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>
45 #include <simgear/Math/SGMath.hxx>
53 #include "globals.hxx"
58 char *homedir = ::getenv( "HOME" );
59 char *hostname = ::getenv( "HOSTNAME" );
60 bool free_hostname = false;
62 // foreward declaration.
65 static bool fpeAbort = false;
66 static void handleFPE(int);
67 static void initFPE();
69 #if defined(HAVE_FEENABLEEXCEPT)
74 int except = fegetexcept();
75 feenableexcept(except | FE_DIVBYZERO | FE_INVALID);
77 signal(SIGFPE, handleFPE);
81 static void handleFPE(int)
83 feclearexcept(FE_ALL_EXCEPT);
84 signal(SIGFPE, handleFPE);
86 #elif defined(__linux__) && defined(__i386__)
91 fpu_control_t fpe_flags = 0;
92 _FPU_GETCW(fpe_flags);
93 // fpe_flags &= ~_FPU_MASK_IM; // invalid operation
94 // fpe_flags &= ~_FPU_MASK_DM; // denormalized operand
95 // fpe_flags &= ~_FPU_MASK_ZM; // zero-divide
96 // fpe_flags &= ~_FPU_MASK_OM; // overflow
97 // fpe_flags &= ~_FPU_MASK_UM; // underflow
98 // fpe_flags &= ~_FPU_MASK_PM; // precision (inexact result)
99 _FPU_SETCW(fpe_flags);
100 signal(SIGFPE, handleFPE);
107 SG_LOG(SG_GENERAL, SG_ALERT, "Floating point interrupt (SIGFPE)");
110 static void handleFPE(int)
114 static void initFPE()
120 int main ( int argc, char **argv );
121 int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
122 LPSTR lpCmdLine, int nCmdShow) {
124 logbuf::has_no_console();
125 main( __argc, __argv );
131 #include <sys/sysmp.h>
135 * set the special "flush zero" bit (FS, bit 24) in the Control Status
136 * Register of the FPU of R4k and beyond so that the result of any
137 * underflowing operation will be clamped to zero, and no exception of
138 * any kind will be generated on the CPU. This has no effect on an
144 f.fc_word = get_fpc_csr();
145 f.fc_struct.flush = 1;
146 set_fpc_csr(f.fc_word);
150 static void fg_terminate() {
152 "Uncaught Exception: you should see a meaningful error message\n"
153 "here, but your GLUT (or SDL) library was apparently compiled\n"
154 "and/or linked without exception support. Please complain to\n"
160 int _bootstrap_OSInit;
162 // Main entry point; catch any exceptions that have made it this far.
163 int main ( int argc, char **argv ) {
165 #ifdef PTW32_STATIC_LIB
166 // Initialise static pthread win32 lib
167 pthread_win32_process_attach_np ();
169 _bootstrap_OSInit = 0;
171 #if defined(__FreeBSD__)
172 // Ignore floating-point exceptions on FreeBSD
173 signal(SIGFPE, SIG_IGN);
175 // Maybe Enable floating-point exceptions on Linux
176 for (int i = 0; i < argc; ++i) {
177 if (!strcmp("--enable-fpe", argv[i])) {
184 #if !defined( _MSC_VER ) && !defined( __MINGW32__ )
185 signal(SIGPIPE, SIG_IGN);
191 // Bind all non-rendering threads to CPU1
192 // This will reduce the jitter caused by them to an absolute minimum,
193 // but it will only work with superuser authority.
194 if ( geteuid() == 0 )
196 sysmp(MP_CLOCK, 0); // bind the timer only to CPU0
197 sysmp(MP_ISOLATE, 1 ); // Isolate CPU1
198 sysmp(MP_NONPREEMPTIVE, 1 ); // disable process time slicing on CPU1
202 // Enable floating-point exceptions for Windows
203 #if defined( _MSC_VER ) && defined( DEBUG )
204 // Christian, we should document what this does
205 _control87( _EM_INEXACT, _MCW_EM );
208 #if defined( HAVE_BC5PLUS )
209 _control87(MCW_EM, MCW_EM); /* defined in float.h */
212 // FIXME: add other, more specific
215 std::set_terminate(fg_terminate);
216 atexit(fgExitCleanup);
217 fgMainInit(argc, argv);
218 } catch (const sg_throwable &t) {
219 // We must use cerr rather than
220 // logging, since logging may be
222 cerr << "Fatal error: " << t.getFormattedMessage() << endl;
223 if (std::strlen(t.getOrigin()) != 0)
224 cerr << " (received from " << t.getOrigin() << ')' << endl;
226 } catch (const string &s) {
227 cerr << "Fatal error: " << s << endl;
229 } catch (const char *s) {
230 cerr << "Fatal error: " << s << endl;
233 cerr << "Unknown exception in the main loop. Aborting..." << endl;
235 perror("Possible cause");
241 // do some clean up on exit. Specifically we want to call alutExit()
242 // which happens in the sound manager destructor.
243 void fgExitCleanup() {
245 if (_bootstrap_OSInit != 0)
246 fgSetMouseCursor(MOUSE_CURSOR_POINTER);
250 if (free_hostname && hostname != NULL)