diff options
| -rw-r--r-- | libbutl/process.cxx | 74 |
1 files changed, 52 insertions, 22 deletions
diff --git a/libbutl/process.cxx b/libbutl/process.cxx index 6aa73ce..b9f3b2f 100644 --- a/libbutl/process.cxx +++ b/libbutl/process.cxx @@ -1246,13 +1246,13 @@ namespace butl ulock l (process_spawn_mutex); inheritability_lock il (l); - // Resolve file descriptor to HANDLE and make sure it is inherited. Note - // that the handle is closed either when CloseHandle() is called for it - // or when _close() is called for the associated file descriptor. Make - // sure that either the original file descriptor or the resulting HANDLE - // is closed but not both of them. + // Resolve file descriptor to HANDLE and make sure it is inherited (if + // requested). Note that the handle is closed either when CloseHandle() + // is called for it or when _close() is called for the associated file + // descriptor. Make sure that either the original file descriptor or the + // resulting HANDLE is closed but not both of them. // - auto get_osfhandle = [&fail, &il] (int fd) -> HANDLE + auto get_osfhandle = [&fail, &il] (int fd, bool inherit = true) -> HANDLE { HANDLE h (reinterpret_cast<HANDLE> (_get_osfhandle (fd))); if (h == INVALID_HANDLE_VALUE) @@ -1261,15 +1261,18 @@ namespace butl // Make the handle inheritable by the child unless it is already // inheritable. // - DWORD f; - if (!GetHandleInformation (h, &f)) - fail (); + if (inherit) + { + DWORD f; + if (!GetHandleInformation (h, &f)) + fail (); - // Note that the flag check is essential as SetHandleInformation() - // fails for standard handles and their duplicates. - // - if ((f & HANDLE_FLAG_INHERIT) == 0) - il.inheritable (h); + // Note that the flag check is essential as SetHandleInformation() + // fails for standard handles and their duplicates. + // + if ((f & HANDLE_FLAG_INHERIT) == 0) + il.inheritable (h); + } return h; }; @@ -1474,9 +1477,15 @@ namespace butl if (msys) { - // Wait a bit and check if the process has terminated. If it is - // still running then we assume all is good. Otherwise, retry if - // this is the DLL initialization error. + // Wait a bit and check if the process has terminated, or has written + // some data to stdout or stderr. If it is still running then we + // assume all is good. Otherwise, retry if this is the DLL + // initialization error. + // + // Note that the process standard output streams probing is possible + // only if they are connected to pipes created by us. We assume that + // data presence at the reading end of any of these pipes means that + // DLLs initialization successfully passed. // system_clock::time_point st (system_clock::now ()); @@ -1487,11 +1496,32 @@ namespace butl il.unlock (); l.unlock (); - // Hidden by butl::duration that is introduced via fdstream.mxx. - // - const chrono::duration<DWORD, milli> wd (1000); + auto probe_fd = [&get_osfhandle] (int fd) -> bool + { + if (fd == -1) + return false; - DWORD r (WaitForSingleObject (pi.hProcess, wd.count ())); + char c; + DWORD n; + HANDLE h (get_osfhandle (fd, false)); + return PeekNamedPipe (h, &c, 1, &n, nullptr, nullptr) && n == 1; + }; + + DWORD r; + system_clock::duration twd (0); // Total wait time. + for (size_t n (0); n != 10; ++n) // Wait n times by 200ms. + { + // Hidden by butl::duration that is introduced via fdstream.mxx. + // + const chrono::duration<DWORD, milli> wd (200); + + r = WaitForSingleObject (pi.hProcess, wd.count ()); + twd += wd; + + if (r != WAIT_TIMEOUT || + probe_fd (in_ofd.in.get ()) || probe_fd (in_efd.in.get ())) + break; + } if (r == WAIT_OBJECT_0 && GetExitCodeProcess (pi.hProcess, &r) && @@ -1502,7 +1532,7 @@ namespace butl // Assume we have waited the full amount if the time adjustment is // detected. // - system_clock::duration d (now > st ? now - st : wd); + system_clock::duration d (now > st ? now - st : twd); // If timeout is not fully exhausted, re-lock the mutex, revert // handles to inheritable state and re-spawn the process. |