From 172d37d3b92ca70e65f11f9a7caf7af4c8a5e44f Mon Sep 17 00:00:00 2001
From: Zachary Turner <zturner@google.com>
Date: Tue, 14 Oct 2014 21:55:08 +0000
Subject: Create a process launcher abstraction.

This implements Host::LaunchProcess for windows, and in doing so
does some minor refactor to move towards a more modular process
launching design.

The original motivation for this is that launching processes on
windows needs some very windows specific code, which would live
most appropriately in source/Host/windows somewhere.  However,
there is already some common code that all platforms use when
launching a process before delegating to the platform specific
stuff, which lives in source/Host/common/Host.cpp which would
be nice to reuse without duplicating.

This commonality has been abstracted into MonitoringProcessLauncher,
a class which abstracts out the notion of launching a process using
an arbitrary algorithm, and then monitoring it for state changes.

The windows specific launching code lives in ProcessLauncherWindows,
and the posix specific launching code lives in ProcessLauncherPosix.
When launching a process MonitoringProcessLauncher is created, and
then an appropriate delegate launcher is created and given to the
MonitoringProcessLauncher.

Reviewed by: Greg Clayton
Differential Revision: http://reviews.llvm.org/D5781

llvm-svn: 219731
---
 lldb/source/Host/windows/HostProcessWindows.cpp | 49 ++++++++++++++++++++++++-
 1 file changed, 47 insertions(+), 2 deletions(-)

(limited to 'lldb/source/Host/windows/HostProcessWindows.cpp')

diff --git a/lldb/source/Host/windows/HostProcessWindows.cpp b/lldb/source/Host/windows/HostProcessWindows.cpp
index 447f672ac77..8388e21b853 100644
--- a/lldb/source/Host/windows/HostProcessWindows.cpp
+++ b/lldb/source/Host/windows/HostProcessWindows.cpp
@@ -8,6 +8,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "lldb/Host/FileSpec.h"
+#include "lldb/Host/HostThread.h"
+#include "lldb/Host/ThreadLauncher.h"
 #include "lldb/Host/windows/windows.h"
 #include "lldb/Host/windows/HostProcessWindows.h"
 
@@ -17,6 +19,16 @@
 
 using namespace lldb_private;
 
+namespace
+{
+struct MonitorInfo
+{
+    HostProcess::MonitorCallback callback;
+    void *baton;
+    HANDLE process_handle;
+};
+}
+
 HostProcessWindows::HostProcessWindows()
     : HostNativeProcessBase()
 {
@@ -61,7 +73,7 @@ Error HostProcessWindows::GetMainModule(FileSpec &file_spec) const
 
 lldb::pid_t HostProcessWindows::GetProcessId() const
 {
-    return ::GetProcessId(m_process);
+    return (m_process == LLDB_INVALID_PROCESS) ? -1 : ::GetProcessId(m_process);
 }
 
 bool HostProcessWindows::IsRunning() const
@@ -76,9 +88,42 @@ bool HostProcessWindows::IsRunning() const
     return (code == STILL_ACTIVE);
 }
 
+HostThread
+HostProcessWindows::StartMonitoring(HostProcess::MonitorCallback callback, void *callback_baton, bool monitor_signals)
+{
+    HostThread monitor_thread;
+    MonitorInfo *info = new MonitorInfo;
+    info->callback = callback;
+    info->baton = callback_baton;
+
+    // Since the life of this HostProcessWindows instance and the life of the process may be different, duplicate the handle so that
+    // the monitor thread can have ownership over its own copy of the handle.
+    HostThread result;
+    if (::DuplicateHandle(GetCurrentProcess(), m_process, GetCurrentProcess(), &info->process_handle, 0, FALSE, DUPLICATE_SAME_ACCESS))
+        result = ThreadLauncher::LaunchThread("ChildProcessMonitor", HostProcessWindows::MonitorThread, info, nullptr);
+    return result;
+}
+
+lldb::thread_result_t
+HostProcessWindows::MonitorThread(void *thread_arg)
+{
+    DWORD exit_code;
+
+    MonitorInfo *info = static_cast<MonitorInfo *>(thread_arg);
+    if (info)
+    {
+        DWORD wait_result = ::WaitForSingleObject(info->process_handle, INFINITE);
+        ::GetExitCodeProcess(info->process_handle, &exit_code);
+        info->callback(info->baton, ::GetProcessId(info->process_handle), true, 0, exit_code);
+
+        delete (info);
+    }
+    return 0;
+}
+
 void HostProcessWindows::Close()
 {
-    if (m_process != nullptr)
+    if (m_process != LLDB_INVALID_PROCESS)
         ::CloseHandle(m_process);
     m_process = nullptr;
 }
-- 
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