[v2] Cache the text section offset of shared libraries
Commit Message
Each time a dll is loaded, update_solib_list is called.
This in turn calls deep down xfer_partial -> windows_xfer_shared_libraries,
which calls windows_xfer_shared_library for each loaded dll,
and pe_text_section_offset reads the dll for the text section offset.
Also if the data provided by xfer_partial is bigger than 4K,
then all of this is done for each 4K chunk (see target_read_alloc_1).
Caching of the text section offset improves the startup time of
an application with >300 dynamically loaded plugins from 2m10s to 10s.
And the shutdown time improves from 2m to 2s.
gdb/ChangeLog:
2019-12-21 Hannes Domani <ssbssa@yahoo.de>
* i386-cygwin-tdep.c (core_process_module_section): Update.
* windows-nat.c (struct lm_info_windows): Add text_offset.
(windows_xfer_shared_libraries): Update.
* windows-tdep.c (windows_xfer_shared_library):
Add text_offset_cached argument.
* windows-tdep.h (windows_xfer_shared_library): Update.
---
gdb/i386-cygwin-tdep.c | 2 +-
gdb/windows-nat.c | 2 ++
gdb/windows-tdep.c | 20 ++++++++++++++------
gdb/windows-tdep.h | 1 +
4 files changed, 18 insertions(+), 7 deletions(-)
@@ -137,7 +137,7 @@ core_process_module_section (bfd *abfd, asection *sect, void *obj)
/* The first module is the .exe itself. */
if (data->module_count != 0)
windows_xfer_shared_library (module_name, base_addr,
- data->gdbarch, data->obstack);
+ NULL, data->gdbarch, data->obstack);
data->module_count++;
out:
@@ -682,6 +682,7 @@ windows_nat_target::store_registers (struct regcache *regcache, int r)
struct lm_info_windows : public lm_info_base
{
LPVOID load_addr = 0;
+ CORE_ADDR text_offset = 0;
};
static struct so_list solib_start, *solib_end;
@@ -2974,6 +2975,7 @@ windows_xfer_shared_libraries (struct target_ops *ops,
windows_xfer_shared_library (so->so_name, (CORE_ADDR)
(uintptr_t) li->load_addr,
+ &li->text_offset,
target_gdbarch (), &obstack);
}
obstack_grow_str0 (&obstack, "</library-list>\n");
@@ -424,19 +424,27 @@ display_tib (const char * args, int from_tty)
void
windows_xfer_shared_library (const char* so_name, CORE_ADDR load_addr,
+ CORE_ADDR *text_offset_cached,
struct gdbarch *gdbarch, struct obstack *obstack)
{
- CORE_ADDR text_offset;
+ CORE_ADDR text_offset = text_offset_cached ? *text_offset_cached : 0;
obstack_grow_str (obstack, "<library name=\"");
std::string p = xml_escape_text (so_name);
obstack_grow_str (obstack, p.c_str ());
obstack_grow_str (obstack, "\"><segment address=\"");
- gdb_bfd_ref_ptr dll (gdb_bfd_open (so_name, gnutarget, -1));
- /* The following calls are OK even if dll is NULL.
- The default value 0x1000 is returned by pe_text_section_offset
- in that case. */
- text_offset = pe_text_section_offset (dll.get ());
+
+ if (!text_offset)
+ {
+ gdb_bfd_ref_ptr dll (gdb_bfd_open (so_name, gnutarget, -1));
+ /* The following calls are OK even if dll is NULL.
+ The default value 0x1000 is returned by pe_text_section_offset
+ in that case. */
+ text_offset = pe_text_section_offset (dll.get ());
+ if (text_offset_cached)
+ *text_offset_cached = text_offset;
+ }
+
obstack_grow_str (obstack, paddress (gdbarch, load_addr + text_offset));
obstack_grow_str (obstack, "\"/></library>");
}
@@ -27,6 +27,7 @@ extern void init_w32_command_list (void);
extern void windows_xfer_shared_library (const char* so_name,
CORE_ADDR load_addr,
+ CORE_ADDR *text_offset_cached,
struct gdbarch *gdbarch,
struct obstack *obstack);