[03/18] support: Add support_create_timer

Message ID 20210617115104.1359598-4-adhemerval.zanella@linaro.org
State New
Headers show
Series
  • More y2038 fixes
Related show

Commit Message

It is a simple wrapper over timer_create, timer_settime, and
sigaction.  It will be used to check for large timeout to trigger an
EINTR.
---
 support/Makefile               |  1 +
 support/support.h              | 11 ++++++
 support/support_create_timer.c | 69 ++++++++++++++++++++++++++++++++++
 3 files changed, 81 insertions(+)
 create mode 100644 support/support_create_timer.c

-- 
2.30.2

Comments

Lukasz Majewski June 21, 2021, 7:42 a.m. | #1
On Thu, 17 Jun 2021 08:50:49 -0300
Adhemerval Zanella <adhemerval.zanella@linaro.org> wrote:

> It is a simple wrapper over timer_create, timer_settime, and

> sigaction.  It will be used to check for large timeout to trigger an

> EINTR.

> ---

>  support/Makefile               |  1 +

>  support/support.h              | 11 ++++++

>  support/support_create_timer.c | 69

> ++++++++++++++++++++++++++++++++++ 3 files changed, 81 insertions(+)

>  create mode 100644 support/support_create_timer.c

> 

> diff --git a/support/Makefile b/support/Makefile

> index f3ebaa8d2e..278f4627d8 100644

> --- a/support/Makefile

> +++ b/support/Makefile

> @@ -50,6 +50,7 @@ libsupport-routines = \

>    support_chroot \

>    support_copy_file \

>    support_copy_file_range \

> +  support_create_timer \

>    support_descriptor_supports_holes \

>    support_descriptors \

>    support_enter_mount_namespace \

> diff --git a/support/support.h b/support/support.h

> index 874204b7fc..9ec8ecb8d7 100644

> --- a/support/support.h

> +++ b/support/support.h

> @@ -24,6 +24,7 @@

>  #define SUPPORT_H

>  

>  #include <stdbool.h>

> +#include <stdint.h>

>  #include <stddef.h>

>  #include <sys/cdefs.h>

>  /* For mode_t.  */

> @@ -153,6 +154,16 @@ extern bool support_select_modifies_timeout

> (void); tv_usec larger than 1000000.  */

>  extern bool support_select_normalizes_timeout (void);

>  

> +/* Create a timer that trigger after SEC seconds and NSEC

> nanoseconds.  If

> +   REPEAT is true the timer will repeat indefinitely.  If CALLBACK

> is not

> +   NULL, the function will be called when the timer expires;

> otherwise a

> +   dummy empty function is used instead.

> +   This is implemented with POSIX per-process timer with

> SIGEV_SIGNAL.  */ +timer_t support_create_timer (uint64_t sec, long

> int nsec, bool repeat,

> +			      void (*callback)(int));

> +/* Disable the timer TIMER.  */

> +void support_delete_timer (timer_t timer);

> +

>  __END_DECLS

>  

>  #endif /* SUPPORT_H */

> diff --git a/support/support_create_timer.c

> b/support/support_create_timer.c new file mode 100644

> index 0000000000..c93aaa5c6b

> --- /dev/null

> +++ b/support/support_create_timer.c

> @@ -0,0 +1,69 @@

> +/* Create a periodic timer.

> +   Copyright (C) 2021 Free Software Foundation, Inc.

> +   This file is part of the GNU C Library.

> +

> +   The GNU C Library is free software; you can redistribute it and/or

> +   modify it under the terms of the GNU Lesser General Public

> +   License as published by the Free Software Foundation; either

> +   version 2.1 of the License, or (at your option) any later version.

> +

> +   The GNU C Library is distributed in the hope that it will be

> useful,

> +   but WITHOUT ANY WARRANTY; without even the implied warranty of

> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

> +   Lesser General Public License for more details.

> +

> +   You should have received a copy of the GNU Lesser General Public

> +   License along with the GNU C Library; if not, see

> +   <https://www.gnu.org/licenses/>.  */

> +

> +#include <support/check.h>

> +#include <support/support.h>

> +#include <support/xsignal.h>

> +#include <time.h>

> +

> +static void

> +dummy_alrm_handler (int sig)

> +{

> +}

> +

> +timer_t

> +support_create_timer (uint64_t sec, long int nsec, bool repeat,

> +		      void (*callback)(int))

> +{

> +  struct sigaction sa;

> +  sa.sa_handler = callback != NULL ? callback : dummy_alrm_handler;

> +  sigemptyset (&sa.sa_mask);

> +  sa.sa_flags = 0;

> +  xsigaction (SIGALRM, &sa, NULL);

> +

> +  struct sigevent ev = {

> +    .sigev_notify = SIGEV_SIGNAL,

> +    .sigev_signo = SIGALRM

> +  };

