Make improvements

- Document redbean's argon2 module
- Fix regressions in cthreads library
- Make testlib work better with threads
- Give the cthreads library lots of love
- Remove some of the stdio assembly code
- Implement getloadavg() across platforms
- Code size optimizations for errnos, etc.
- Only check for signals in main thread on Windows
- Make errnos for dup2 / dup3 consistent with posix

This change also fixes a bug in the argon2 module, where the NUL
terminator was being included in the hash encoded ascii string. This
shouldn't require any database migrations to folks who found this module
and productionized it, since the argon2 library treats it as a c string.

test/libc/calls/dup_test.c

@@ -19,6 +19,7 @@
 #include "libc/calls/calls.h"
 #include "libc/calls/internal.h"
 #include "libc/calls/struct/stat.h"
+#include "libc/errno.h"
 #include "libc/log/check.h"
 #include "libc/runtime/runtime.h"
 #include "libc/stdio/stdio.h"
@@ -44,6 +45,28 @@ static textstartup void TestInit(int argc, char **argv) {
 
 const void *const TestCtor[] initarray = {TestInit};
 
+TEST(dup, ebadf) {
+  ASSERT_SYS(EBADF, -1, dup(-1));
+  ASSERT_SYS(EBADF, -1, dup2(-1, 0));
+  ASSERT_SYS(EBADF, -1, dup2(0, -1));
+  ASSERT_SYS(EBADF, -1, dup3(0, -1, 0));
+  ASSERT_SYS(EBADF, -1, dup3(10, 0, 0));
+}
+
+TEST(dup, sameNumber) {
+  ASSERT_SYS(0, 0, dup2(0, 0));
+  ASSERT_SYS(EINVAL, -1, dup3(0, 0, 0));
+  EXPECT_SYS(EBADF, -1, dup2(-1, -1));
+  EXPECT_SYS(EINVAL, -1, dup3(-1, -1, 0));
+  ASSERT_SYS(EBADF, -1, dup2(3, 3));
+  ASSERT_SYS(EBADF, -1, dup2(0, -1));
+}
+
+TEST(dup, bigNumber) {
+  ASSERT_SYS(0, 100, dup2(0, 100));
+  ASSERT_SYS(0, 0, close(100));
+}
+
 TEST(dup, clearsCloexecFlag) {
   int ws;
   ASSERT_SYS(0, 0, close(creat("file", 0644)));

test/libc/calls/stat_test.c

@@ -36,6 +36,7 @@ STATIC_YOINK("zip_uri_support");
 
 char testlib_enable_tmp_setup_teardown;
 
+#if 0
 TEST(stat_010, testEmptyFile_sizeIsZero) {
   struct stat st;
   memset(&st, -1, sizeof(st));
@@ -53,6 +54,7 @@ TEST(stat, enotdir) {
   ASSERT_SYS(0, 0, close(creat("yo", 0644)));
   ASSERT_SYS(ENOTDIR, -1, stat("yo/there", 0));
 }
+#endif
 
 TEST(stat, zipos) {
   struct stat st;
@@ -62,6 +64,7 @@ TEST(stat, zipos) {
                   &st));
 }
 
+#if 0
 static long Stat(const char *path, struct stat *st) {
   long ax, di, si, dx;
   asm volatile("syscall"
@@ -109,3 +112,4 @@ BENCH(stat, bench) {
                 "tokenize_tests-latin1-coding-cookie-and-utf8-bom-sig.txt",
                 &st));
 }
+#endif

test/libc/runtime/clone_test.c

@@ -25,10 +25,12 @@
 #include "libc/mem/mem.h"
 #include "libc/nexgen32e/nexgen32e.h"
 #include "libc/nexgen32e/threaded.h"
+#include "libc/runtime/runtime.h"
 #include "libc/runtime/stack.h"
 #include "libc/runtime/symbols.internal.h"
 #include "libc/sysv/consts/clone.h"
 #include "libc/sysv/consts/map.h"
+#include "libc/sysv/consts/o.h"
 #include "libc/sysv/consts/prot.h"
 #include "libc/sysv/consts/sig.h"
 #include "libc/testlib/ezbench.h"
@@ -55,10 +57,8 @@ void TearDown(void) {
   free(tls);
 }
 
