+
+/* Return a random number between 0 and MAX-1, inclusive.
+
+ If MAX is greater than the value of RAND_MAX+1 on the system, the
+ returned value will be in the range [0, RAND_MAX]. This may be
+ fixed in a future release.
+
+ The random number generator is seeded automatically the first time
+ it is called.
+
+ This uses rand() for portability. It has been suggested that
+ random() offers better randomness, but this is not required for
+ Wget, so I chose to go for simplicity and use rand
+ unconditionally. */
+
+int
+random_number (int max)
+{
+ static int seeded;
+ double bounded;
+ int rnd;
+
+ if (!seeded)
+ {
+ srand (time (NULL));
+ seeded = 1;
+ }
+ rnd = rand ();
+
+ /* On systems that don't define RAND_MAX, assume it to be 2**15 - 1,
+ and enforce that assumption by masking other bits. */
+#ifndef RAND_MAX
+# define RAND_MAX 32767
+ rnd &= RAND_MAX;
+#endif
+
+ /* This is equivalent to rand() % max, but uses the high-order bits
+ for better randomness on architecture where rand() is implemented
+ using a simple congruential generator. */
+
+ bounded = (double)max * rnd / (RAND_MAX + 1.0);
+ return (int)bounded;
+}
+
+#if 0
+/* A debugging function for checking whether an MD5 library works. */
+
+#include "gen-md5.h"
+
+char *
+debug_test_md5 (char *buf)
+{
+ unsigned char raw[16];
+ static char res[33];
+ unsigned char *p1;
+ char *p2;
+ int cnt;
+ ALLOCA_MD5_CONTEXT (ctx);
+
+ gen_md5_init (ctx);
+ gen_md5_update ((unsigned char *)buf, strlen (buf), ctx);
+ gen_md5_finish (ctx, raw);
+
+ p1 = raw;
+ p2 = res;
+ cnt = 16;
+ while (cnt--)
+ {
+ *p2++ = XDIGIT_TO_xchar (*p1 >> 4);
+ *p2++ = XDIGIT_TO_xchar (*p1 & 0xf);
+ ++p1;
+ }
+ *p2 = '\0';
+
+ return res;
+}
+#endif
+\f
+/* Implementation of run_with_timeout, a generic timeout handler for
+ systems with Unix-like signal handling. */
+#ifdef HAVE_SIGSETJMP
+#define SETJMP(env) sigsetjmp (env, 1)
+
+static sigjmp_buf run_with_timeout_env;
+
+static RETSIGTYPE
+abort_run_with_timeout (int sig)
+{
+ assert (sig == SIGALRM);
+ siglongjmp (run_with_timeout_env, -1);
+}
+#else /* not HAVE_SIGSETJMP */
+#define SETJMP(env) setjmp (env)
+
+static jmp_buf run_with_timeout_env;
+
+static RETSIGTYPE
+abort_run_with_timeout (int sig)
+{
+ assert (sig == SIGALRM);
+ /* We don't have siglongjmp to preserve the set of blocked signals;
+ if we longjumped out of the handler at this point, SIGALRM would
+ remain blocked. We must unblock it manually. */
+ int mask = siggetmask ();
+ mask &= ~sigmask(SIGALRM);
+ sigsetmask (mask);
+
+ /* Now it's safe to longjump. */
+ longjmp (run_with_timeout_env, -1);
+}
+#endif /* not HAVE_SIGSETJMP */
+
+int
+run_with_timeout (long timeout, void (*fun) (void *), void *arg)
+{
+#ifndef USE_SIGNAL_TIMEOUT
+ fun (arg);
+ return 0;
+#else
+ int saved_errno;
+
+ if (timeout == 0)
+ {
+ fun (arg);
+ return 0;
+ }
+
+ signal (SIGALRM, abort_run_with_timeout);
+ if (SETJMP (run_with_timeout_env) != 0)
+ {
+ /* Longjumped out of FUN with a timeout. */
+ signal (SIGALRM, SIG_DFL);
+ return 1;
+ }
+ alarm (timeout);
+ fun (arg);
+
+ /* Preserve errno in case alarm() or signal() modifies it. */
+ saved_errno = errno;
+ alarm (0);
+ signal (SIGALRM, SIG_DFL);
+ errno = saved_errno;
+
+ return 0;
+#endif
+}
+
projects / wget / blobdiff