1 // bootstrap.cxx -- bootstrap routines: main()
3 // Written by Curtis Olson, started May 1997.
5 // Copyright (C) 1997 - 2002 Curtis L. Olson - http://www.flightgear.org/~curt
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
28 #if defined(HAVE_FEENABLEEXCEPT)
33 #elif defined(__linux__) && defined(__i386__)
34 # include <fpu_control.h>
42 #include <simgear/compiler.h>
43 #include <simgear/structure/exception.hxx>
44 #include <simgear/debug/logstream.hxx>
52 #include "globals.hxx"
57 char *homedir = ::getenv( "HOME" );
58 char *hostname = ::getenv( "HOSTNAME" );
59 bool free_hostname = false;
61 // foreward declaration.
64 static bool fpeAbort = false;
65 static void handleFPE(int);
66 static void initFPE();
68 #if defined(HAVE_FEENABLEEXCEPT)
73 int except = fegetexcept();
74 feenableexcept(except | FE_DIVBYZERO | FE_INVALID);
76 signal(SIGFPE, handleFPE);
80 static void handleFPE(int)
82 feclearexcept(FE_ALL_EXCEPT);
83 signal(SIGFPE, handleFPE);
85 #elif defined(__linux__) && defined(__i386__)
90 fpu_control_t fpe_flags = 0;
91 _FPU_GETCW(fpe_flags);
92 // fpe_flags &= ~_FPU_MASK_IM; // invalid operation
93 // fpe_flags &= ~_FPU_MASK_DM; // denormalized operand
94 // fpe_flags &= ~_FPU_MASK_ZM; // zero-divide
95 // fpe_flags &= ~_FPU_MASK_OM; // overflow
96 // fpe_flags &= ~_FPU_MASK_UM; // underflow
97 // fpe_flags &= ~_FPU_MASK_PM; // precision (inexact result)
98 _FPU_SETCW(fpe_flags);
99 signal(SIGFPE, handleFPE);
106 SG_LOG(SG_GENERAL, SG_ALERT, "Floating point interrupt (SIGFPE)");
109 static void handleFPE(int)
113 static void initFPE()
119 int main ( int argc, char **argv );
120 int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
121 LPSTR lpCmdLine, int nCmdShow) {
123 logbuf::has_no_console();
124 main( __argc, __argv );
130 #include <sys/sysmp.h>
134 * set the special "flush zero" bit (FS, bit 24) in the Control Status
135 * Register of the FPU of R4k and beyond so that the result of any
136 * underflowing operation will be clamped to zero, and no exception of
137 * any kind will be generated on the CPU. This has no effect on an
143 f.fc_word = get_fpc_csr();
144 f.fc_struct.flush = 1;
145 set_fpc_csr(f.fc_word);
149 static void fg_terminate() {
151 "Uncaught Exception: you should see a meaningful error message\n"
152 "here, but your GLUT (or SDL) library was apparently compiled\n"
153 "and/or linked without exception support. Please complain to\n"
159 int _bootstrap_OSInit;
161 // Main entry point; catch any exceptions that have made it this far.
162 int main ( int argc, char **argv ) {
164 #ifdef PTW32_STATIC_LIB
165 // Initialise static pthread win32 lib
166 pthread_win32_process_attach_np ();
168 _bootstrap_OSInit = 0;
170 #if defined(__FreeBSD__)
171 // Ignore floating-point exceptions on FreeBSD
172 signal(SIGFPE, SIG_IGN);
174 // Maybe Enable floating-point exceptions on Linux
175 for (int i = 0; i < argc; ++i) {
176 if (!strcmp("--enable-fpe", argv[i])) {
183 #if !defined( _MSC_VER ) && !defined( __MINGW32__ )
184 signal(SIGPIPE, SIG_IGN);
190 // Bind all non-rendering threads to CPU1
191 // This will reduce the jitter caused by them to an absolute minimum,
192 // but it will only work with superuser authority.
193 if ( geteuid() == 0 )
195 sysmp(MP_CLOCK, 0); // bind the timer only to CPU0
196 sysmp(MP_ISOLATE, 1 ); // Isolate CPU1
197 sysmp(MP_NONPREEMPTIVE, 1 ); // disable process time slicing on CPU1
201 // Enable floating-point exceptions for Windows
202 #if defined( _MSC_VER ) && defined( DEBUG )
203 // Christian, we should document what this does
204 _control87( _EM_INEXACT, _MCW_EM );
207 #if defined( HAVE_BC5PLUS )
208 _control87(MCW_EM, MCW_EM); /* defined in float.h */
211 // FIXME: add other, more specific
214 std::set_terminate(fg_terminate);
215 atexit(fgExitCleanup);
216 fgMainInit(argc, argv);
217 } catch (const sg_throwable &t) {
218 // We must use cerr rather than
219 // logging, since logging may be
221 cerr << "Fatal error: " << t.getFormattedMessage() << endl;
222 if (std::strlen(t.getOrigin()) != 0)
223 cerr << " (received from " << t.getOrigin() << ')' << endl;
225 } catch (const string &s) {
226 cerr << "Fatal error: " << s << endl;
228 } catch (const char *s) {
229 cerr << "Fatal error: " << s << endl;
232 cerr << "Unknown exception in the main loop. Aborting..." << endl;
234 perror("Possible cause");
240 // do some clean up on exit. Specifically we want to call alutExit()
241 // which happens in the sound manager destructor.
242 void fgExitCleanup() {
244 if (_bootstrap_OSInit != 0)
245 fgSetMouseCursor(MOUSE_CURSOR_POINTER);
249 if (free_hostname && hostname != NULL)