This is the mail archive of the
gdb-patches@sourceware.org
mailing list for the GDB project.
RFC: speed up have_live_inferiors
- From: Tom Tromey <tromey at redhat dot com>
- To: gdb-patches at sourceware dot org
- Date: Tue, 01 Mar 2011 12:06:38 -0700
- Subject: RFC: speed up have_live_inferiors
I would appreciate comments on this patch.
In the absence of comments I will check it in.
I am working on making it possible to lazily read debuginfo. I think
this is important for a multi-inferior scenario where most processes are
actually uninteresting.
Part of this work is tracking down places that inadvertently require
debuginfo and somehow fixing them.
have_live_inferiors calls make_cleanup_restore_current_thread.
This in turn does a surprising (to me) amount of work, including storing
the selected frame, which in turn might call the inline frame sniffer.
This patch fixes have_live_inferiors by changing to_has_execution to
accept a ptid_t, so that the check can be done without switching
threads. It also updates all implementations of to_has_execution, of
which there are few.
Built and regtested on x86-64 (compile farm).
Tom
2011-03-01 Tom Tromey <tromey@redhat.com>
* target.h (struct target_ops) <to_has_execution>: Add ptid_t
parameter.
(target_has_execution_1): Update.
(target_has_execution_current): Declare.
(target_has_execution): Call target_has_execution_current.
(default_child_has_execution): Update.
* target.c (default_child_has_execution): Add 'the_ptid'
parameter.
(target_has_execution_1): Likewise.
(target_has_execution_current): New function.
(add_target): Update.
(init_dummy_target): Update.
* remote-m32r-sdi.c (m32r_has_execution): New function.
(init_m32r_ops): Use it.
* record.c (record_core_has_execution): Now static. Add
'the_ptid' parameter.
* inferior.c (have_live_inferiors): Don't save current thread.
Use target_has_execution_1.
diff --git a/gdb/inferior.c b/gdb/inferior.c
index 76f81c3..eb33b9a 100644
--- a/gdb/inferior.c
+++ b/gdb/inferior.c
@@ -462,28 +462,18 @@ have_inferiors (void)
int
have_live_inferiors (void)
{
- struct cleanup *old_chain;
struct inferior *inf;
- old_chain = make_cleanup_restore_current_thread ();
-
for (inf = inferior_list; inf; inf = inf->next)
if (inf->pid != 0)
{
struct thread_info *tp;
tp = any_thread_of_process (inf->pid);
- if (tp)
- {
- switch_to_thread (tp->ptid);
-
- if (target_has_execution)
- break;
- }
+ if (tp && target_has_execution_1 (tp->ptid))
+ break;
}
- do_cleanups (old_chain);
-
return inf != NULL;
}
diff --git a/gdb/record.c b/gdb/record.c
index 784f5fa..cf21779 100644
--- a/gdb/record.c
+++ b/gdb/record.c
@@ -1923,8 +1923,8 @@ record_core_remove_breakpoint (struct gdbarch *gdbarch,
/* "to_has_execution" method for prec over corefile. */
-int
-record_core_has_execution (struct target_ops *ops)
+static int
+record_core_has_execution (struct target_ops *ops, ptid_t the_ptid)
{
return 1;
}
diff --git a/gdb/remote-m32r-sdi.c b/gdb/remote-m32r-sdi.c
index 3247b6f..70d6dd5 100644
--- a/gdb/remote-m32r-sdi.c
+++ b/gdb/remote-m32r-sdi.c
@@ -1610,6 +1610,14 @@ m32r_return_one (struct target_ops *target)
return 1;
}
+/* Implementation of the to_has_execution method. */
+
+static int
+m32r_has_execution (struct target_ops *target, ptid_t the_ptid)
+{
+ return 1;
+}
+
/* Define the target subroutine names. */
struct target_ops m32r_ops;
@@ -1650,7 +1658,7 @@ init_m32r_ops (void)
m32r_ops.to_has_memory = m32r_return_one;
m32r_ops.to_has_stack = m32r_return_one;
m32r_ops.to_has_registers = m32r_return_one;
- m32r_ops.to_has_execution = m32r_return_one;
