[PATCH 3/4] lockfile: convert retry timeout computations to millisecond
- From
Johannes Sixt <j6t@kdbg.org>
- Date
- Jun 5, 2015, 19:45 UTC
- Message-ID
- <e47ba0d3c1ba83b50d2d241047863b2ba7b7341b.1433532968.git.j6t@kdbg.org>
- In-Reply-To
- <55700F10.8030806@kdbg.org>
When the goal is to wait for some random amount of time up to one second, it is not necessary to compute with microsecond precision. This is a preparation to re-use sleep_millisec().
Signed-off-by: Johannes Sixt <j6t@kdbg.org> --- lockfile.c | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-)
diff --git a/lockfile.c b/lockfile.c index 738f202..3f5b699 100644 --- a/lockfile.c +++ b/lockfile.c @@ -184,7 +184,7 @@ static int lock_file_timeout(struct lock_file *lk, const char *path, { int n = 1; int multiplier = 1; - long remaining_us = 0; + long remaining_ms = 0; static int random_initialized = 0; if (timeout_ms == 0) @@ -195,16 +195,11 @@ static int lock_file_timeout(struct lock_file *lk, const char *path, random_initialized = 1; } - if (timeout_ms > 0) { - /* avoid overflow */ - if (timeout_ms <= LONG_MAX / 1000) - remaining_us = timeout_ms * 1000; - else - remaining_us = LONG_MAX; - } + if (timeout_ms > 0) + remaining_ms = timeout_ms; while (1) { - long backoff_ms, wait_us; + long backoff_ms, wait_ms; int fd; fd = lock_file(lk, path, flags); @@ -213,14 +208,14 @@ static int lock_file_timeout(struct lock_file *lk, const char *path, return fd; /* success */ else if (errno != EEXIST) return -1; /* failure other than lock held */ - else if (timeout_ms > 0 && remaining_us <= 0) + else if (timeout_ms > 0 && remaining_ms <= 0) return -1; /* failure due to timeout */ backoff_ms = multiplier * INITIAL_BACKOFF_MS; /* back off for between 0.75*backoff_ms and 1.25*backoff_ms */ - wait_us = (750 + rand() % 500) * backoff_ms; - sleep_microseconds(wait_us); - remaining_us -= wait_us; + wait_ms = (750 + rand() % 500) * backoff_ms / 1000; + sleep_microseconds(wait_ms*1000); + remaining_ms -= wait_ms; /* Recursion: (n+1)^2 = n^2 + 2n + 1 */ multiplier += 2*n + 1;
-- 2.3.2.245.gb5bf9d3