[07/19] nptl: Add __pthread_attr_copy for copying pthread_attr_t objects

Message ID 653128d1dee168e40595a2228e0100dcad3ac2fe.1589884403.git.fweimer@redhat.com
State New
Headers show
Series
  • Signal mask for timer helper thread
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Commit Message

Florian Weimer via Libc-alpha May 19, 2020, 10:44 a.m.
Also add the private type union pthread_attr_transparent, to reduce
the amount of casting that is required.
---
 nptl/Makefile                |  1 +
 nptl/Versions                |  1 +
 nptl/pthreadP.h              |  6 ++++
 nptl/pthread_attr_copy.c     | 57 ++++++++++++++++++++++++++++++++++++
 sysdeps/nptl/internaltypes.h |  7 +++++
 5 files changed, 72 insertions(+)
 create mode 100644 nptl/pthread_attr_copy.c

-- 
2.25.4

Comments

Florian Weimer via Libc-alpha May 20, 2020, 2:10 p.m. | #1
On 5/19/20 6:44 AM, Florian Weimer via Libc-alpha wrote:
> Also add the private type union pthread_attr_transparent, to reduce

> the amount of casting that is required.


OK for master.

Tested clean on x86_64 and i686.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

Tested-by: Carlos O'Donell <carlos@redhat.com>


> ---

>  nptl/Makefile                |  1 +

>  nptl/Versions                |  1 +

>  nptl/pthreadP.h              |  6 ++++

>  nptl/pthread_attr_copy.c     | 57 ++++++++++++++++++++++++++++++++++++

>  sysdeps/nptl/internaltypes.h |  7 +++++

>  5 files changed, 72 insertions(+)

>  create mode 100644 nptl/pthread_attr_copy.c

> 

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

> index 0dd8800f19..b4aaad0f20 100644

> --- a/nptl/Makefile

> +++ b/nptl/Makefile

> @@ -39,6 +39,7 @@ routines = \

>    old_pthread_cond_destroy \

>    old_pthread_cond_init \

>    pthread_atfork \

> +  pthread_attr_copy \


OK

>    pthread_attr_destroy \

>    pthread_attr_getdetachstate \

>    pthread_attr_getinheritsched \

> diff --git a/nptl/Versions b/nptl/Versions

> index 65f0c077da..4c7b43354d 100644

> --- a/nptl/Versions

> +++ b/nptl/Versions

> @@ -60,6 +60,7 @@ libc {

>      __pthread_cond_destroy; __pthread_cond_init;

>      __pthread_attr_setaffinity_np;

>      __pthread_attr_init; __pthread_attr_destroy;

> +    __pthread_attr_copy;


OK.

>    }

>  }

>  

> diff --git a/nptl/pthreadP.h b/nptl/pthreadP.h

> index f218b01574..41b693d034 100644

> --- a/nptl/pthreadP.h

> +++ b/nptl/pthreadP.h

> @@ -580,6 +580,12 @@ extern void __wait_lookup_done (void) attribute_hidden;

>  # define PTHREAD_STATIC_FN_REQUIRE(name) __asm (".globl " #name);

>  #endif

>  

> +/* Make a deep copy of the attribute *SOURCE in *TARGET.  *TARGET is

> +   not assumed to have been initialized.  Returns 0 on success, or a

> +   positive error code otherwise.  */

> +int __pthread_attr_copy (pthread_attr_t *target, const pthread_attr_t *source);

> +libc_hidden_proto (__pthread_attr_copy)


OK.

> +

>  /* Returns 0 if POL is a valid scheduling policy.  */

>  static inline int

>  check_sched_policy_attr (int pol)

> diff --git a/nptl/pthread_attr_copy.c b/nptl/pthread_attr_copy.c

> new file mode 100644

> index 0000000000..77a1a43eeb

> --- /dev/null

> +++ b/nptl/pthread_attr_copy.c

> @@ -0,0 +1,57 @@

> +/* Deep copy of a pthread_attr_t object.

> +   Copyright (C) 2020 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 <errno.h>

> +#include <pthreadP.h>

> +#include <stdlib.h>

> +

> +int

> +__pthread_attr_copy (pthread_attr_t *target, const pthread_attr_t *source)

> +{

> +  /* Avoid overwriting *TARGET until all allocations have

> +     succeeded.  */

> +  union pthread_attr_transparent temp;

> +  temp.external = *source;

> +

> +  /* Force new allocation.  This function has full ownership of temp.  */

> +  temp.internal.cpuset = NULL;

> +  temp.internal.cpusetsize = 0;

> +

> +  int ret = 0;

> +

> +  struct pthread_attr *isource = (struct pthread_attr *) source;

> +

> +  /* Propagate affinity mask information.  */

> +  if (isource->cpusetsize > 0)

> +    ret = __pthread_attr_setaffinity_np (&temp.external,

> +                                         isource->cpusetsize,

> +                                         isource->cpuset);

> +

> +  if (ret != 0)

> +    {

> +      /* Deallocate because we have ownership.  */

> +      __pthread_attr_destroy (&temp.external);

> +      return ret;

> +    }

> +

> +  /* Transfer ownership.  *target is not assumed to have been

> +     initialized.  */


OK. At this point we copy pointers and we no longer own the memory
that was allocated at the extension pointer.

