runtime/gdb: use goroutine atomicstatus to determine the state
Previously find_goroutine determined whether a goroutine is
stopped by checking the sched.sp field. This heuristic doesn't
always hold but causes find_goroutine to return bogus pc/sp
info for running goroutines.
This change uses the atomicstatus bit to determine
the state which is more accurate.
R=go1.11
Change-Id: I537d432d9e0363257120a196ce2ba52da2970f59
Reviewed-on: https://go-review.googlesource.com/49691
Reviewed-by: Austin Clements <austin@google.com>
diff --git a/src/runtime/runtime-gdb.py b/src/runtime/runtime-gdb.py
index 3e8e1aa..cd16a6c 100644
--- a/src/runtime/runtime-gdb.py
+++ b/src/runtime/runtime-gdb.py
@@ -462,9 +462,11 @@
return None, None
# Get the goroutine's saved state.
pc, sp = ptr['sched']['pc'], ptr['sched']['sp']
- # If the goroutine is stopped, sched.sp will be non-0.
- if sp != 0:
+ status = ptr['atomicstatus']&~G_SCAN
+ # Goroutine is not running nor in syscall, so use the info in goroutine
+ if status != G_RUNNING and status != G_SYSCALL:
return pc.cast(vp), sp.cast(vp)
+
# If the goroutine is in a syscall, use syscallpc/sp.
pc, sp = ptr['syscallpc'], ptr['syscallsp']
if sp != 0:
diff --git a/src/runtime/runtime-gdb_test.go b/src/runtime/runtime-gdb_test.go
index 5e05086..c96bb95 100644
--- a/src/runtime/runtime-gdb_test.go
+++ b/src/runtime/runtime-gdb_test.go
@@ -87,13 +87,24 @@
ptrvar := &strvar
slicevar := make([]string, 0, 16)
slicevar = append(slicevar, mapvar["abc"])
- fmt.Println("hi") // line 13
+ fmt.Println("hi")
runtime.KeepAlive(ptrvar)
+ _ = ptrvar
gslice = slicevar
runtime.KeepAlive(mapvar)
-}
+} // END_OF_PROGRAM
`
+func lastLine(src []byte) int {
+ eop := []byte("END_OF_PROGRAM")
+ for i, l := range bytes.Split(src, []byte("\n")) {
+ if bytes.Contains(l, eop) {
+ return i
+ }
+ }
+ return 0
+}
+
func TestGdbPython(t *testing.T) {
testGdbPython(t, false)
}
@@ -128,11 +139,13 @@
}
buf.WriteString(helloSource)
- src := filepath.Join(dir, "main.go")
- err = ioutil.WriteFile(src, buf.Bytes(), 0644)
+ src := buf.Bytes()
+
+ err = ioutil.WriteFile(filepath.Join(dir, "main.go"), src, 0644)
if err != nil {
t.Fatalf("failed to create file: %v", err)
}
+ nLines := lastLine(src)
cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", "a.exe")
cmd.Dir = dir
@@ -168,9 +181,16 @@
"-ex", "echo BEGIN goroutine 2 bt\n",
"-ex", "goroutine 2 bt",
"-ex", "echo END\n",
+ "-ex", "clear fmt.Println", // clear the previous break point
+ "-ex", fmt.Sprintf("br main.go:%d", nLines), // new break point at the end of main
+ "-ex", "c",
+ "-ex", "echo BEGIN goroutine 1 bt at the end\n",
+ "-ex", "goroutine 1 bt",
+ "-ex", "echo END\n",
filepath.Join(dir, "a.exe"),
}
got, _ := exec.Command("gdb", args...).CombinedOutput()
+ t.Logf("gdb output: %s\n", got)
firstLine := bytes.SplitN(got, []byte("\n"), 2)[0]
if string(firstLine) != "Loading Go Runtime support." {
@@ -232,6 +252,10 @@
if bl := blocks["goroutine 2 bt"]; !btGoroutine2Re.MatchString(bl) {
t.Fatalf("goroutine 2 bt failed: %s", bl)
}
+ btGoroutine1AtTheEndRe := regexp.MustCompile(`(?m)^#0\s+(0x[0-9a-f]+\s+in\s+)?main\.main.+at`)
+ if bl := blocks["goroutine 1 bt at the end"]; !btGoroutine1AtTheEndRe.MatchString(bl) {
+ t.Fatalf("goroutine 1 bt at the end failed: %s", bl)
+ }
}
const backtraceSource = `
