diff options
Diffstat (limited to 'erts/emulator/drivers/unix')
-rw-r--r-- | erts/emulator/drivers/unix/unix_efile.c | 102 |
1 files changed, 40 insertions, 62 deletions
diff --git a/erts/emulator/drivers/unix/unix_efile.c b/erts/emulator/drivers/unix/unix_efile.c index 7cf0a712ce..796843a735 100644 --- a/erts/emulator/drivers/unix/unix_efile.c +++ b/erts/emulator/drivers/unix/unix_efile.c @@ -1004,13 +1004,11 @@ efile_writev(Efile_error* errInfo, /* Where to return error codes */ * opened */ int fd, /* File descriptor to write to */ SysIOVec* iov, /* Vector of buffer structs. - * The structs are unchanged - * after the call */ - int iovcnt, /* Number of structs in vector */ - size_t size) /* Number of bytes to write */ + * The structs may be changed i.e. + * due to incomplete writes */ + int iovcnt) /* Number of structs in vector */ { int cnt = 0; /* Buffers so far written */ - int p = 0; /* Position in next buffer */ ASSERT(iovcnt >= 0); @@ -1021,66 +1019,47 @@ efile_writev(Efile_error* errInfo, /* Where to return error codes */ #endif while (cnt < iovcnt) { + if ((! iov[cnt].iov_base) || (iov[cnt].iov_len <= 0)) { + /* Empty buffer - skip */ + cnt++; + } else { /* Non-empty buffer */ + ssize_t w; /* Bytes written in this call */ #ifdef HAVE_WRITEV - int w; /* Bytes written in this call */ - int b = iovcnt - cnt; /* Buffers to write */ - if (b > MAXIOV) - b = MAXIOV; - if (iov[cnt].iov_base && iov[cnt].iov_len > 0) { - if (b == 1) { - /* Degenerated io vector */ - do { - w = write(fd, iov[cnt].iov_base + p, iov[cnt].iov_len - p); - } while (w < 0 && errno == EINTR); - } else { - /* Non-empty vector first. - * Adjust pos in first buffer in case of - * previous incomplete writev */ - iov[cnt].iov_base += p; - iov[cnt].iov_len -= p; + int b = iovcnt - cnt; /* Buffers to write */ + /* Use as many buffers as MAXIOV allows */ + if (b > MAXIOV) + b = MAXIOV; + if (b > 1) { do { w = writev(fd, &iov[cnt], b); } while (w < 0 && errno == EINTR); - iov[cnt].iov_base -= p; - iov[cnt].iov_len += p; - } - if (w < 0) - return check_error(-1, errInfo); - } else { - /* Empty vector first - skip */ - cnt++; - continue; - } - ASSERT(w >= 0); - /* Move forward to next vector to write */ - for (; cnt < iovcnt; cnt++) { - if (iov[cnt].iov_base && iov[cnt].iov_len > 0) { - if (w < iov[cnt].iov_len) - break; - else - w -= iov[cnt].iov_len; - } - } - ASSERT(w >= 0); - p = w > 0 ? w : 0; /* Skip p bytes next writev */ -#else /* #ifdef HAVE_WRITEV */ - if (iov[cnt].iov_base && iov[cnt].iov_len > 0) { - /* Non-empty vector */ - int w; /* Bytes written in this call */ - while (p < iov[cnt].iov_len) { - do { - w = write(fd, iov[cnt].iov_base + p, iov[cnt].iov_len - p); - } while (w < 0 && errno == EINTR); - if (w < 0) - return check_error(-1, errInfo); - p += w; + } else + /* Degenerated io vector - use regular write */ +#endif + { + do { + w = write(fd, iov[cnt].iov_base, iov[cnt].iov_len); + } while (w < 0 && errno == EINTR); + ASSERT(w <= iov[cnt].iov_len); + } + if (w < 0) return check_error(-1, errInfo); + /* Move forward to next buffer to write */ + for (; cnt < iovcnt && w > 0; cnt++) { + if (iov[cnt].iov_base && iov[cnt].iov_len > 0) { + if (w < iov[cnt].iov_len) { + /* Adjust the buffer for next write */ + iov[cnt].iov_len -= w; + iov[cnt].iov_base += w; + w = 0; + break; + } else { + w -= iov[cnt].iov_len; + } + } } - } - cnt++; - p = 0; -#endif /* #ifdef HAVE_WRITEV */ + ASSERT(w == 0); + } /* else Non-empty buffer */ } /* while (cnt< iovcnt) */ - size = 0; /* Avoid compiler warning */ return 1; } @@ -1427,10 +1406,9 @@ efile_fadvise(Efile_error* errInfo, int fd, Sint64 offset, } #ifdef HAVE_SENDFILE - // For some reason the maximum size_t cannot be used as the max size // 3GB seems to work on all platforms -#define SENDFILE_CHUNK_SIZE ((1 << 30) -1) +#define SENDFILE_CHUNK_SIZE ((1UL << 30) -1) /* * sendfile: The implementation of the sendfile system call varies @@ -1467,7 +1445,7 @@ efile_sendfile(Efile_error* errInfo, int in_fd, int out_fd, written += retval; *nbytes -= retval; } - } while (retval != -1 && retval == SENDFILE_CHUNK_SIZE); + } while (retval == SENDFILE_CHUNK_SIZE); *nbytes = written; return check_error(retval == -1 ? -1 : 0, errInfo); #elif defined(__sun) && defined(__SVR4) && defined(HAVE_SENDFILEV) |