diff mbox series

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

Message ID 653128d1dee168e40595a2228e0100dcad3ac2fe.1589884403.git.fweimer@redhat.com
State Committed
Headers show
Series Signal mask for timer helper thread | expand

Commit Message

Florian Weimer May 19, 2020, 10:44 a.m. UTC
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

Comments

Carlos O'Donell May 20, 2020, 2:10 p.m. UTC | #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
>
diff mbox series

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