win32: Thoroughly test for usability of WakeByAddress

tools-for-build/Makefile

@@ -7,6 +7,10 @@
 # provided with absolutely no warranty. See the COPYING and CREDITS
 # files for more information.
 
+# it is illogical that this makefile pulls in Makefile.features,
+# which is presumed not to exist, and which when it does exist causes
+# confusion as to what flags should be added in for a generic C compile.
+# Why do we do this???
 -include genesis/Makefile.features
 -include Config
 

tools-for-build/grovel-features.sh

@@ -6,29 +6,26 @@ cd ./tools-for-build > /dev/null
 
 # Assumes the presence of $1-test.c, which when built and
 # run should return with 104 if the feature is present.
+# We presumes that the build machine matches the target machine
+# in terms of a whether each feature presence test should pass.
 featurep() {
     bin="$1-test"
+    featurename=${2:-$1}
     rm -f $bin
     $GNUMAKE $bin -I ../src/runtime > /dev/null 2>&1 && echo "input" | ./$bin> /dev/null 2>&1
     if [ "$?" -eq 104 ]
     then
-        printf " :$1"
+        printf " :$featurename"
     fi
     rm -f $bin
 }
 
 # Adding a nonexistent link library to Config.*-win32 will fail,
-# so this needs its own recipe to detect the library.
+# so we pass -lSynchronization to the featurep test specifically
+# and not in the general make rule.
+# It will get added in by Config.*-win32 only if LISP_FEATURE_SB_FUTEX.
 if [ "$sbcl_os" = win32 ] ; then
-    bin=os-provides-wakebyaddr-test
+   LOADLIBES=-lSynchronization featurep os-provides-wakebyaddr sb-futex
-    rm -f $bin
-    # pass -f /dev/null to use only builtin Make recipes
-    LOADLIBES=-lSynchronization $GNUMAKE -f /dev/null $bin > /dev/null 2>&1
-    if [ "$?" -eq 0 ]
-    then
-        printf " :sb-futex"
-    fi
-    rm -f $bin
 fi
 
 # KLUDGE: ppc/darwin dlopen is special cased in make-config.sh, as

tools-for-build/os-provides-wakebyaddr-test.c

@@ -1,7 +1,50 @@
 #include <windows.h>
 
+int mutex_word = 0;
+int expect = 9;
+
+DWORD waiter(void* arg) {
+    mutex_word = expect = 2;
+    return WaitOnAddress(&mutex_word, &expect, 4, 100); // .1 sec max
+}
+DWORD waker(void* arg) {
+    mutex_word = 0;
+    WakeByAddressSingle(&mutex_word);
+    return 0;
+}
+
 int main()
 {
-    WakeByAddressAll((void*)&main);
+    // Verify that WaitOnAddress returns right away if the mutex word has the wrong value.
-    return 104;
+    int result = WaitOnAddress(&mutex_word, &expect, 4, 500); // max = .5 sec
+    if (!result) return 0; // what? shouldn't be an error to mismatch
+
+    // Try really waiting
+    mutex_word = 9;
+    result = WaitOnAddress(&mutex_word, &expect, 4, 20); // wait 20 millisec
+    // expect a timeout
+    if (!(result == 0 && GetLastError()==ERROR_TIMEOUT)) return 0;
+
+    // Simulate a lisp mutex being woken
+    HANDLE hWaiter, hWaker;
+    hWaiter = CreateThread(NULL, 0,
+                           waiter, 0, /* function and argument */
+                           0,  /* flags */
+                           0); /* id */
+
+    hWaker = CreateThread(NULL, 0,
+                          waker, 0, /* function and argument */
+                          CREATE_SUSPENDED,  /* flags */
+                          0); /* id */
+
+    for (;;) {
+        // wait for the waiter to place itself into a wait state on the mutex
+        if (mutex_word == 2) break;
+        Sleep(10); // 10 millisec
+    }
+    // Give them some time to rendezvous
+    ResumeThread(hWaker);
+    WaitForSingleObject(hWaiter, 200); // .2 sec max
+    if (mutex_word == 0) return 104;
+    return 1;
 }