From 4d2d6c5b7c455392617609ae21b6b21879e12975 Mon Sep 17 00:00:00 2001 From: Pádraig Brady
Date: Wed, 15 Oct 2014 02:18:35 +0100 Subject: factor: avoid interspersed lines for parallel runs * src/factor.c (n_out): A new global variable to track how much data has been written to stdout. (print_factors_single): Use n_out to determine whether to flush the current (and previous) lines. * tests/misc/factor-parallel.sh: Add a new test. * tests/local.mk: Reference the new test. * NEWS: Mention the bug fix. --- src/factor.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) (limited to 'src/factor.c') diff --git a/src/factor.c b/src/factor.c index f27bf22f2..5b7ae22ab 100644 --- a/src/factor.c +++ b/src/factor.c @@ -2323,13 +2323,15 @@ strto2uintmax (uintmax_t *hip, uintmax_t *lop, const char *s) return err; } +static size_t n_out; /* How much data we've written to stdout. */ + static void print_uintmaxes (uintmax_t t1, uintmax_t t0) { uintmax_t q, r; if (t1 == 0) - printf ("%"PRIuMAX, t0); + n_out += printf ("%"PRIuMAX, t0); else { /* Use very plain code here since it seems hard to write fast code @@ -2338,7 +2340,7 @@ print_uintmaxes (uintmax_t t1, uintmax_t t0) r = t1 % 1000000000; udiv_qrnnd (t0, r, r, t0, 1000000000); print_uintmaxes (q, t0); - printf ("%09u", (unsigned int) r); + n_out += printf ("%09u", (unsigned int) r); } } @@ -2350,6 +2352,7 @@ print_factors_single (uintmax_t t1, uintmax_t t0) print_uintmaxes (t1, t0); putchar (':'); + n_out++; factor (t1, t0, &factors); @@ -2358,15 +2361,29 @@ print_factors_single (uintmax_t t1, uintmax_t t0) { char buf[INT_BUFSIZE_BOUND (uintmax_t)]; putchar (' '); - fputs (umaxtostr (factors.p[j], buf), stdout); + char *umaxstr = umaxtostr (factors.p[j], buf); + fputs (umaxstr, stdout); + n_out += strlen (umaxstr) + 1; } if (factors.plarge[1]) { putchar (' '); + n_out++; print_uintmaxes (factors.plarge[1], factors.plarge[0]); } putchar ('\n'); + n_out++; + + /* Assume the stdout buffer is > this value. + Flush here to avoid partial lines being output. + Flushing every line has too much overhead. + TODO: Buffer internally and avoid stdio. */ + if (n_out >= 512) + { + fflush (stdout); + n_out = 0; + } } /* Emit the factors of the indicated number. If we have the option of using @@ -2422,6 +2439,7 @@ print_factors (const char *input) mp_factor_clear (&factors); mpz_clear (t); putchar ('\n'); + fflush (stdout); return true; #else error (0, 0, _("%s is too large"), quote (input)); -- cgit v1.2.3-70-g09d2