Changeset 48

Timestamp:

06/30/08 17:37:24 (2 months ago)

Author:

jtang

Message:

Modified sipc_recv_data() and sipc_shm_recv_done() to be signal-safe.
sipc_recv_data() can now be [re-]invoked without loss of data.

Files:

• trunk/libsipc/src/mqueue_internal.c (modified) (1 diff)
• trunk/libsipc/src/shm_internal.c (modified) (1 diff)
• trunk/libsipc/src/sipc.c (modified) (1 diff)
• trunk/libsipc/src/sipc_internal.h (modified) (2 diffs)
• trunk/libsipc/src/sipc_mqueue.c (modified) (9 diffs)
• trunk/libsipc/src/sipc_shm.c (modified) (4 diffs)
• trunk/libsipc/tests/mqueue.c (modified) (2 diffs)

trunk/libsipc/src/mqueue_internal.c

@@ -120 +120 @@
-        int flags = block ? 0 : IPC_NOWAIT;
-
-
-
+
+
+
+
+
-                        return 0;
-                return -1;

trunk/libsipc/src/shm_internal.c

@@ -36 +36 @@
-int sipc_shm_recv_done(sipc_t *sipc)
-{
-
+
+
-                return -1;
+        }
-
-
-
+
+
+
+
+
+
+
-        return 0;
-}

trunk/libsipc/src/sipc.c

@@ -54 +54 @@
-        new_sipc->role = role;
-        new_sipc->non_blocking = 0;
-
-
+
+
+
+
-
-        /* call backend specific init to fill in function table */

trunk/libsipc/src/sipc_internal.h

@@ -34 +34 @@
-#define SIPC_MSG_LEN    0x09
-#define SIPC_END_XMIT   0x0c
-
-/* Invalid message length */
-#define SIPC_MSGLEN_NOT_SET -1
-
-/* Creation functions */
@@ -90 +87 @@
-        };
-
-
+                   /* Buffer for sending data */
-        struct msgbuf *mbuf;
-
-
-
+
+
+
+
+
-        struct sipc_func_table *funcs;
-};

