[binutils-gdb] debuginfod-support.c: Use long-lived debuginfod_client

[Aaron Merey]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=1d1669e40f89a34ae2804ee040df2bf77ed29df8

commit 1d1669e40f89a34ae2804ee040df2bf77ed29df8
Author: Aaron Merey <amerey@redhat.com>
Date:   Fri May 7 11:37:16 2021 -0400

    debuginfod-support.c: Use long-lived debuginfod_client
    
    Instead of initializing a new debuginfod_client for each query, store
    the first initialized client for the remainder of the GDB session and
    use it for every debuginfod query.
    
    In conjunction with upcoming changes to libdebuginfod, using one client
    for all queries will avoid latency caused by unneccesarily setting up
    TCP connections multiple times.
    
    Tested on Fedora 33 x86_64.
    
    gdb/ChangeLog:
    
            * debuginfod-support.c (debuginfod_init): Remove.
            (get_debuginfod_client): New function.

Diff:
---
 gdb/ChangeLog            |  5 +++++
 gdb/debuginfod-support.c | 32 ++++++++++++++++++++------------
 2 files changed, 25 insertions(+), 12 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 76ccb6beb3c..50e87fb6538 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2021-05-07  Aaron Merey  <amerey@redhat.com>
+
+	* debuginfod-support.c (debuginfod_init): Remove.
+	(get_debuginfod_client): New function.
+
 2021-05-07  Tom Tromey  <tom@tromey.com>
 
 	* breakpoint.c (ambiguous_names_p): Use htab_eq_string.
diff --git a/gdb/debuginfod-support.c b/gdb/debuginfod-support.c
index 9778e2e4cfe..2d626e335a0 100644
--- a/gdb/debuginfod-support.c
+++ b/gdb/debuginfod-support.c
@@ -72,6 +72,7 @@ static int
 progressfn (debuginfod_client *c, long cur, long total)
 {
   user_data *data = static_cast<user_data *> (debuginfod_get_user_data (c));
+  gdb_assert (data != nullptr);
 
   if (check_quit_flag ())
     {
@@ -103,15 +104,20 @@ progressfn (debuginfod_client *c, long cur, long total)
   return 0;
 }
 
-static debuginfod_client_up
-debuginfod_init ()
+static debuginfod_client *
+get_debuginfod_client ()
 {
-  debuginfod_client_up c (debuginfod_begin ());
+  static debuginfod_client_up global_client;
 
-  if (c != nullptr)
-    debuginfod_set_progressfn (c.get (), progressfn);
+  if (global_client == nullptr)
+    {
+      global_client.reset (debuginfod_begin ());
+
+      if (global_client != nullptr)
+	debuginfod_set_progressfn (global_client.get (), progressfn);
+    }
 
-  return c;
+  return global_client.get ();
 }
 
 /* See debuginfod-support.h  */
@@ -126,19 +132,20 @@ debuginfod_source_query (const unsigned char *build_id,
   if (urls_env_var == NULL || urls_env_var[0] == '\0')
     return scoped_fd (-ENOSYS);
 
-  debuginfod_client_up c = debuginfod_init ();
+  debuginfod_client *c = get_debuginfod_client ();
 
   if (c == nullptr)
     return scoped_fd (-ENOMEM);
 
   user_data data ("source file", srcpath);
 
-  debuginfod_set_user_data (c.get (), &data);
-  scoped_fd fd (debuginfod_find_source (c.get (),
+  debuginfod_set_user_data (c, &data);
+  scoped_fd fd (debuginfod_find_source (c,
 					build_id,
 					build_id_len,
 					srcpath,
 					nullptr));
+  debuginfod_set_user_data (c, nullptr);
 
   /* TODO: Add 'set debug debuginfod' command to control when error messages are shown.  */
   if (fd.get () < 0 && fd.get () != -ENOENT)
@@ -164,7 +171,7 @@ debuginfod_debuginfo_query (const unsigned char *build_id,
   if (urls_env_var == NULL || urls_env_var[0] == '\0')
     return scoped_fd (-ENOSYS);
 
-  debuginfod_client_up c = debuginfod_init ();
+  debuginfod_client *c = get_debuginfod_client ();
 
   if (c == nullptr)
     return scoped_fd (-ENOMEM);
@@ -172,9 +179,10 @@ debuginfod_debuginfo_query (const unsigned char *build_id,
   char *dname = nullptr;
   user_data data ("separate debug info for", filename);
 
-  debuginfod_set_user_data (c.get (), &data);
-  scoped_fd fd (debuginfod_find_debuginfo (c.get (), build_id, build_id_len,
+  debuginfod_set_user_data (c, &data);
+  scoped_fd fd (debuginfod_find_debuginfo (c, build_id, build_id_len,
 					   &dname));
+  debuginfod_set_user_data (c, nullptr);
 
   if (fd.get () < 0 && fd.get () != -ENOENT)
     printf_filtered (_("Download failed: %s.  Continuing without debug info for %ps.\n"),