rand: fix leaks with -autofree

vlib/rand/mt19937/mt19937.v

@@ -323,3 +323,9 @@ pub fn (mut rng MT19937RNG) f64_in_range(min f64, max f64) f64 {
 	}
 	return min + rng.f64n(max - min)
 }
+
+// free should be called when the generator is no longer needed
+[unsafe]
+pub fn (mut rng MT19937RNG) free() {
+	unsafe { free(rng) }
+}

vlib/rand/musl/musl_rng.v

@@ -239,3 +239,9 @@ pub fn (mut rng MuslRNG) f64_in_range(min f64, max f64) f64 {
 	}
 	return min + rng.f64n(max - min)
 }
+
+// free should be called when the generator is no longer needed
+[unsafe]
+pub fn (mut rng MuslRNG) free() {
+	unsafe { free(rng) }
+}

vlib/rand/pcg32/pcg32.v

@@ -224,3 +224,9 @@ pub fn (mut rng PCG32RNG) f64_in_range(min f64, max f64) f64 {
 	}
 	return min + rng.f64n(max - min)
 }
+
+// free should be called when the generator is no longer needed
+[unsafe]
+pub fn (mut rng PCG32RNG) free() {
+	unsafe { free(rng) }
+}

vlib/rand/rand.v

@@ -31,6 +31,7 @@ pub interface PRNG {
 	f64n(max f64) f64
 	f32_in_range(min f32, max f32) f32
 	f64_in_range(min f64, max f64) f64
+	free()
 }
 
 __global (
@@ -40,13 +41,23 @@ __global (
 // init initializes the default RNG.
 fn init() {
 	default_rng = new_default()
+	C.atexit(deinit)
+}
+
+fn deinit() {
+	unsafe {
+		default_rng.free() // free the implementation
+		free(default_rng) // free the interface wrapper itself
+	}
 }
 
 // new_default returns a new instance of the default RNG. If the seed is not provided, the current time will be used to seed the instance.
+[manualfree]
 pub fn new_default(config config.PRNGConfigStruct) &PRNG {
 	mut rng := &wyrand.WyRandRNG{}
 	rng.seed(config.seed_)
-	return rng
+	unsafe { config.seed_.free() }
+	return &PRNG(rng)
 }
 
 // get_current_rng returns the PRNG instance currently in use. If it is not changed, it will be an instance of wyrand.WyRandRNG.

vlib/rand/seed/seed.v

@@ -12,7 +12,6 @@ fn nr_next(prev u32) u32 {
 }
 
 // time_seed_array returns the required number of u32s generated from system time.
-[inline]
 pub fn time_seed_array(count int) []u32 {
 	ctime := time.sys_mono_now()
 	mut seed := u32(ctime >> 32 ^ (ctime & 0x0000_0000_FFFF_FFFF))
@@ -25,16 +24,21 @@ pub fn time_seed_array(count int) []u32 {
 }
 
 // time_seed_32 returns a 32-bit seed generated from system time.
-[inline]
+[manualfree]
 pub fn time_seed_32() u32 {
-	return time_seed_array(1)[0]
+	sa := time_seed_array(1)
+	res := sa[0]
+	unsafe { sa.free() }
+	return res
 }
 
 // time_seed_64 returns a 64-bit seed generated from system time.
-[inline]
+[manualfree]
 pub fn time_seed_64() u64 {
 	seed_data := time_seed_array(2)
 	lower := u64(seed_data[0])
 	upper := u64(seed_data[1])
-	return lower | (upper << 32)
+	unsafe { seed_data.free() }
+	res := lower | (upper << 32)
+	return res
 }

vlib/rand/splitmix64/splitmix64.v

@@ -223,3 +223,9 @@ pub fn (mut rng SplitMix64RNG) f64_in_range(min f64, max f64) f64 {
 	}
 	return min + rng.f64n(max - min)
 }
+
+// free should be called when the generator is no longer needed
+[unsafe]
+pub fn (mut rng SplitMix64RNG) free() {
+	unsafe { free(rng) }
+}

vlib/rand/sys/system_rng.c.v

@@ -273,3 +273,9 @@ pub fn (r SysRNG) f64_in_range(min f64, max f64) f64 {
 	}
 	return min + r.f64n(max - min)
 }
+
+// free should be called when the generator is no longer needed
+[unsafe]
+pub fn (mut rng SysRNG) free() {
+	unsafe { free(rng) }
+}

vlib/rand/wyrand/wyrand.v

@@ -22,6 +22,12 @@ mut:
 	extra     u32
 }
 
+// free should be called when the generator is no longer needed
+[unsafe]
+pub fn (mut rng WyRandRNG) free() {
+	unsafe { free(rng) }
+}
+
 // seed sets the seed, needs only two `u32`s in little-endian format as [lower, higher].
 pub fn (mut rng WyRandRNG) seed(seed_data []u32) {
 	if seed_data.len != 2 {

vlib/v/tests/valgrind/rand_module.v

@@ -0,0 +1,6 @@
+import rand
+
+fn main() {
+	n := rand.intn(1000)
+	println(n)
+}