procyberian/gcc
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Document libgfortran thread-safety

Browse source 
From-SVN: r169864
This commit is contained in:
Janne Blomqvist 2011-02-06 18:08:03 +02:00
parent b1b0c7e63d
commit 6985b4a110
3 changed files with 56 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
gcc/fortran/ChangeLog
View file

@ -1,3 +1,11 @@
2011-02-06 Janne Blomqvist <jb@gcc.gnu.org>
* gfortran.texi (Thread-safety): New section.
* intrinsic.texi (EXECUTE_COMMAND_LINE): Mention thread-safety.
(GETENV): Likewise.
(GET_ENVIRONMENT_VARIABLE): Likewise.
(SYSTEM): Likewise.
2011-02-06 Paul Thomas <pault@gcc.gnu.org>
PR fortran/47592

30
gcc/fortran/gfortran.texi
View file

@ -1157,6 +1157,36 @@ representation of @code{LOGICAL} variables in GNU Fortran is identical
to C99 _Bool, except for a possible difference in storage size
depending on the kind.
@node Thread-safety of the runtime library
@section Thread-safety of the runtime library
@cindex thread-safety, threads
GNU Fortran can be used in programs with multiple threads, e.g. by
using OpenMP, by calling OS thread handling functions via the
@code{ISO_C_BINDING} facility, or by GNU Fortran compiled library code
being called from a multi-threaded program.
The GNU Fortran runtime library, (@var{libgfortran}), supports being
called concurrently from multiple threads with the following
exceptions.
During library initialization, the C @code{getenv()} function is used,
which need not be thread-safe. Similarly, the @code{getenv()}
function is used to implement the @code{GET_ENVIRONMENT_VARIABLE} and
@code{GETENV} intrinsics. It is the responsibility of the user to
ensure that the environment is not being updated concurrently when any
of these actions are taking place.
The @code{EXECUTE_COMMAND_LINE} and @code{SYSTEM} intrinsics are
implemented with the @code{system()} function, which need not be
thread-safe. It is the responsibility of the user to ensure that
@code{system()} is not called concurrently.
Finally, for platforms not supporting thread-safe @code{POSIX}
functions, further functionality might not be thread-safe. For
details, please consult the documentation for your operating system.
@c ---------------------------------------------------------------------
@c Extensions
@c ---------------------------------------------------------------------

20
gcc/fortran/intrinsic.texi
View file

@ -4162,6 +4162,9 @@ the command, as returned by @code{system}. @code{CMDSTAT} is set to zero
if the command line was executed (whatever its exit status was).
@code{CMDMSG} is assigned an error message if an error has occurred.
Note that the @code{system()} call need not be thread-safe. It is the
responsibility of the user to ensure that @code{system()} is not
called concurrently.
@item @emph{Standard}:
Fortran 2008 and later
@ -5452,11 +5455,15 @@ END PROGRAM
@item @emph{Description}:
Get the @var{VALUE} of the environmental variable @var{NAME}.
This intrinsic routine is provided for backwards compatibility with
GNU Fortran 77. In new code, programmers should consider the use of
This intrinsic routine is provided for backwards compatibility with
GNU Fortran 77. In new code, programmers should consider the use of
the @ref{GET_ENVIRONMENT_VARIABLE} intrinsic defined by the Fortran
2003 standard.
Note that @code{GETENV} need not be thread-safe. It is the
responsibility of the user to ensure that the environment is not being
updated concurrently with a call to the @code{GETENV} intrinsic.
@item @emph{Standard}:
GNU extension
@ -5501,6 +5508,11 @@ END PROGRAM
@item @emph{Description}:
Get the @var{VALUE} of the environmental variable @var{NAME}.
Note that @code{GET_ENVIRONMENT_VARIABLE} need not be thread-safe. It
is the responsibility of the user to ensure that the environment is
not being updated concurrently with a call to the
@code{GET_ENVIRONMENT_VARIABLE} intrinsic.
@item @emph{Standard}:
Fortran 2003 and later
@ -11779,6 +11791,10 @@ and environment-dependent.
This intrinsic is provided in both subroutine and function forms;
however, only one form can be used in any given program unit.
Note that the @code{system()} call need not be thread-safe. It is the
responsibility of the user to ensure that @code{system()} is not
called concurrently.
@item @emph{Standard}:
GNU extension