trunk/libsipc/src/sipc_mqueue.c

@@ -56 +56 @@
-static int is_msg_len(struct msgbuf *mbuf);
-static int is_end_xmit(struct msgbuf *mbuf);
-static size_t next_alloc_sz(int recv, int recv_sz, int max_packet_sz, int msg_len);
-
-int sipc_mqueue_init(sipc_t *sipc)
@@ -104 +103 @@
-{
-        /* Allocate data member */
-len
+data_size
-        if (!sipc->data) {
-                sipc_error(sipc, "Out of memory\n");
@@ -182 +181 @@
-int sipc_mqueue_recv_data(sipc_t *sipc, char **data, int *len)
-{
-, alloc_sz = 0, idx = 0, recv_sz
-int msgtxt_sz = SIPC_MQUEUE_MSG_SZ - sizeof(struct msgbuf)
+
+size_t idx, recv_sz
-        int error = 0;
-
-        if (data)
-                *data = NULL;          /* Pointer to a buffer created here */
-        if (len)
-                *len = 0;              /* Bytes received so far */
-        if (!sipc || !data || !len) {
-                error = EINVAL;
-                goto err;
-        }
-
-        idx = 0;                       /* Current index into the buffer */
-
-        if (sipc->role != SIPC_RECEIVER) {
-                error = EBADF;
-                sipc_error(sipc, "sipc_send_data called without receiver flag enabled in IPC structure\n");
-                goto err;
-        }
-
-        struct msgbuf *mbuf = sipc->mbuf;
@@ -208 +192 @@
-
-        /* Receive and validate the length of message marker */
-msg_len == SIPC_MSGLEN_NOT_SET
-if
+recv_len == 0
+while
-                        error = errno;
+                        if (error == EINTR) {
+                                continue;
+                        }
-                        if (error == ENOMSG || error == EAGAIN)
-                                error = EAGAIN;
@@ -223 +210 @@
-
-                if (is_msg_len(mbuf)) {
-
-
+
+
+
-                                error = EIO;
-                                sipc_error(sipc, "libsipc: bad message length\n");
-                                goto err;
-                        }
-msg_len > sipc->len
+recv_len > sipc->data_size
-                                error = EIO;
-                                sipc_error(sipc, "libsipc: cannot receive buffer of size %zd, can only receive %zd\n",
-msg_len, sipc->len
+recv_len, sipc->data_size
-                                goto err;
-                        }
@@ -240 +228 @@
-                        goto err;
-                }
+                sipc->len = 0;
+        }
+
+        if (sipc->recv_len == 0) {
+                /* special case if there is no data to be received: *data
+                   needs to point to a buffer, but a malloc() of 0 is not
+                   defined, so allocate a single byte for it. */
+                if ((sipc->recv_data = malloc(1)) == NULL) {
+                        error = errno;
+                        sipc_error(sipc, "%s\n", "Out of memory");
+                        goto err;
+                }
-        }
-
@@ -245 +245 @@
-         * Stop when we have received the total number of bytes
-         * or upon receiving the end of message marker. */
-if
+while
-                error = errno;
+                if (error == EINTR) {
+                        continue;
+                }
-                if (error == ENOMSG || error == EAGAIN)
-                        error = EAGAIN;
@@ -255 +258 @@
-
-        while (!is_end_xmit(mbuf)) {
-
-
-
-
-
-
-
-
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
-                        error = errno;
-
-
-
-
-
-
-
-
-
-
-
-
+
+
+
-                        if (error == ENOMSG || error == EAGAIN)
-                                error = EAGAIN;
-                        else
-                                sipc_error(sipc, "msgrcv: %s\n", strerror(errno));
-                        /* Note that it is possible for a non-blocking
-                         * SIPC to fail while receiving a chunked message,
-                         * in which case the entire message becomes lost.
-                         * This is probably not the best design possible.
-                         */
-                        goto err;
-                }
-        }
-
+        *data = sipc->recv_data;
+        *len = sipc->len;
+        sipc->recv_len = 0;
+        sipc->len = 0;
+        sipc->recv_data = NULL;
-        retv = 0;
+
-      err:
-
+
+
+
+
+
+
-        errno = error;
-        if (retv) {
-                free(*data);
-                *data = NULL;
-                *len = 0;
-        }
-        return retv;
-}
@@ -408 +412 @@
-        return 0;
-}
-
-/* Determine how much memory to allocate for receiving a packet.
- * A packet should not contain extra padding.
- * Returns the size of the next allocation on success, -1 on failure. */
-static size_t next_alloc_sz(int need, int recv_sz, int max_packet_sz, int msg_len)
-{
-        if (need < 0 || max_packet_sz <= 0 || msg_len <= 0)
-                return -1;
-
-        if (need > msg_len)
-                return max_packet_sz;
-
-        return recv_sz;
-}

trunk/libsipc/src/sipc_shm.c

@@ -67 +67 @@
-
-        /* Create the shm segment */
-len
+data_size
-        if (sipc->s.shmid < 0) {
-                sipc_error(sipc, "shmget: %s\n", strerror(errno));
@@ -99 +99 @@
-        /* Get the (existing) shm segment */
-        flags = sipc->role == SIPC_SENDER ? SHM_SPERMS : SHM_RPERMS;
-len
+data_size
-        if (sipc->s.shmid < 0) {
-                sipc_error(sipc, "shmget: %s\n", strerror(errno));
@@ -163 +163 @@
-
-        /* Send a DATA_READY marker */
+        sipc->len = msg_len;
-        if (mqueue_send_msg_type(sipc->s.msqid, SIPC_DATA_READY, MQ_BLOCK) < 0) {
-                error = errno;
@@ -207 +208 @@
-                /* It is now OK to read shared memory */
-                *data = sipc->data;
-len
+data_size
-                return 0;
-        } else {

trunk/libsipc/tests/mqueue.c

@@ -330 +330 @@
-        int len = 0;
-
-
-
-
-
-
-
-
-
-
-
-
-
+
+
+
+
+
+
+
+
+
-                }
-
-
-
-
+
+
+
+
+
+
+
+
+
+
+
+
+
+
-                }
-        }
-CU_FAIL("Did not receive as much data as expected."
+free(data
-}
-
@@ -366 +373 @@
-                }
-                data[i] = j;
+        }
+
+        /* Send data, then end of xmit */
+        CU_ASSERT(sipc_send_data(writer2_ipc, i) == 0);
+
+        /* This time send data that does not nicely fit on a word boundary */
+        j = 42;
+        for (i = 0; i < BIG_DATA_LEN - 1; i++) {
+                data[i] = j++;
+                if (i % 120 == 0) {
+                        j = 0;
+                }
-        }
-