+ m32r_ops.to_has_execution = m32r_has_execution;
m32r_ops.to_magic = OPS_MAGIC;
};
diff --git a/gdb/target.c b/gdb/target.c
index a4e2ae9..edf7e1c 100644
--- a/gdb/target.c
+++ b/gdb/target.c
@@ -314,11 +314,11 @@ default_child_has_registers (struct target_ops *ops)
}
int
-default_child_has_execution (struct target_ops *ops)
+default_child_has_execution (struct target_ops *ops, ptid_t the_ptid)
{
/* If there's no thread selected, then we can't make it run through
hoops. */
- if (ptid_equal (inferior_ptid, null_ptid))
+ if (ptid_equal (the_ptid, null_ptid))
return 0;
return 1;
@@ -374,17 +374,23 @@ target_has_registers_1 (void)
}
int
-target_has_execution_1 (void)
+target_has_execution_1 (ptid_t the_ptid)
{
struct target_ops *t;
for (t = current_target.beneath; t != NULL; t = t->beneath)
- if (t->to_has_execution (t))
+ if (t->to_has_execution (t, the_ptid))
return 1;
return 0;
}
+int
+target_has_execution_current (void)
+{
+ return target_has_execution_1 (inferior_ptid);
+}
+
/* Add a possible target architecture to the list. */
void
@@ -407,7 +413,7 @@ add_target (struct target_ops *t)
t->to_has_registers = (int (*) (struct target_ops *)) return_zero;
if (t->to_has_execution == NULL)
- t->to_has_execution = (int (*) (struct target_ops *)) return_zero;
+ t->to_has_execution = (int (*) (struct target_ops *, ptid_t)) return_zero;
if (!target_structs)
{
@@ -3218,7 +3224,8 @@ init_dummy_target (void)
dummy_target.to_has_memory = (int (*) (struct target_ops *)) return_zero;
dummy_target.to_has_stack = (int (*) (struct target_ops *)) return_zero;
dummy_target.to_has_registers = (int (*) (struct target_ops *)) return_zero;
- dummy_target.to_has_execution = (int (*) (struct target_ops *)) return_zero;
+ dummy_target.to_has_execution
+ = (int (*) (struct target_ops *, ptid_t)) return_zero;
dummy_target.to_stopped_by_watchpoint = return_zero;
dummy_target.to_stopped_data_address =
(int (*) (struct target_ops *, CORE_ADDR *)) return_zero;
diff --git a/gdb/target.h b/gdb/target.h
index e856dde..e19f7b7 100644
--- a/gdb/target.h
+++ b/gdb/target.h
@@ -510,7 +510,7 @@ struct target_ops
int (*to_has_memory) (struct target_ops *);
int (*to_has_stack) (struct target_ops *);
int (*to_has_registers) (struct target_ops *);
- int (*to_has_execution) (struct target_ops *);
+ int (*to_has_execution) (struct target_ops *, ptid_t);
int to_has_thread_control; /* control thread execution */
int to_attach_no_wait;
/* ASYNC target controls */
@@ -1189,8 +1189,13 @@ extern int target_has_registers_1 (void);
case this will become true after target_create_inferior or
target_attach. */
-extern int target_has_execution_1 (void);
-#define target_has_execution target_has_execution_1 ()
+extern int target_has_execution_1 (ptid_t);
+
+/* Like target_has_execution_1, but always passes inferior_ptid. */
+
+extern int target_has_execution_current (void);
+
+#define target_has_execution target_has_execution_current ()
/* Default implementations for process_stratum targets. Return true
if there's a selected inferior, false otherwise. */
@@ -1199,7 +1204,8 @@ extern int default_child_has_all_memory (struct target_ops *ops);
extern int default_child_has_memory (struct target_ops *ops);
extern int default_child_has_stack (struct target_ops *ops);
extern int default_child_has_registers (struct target_ops *ops);
-extern int default_child_has_execution (struct target_ops *ops);
+extern int default_child_has_execution (struct target_ops *ops,
+ ptid_t the_ptid);
/* Can the target support the debugger control of thread execution?
Can it lock the thread scheduler? */