From 4da4aea89c4fe6106fa2ef0666f284ba6752d701 Mon Sep 17 00:00:00 2001
From: aarzilli <alessandro.arzilli@gmail.com>
Date: Thu, 7 Jan 2016 19:33:15 +0100
Subject: [PATCH] proc: wait for full process stop before evaluating anything

---
 proc/proc_darwin.c    |  2 +-
 proc/proc_darwin.go   | 33 ++++++++++++++++++++++++++++-----
 proc/threads_darwin.c | 33 +++++++++++++++++++++++++++++++++
 proc/threads_darwin.h |  3 +++
 4 files changed, 65 insertions(+), 6 deletions(-)

diff --git a/proc/proc_darwin.c b/proc/proc_darwin.c
index 25e2a9f7..4d17c54d 100644
--- a/proc/proc_darwin.c
+++ b/proc/proc_darwin.c
@@ -127,7 +127,7 @@ mach_port_wait(mach_port_t port_set, int nonblocking) {
 
 	// Wait for mach msg.
 	kret = mach_msg(&msg.hdr, opts,
-			0, sizeof(msg.data), port_set, 0, MACH_PORT_NULL);
+			0, sizeof(msg.data), port_set, 10, MACH_PORT_NULL);
 	if (kret == MACH_RCV_INTERRUPTED) return kret;
 	if (kret != MACH_MSG_SUCCESS) return 0;
 
diff --git a/proc/proc_darwin.go b/proc/proc_darwin.go
index e11b9aa7..fa291be2 100644
--- a/proc/proc_darwin.go
+++ b/proc/proc_darwin.go
@@ -1,6 +1,7 @@
 package proc
 
 // #include "proc_darwin.h"
+// #include "threads_darwin.h"
 // #include "exec_darwin.h"
 // #include <stdlib.h>
 import "C"
@@ -314,20 +315,42 @@ func (dbp *Process) trapWait(pid int) (*Thread, error) {
 	}
 }
 
-func (dbp *Process) setCurrentBreakpoints(trapthread *Thread) error {
-	trapthread.SetCurrentBreakpoint()
+func (dbp *Process) waitForStop() ([]int, error) {
+	ports := make([]int, 0, len(dbp.Threads))
+	count := 0
 	for {
 		port := C.mach_port_wait(dbp.os.portSet, C.int(1))
-		if port == 0 {
-			return nil
+		if port != 0 {
+			count = 0
+			ports = append(ports, int(port))
+		} else {
+			n := C.num_running_threads(C.task_t(dbp.os.task))
+			if n == 0 {
+				return ports, nil
+			} else if n < 0 {
+				return nil, fmt.Errorf("error waiting for thread stop %d", n)
+			} else if count > 16 {
+				return nil, fmt.Errorf("could not stop porcess %d", n)
+			}
 		}
-		if th, ok := dbp.Threads[int(port)]; ok {
+	}
+}
+
+func (dbp *Process) setCurrentBreakpoints(trapthread *Thread) error {
+	ports, err := dbp.waitForStop()
+	if err != nil {
+		return err
+	}
+	trapthread.SetCurrentBreakpoint()
+	for _, port := range ports {
+		if th, ok := dbp.Threads[port]; ok {
 			err := th.SetCurrentBreakpoint()
 			if err != nil {
 				return err
 			}
 		}
 	}
+	return nil
 }
 
 func (dbp *Process) loadProcessInformation(wg *sync.WaitGroup) {
diff --git a/proc/threads_darwin.c b/proc/threads_darwin.c
index 51d0e97a..16f7a6da 100644
--- a/proc/threads_darwin.c
+++ b/proc/threads_darwin.c
@@ -135,3 +135,36 @@ thread_blocked(thread_act_t thread) {
 
 	return info.suspend_count;
 }
+
+int
+num_running_threads(task_t task) {
+	kern_return_t kret;
+	thread_act_array_t list;
+	mach_msg_type_number_t count;
+	int i, n = 0;
+
+	kret = task_threads(task, &list, &count);
+	if (kret != KERN_SUCCESS) {
+		return -kret;
+	}
+
+	for (i = 0; i < count; ++i) {
+		thread_act_t thread = list[i];
+		struct thread_basic_info info;
+		unsigned int info_count = THREAD_BASIC_INFO_COUNT;
+
+		kret = thread_info((thread_t)thread, THREAD_BASIC_INFO, (thread_info_t)&info, &info_count);
+
+		if (kret == KERN_SUCCESS) {
+			if (info.suspend_count == 0) {
+				++n;
+			} else {
+			}
+		}
+	}
+
+	kret = vm_deallocate(mach_task_self(), (vm_address_t) list, count * sizeof(list[0]));
+	if (kret != KERN_SUCCESS) return -kret;
+
+	return n;
+}
diff --git a/proc/threads_darwin.h b/proc/threads_darwin.h
index 4a64d49d..a77d434d 100644
--- a/proc/threads_darwin.h
+++ b/proc/threads_darwin.h
@@ -33,3 +33,6 @@ get_identity(mach_port_name_t, thread_identifier_info_data_t *);
 
 int
 thread_blocked(thread_act_t thread);
+
+int
+num_running_threads(task_t task);