| /* |
| Copyright (c) 2012 Martin Sustrik All rights reserved. |
| |
| Permission is hereby granted, free of charge, to any person obtaining a copy |
| of this software and associated documentation files (the "Software"), |
| to deal in the Software without restriction, including without limitation |
| the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| and/or sell copies of the Software, and to permit persons to whom |
| the Software is furnished to do so, subject to the following conditions: |
| |
| The above copyright notice and this permission notice shall be included |
| in all copies or substantial portions of the Software. |
| |
| THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| IN THE SOFTWARE. |
| */ |
| |
| #include "random.h" |
| #include "clock.h" |
| #include "fast.h" |
| |
| #ifdef NN_HAVE_WINDOWS |
| #include "win.h" |
| #else |
| #include <sys/types.h> |
| #include <unistd.h> |
| #endif |
| |
| #include <string.h> |
| |
| static uint64_t nn_random_state; |
| |
| void nn_random_seed () |
| { |
| uint64_t pid; |
| |
| #ifdef NN_HAVE_WINDOWS |
| pid = (uint64_t) GetCurrentProcessId (); |
| #else |
| pid = (uint64_t) getpid (); |
| #endif |
| |
| /* The initial state for pseudo-random number generator is computed from |
| the exact timestamp and process ID. */ |
| memcpy (&nn_random_state, "\xfa\x9b\x23\xe3\x07\xcc\x61\x1f", 8); |
| nn_random_state ^= pid + nn_clock_timestamp (); |
| } |
| |
| void nn_random_generate (void *buf, size_t len) |
| { |
| uint8_t *pos; |
| |
| pos = (uint8_t*) buf; |
| |
| while (1) { |
| |
| /* Generate a pseudo-random integer. */ |
| nn_random_state = nn_random_state * 1103515245 + 12345; |
| |
| /* Move the bytes to the output buffer. */ |
| memcpy (pos, &nn_random_state, len > 8 ? 8 : len); |
| if (nn_fast (len <= 8)) |
| return; |
| len -= 8; |
| pos += 8; |
| } |
| } |
| |