diff options
author | Philip Hazel <ph10@hermes.cam.ac.uk> | 2005-05-24 14:56:26 +0000 |
---|---|---|
committer | Philip Hazel <ph10@hermes.cam.ac.uk> | 2005-05-24 14:56:26 +0000 |
commit | 958541e992051a5afcf573985eb5d4e772dc6979 (patch) | |
tree | 297fb8867b12ea04e648e0ce3ca734a3a71ac79b /src | |
parent | 21d59bc5e5c2332fed420840d80028b7cec3981a (diff) |
Reduce the timeout when writing a block has to be done in several
write() calls.
Diffstat (limited to 'src')
-rw-r--r-- | src/src/transport.c | 55 |
1 files changed, 41 insertions, 14 deletions
diff --git a/src/src/transport.c b/src/src/transport.c index c38818770..a104f51b4 100644 --- a/src/src/transport.c +++ b/src/src/transport.c @@ -1,4 +1,4 @@ -/* $Cambridge: exim/src/src/transport.c,v 1.8 2005/05/03 14:20:01 ph10 Exp $ */ +/* $Cambridge: exim/src/src/transport.c,v 1.9 2005/05/24 14:56:27 ph10 Exp $ */ /************************************************* * Exim - an Internet mail transport agent * @@ -199,26 +199,42 @@ BOOL transport_write_block(int fd, uschar *block, int len) { int i, rc, save_errno; +int local_timeout = transport_write_timeout; + +/* This loop is for handling incomplete writes and other retries. In most +normal cases, it is only ever executed once. */ for (i = 0; i < 100; i++) { DEBUG(D_transport) debug_printf("writing data block fd=%d size=%d timeout=%d\n", - fd, len, transport_write_timeout); - if (transport_write_timeout > 0) alarm(transport_write_timeout); + fd, len, local_timeout); - #ifdef SUPPORT_TLS - if (tls_active == fd) rc = tls_write(block, len); else - #endif + /* This code makes use of alarm() in order to implement the timeout. This + isn't a very tidy way of doing things. Using non-blocking I/O with select() + provides a neater approach. However, I don't know how to do this when TLS is + in use. */ - rc = write(fd, block, len); - save_errno = errno; + if (transport_write_timeout <= 0) /* No timeout wanted */ + { + #ifdef SUPPORT_TLS + if (tls_active == fd) rc = tls_write(block, len); else + #endif + rc = write(fd, block, len); + save_errno = errno; + } - /* Cancel the alarm and deal with a timeout */ + /* Timeout wanted. */ - if (transport_write_timeout > 0) + else { - alarm(0); + alarm(local_timeout); + #ifdef SUPPORT_TLS + if (tls_active == fd) rc = tls_write(block, len); else + #endif + rc = write(fd, block, len); + save_errno = errno; + local_timeout = alarm(0); if (sigalrm_seen) { errno = ETIMEDOUT; @@ -230,7 +246,8 @@ for (i = 0; i < 100; i++) if (rc == len) { transport_count += len; return TRUE; } - /* A non-negative return code is an incomplete write. Try again. */ + /* A non-negative return code is an incomplete write. Try again for the rest + of the block. If we have exactly hit the timeout, give up. */ if (rc >= 0) { @@ -238,7 +255,7 @@ for (i = 0; i < 100; i++) block += rc; transport_count += rc; DEBUG(D_transport) debug_printf("write incomplete (%d)\n", rc); - continue; + goto CHECK_TIMEOUT; /* A few lines below */ } /* A negative return code with an EINTR error is another form of @@ -248,7 +265,7 @@ for (i = 0; i < 100; i++) { DEBUG(D_transport) debug_printf("write interrupted before anything written\n"); - continue; + goto CHECK_TIMEOUT; /* A few lines below */ } /* A response of EAGAIN from write() is likely only in the case of writing @@ -259,6 +276,16 @@ for (i = 0; i < 100; i++) DEBUG(D_transport) debug_printf("write temporarily locked out, waiting 1 sec\n"); sleep(1); + + /* Before continuing to try another write, check that we haven't run out of + time. */ + + CHECK_TIMEOUT: + if (transport_write_timeout > 0 && local_timeout <= 0) + { + errno = ETIMEDOUT; + return FALSE; + } continue; } |