From 5fe89d0126ec215ac2a09884bfbd4dd7bf8e7d2f Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Thu, 6 May 2010 01:27:36 +0000 Subject: Handle EWOULDBLOCK as EAGAIN. And add a comment explaining why EAGAIN and EWOULDBLOCK are used here. Also, handle the case where a write call is interrupted after some data has already been written. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103153 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Support/raw_ostream.cpp | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) (limited to 'lib') diff --git a/lib/Support/raw_ostream.cpp b/lib/Support/raw_ostream.cpp index f8ac65d..ad47cb6 100644 --- a/lib/Support/raw_ostream.cpp +++ b/lib/Support/raw_ostream.cpp @@ -422,11 +422,30 @@ void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) { assert(FD >= 0 && "File already closed."); pos += Size; ssize_t ret; + do { ret = ::write(FD, Ptr, Size); - } while (ret < 0 && (errno == EAGAIN || errno == EINTR)); - if (ret != (ssize_t) Size) - error_detected(); + + if (ret < 0) { + // If it's a recoverable error, swallow it and retry the write. + // EAGAIN and EWOULDBLOCK are not unambiguously recoverable, but + // some programs, such as bjam, assume that their child processes + // will treat them as if they are. If you don't want this code to + // spin, don't use O_NONBLOCK file descriptors with raw_ostream. + if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK) + continue; + + // Otherwise it's a non-recoverable error. Note it and quit. + error_detected(); + break; + } + + // The write may have written some or all of the data. Update the + // size and buffer pointer to reflect the remainder that needs + // to be written. If there are no bytes left, we're done. + Ptr += ret; + Size -= ret; + } while (Size > 0); } void raw_fd_ostream::close() { -- cgit v1.1