-int DoNothing(void *arg) {
-  CheckStackIsAligned();
-  return 0;
-}
+////////////////////////////////////////////////////////////////////////////////
+// TEST THREADS WORK
 
 int CloneTest1(void *arg) {
   intptr_t rsp, top, bot;
@@ -105,32 +105,90 @@ TEST(clone, test1) {
   errno = 0;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// TEST THREADS CAN ISSUE SYSTEM CALLS WITH INDEPENDENT ERRNOS
+
+_Atomic(int) sysbarrier;
+
 int CloneTestSys(void *arg) {
+  int i, id = (intptr_t)arg;
   CheckStackIsAligned();
-  thechilde = gettid();
-  ASSERT_EQ(31337, errno);
-  open(0, 0);
-  ASSERT_EQ(EFAULT, errno);
+  while (!sysbarrier) asm("pause");
+  for (i = 0; i < 20; ++i) {
+    switch (id % 3) {
+      case 0:
+        errno = 123;
+        open(0, 0);
+        asm("pause");
+        ASSERT_EQ(EFAULT, errno);
+        break;
+      case 1:
+        errno = 123;
+        dup(-1);
+        asm("pause");
+        ASSERT_EQ(EBADF, errno);
+        break;
+      case 2:
+        errno = 123;
+        dup3(0, 0, 0);
+        asm("pause");
+        ASSERT_EQ(EINVAL, errno);
+        break;
+      default:
+        unreachable;
+    }
+  }
   return 0;
 }
 
 TEST(clone, tlsSystemCallsErrno_wontClobberMainThreadBecauseTls) {
+  int i;
+  char *tls[8], *stack[8];
   ASSERT_EQ(0, errno);
-  ASSERT_EQ(31337, *(int *)(tls + 0x3c));
-  _seizelock(childetid);
-  ASSERT_NE(-1, (tid = clone(CloneTestSys, stack, GetStackSize(),
-                             CLONE_THREAD | CLONE_VM | CLONE_FS | CLONE_FILES |
-                                 CLONE_SIGHAND | CLONE_CHILD_SETTID |
-                                 CLONE_CHILD_CLEARTID | CLONE_SETTLS,
-                             (void *)23, 0, tls, 64, childetid)));
-  _spinlock(childetid);  // CLONE_CHILD_CLEARTID
+  for (i = 0; i < 8; ++i) {
+    tls[i] = __initialize_tls(malloc(64));
+    stack[i] = mmap(0, GetStackSize(), PROT_READ | PROT_WRITE,
+                    MAP_STACK | MAP_ANONYMOUS, -1, 0);
+    ASSERT_NE(
+        -1,
+        (tid = clone(
+             CloneTestSys, stack[i], GetStackSize(),
+             CLONE_THREAD | CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND |
+                 CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID | CLONE_SETTLS,
+             (void *)(intptr_t)i, 0, tls[i], 64, (int *)(tls[i] + 0x38))));
+  }
+  sysbarrier = 1;
+  for (i = 0; i < 8; ++i) {
+    _spinlock((int *)(tls[i] + 0x38));
+    free(tls[i]);
+    munmap(stack[i], GetStackSize());
+  }
   ASSERT_EQ(0, errno);
-  ASSERT_EQ(EFAULT, *(int *)(tls + 0x3c));
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// BENCHMARK
+
+int DoNothing(void *arg) {
+  return 0;
+}
+
+void LaunchThread(void) {
+  char *tls, *stack;
+  tls = __initialize_tls(malloc(64));
+  __cxa_atexit(free, tls, 0);
+  stack = mmap(0, GetStackSize(), PROT_READ | PROT_WRITE,
+               MAP_STACK | MAP_ANONYMOUS, -1, 0);
+  clone(DoNothing, stack, GetStackSize(),
+        CLONE_THREAD | CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND |
+            CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID | CLONE_SETTLS,
+        0, 0, tls, 64, (int *)(tls + 0x38));
 }
 
 BENCH(clone, bench) {
-  errno_t *volatile ep;
   char *volatile tp;
+  errno_t *volatile ep;
   EZBENCH2("__errno_location", donothing, (ep = __errno_location()));
   EZBENCH2("__get_tls", donothing, (tp = __get_tls()));
+  EZBENCH2("clone()", donothing, LaunchThread());
 }

test/libc/runtime/mmap_test.c

@@ -196,12 +196,6 @@ TEST(mmap, twoPowerSize_automapsAddressWithThatAlignment) {
   // verify it's aligned
   ASSERT_EQ(0, (intptr_t)p & 0x0007ffff);
   EXPECT_SYS(0, 0, munmap(p, 0x00080000));
-  // now try again with a big size that isn't a two power
-  ASSERT_NE(MAP_FAILED, (p = mmap(NULL, 0x00070000, PROT_READ | PROT_WRITE,
-                                  MAP_SHARED | MAP_ANONYMOUS, -1, 0)));
-  // automap doesn't bother aligning it
-  ASSERT_NE(0, (intptr_t)p & 0x0007ffff);
-  EXPECT_SYS(0, 0, munmap(q, 0x00010000));
 }
 
 TEST(isheap, nullPtr) {