Revert "Seed Libc rng from system entropy"

base/Base.jl

@@ -292,9 +292,6 @@ include("process.jl")
 include("ttyhascolor.jl")
 include("secretbuffer.jl")
 
-# RandomDevice support
-include("randomdevice.jl")
-
 # core math functions
 include("floatfuncs.jl")
 include("math.jl")

base/libc.jl

@@ -400,7 +400,7 @@ rand(::Type{Float64}) = rand(UInt32) * 2.0^-32
 
 Interface to the C `srand(seed)` function.
 """
-srand(seed=Base._make_uint_seed()) = ccall(:srand, Cvoid, (Cuint,), seed)
+srand(seed=floor(Int, time()) % Cuint) = ccall(:srand, Cvoid, (Cuint,), seed)
 
 struct Cpasswd
    username::Cstring

stdlib/Random/src/RNGs.jl

@@ -23,20 +23,42 @@ else # !windows
         RandomDevice(; unlimited::Bool=true) = new(unlimited)
     end
 
-    getfile(rd::RandomDevice) = Base._get_dev_random_fd(rd.unlimited)
-
     rand(rd::RandomDevice, sp::SamplerBoolBitInteger) = read(getfile(rd), sp[])
     rand(rd::RandomDevice, ::SamplerType{Bool}) = read(getfile(rd), UInt8) % Bool
 
+    mutable struct FileRef
+        @atomic file::Union{IOStream, Nothing}
+    end
+
+    const DEV_RANDOM  = FileRef(nothing)
+    const DEV_URANDOM = FileRef(nothing)
+
+    function getfile(rd::RandomDevice)
+        ref = rd.unlimited ? DEV_URANDOM : DEV_RANDOM
+        fd = ref.file
+        if fd === nothing
+            fd = open(rd.unlimited ? "/dev/urandom" : "/dev/random")
+            old, ok = @atomicreplace ref.file nothing => fd
+            if !ok
+                close(fd)
+                fd = old::IOStream
+            end
+        end
+        return fd
+    end
+
     show(io::IO, rd::RandomDevice) =
         print(io, RandomDevice, rd.unlimited ? "()" : "(unlimited=false)")
+
 end # os-test
 
 # NOTE: this can't be put within the if-else block above
 for T in (Bool, BitInteger_types...)
     if Sys.iswindows()
         @eval function rand!(rd::RandomDevice, A::Array{$T}, ::SamplerType{$T})
-            Base.RtlGenRandom!(A)
+            Base.windowserror("SystemFunction036 (RtlGenRandom)", 0 == ccall(
+                (:SystemFunction036, :Advapi32), stdcall, UInt8, (Ptr{Cvoid}, UInt32),
+                  A, sizeof(A)))
             A
         end
     else
@@ -310,7 +332,14 @@ function make_seed()
     catch
         println(stderr,
                 "Entropy pool not available to seed RNG; using ad-hoc entropy sources.")
-        Base._ad_hoc_entropy_source()
+        seed = reinterpret(UInt64, time())
+        seed = hash(seed, getpid() % UInt)
+        try
+            seed = hash(seed, parse(UInt64,
+                                    read(pipeline(`ifconfig`, `sha1sum`), String)[1:40],
+                                    base = 16) % UInt)
+        catch
+        end
         return make_seed(seed)
     end
 end
@@ -399,6 +428,10 @@ for T in BitInteger_types
 end
 
 function __init__()
+    @static if !Sys.iswindows()
+        @atomic DEV_RANDOM.file = nothing
+        @atomic DEV_URANDOM.file = nothing
+    end
     seed!(GLOBAL_RNG)
 end