
> +++ b/lto-plugin/configure
> @@ -6011,14 +6011,22 @@ fi
>
>
> # Check for thread headers.
> -ac_fn_c_check_header_mongrel "$LINENO" "pthread.h" "ac_cv_header_pthread_h"
> "$ac_includes_default"
> -if test "x$ac_cv_header_pthread_h" = xyes; then :
> +use_locking=no
>
> -$as_echo "#define HAVE_PTHREAD_H 1" >>confdefs.h
> +case $target in
> + riscv*)
> + # do not use locking as pthread depends on libatomic
> + ;;
> + *-linux*)
> + use_locking=yes
> + ;;
> +esac
>
> -fi
> +if test x$use_locking = xyes; then
>
> +$as_echo "#define HAVE_PTHREAD_LOCKING 1" >>confdefs.h
>
> +fi
>
> case `pwd` in
> *\ * | *\ *)
> @@ -12091,7 +12099,7 @@ else
> lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
> lt_status=$lt_dlunknown
> cat > conftest.$ac_ext <<_LT_EOF
> -#line 12094 "configure"
> +#line 12102 "configure"
> #include "confdefs.h"
>
> #if HAVE_DLFCN_H
> @@ -12197,7 +12205,7 @@ else
> lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
> lt_status=$lt_dlunknown
> cat > conftest.$ac_ext <<_LT_EOF
> -#line 12200 "configure"
> +#line 12208 "configure"
> #include "confdefs.h"
>
> #if HAVE_DLFCN_H
> diff --git a/lto-plugin/configure.ac b/lto-plugin/configure.ac
> index c2ec512880f..69bc5139193 100644
> --- a/lto-plugin/configure.ac
> +++ b/lto-plugin/configure.ac
> @@ -88,8 +88,21 @@ AM_CONDITIONAL(LTO_PLUGIN_USE_SYMVER_GNU, [test
> "x$lto_plugin_use_symver" = xgnu
> AM_CONDITIONAL(LTO_PLUGIN_USE_SYMVER_SUN, [test "x$lto_plugin_use_symver" =
> xsun])
>
> # Check for thread headers.
> -AC_CHECK_HEADER(pthread.h,
> - [AC_DEFINE(HAVE_PTHREAD_H, 1, [Define to 1 if pthread.h is present.])])
> +use_locking=no
> +
> +case $target in
> + riscv*)
> + # do not use locking as pthread depends on libatomic
> + ;;
> + *-linux*)
> + use_locking=yes
> + ;;
> +esac
> +
> +if test x$use_locking = xyes; then
> + AC_DEFINE(HAVE_PTHREAD_LOCKING, 1,
> + [Define if the system-provided pthread locking mechanism.])
> +fi
>
> AM_PROG_LIBTOOL
> ACX_LT_HOST_FLAGS
> diff --git a/lto-plugin/lto-plugin.c b/lto-plugin/lto-plugin.c
> index 635e126946b..cba58f5999b 100644
> --- a/lto-plugin/lto-plugin.c
> +++ b/lto-plugin/lto-plugin.c
> @@ -40,11 +40,7 @@ along with this program; see the file COPYING3. If not see
>
> #ifdef HAVE_CONFIG_H
> #include "config.h"
> -#if !HAVE_PTHREAD_H
> -#error POSIX threads are mandatory dependency
> #endif
> -#endif
> -
> #if HAVE_STDINT_H
> #include <stdint.h>
> #endif
> @@ -59,7 +55,9 @@ along with this program; see the file COPYING3. If not see
> #include <unistd.h>
> #include <fcntl.h>
> #include <sys/types.h>
> +#if HAVE_PTHREAD_LOCKING
> #include <pthread.h>
> +#endif
> #ifdef HAVE_SYS_WAIT_H
> #include <sys/wait.h>
> #endif
> @@ -162,9 +160,18 @@ enum symbol_style
> ss_uscore, /* Underscore prefix all symbols. */
> };
>
> +#if HAVE_PTHREAD_LOCKING
> /* Plug-in mutex. */
> static pthread_mutex_t plugin_lock;
>
> +#define LOCK_SECTION pthread_mutex_lock (&plugin_lock)
> +#define UNLOCK_SECTION pthread_mutex_unlock (&plugin_lock)
> +#else
> +
> +#define LOCK_SECTION
> +#define UNLOCK_SECTION
> +#endif
> +
> static char *arguments_file_name;
> static ld_plugin_register_claim_file register_claim_file;
> static ld_plugin_register_all_symbols_read register_all_symbols_read;
> @@ -1270,18 +1277,18 @@ claim_file_handler (const struct ld_plugin_input_file
> *file, int *claimed)
> lto_file.symtab.syms);
> check (status == LDPS_OK, LDPL_FATAL, "could not add symbols");
>
> - pthread_mutex_lock (&plugin_lock);
> + LOCK_SECTION;
> num_claimed_files++;
> claimed_files =
> xrealloc (claimed_files,
> num_claimed_files * sizeof (struct plugin_file_info));
> claimed_files[num_claimed_files - 1] = lto_file;
> - pthread_mutex_unlock (&plugin_lock);
> + UNLOCK_SECTION;
>
> *claimed = 1;
> }
>
> - pthread_mutex_lock (&plugin_lock);
> + LOCK_SECTION;
> if (offload_files == NULL)
> {
> /* Add dummy item to the start of the list. */
> @@ -1344,14 +1351,15 @@ claim_file_handler (const struct ld_plugin_input_file
> *file, int *claimed)
> offload_files_last_lto = ofld;
> num_offload_files++;
> }
> - pthread_mutex_unlock (&plugin_lock);
> +
> + UNLOCK_SECTION;
>
> goto cleanup;
>
> err:
> - pthread_mutex_lock (&plugin_lock);
> + LOCK_SECTION;
> non_claimed_files++;
> - pthread_mutex_unlock (&plugin_lock);
> + UNLOCK_SECTION;
> free (lto_file.name);
>
> cleanup:
> @@ -1429,11 +1437,13 @@ onload (struct ld_plugin_tv *tv)
> struct ld_plugin_tv *p;
> enum ld_plugin_status status;
>
> +#if HAVE_PTHREAD_LOCKING
> if (pthread_mutex_init (&plugin_lock, NULL) != 0)
> {
> fprintf (stderr, "mutex init failed\n");
> abort ();
> }
> +#endif
>
> p = tv;
> while (p->tv_tag)
> --
> 2.36.1
>
