configure: Distinguish glibc and NetBSD pthread_setname_np() variants.

[sliver-openvswitch.git] / lib / util.c

diff --git a/lib/util.c b/lib/util.c
index cd4019e..1751c6f 100644 (file)
--- a/lib/util.c
+++ b/lib/util.c
@@ -18,6 +18,7 @@
 #include "util.h"
 #include <errno.h>
 #include <limits.h>
+#include <pthread.h>
 #include <stdarg.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -27,7 +28,7 @@
 #include <unistd.h>
 #include "byte-order.h"
 #include "coverage.h"
-#include "openvswitch/types.h"
+#include "ovs-thread.h"
 #include "vlog.h"
 
 VLOG_DEFINE_THIS_MODULE(util);
@@ -37,13 +38,16 @@ COVERAGE_DEFINE(util_xalloc);
 /* argv[0] without directory names. */
 const char *program_name;
 
-/* Ordinarily "" but set to "monitor" for a monitor process or "worker" for a
- * worker process. */
-const char *subprogram_name = "";
+/* Name for the currently running thread or process, for log messages, process
+ * listings, and debuggers. */
+DEFINE_PER_THREAD_MALLOCED_DATA(char *, subprogram_name);
 
 /* --version option output. */
 static char *program_version;
 
+/* Buffer used by ovs_strerror(). */
+DEFINE_PER_THREAD_DATA(struct { char s[128]; }, strerror_buffer, { "" });
+
 void
 ovs_assert_failure(const char *where, const char *function,
                    const char *condition)
@@ -277,6 +281,7 @@ ovs_error(int err_no, const char *format, ...)
 void
 ovs_error_valist(int err_no, const char *format, va_list args)
 {
+    const char *subprogram_name = get_subprogram_name();
     int save_errno = errno;
 
     if (subprogram_name[0]) {
@@ -306,19 +311,41 @@ ovs_error_valist(int err_no, const char *format, va_list args)
 const char *
 ovs_retval_to_string(int retval)
 {
-    static char unknown[48];
+    return (!retval ? ""
+            : retval == EOF ? "End of file"
+            : ovs_strerror(retval));
+}
 
-    if (!retval) {
-        return "";
-    }
-    if (retval > 0) {
-        return strerror(retval);
-    }
-    if (retval == EOF) {
-        return "End of file";
+const char *
+ovs_strerror(int error)
+{
+    enum { BUFSIZE = sizeof strerror_buffer_get()->s };
+    int save_errno;
+    char *buffer;
+    char *s;
+
+    save_errno = errno;
+    buffer = strerror_buffer_get()->s;
+
+#if STRERROR_R_CHAR_P
+    /* GNU style strerror_r() might return an immutable static string, or it
+     * might write and return 'buffer', but in either case we can pass the
+     * returned string directly to the caller. */
+    s = strerror_r(error, buffer, BUFSIZE);
+#else  /* strerror_r() returns an int. */
+    s = buffer;
+    if (strerror_r(error, buffer, BUFSIZE)) {
+        /* strerror_r() is only allowed to fail on ERANGE (because the buffer
+         * is too short).  We don't check the actual failure reason because
+         * POSIX requires strerror_r() to return the error but old glibc
+         * (before 2.13) returns -1 and sets errno. */
+        snprintf(buffer, BUFSIZE, "Unknown error %d", error);
     }
-    snprintf(unknown, sizeof unknown, "***unknown return value: %d***", retval);
-    return unknown;
+#endif
+
+    errno = save_errno;
+
+    return s;
 }
 
 /* Sets global "program_name" and "program_version" variables.  Should
@@ -340,6 +367,9 @@ set_program_name__(const char *argv0, const char *version, const char *date,
                    const char *time)
 {
     const char *slash = strrchr(argv0, '/');
+
+    assert_single_threaded();
+
     program_name = slash ? slash + 1 : argv0;
 
     free(program_version);
@@ -356,6 +386,30 @@ set_program_name__(const char *argv0, const char *version, const char *date,
     }
 }
 
+/* Returns the name of the currently running thread or process. */
+const char *
+get_subprogram_name(void)
+{
+    const char *name = subprogram_name_get();
+    return name ? name : "";
+}
+
+/* Sets 'name' as the name of the currently running thread or process.  (This
+ * appears in log messages and may also be visible in system process listings
+ * and debuggers.) */
+void
+set_subprogram_name(const char *name)
+{
+    free(subprogram_name_set(xstrdup(name)));
+#if HAVE_GLIBC_PTHREAD_SETNAME_NP
+    pthread_setname_np(pthread_self(), name);
+#elif HAVE_NETBSD_PTHREAD_SETNAME_NP
+    pthread_setname_np(pthread_self(), "%s", name);
+#elif HAVE_PTHREAD_SET_NAME_NP
+    pthread_set_name_np(pthread_self(), name);
+#endif
+}
+
 /* Returns a pointer to a string describing the program version.  The
  * caller must not modify or free the returned string.
  */
@@ -587,7 +641,7 @@ get_cwd(void)
             int error = errno;
             free(buf);
             if (error != ERANGE) {
-                VLOG_WARN("getcwd failed (%s)", strerror(error));
+                VLOG_WARN("getcwd failed (%s)", ovs_strerror(error));
                 return NULL;
             }
             size *= 2;
@@ -725,7 +779,8 @@ follow_symlinks(const char *filename)
 
         linkname = xreadlink(fn);
         if (!linkname) {
-            VLOG_WARN("%s: readlink failed (%s)", filename, strerror(errno));
+            VLOG_WARN("%s: readlink failed (%s)",
+                      filename, ovs_strerror(errno));
             return fn;
         }