added better random initialization and rr/rand hash algos

core/hash.c

@@ -17,7 +17,7 @@ uint32_t djb33x_hash(char *key, uint64_t keylen) {
 
 // Murmur2 hash Copyright (C) Austin Appleby
 // adapted from nginx
-uint32_t murmur2_hash(char *key, uint64_t keylen) {
+static uint32_t murmur2_hash(char *key, uint64_t keylen) {
 
 	uint32_t  h, k;
 	uint8_t *ukey = (uint8_t *) key;
@@ -56,6 +56,23 @@ uint32_t murmur2_hash(char *key, uint64_t keylen) {
 	return h;
 }
 
+static uint32_t random_hash(char *key, uint64_t keylen) {
+	return (uint32_t) rand();
+}
+
+/*
+	not atomic, avoid its use in multithreaded modes
+*/
+static uint32_t rr_hash(char *key, uint64_t keylen) {
+	static uint32_t rr = 0;
+	uint32_t max_value = uwsgi_str_num(key, keylen);
+	uint32_t ret = rr;
+	rr++;
+	if (rr > max_value) {
+		rr = 0;
+	}
+	return ret;
+}
 
 struct uwsgi_hash_algo *uwsgi_hash_algo_get(char *name) {
 	struct uwsgi_hash_algo *uha = uwsgi.hash_algos;
@@ -90,4 +107,7 @@ void uwsgi_hash_algo_register(char *name, uint32_t (*func)(char *, uint64_t)) {
 void uwsgi_hash_algo_register_all() {
 	uwsgi_hash_algo_register("djb33x", djb33x_hash);
 	uwsgi_hash_algo_register("murmur2", murmur2_hash);
+	uwsgi_hash_algo_register("random", random_hash);
+	uwsgi_hash_algo_register("rand", random_hash);
+	uwsgi_hash_algo_register("rr", rr_hash);
 }

core/utils.c

@@ -3972,7 +3972,6 @@ void uwsgi_uuid(char *buf) {
 	uuid_unparse(uuid_zmq, buf);
 #else
 	int i,r[11];
-	static int srand_called = 0;
 	if (!uwsgi_file_exists("/dev/urandom")) goto fallback;
 	int fd = open("/dev/urandom", O_RDONLY);
 	if (fd < 0) goto fallback;
@@ -3984,10 +3983,6 @@ void uwsgi_uuid(char *buf) {
 	close(fd);
 	goto done;
 fallback:
-	if (!srand_called) {
-		srand((unsigned int) getpid());
-		srand_called = 1;
-	}
 	for(i=0;i<11;i++) {
 		r[i] = rand();
 	}

core/uwsgi.c

@@ -1869,6 +1869,12 @@ static struct uwsgi_clock uwsgi_unix_clock = {
 	.microseconds = uwsgi_unix_microseconds,
 };
 
+void uwsgi_init_random() {
+	struct timeval t;
+        gettimeofday(&t, NULL);
+        srand((unsigned int) (t.tv_usec * t.tv_sec));
+}
+
 #ifdef UWSGI_AS_SHARED_LIBRARY
 int uwsgi_init(int argc, char *argv[], char *envp[]) {
 
@@ -1903,6 +1909,9 @@ int main(int argc, char *argv[], char *envp[]) {
 	//initialize masterpid with a default value
 	masterpid = getpid();
 
+	// initialize random engine
+	uwsgi_init_random();
+
 	memset(&uwsgi, 0, sizeof(struct uwsgi_server));
 	uwsgi_proto_hooks_setup();
 	uwsgi.cwd = uwsgi_get_cwd();