From: Joe Orton <jorton@apache.org>
Date: Tue, 7 Jul 2020 13:40:15 +0000 (+0000)
Subject: Check for and use gettid() directly if available; glibc 2.30 and later
X-Git-Tag: 2.5.0-alpha2-ci-test-only~1274
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=33d99cf67f4bbdce86be0a0fdbb3d26f18e0f2a7;p=thirdparty%2Fapache%2Fhttpd.git

Check for and use gettid() directly if available; glibc 2.30 and later
provides a wrapper for the system call:

* configure.in: Check for gettid() and define HAVE_SYS_GETTID if
  gettid() is only usable via syscall().

* server/log.c (log_tid): Use gettid() directly if available.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1879591 13f79535-47bb-0310-9956-ffa450edef68
---

diff --git a/configure.in b/configure.in
index 423d58d4b9a..60cbf7b7f81 100644
--- a/configure.in
+++ b/configure.in
@@ -535,22 +535,26 @@ prctl \
 timegm \
 getpgid \
 fopen64 \
-getloadavg
+getloadavg \
+gettid
 )
 
 dnl confirm that a void pointer is large enough to store a long integer
 APACHE_CHECK_VOID_PTR_LEN
 
-AC_CACHE_CHECK([for gettid()], ac_cv_gettid,
+if test $ac_cv_func_gettid = no; then
+  # On Linux before glibc 2.30, gettid() is only usable via syscall()
+  AC_CACHE_CHECK([for gettid() via syscall], ap_cv_gettid,
 [AC_TRY_RUN(#define _GNU_SOURCE
 #include <unistd.h>
 #include <sys/syscall.h>
 #include <sys/types.h>
 int main(int argc, char **argv) {
 pid_t t = syscall(SYS_gettid); return t == -1 ? 1 : 0; },
-[ac_cv_gettid=yes], [ac_cv_gettid=no], [ac_cv_gettid=no])])
-if test "$ac_cv_gettid" = "yes"; then
-    AC_DEFINE(HAVE_GETTID, 1, [Define if you have gettid()])
+  [ap_cv_gettid=yes], [ap_cv_gettid=no], [ap_cv_gettid=no])])
+  if test "$ap_cv_gettid" = "yes"; then
+      AC_DEFINE(HAVE_SYS_GETTID, 1, [Define if you have gettid() via syscall()])
+  fi
 fi
 
 dnl ## Check for the tm_gmtoff field in struct tm to get the timezone diffs
diff --git a/server/log.c b/server/log.c
index 9ebbebd87a4..1a32ebb2d95 100644
--- a/server/log.c
+++ b/server/log.c
@@ -56,7 +56,7 @@
 #include "ap_provider.h"
 #include "ap_listen.h"
 
-#if HAVE_GETTID
+#ifdef HAVE_SYS_GETTID
 #include <sys/syscall.h>
 #include <sys/types.h>
 #endif
@@ -538,14 +538,18 @@ static int log_tid(const ap_errorlog_info *info, const char *arg,
 #if APR_HAS_THREADS
     int result;
 #endif
-#if HAVE_GETTID
+#if defined(HAVE_GETTID) || defined(HAVE_SYS_GETTID)
     if (arg && *arg == 'g') {
+#ifdef HAVE_GETTID
+        pid_t tid = gettid();
+#else
         pid_t tid = syscall(SYS_gettid);
+#endif
         if (tid == -1)
             return 0;
         return apr_snprintf(buf, buflen, "%"APR_PID_T_FMT, tid);
     }
-#endif
+#endif /* HAVE_GETTID || HAVE_SYS_GETTID */
 #if APR_HAS_THREADS
     if (ap_mpm_query(AP_MPMQ_IS_THREADED, &result) == APR_SUCCESS
         && result != AP_MPMQ_NOT_SUPPORTED)