Fix windows profiler deadlock (#60056)

Wasn't sure if we could get away with deleting the `uv_thread_detach`,
but
apparently we can. On Windows, it's definitely unsafe to keep using the
thread
handle after closing it. POSIX is a little less clear about what you're
allowed
to do with a `pthread_t` after detaching it, but the GC threads never
exit
normally anyway.

Fixes #60042.

(cherry picked from commit d8b5662)

Author: xal-0

src/gc-stock.c

@@ -3612,7 +3612,6 @@ void jl_start_gc_threads(void)
         else {
             uv_thread_create(&uvtid, jl_parallel_gc_threadfun, t);
         }
-        uv_thread_detach(&uvtid);
     }
 }
 

src/signals-win.c

@@ -445,6 +445,7 @@ static int jl_thread_suspend_and_get_state(int tid, int timeout, bt_context_t *c
     if (ct2 == NULL) // this thread is already dead
         return 0;
     HANDLE hThread = ptls2->system_id;
+    assert(GetCurrentThreadId() != GetThreadId(hThread));
     if ((DWORD)-1 == SuspendThread(hThread)) {
         // jl_safe_fprintf(ios_safe_stderr, "failed to suspend thread %d: %lu\n", tid, GetLastError());
         return 0;

stdlib/Profile/test/runtests.jl

@@ -246,6 +246,23 @@ end
     @test occursin("@julialib" * slash, str)
 end
 
+function run_with_watchdog(cmd, timeout=120)
+    p = open(cmd)
+    t = Timer(timeout) do t
+        # should be under 10 seconds, so give it 2 minutes then report failure
+        println("KILLING debuginfo registration test BY PROFILE TEST WATCHDOG\n")
+        kill(p, Base.SIGQUIT)
+        sleep(30)
+        kill(p, Base.SIGQUIT)
+        sleep(30)
+        kill(p, Base.SIGKILL)
+    end
+    s = read(p, String)
+    close(t)
+    close(p)
+    success(p) ? s : ""
+end
+
 # Profile deadlocking in compilation (debuginfo registration)
 let cmd = Base.julia_cmd()
     script = """
@@ -259,24 +276,26 @@ let cmd = Base.julia_cmd()
         print(Profile.len_data())
         """
     # use multiple threads here to ensure that profiling works with threading
-    p = open(`$cmd -t2 -e $script`)
-    t = Timer(120) do t
-        # should be under 10 seconds, so give it 2 minutes then report failure
-        println("KILLING debuginfo registration test BY PROFILE TEST WATCHDOG\n")
-        kill(p, Base.SIGQUIT)
-        sleep(30)
-        kill(p, Base.SIGQUIT)
-        sleep(30)
-        kill(p, Base.SIGKILL)
-    end
-    s = read(p, String)
-    close(t)
-    @test success(p)
+    s = run_with_watchdog(`$cmd -t2 -e $script`)
     @test !isempty(s)
     @test occursin("done", s)
     @test parse(Int, split(s, '\n')[end]) > 100
 end
 
+# Thread suspend deadlock - run many times (#60042)
+let cmd = Base.julia_cmd()
+    script = """
+        using Profile
+        @profile println("done")
+        """
+    good = true
+    for i=1:100
+        s = run_with_watchdog(`$cmd -t2 -e $script`, 5)
+        good &= occursin("done", s)
+    end
+    @test good
+end
+
 if Sys.isbsd() || Sys.islinux()
     @testset "SIGINFO/SIGUSR1 profile triggering" begin
         let cmd = Base.julia_cmd()