Merge pull request #5421 from andralex/no-more-durn-stdiobase

Get rid of static this for initializing std{in,out,err}
merged-on-behalf-of: unknown

index.d

@@ -470,7 +470,6 @@ $(COMMENT
             $(LINK2 std_regex_internal_parser.html, std.regex.internal.parser)$(BR)
             $(LINK2 std_regex_internal_tests.html, std.regex.internal.tests)$(BR)
             $(LINK2 std_regex_internal_thompson.html, std.regex.internal.thompson)$(BR)
-            $(LINK2 std_stdiobase.html, std.stdiobase)$(BR)
         )
         $(TD
              Internal modules.

posix.mak

@@ -227,7 +227,6 @@ EXTRA_MODULES_INTERNAL := $(addprefix std/, \
 		processinit scopebuffer test/dummyrange \
 		$(addprefix unicode_, comp decomp grapheme norm tables) \
 	) \
-	stdiobase \
 )
 
 EXTRA_MODULES += $(EXTRA_DOCUMENTABLES) $(EXTRA_MODULES_INTERNAL)

std/stdio.d

@@ -19,7 +19,6 @@ import std.algorithm.mutation; // copy
 import std.meta; // allSatisfy
 import std.range.primitives; // ElementEncodingType, empty, front,
     // isBidirectionalRange, isInputRange, put
-import std.stdiobase;
 import std.traits; // isSomeChar, isSomeString, Unqual, isPointer
 import std.typecons; // Flag
 
@@ -4522,70 +4521,82 @@ Initialize with a message and an error code.
     }
 }
 
-extern(C) void std_stdio_static_this()
+// Undocumented but public because the std* handles are aliasing it.
+ref File makeGlobal(alias handle)()
 {
-    static import core.stdc.stdio;
-    //Bind stdin, stdout, stderr
-    __gshared File.Impl stdinImpl;
-    stdinImpl.handle = core.stdc.stdio.stdin;
-    .stdin._p = &stdinImpl;
-    // stdout
-    __gshared File.Impl stdoutImpl;
-    stdoutImpl.handle = core.stdc.stdio.stdout;
-    .stdout._p = &stdoutImpl;
-    // stderr
-    __gshared File.Impl stderrImpl;
-    stderrImpl.handle = core.stdc.stdio.stderr;
-    .stderr._p = &stderrImpl;
-}
+    static __gshared File.Impl impl;
+    static __gshared File result;
 
-//---------
-__gshared
-{
-    /** The standard input stream.
-        Bugs:
-            Due to $(LINK2 https://issues.dlang.org/show_bug.cgi?id=15768, bug 15768),
-            it is thread un-safe to reassign `stdin` to a different `File` instance
-            than the default.
-     */
-    File stdin;
-    ///
-    @safe unittest
+    // Use an inline spinlock to make sure the initializer is only run once.
+    // We assume there will be at most uint.max / 2 threads trying to initialize
+    // `handle` at once and steal the high bit to indicate that the globals have
+    // been initialized.
+    static shared uint spinlock;
+    import core.atomic;
+    if (atomicLoad!(MemoryOrder.acq)(spinlock) <= uint.max / 2)
     {
-        // Read stdin, sort lines, write to stdout
-        import std.array : array;
-        import std.algorithm.sorting : sort;
-        import std.algorithm.mutation : copy;
-        import std.typecons : Yes;
-
-        void main() {
-            stdin                       // read from stdin
-            .byLineCopy(Yes.keepTerminator) // copying each line
-            .array()                    // convert to array of lines
-            .sort()                     // sort the lines
-            .copy(                      // copy output of .sort to an OutputRange
-                stdout.lockingTextWriter()); // the OutputRange
+        for (;;)
+        {
+            if (atomicLoad!(MemoryOrder.acq)(spinlock) > uint.max / 2)
+                break;
+            if (atomicOp!"+="(spinlock, 1) == 1)
+            {
+                impl.handle = handle;
+                result._p = &impl;
+                atomicOp!"+="(spinlock, uint.max / 2);
+                break;
+            }
+            atomicOp!"-="(spinlock, 1);
         }
     }
-
-    /**
-        The standard output stream.
-        Bugs:
-            Due to $(LINK2 https://issues.dlang.org/show_bug.cgi?id=15768, bug 15768),
-            it is thread un-safe to reassign `stdout` to a different `File` instance
-            than the default.
-    */
-    File stdout;
-    /**
-        The standard error stream.
-        Bugs:
-            Due to $(LINK2 https://issues.dlang.org/show_bug.cgi?id=15768, bug 15768),
-            it is thread un-safe to reassign `stderr` to a different `File` instance
-            than the default.
-    */
-    File stderr;
+    return result;
 }
 
