diff options
Diffstat (limited to 'lib/util/genrand_util.c')
| -rw-r--r-- | lib/util/genrand_util.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/lib/util/genrand_util.c b/lib/util/genrand_util.c index 05d1f3ef6e5..26b52a1c814 100644 --- a/lib/util/genrand_util.c +++ b/lib/util/genrand_util.c @@ -47,7 +47,30 @@ _PUBLIC_ uint64_t generate_random_u64(void) return BVAL(v, 0); } +static struct generate_unique_u64_state { + uint64_t next_value; + int pid; +} generate_unique_u64_state; +_PUBLIC_ uint64_t generate_unique_u64(uint64_t veto_value) +{ + int pid = getpid(); + + if (unlikely(pid != generate_unique_u64_state.pid)) { + generate_unique_u64_state = (struct generate_unique_u64_state) { + .pid = pid, + .next_value = veto_value, + }; + } + + while (unlikely(generate_unique_u64_state.next_value == veto_value)) { + generate_nonce_buffer( + (void *)&generate_unique_u64_state.next_value, + sizeof(generate_unique_u64_state.next_value)); + } + + return generate_unique_u64_state.next_value++; +} /** Microsoft composed the following rules (among others) for quality |