> +  timer_t timerid;

> +  int r = timer_create (CLOCK_REALTIME, &ev, &timerid);

> +  if (r == -1)

> +    FAIL_EXIT1 ("timer_create: %m");

> +

> +  /* Single timer with 0.1s.  */

> +  struct itimerspec its =

> +    {

> +      { .tv_sec = repeat ? sec : 0, .tv_nsec = repeat ? nsec : 0 },

> +      { .tv_sec = sec, .tv_nsec = nsec }

> +    };

> +  r = timer_settime (timerid, 0, &its, NULL);

> +  if (r == -1)

> +    FAIL_EXIT1 ("timer_settime: %m");

> +

> +  return timerid;

> +}

> +

> +/* Disable the timer TIMER.  */

> +void

> +support_delete_timer (timer_t timer)

> +{

> +  int r = timer_delete (timer);

> +  if (r == -1)

> +    FAIL_EXIT1 ("timer_delete: %m");

> +  xsignal (SIGALRM, SIG_DFL);

> +}


Reviewed-by: Lukasz Majewski <lukma@denx.de>



Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de

Patch

diff --git a/support/Makefile b/support/Makefile
index f3ebaa8d2e..278f4627d8 100644
--- a/support/Makefile
+++ b/support/Makefile
@@ -50,6 +50,7 @@  libsupport-routines = \
   support_chroot \
   support_copy_file \
   support_copy_file_range \
+  support_create_timer \
   support_descriptor_supports_holes \
   support_descriptors \
   support_enter_mount_namespace \
diff --git a/support/support.h b/support/support.h
index 874204b7fc..9ec8ecb8d7 100644
--- a/support/support.h
+++ b/support/support.h
@@ -24,6 +24,7 @@ 
 #define SUPPORT_H
 
 #include <stdbool.h>
+#include <stdint.h>
 #include <stddef.h>
 #include <sys/cdefs.h>
 /* For mode_t.  */
@@ -153,6 +154,16 @@  extern bool support_select_modifies_timeout (void);
    tv_usec larger than 1000000.  */
 extern bool support_select_normalizes_timeout (void);
 
+/* Create a timer that trigger after SEC seconds and NSEC nanoseconds.  If
+   REPEAT is true the timer will repeat indefinitely.  If CALLBACK is not
+   NULL, the function will be called when the timer expires; otherwise a
+   dummy empty function is used instead.
+   This is implemented with POSIX per-process timer with SIGEV_SIGNAL.  */
+timer_t support_create_timer (uint64_t sec, long int nsec, bool repeat,
+			      void (*callback)(int));
+/* Disable the timer TIMER.  */
+void support_delete_timer (timer_t timer);
+
 __END_DECLS
 
 #endif /* SUPPORT_H */
diff --git a/support/support_create_timer.c b/support/support_create_timer.c
new file mode 100644
index 0000000000..c93aaa5c6b
--- /dev/null
+++ b/support/support_create_timer.c
@@ -0,0 +1,69 @@ 
+/* Create a periodic timer.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <support/check.h>
+#include <support/support.h>
+#include <support/xsignal.h>
+#include <time.h>
+
+static void
+dummy_alrm_handler (int sig)
+{
+}
+
+timer_t
+support_create_timer (uint64_t sec, long int nsec, bool repeat,
+		      void (*callback)(int))
+{
+  struct sigaction sa;
+  sa.sa_handler = callback != NULL ? callback : dummy_alrm_handler;
+  sigemptyset (&sa.sa_mask);
+  sa.sa_flags = 0;
+  xsigaction (SIGALRM, &sa, NULL);
+
+  struct sigevent ev = {
+    .sigev_notify = SIGEV_SIGNAL,
+    .sigev_signo = SIGALRM
+  };
+  timer_t timerid;
+  int r = timer_create (CLOCK_REALTIME, &ev, &timerid);
+  if (r == -1)
+    FAIL_EXIT1 ("timer_create: %m");
+
+  /* Single timer with 0.1s.  */
+  struct itimerspec its =
+    {
+      { .tv_sec = repeat ? sec : 0, .tv_nsec = repeat ? nsec : 0 },
+      { .tv_sec = sec, .tv_nsec = nsec }
+    };
+  r = timer_settime (timerid, 0, &its, NULL);
+  if (r == -1)
+    FAIL_EXIT1 ("timer_settime: %m");
+
+  return timerid;
+}
+
+/* Disable the timer TIMER.  */
+void
+support_delete_timer (timer_t timer)
+{
+  int r = timer_delete (timer);
+  if (r == -1)
+    FAIL_EXIT1 ("timer_delete: %m");
+  xsignal (SIGALRM, SIG_DFL);
+}