1 //===========================================================================
5 // ISO C and POSIX error code
7 //===========================================================================
8 //####ECOSGPLCOPYRIGHTBEGIN####
9 // -------------------------------------------
10 // This file is part of eCos, the Embedded Configurable Operating System.
11 // Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
13 // eCos is free software; you can redistribute it and/or modify it under
14 // the terms of the GNU General Public License as published by the Free
15 // Software Foundation; either version 2 or (at your option) any later version.
17 // eCos is distributed in the hope that it will be useful, but WITHOUT ANY
18 // WARRANTY; without even the implied warranty of MERCHANTABILITY or
19 // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
22 // You should have received a copy of the GNU General Public License along
23 // with eCos; if not, write to the Free Software Foundation, Inc.,
24 // 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
26 // As a special exception, if other files instantiate templates or use macros
27 // or inline functions from this file, or you compile this file and link it
28 // with other works to produce a work based on this file, this file does not
29 // by itself cause the resulting work to be covered by the GNU General Public
30 // License. However the source code for this file must still be made available
31 // in accordance with section (3) of the GNU General Public License.
33 // This exception does not invalidate any other reasons why a work based on
34 // this file might be covered by the GNU General Public License.
36 // Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
37 // at http://sources.redhat.com/ecos/ecos-license/
38 // -------------------------------------------
39 //####ECOSGPLCOPYRIGHTEND####
40 //===========================================================================
41 //#####DESCRIPTIONBEGIN####
43 // Author(s): jlarmour
44 // Contributors: jlarmour
46 // Purpose: Provide the errno variable
47 // Description: This file either provides the errno variable directly,
48 // or if thread-safe, using a kernel per-thread data
52 //####DESCRIPTIONEND####
54 //===========================================================================
58 #include <pkgconf/system.h>
59 #include <pkgconf/error.h> // Configuration header
61 #ifdef CYGPKG_ERROR_ERRNO
65 #include <cyg/infra/cyg_type.h> // Common project-wide type definitions
66 #include <cyg/infra/cyg_trac.h> // Common tracing functions
67 #include <cyg/error/errno.h> // Header for this file
69 #ifdef CYGSEM_ERROR_PER_THREAD_ERRNO
70 # include <pkgconf/kernel.h> // kernel configuration
71 # include <cyg/kernel/thread.hxx> // per-thread data
72 # include <cyg/kernel/thread.inl> // per-thread data
73 # include <cyg/kernel/mutex.hxx> // mutexes
78 #ifndef CYGSEM_ERROR_PER_THREAD_ERRNO
80 // errno is initialised to 0 at program startup - ANSI 7.1.4
83 #else // ifndef CYGSEM_ERROR_PER_THREAD_ERRNO
85 # if defined(CYGDBG_USE_TRACING) && defined(CYGNUM_ERROR_ERRNO_TRACE_LEVEL)
86 static int errno_trace = CYGNUM_ERROR_ERRNO_TRACE_LEVEL;
87 # define TL1 (0 < errno_trace)
95 cyg_error_get_errno_p( void )
99 CYG_REPORT_FUNCNAMETYPE( "cyg_error_get_errno_p", "&errno is %d");
101 // set up the thread data, allocating if necessary (even though the
102 // user _shouldn't_ read errno before its set, we can't stop them - and
103 // ANSI prescribes it has a sensible value (0) before its set too anyway.
105 Cyg_Thread *self = Cyg_Thread::self();
107 errno_p = (Cyg_ErrNo *)self->get_data_ptr(CYGNUM_KERNEL_THREADS_DATA_ERRNO);
109 CYG_TRACE1( TL1, "errno is %d", *errno_p );
111 CYG_REPORT_RETVAL( errno_p );
113 // return the internal data's errno
115 } // cyg_error_get_errno_p()
117 #endif // ifdef CYGSEM_ERROR_PER_THREAD_ERRNO
119 #endif // ifdef CYGPKG_ERROR_ERRNO