Thanks for this. A few comments inline.
On 20/02/2016 08:16, Mark Geisert wrote:
diff --git a/winsup/cygwin/cygheap.cc b/winsup/cygwin/cygheap.cc
index 6493485..4932cf0 100644
--- a/winsup/cygwin/cygheap.cc
+++ b/winsup/cygwin/cygheap.cc
@@ -744,3 +744,15 @@ init_cygheap::find_tls (int sig, bool& issig_wait)
WaitForSingleObject (t->mutex, INFINITE);
return t;
}
+
+/* Called from profil.c to sample all non-main thread PC values for profiling
*/
+extern "C" void
+cygheap_profthr_all (void (*profthr_byhandle) (HANDLE))
+{
+ for (uint32_t ix = 0; ix < nthreads; ix++)
+ {
+ _cygtls *tls = cygheap->threadlist[ix].thread;
+ if (tls->tid)
+ profthr_byhandle (tls->tid->win32_obj_id);
+ }
+}
There doesn't seem to be anything specific to profiling about this, so
it could be written in a more generic way, as "call a callback function
for each thread".
diff --git a/winsup/cygwin/external.cc b/winsup/cygwin/external.cc
index e379df1..02335eb 100644
--- a/winsup/cygwin/external.cc
+++ b/winsup/cygwin/external.cc
@@ -702,6 +702,17 @@ cygwin_internal (cygwin_getinfo_types t, ...)
}
break;
+ case CW_CYGHEAP_PROFTHR_ALL:
+ {
+ typedef void (*func_t) (HANDLE);
+ extern void cygheap_profthr_all (func_t);
+
+ func_t profthr_byhandle = va_arg(arg, func_t);
+ cygheap_profthr_all (profthr_byhandle);
+ res = 0;
+ }
+ break;
+
Is this exposed via cygwin_internal() operation just for testing
purposes? Or is there some other use envisioned?
+ /* We copy an undocumented glibc feature: customizing the profiler's
+ output file name somewhat, depending on the env var GMON_OUT_PREFIX.
+ if GMON_OUT_PREFIX is unspecified, the file's name is "gmon.out".
+
+ if GMON_OUT_PREFIX is specified with at least one character, the
+ file's name is computed as "$GMON_OUT_PREFIX.$pid".
+
+ if GMON_OUT_PREFIX is specified but contains no characters, the
+ file's name is computed as "gmon.out.$pid". Cygwin-specific.
+ */
+ if ((prefix = getenv("GMON_OUT_PREFIX")) != NULL) {
setup-env.xml might be an appropriate place to mention this environment
variable.
static void CALLBACK
profthr_func (LPVOID arg)
{
struct profinfo *p = (struct profinfo *) arg;
- size_t pc, idx;
for (;;)
{
- pc = (size_t) get_thrpc (p->targthr);
- if (pc >= p->lowpc && pc < p->highpc)
- {
- idx = PROFIDX (pc, p->lowpc, p->scale);
- p->counter[idx]++;
- }
+ // record profiling sample for main thread
+ profthr_byhandle (p->targthr);
+
+ // record profiling samples for other pthreads, if any
+ cygwin_internal (CW_CYGHEAP_PROFTHR_ALL, profthr_byhandle);
+
Hmm.. so why isn't this written as cygheap_profthr_all (profthr_byhandle) ?
