Hi there, the following shows a problem in Cygwin 1.7 that is not present in Cygwin 1.5: roberto@sissi /tmp $ cat bug.c #include <sys/time.h> #include <time.h> #include <signal.h> #include <stdio.h> volatile int alarm_called = 0; void alarm(int sig) { alarm_called = 1; } int main() { unsigned long i; struct itimerval it; it.it_interval.tv_sec = 0; it.it_interval.tv_usec = 0; /* 100,000 microseconds. */ it.it_value = (struct timeval) { 0, 100000 }; signal(SIGALRM, alarm); setitimer(ITIMER_REAL, &it, (struct itimerval *) 0); for (i = 0; i <= 2000000000; ++i) if (alarm_called) break; if (alarm_called) printf("alarm() called\n"); else printf("alarm() NOT called\n"); return 0; } roberto@sissi /tmp $ gcc -v Reading specs from /usr/lib/gcc/i686-pc-cygwin/3.4.4/specs Configured with: /usr/build/package/orig/test.respin/gcc-3.4.4-3/configure --verbose --prefix=/usr --exec-prefix=/usr --sysconfdir=/etc --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --enable-languages=c,ada,c++,d,f77,pascal,java,objc --enable-nls --without-included-gettext --enable-version-specific-runtime-libs --without-x --enable-libgcj --disable-java-awt --with-system-zlib --enable-interpreter --disable-libgcj-debug --enable-threads=posix --enable-java-gc=boehm --disable-win32-registry --enable-sjlj-exceptions --enable-hash-synchronization --enable-libstdcxx-debug Thread model: posix gcc version 3.4.4 (cygming special, gdc 0.12, using dmd 0.125) roberto@sissi /tmp $ gcc bug.c roberto@sissi /tmp $ time ./a.exe alarm() NOT called real 0m7.203s user 0m7.201s sys 0m0.015s roberto@sissi /tmp $ As you see, the alarm() function is not invoked as it should (and as it is in Cygwin 1.5). All the best, Roberto -- Prof. Roberto Bagnara Computer Science Group Department of Mathematics, University of Parma, Italy http://www.cs.unipr.it/~bagnara/ mailto:bagnara@cs.unipr.it