[glibc] posix: Use unique PID file in tst-spawn3 and tst-spawn3-pidfd

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=980089ebab2a05af6d675d614bb2ec84c58b6615

commit 980089ebab2a05af6d675d614bb2ec84c58b6615
Author: Florian Weimer <[email protected]>
Date:   Thu Jul 9 17:09:32 2026 +0200

    posix: Use unique PID file in tst-spawn3 and tst-spawn3-pidfd
    
    The test sources are built twice and the two tests may run in parallel.
    They cannot use the same PID file.
    
    Reviewed-by: Sam James <[email protected]>

Diff:
---
 posix/tst-spawn3.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/posix/tst-spawn3.c b/posix/tst-spawn3.c
index 70a5a8ba49..8b946cbb4d 100644
--- a/posix/tst-spawn3.c
+++ b/posix/tst-spawn3.c
@@ -30,6 +30,7 @@
 #include <intprops.h>
 
 #include <support/check.h>
+#include <support/support.h>
 #include <support/temp_file.h>
 #include <support/xunistd.h>
 #include <tst-spawn.h>
@@ -84,8 +85,12 @@ do_test (void)
   posix_spawn_file_actions_t a;
   TEST_COMPARE (posix_spawn_file_actions_init (&a), 0);
 
-  /* Executes a /bin/sh echo $$ 2>&1 > ${objpfx}tst-spawn3.pid .  */
-  const char pidfile[] = OBJPFX "tst-spawn3.pid";
+  /* Executes a /bin/sh echo $$ 2>&1 > ${objpfx}tst-spawn3-$$.pid .
+     Embed this PID into the path because the test is built multiple
+     times and can run in parallel.  */
+  char *pidfile = xasprintf ("%s/tst-spawn3-%d.pid",
+			     OBJPFX, (int) getpid ());
+  add_temp_file (pidfile);
   TEST_COMPARE (posix_spawn_file_actions_addopen (&a, STDOUT_FILENO, pidfile,
 						  O_WRONLY| O_CREAT | O_TRUNC,
 						  0644),
@@ -145,7 +150,7 @@ do_test (void)
   ssize_t n = read (pidfd, buf, sizeof (buf));
   TEST_VERIFY (n < sizeof buf && n >= 0);
 
-  xunlink (pidfile);
+  free (pidfile);
 
   /* We only expect to read the PID.  */
   char *endp;