+/** The standard input stream.
+    Bugs:
+        Due to $(LINK2 https://issues.dlang.org/show_bug.cgi?id=15768, bug 15768),
+        it is thread un-safe to reassign `stdin` to a different `File` instance
+        than the default.
+*/
+alias stdin = makeGlobal!(core.stdc.stdio.stdin);
+
+///
+@safe unittest
+{
+    // Read stdin, sort lines, write to stdout
+    import std.array : array;
+    import std.algorithm.sorting : sort;
+    import std.algorithm.mutation : copy;
+    import std.typecons : Yes;
+
+    void main() {
+        stdin                       // read from stdin
+        .byLineCopy(Yes.keepTerminator) // copying each line
+        .array()                    // convert to array of lines
+        .sort()                     // sort the lines
+        .copy(                      // copy output of .sort to an OutputRange
+            stdout.lockingTextWriter()); // the OutputRange
+    }
+}
+
+/**
+    The standard output stream.
+    Bugs:
+        Due to $(LINK2 https://issues.dlang.org/show_bug.cgi?id=15768, bug 15768),
+        it is thread un-safe to reassign `stdout` to a different `File` instance
+        than the default.
+*/
+alias stdout = makeGlobal!(core.stdc.stdio.stdout);
+
+/**
+    The standard error stream.
+    Bugs:
+        Due to $(LINK2 https://issues.dlang.org/show_bug.cgi?id=15768, bug 15768),
+        it is thread un-safe to reassign `stderr` to a different `File` instance
+        than the default.
+*/
+alias stderr = makeGlobal!(core.stdc.stdio.stderr);
+
 @system unittest
 {
     static import std.file;

std/stdiobase.d

@@ -1,24 +0,0 @@
-// Written in the D programming language.
-
-/**
- * The only purpose of this module is to do the static construction for
- * std.stdio, to eliminate cyclic construction errors.
- *
- * Copyright: Copyright Andrei Alexandrescu 2008 - 2009.
- * License:   $(HTTP www.boost.org/LICENSE_1_0.txt, Boost License 1.0).
- * Authors:   $(HTTP erdani.org, Andrei Alexandrescu)
- * Source:    $(PHOBOSSRC std/_stdiobase.d)
- */
-/*          Copyright Andrei Alexandrescu 2008 - 2009.
- * Distributed under the Boost Software License, Version 1.0.
- *    (See accompanying file LICENSE_1_0.txt or copy at
- *          http://www.boost.org/LICENSE_1_0.txt)
- */
-module std.stdiobase;
-
-extern(C) void std_stdio_static_this();
-
-shared static this()
-{
-    std_stdio_static_this();
-}

win32.mak

@@ -108,7 +108,6 @@ SRC= \
 # The separation is a workaround for bug 4904 (optlink bug 3372).
 SRC_STD_1= \
 	std\stdio.d \
-	std\stdiobase.d \
 	std\string.d \
 	std\format.d \
 	std\file.d
@@ -603,7 +602,6 @@ cov : $(SRC_TO_COMPILE) $(LIB)
 #	cov
 	del *.lst
 	$(DMD) -conf= -cov=83 -unittest -main -run std\stdio.d
-	$(DMD) -conf= -cov=100 -unittest -main -run std\stdiobase.d
 	$(DMD) -conf= -cov=95 -unittest -main -run std\string.d
 	$(DMD) -conf= -cov=71 -unittest -main -run std\format.d
 	$(DMD) -conf= -cov=83 -unittest -main -run std\file.d

win64.mak

@@ -112,7 +112,6 @@ SRC= \
 # The separation is a workaround for bug 4904 (optlink bug 3372).
 SRC_STD_1= \
 	std\stdio.d \
-	std\stdiobase.d \
 	std\string.d \
 	std\format.d \
 	std\file.d