configure.ac

@@ -149,6 +149,8 @@ AC_CHECK_MEMBER([struct tm.tm_gmtoff], [AC_DEFINE([HAVE_TM_TM_GMT_OFF],1,[Define AC_CHECK_MEMBER([struct tm.__tm_gmtoff], [AC_DEFINE([HAVE_TM___TM_GMT_OFF],1,[Define to 1 if the system has the __tm_gmt_off field in struct tm])],                 [], [[#include <time.h>]]) AC_FIND_FUNC([setlocale], [c], [#include <locale.h>], [0,0])+AC_FIND_FUNC([arc4random], [c], [#include <stdlib.h>], [])+AC_FIND_FUNC([getentropy], [c], [#include <unistd.h>], [0, 0])  dnl Figure out if we have the pthread functions we actually need AC_FIND_FUNC_NO_LIBS([pthread_key_create], [], [#include <pthread.h>], [NULL, NULL])

src/jv.c

@@ -40,6 +40,10 @@ #include <limits.h> #include <math.h> #include <float.h>+#include <time.h>+#include <unistd.h>+#include <fcntl.h>+#include <pthread.h>  #include "jv_alloc.h" #include "jv.h"@@ -1206,7 +1210,33 @@ static jv jvp_string_append(jv string, const char* data, uint32_t len) {   } } -static const uint32_t HASH_SEED = 0x432A9843;+static uint32_t hash_seed;+static pthread_once_t hash_seed_once = PTHREAD_ONCE_INIT;++static void jvp_hash_seed_init(void) {+  uint32_t seed;+#if defined(HAVE_ARC4RANDOM)+  seed = arc4random();+#elif defined(HAVE_GETENTROPY)+  if (getentropy(&seed, sizeof(seed)) != 0)+    seed = (uint32_t)getpid() ^ (uint32_t)time(NULL);+#else+  int fd = open("/dev/urandom", O_RDONLY);+  if (fd >= 0) {+    if (read(fd, &seed, sizeof(seed)) != 4)+      seed = (uint32_t)getpid() ^ (uint32_t)time(NULL);+    close(fd);+  } else {+    seed = (uint32_t)getpid() ^ (uint32_t)time(NULL);+  }+#endif+  hash_seed = seed;+}++static uint32_t jvp_hash_seed(void) {+  pthread_once(&hash_seed_once, jvp_hash_seed_init);+  return hash_seed;+}  static uint32_t rotl32 (uint32_t x, int8_t r){   return (x << r) | (x >> (32 - r));@@ -1225,7 +1255,7 @@ static uint32_t jvp_string_hash(jv jstr) {   int len = (int)jvp_string_length(str);   const int nblocks = len / 4; -  uint32_t h1 = HASH_SEED;+  uint32_t h1 = jvp_hash_seed();    const uint32_t c1 = 0xcc9e2d51;   const uint32_t c2 = 0x1b873593;