From af077f06d30703088d784e73e6088ce69a419561 Mon Sep 17 00:00:00 2001 From: Karen Arutyunov Date: Sat, 16 Nov 2019 14:43:56 +0300 Subject: Try to re-exec POSIX process after "text file busy" failure for 450ms --- libbutl/process.cxx | 27 +++++++++++++++++++++------ 1 file changed, 21 insertions(+), 6 deletions(-) diff --git a/libbutl/process.cxx b/libbutl/process.cxx index e2a8af1..8d067f4 100644 --- a/libbutl/process.cxx +++ b/libbutl/process.cxx @@ -624,12 +624,14 @@ namespace butl // "text file busy" issue: if some other thread creates a shell script // and the write-open file descriptor leaks into some child process, // then exec() for this script fails with ETXTBSY (see exec() man page - // for details). + // for details). If that's the case, it feels like such a descriptor + // should not stay open for too long. Thus, we will retry the exec() + // calls for about half a second. // handle = fork (); if (handle == -1) - fail (false); + fail (false /* child */); if (handle == 0) { @@ -647,7 +649,7 @@ namespace butl assert (fd > -1); if (dup2 (fd, sd) == -1) - fail (true); + fail (true /* child */); pd.in.reset (); // Silently close. pd.out.reset (); // Silently close. @@ -680,7 +682,7 @@ namespace butl // Change current working directory if requested. // if (cwd != nullptr && *cwd != '\0' && chdir (cwd) != 0) - fail (true); + fail (true /* child */); // Set/unset environment variables if requested. // @@ -704,8 +706,21 @@ namespace butl } } - if (execv (pp.effect_string (), const_cast (&args[0])) == -1) - fail (true); + // Try to re-exec after the "text file busy" failure for 450ms. + // + // Note that execv() does not return on success. + // + for (size_t i (1); i != 10; ++i) + { + execv (pp.effect_string (), const_cast (&args[0])); + + if (errno != ETXTBSY) + break; + + this_thread::sleep_for (i * 10ms); + } + + fail (true /* child */); } } // Release the lock in parent. #endif // LIBBUTL_POSIX_SPAWN_CHDIR -- cgit v1.1