> +  *target = temp.external;

> +  return 0;

> +}

> +libc_hidden_def (__pthread_attr_copy)

> diff --git a/sysdeps/nptl/internaltypes.h b/sysdeps/nptl/internaltypes.h

> index 71f09b4624..6d06a76baf 100644

> --- a/sysdeps/nptl/internaltypes.h

> +++ b/sysdeps/nptl/internaltypes.h

> @@ -49,6 +49,13 @@ struct pthread_attr

>  #define ATTR_FLAG_SCHED_SET		0x0020

>  #define ATTR_FLAG_POLICY_SET		0x0040

>  

> +/* Used to allocate a pthread_attr_t object which is also accessed

> +   internally.  */

> +union pthread_attr_transparent

> +{

> +  pthread_attr_t external;

> +  struct pthread_attr internal;

> +};


OK.

>  

>  /* Mutex attribute data structure.  */

>  struct pthread_mutexattr

> 



-- 
Cheers,
Carlos.

Patch

diff --git a/nptl/Makefile b/nptl/Makefile
index 0dd8800f19..b4aaad0f20 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -39,6 +39,7 @@  routines = \
   old_pthread_cond_destroy \
   old_pthread_cond_init \
   pthread_atfork \
+  pthread_attr_copy \
   pthread_attr_destroy \
   pthread_attr_getdetachstate \
   pthread_attr_getinheritsched \
diff --git a/nptl/Versions b/nptl/Versions
index 65f0c077da..4c7b43354d 100644
--- a/nptl/Versions
+++ b/nptl/Versions
@@ -60,6 +60,7 @@  libc {
     __pthread_cond_destroy; __pthread_cond_init;
     __pthread_attr_setaffinity_np;
     __pthread_attr_init; __pthread_attr_destroy;
+    __pthread_attr_copy;
   }
 }
 
diff --git a/nptl/pthreadP.h b/nptl/pthreadP.h
index f218b01574..41b693d034 100644
--- a/nptl/pthreadP.h
+++ b/nptl/pthreadP.h
@@ -580,6 +580,12 @@  extern void __wait_lookup_done (void) attribute_hidden;
 # define PTHREAD_STATIC_FN_REQUIRE(name) __asm (".globl " #name);
 #endif
 
+/* Make a deep copy of the attribute *SOURCE in *TARGET.  *TARGET is
+   not assumed to have been initialized.  Returns 0 on success, or a
+   positive error code otherwise.  */
+int __pthread_attr_copy (pthread_attr_t *target, const pthread_attr_t *source);
+libc_hidden_proto (__pthread_attr_copy)
+
 /* Returns 0 if POL is a valid scheduling policy.  */
 static inline int
 check_sched_policy_attr (int pol)
diff --git a/nptl/pthread_attr_copy.c b/nptl/pthread_attr_copy.c
new file mode 100644
index 0000000000..77a1a43eeb
--- /dev/null
+++ b/nptl/pthread_attr_copy.c
@@ -0,0 +1,57 @@ 
+/* Deep copy of a pthread_attr_t object.
+   Copyright (C) 2020 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 <errno.h>
+#include <pthreadP.h>
+#include <stdlib.h>
+
+int
+__pthread_attr_copy (pthread_attr_t *target, const pthread_attr_t *source)
+{
+  /* Avoid overwriting *TARGET until all allocations have
+     succeeded.  */
+  union pthread_attr_transparent temp;
+  temp.external = *source;
+
+  /* Force new allocation.  This function has full ownership of temp.  */
+  temp.internal.cpuset = NULL;
+  temp.internal.cpusetsize = 0;
+
+  int ret = 0;
+
+  struct pthread_attr *isource = (struct pthread_attr *) source;
+
+  /* Propagate affinity mask information.  */
+  if (isource->cpusetsize > 0)
+    ret = __pthread_attr_setaffinity_np (&temp.external,
+                                         isource->cpusetsize,
+                                         isource->cpuset);
+
+  if (ret != 0)
+    {
+      /* Deallocate because we have ownership.  */
+      __pthread_attr_destroy (&temp.external);
+      return ret;
+    }
+
+  /* Transfer ownership.  *target is not assumed to have been
+     initialized.  */
+  *target = temp.external;
+  return 0;
+}
+libc_hidden_def (__pthread_attr_copy)
diff --git a/sysdeps/nptl/internaltypes.h b/sysdeps/nptl/internaltypes.h
index 71f09b4624..6d06a76baf 100644
--- a/sysdeps/nptl/internaltypes.h
+++ b/sysdeps/nptl/internaltypes.h
@@ -49,6 +49,13 @@  struct pthread_attr
 #define ATTR_FLAG_SCHED_SET		0x0020
 #define ATTR_FLAG_POLICY_SET		0x0040
 
+/* Used to allocate a pthread_attr_t object which is also accessed
+   internally.  */
+union pthread_attr_transparent
+{
+  pthread_attr_t external;
+  struct pthread_attr internal;
+};
 
 /* Mutex attribute data structure.  */
 struct pthread_mutexattr