a few comments

1 files changed, 37 insertions, 10 deletions

diff --git a/src/shared/util.cpp b/src/shared/util.cpp
index b14a02b1..36800d5b 100644
--- a/src/shared/util.cpp
+++ b/src/shared/util.cpp
@@ -1205,11 +1205,16 @@ struct Process
   }

 };

 

+// returns the filename of the given process or the current one

+//

 std::wstring processFilename(HANDLE process=INVALID_HANDLE_VALUE)

 {

+  // double the buffer size 10 times

+  const int MaxTries = 10;

+

   DWORD bufferSize = MAX_PATH;

 

-  for (int tries=0; tries<10; ++tries)

+  for (int tries=0; tries<MaxTries; ++tries)

   {

     auto buffer = std::make_unique<wchar_t[]>(bufferSize + 1);

     std::fill(buffer.get(), buffer.get() + bufferSize + 1, 0);

@@ -1225,6 +1230,7 @@ std::wstring processFilename(HANDLE process=INVALID_HANDLE_VALUE)
     }

 

     if (writtenSize == 0) {

+      // hard failure

       const auto e = GetLastError();

       std::wcerr << formatSystemMessage(e) << L"\n";

       break;

@@ -1241,6 +1247,7 @@ std::wstring processFilename(HANDLE process=INVALID_HANDLE_VALUE)
     }

   }

 

+  // something failed or the path is way too long to make sense

 

   std::wstring what;

   if (process == INVALID_HANDLE_VALUE) {

@@ -1255,10 +1262,13 @@ std::wstring processFilename(HANDLE process=INVALID_HANDLE_VALUE)
 

 std::vector<DWORD> runningProcessesIds()

 {

+  // double the buffer size 10 times

+  const int MaxTries = 10;

+

   // initial size of 300 processes, unlikely to be more than that

   std::size_t size = 300;

 

-  for (int tries=0; tries<10; ++tries) {

+  for (int tries=0; tries<MaxTries; ++tries) {

     auto ids = std::make_unique<DWORD[]>(size);

     std::fill(ids.get(), ids.get() + size, 0);

 

@@ -1277,6 +1287,8 @@ std::vector<DWORD> runningProcessesIds()
     }

 

     if (bytesWritten == bytesGiven) {

+      // no way to distinguish between an exact fit and not enough space,

+      // just try again

       size *= 2;

       continue;

     }

@@ -1296,7 +1308,7 @@ std::vector<Process> runningProcesses()
 

   for (const auto& pid : pids) {

     if (pid == 0) {

-      // the idle process seems to be picked up by EnumProcesses()

+      // the idle process has pid 0 and seems to be picked up by EnumProcesses()

       continue;

     }

 

@@ -1307,7 +1319,8 @@ std::vector<Process> runningProcesses()
       const auto e = GetLastError();

 

       if (e != ERROR_ACCESS_DENIED) {

-        // don't log access denied, will happen a lot when not elevated

+        // don't log access denied, will happen a lot for system processes, even

+        // when elevated

         std::wcerr

           << L"failed to open process " << pid << L", "

           << formatSystemMessage(e) << L"\n";

@@ -1331,9 +1344,12 @@ DWORD findOtherPid()
 

   std::wclog << L"looking for the other process...\n";

 

+  // used to skip the current process below

   const auto thisPid = GetCurrentProcessId();

   std::wclog << L"this process id is " << thisPid << L"\n";

 

+  // getting the filename for this process, assumes the other process has the

+  // smae one

   auto filename = processFilename();

   if (filename.empty()) {

     std::wcerr

@@ -1345,9 +1361,12 @@ DWORD findOtherPid()
     std::wclog << L"this process filename is " << filename << L"\n";

   }

 

+  // getting all running processes

   const auto processes = runningProcesses();

   std::wclog << L"there are " << processes.size() << L" processes running\n";

 

+  // going through processes, trying to find one with the same name and a

+  // different pid than this process has

   for (const auto& p : processes) {

     if (p.filename == filename) {

       if (p.pid != thisPid) {

@@ -1364,7 +1383,6 @@ DWORD findOtherPid()
   return 0;

 }

 

-

 std::wstring tempDir()

 {

   const DWORD bufferSize = MAX_PATH + 1;

@@ -1386,9 +1404,15 @@ std::wstring tempDir()
 

 HandlePtr tempFile(const std::wstring dir)

 {

+  // maximum tries of incrementing the counter

+  const int MaxTries = 100;

+

+  // UTC time and date will be in the filename

   const auto now = std::time(0);

   const auto tm = std::gmtime(&now);

 

+  // "ModOrganizer-YYYYMMDDThhmmss.dmp", with a possible "-i" appended, where

+  // i can go until MaxTries

   std::wostringstream oss;

   oss

     << L"ModOrganizer-"

@@ -1402,8 +1426,10 @@ HandlePtr tempFile(const std::wstring dir)
   const std::wstring prefix = oss.str();

   const std::wstring ext = L".dmp";

 

+  // first path to try, without counter in it

   std::wstring path = dir + L"\\" + prefix + ext;

-  for (int i=0; i<100; ++i) {

+

+  for (int i=0; i<MaxTries; ++i) {

     std::wclog << L"trying file '" << path << L"'\n";

 

     HandlePtr h (CreateFileW(

@@ -1411,10 +1437,12 @@ HandlePtr tempFile(const std::wstring dir)
       CREATE_NEW, FILE_ATTRIBUTE_NORMAL, nullptr));

 

     if (h.get() != INVALID_HANDLE_VALUE) {

+      // worked

       return h;

     }

 

     const auto e = GetLastError();

+

     if (e != ERROR_FILE_EXISTS) {

       // probably no write access

       std::wcerr

@@ -1423,6 +1451,7 @@ HandlePtr tempFile(const std::wstring dir)
       return {};

     }

 

+    // try again with "-i"

     path = dir + L"\\" + prefix + L"-" + std::to_wstring(i + 1) + ext;

   }

 

@@ -1443,16 +1472,13 @@ HandlePtr dumpFile()
   // try the temp directory

   const auto dir = tempDir();

 

-  if (dir.empty()) {

-     std::wclog << L"can't get the temp directory\n";

-  } else {

+  if (!dir.empty()) {

     h = tempFile(dir.c_str());

     if (h.get() != INVALID_HANDLE_VALUE) {

       return h;

     }

   }

 

-  std::wcerr << L"nowhere to write the dump file\n";

   return {};

 }

 

@@ -1462,6 +1488,7 @@ bool createMiniDump(HANDLE process, CoreDumpTypes type)
 

   const HandlePtr file = dumpFile();

   if (!file) {

+    std::wcerr << L"nowhere to write the dump file\n";

     return false;

   }