(previous were without -u option :( )
Amit Athavale wrote:
Here is initial patch:
- only for unix, if this OK I will write for other platforms
- Tested on linux RH 8.0 and solaris 9
- New test case added in testshm.c
Please review it so I can provide patch for other platforms ASAP.
Thanks
Amit
Joe Orton wrote:
On Fri, May 28, 2004 at 12:31:37PM +0530, Amit Athavale wrote:It would be very useful for programmers. They could simply do one of the following to avoid headaches of admins :)- call apr_shm_remove right before apr_shm_create() - detect unclean shutdown case and call apr_shm_remove() I could prepare a patch for this if people are happy with this idea ;)Great, yes please! joe
Index: apr_shm.h
===================================================================
RCS file: /home/cvspublic/apr/include/apr_shm.h,v
retrieving revision 1.5.2.1
diff -u -r1.5.2.1 apr_shm.h
--- apr_shm.h 13 Feb 2004 09:33:45 -0000 1.5.2.1
+++ apr_shm.h 28 May 2004 11:40:46 -0000
@@ -69,6 +69,21 @@
const char *filename,
apr_pool_t *pool);
+
+/**
+ * Remove shared memory segment associated with a file.
+ * @param filename The file associated with shared-memory segment which
+ * needs to be removed
+ * @param pool To be used for file operations
+ * @remark This function is only supported for name-based shared
+ * memory segments. This function will return APR_ENOTIMPL if
+ * anonymous shared memory is prefered over name-based shared memory.
+ *
+ */
+APR_DECLARE(apr_status_t) apr_shm_remove(const char *filename,
+ apr_pool_t *pool);
+
+
/**
* Destroy a shared memory segment and associated memory.
* @param m The shared memory segment structure to destroy.
Index: shm.c
===================================================================
RCS file: /home/cvspublic/apr/shmem/unix/shm.c,v
retrieving revision 1.21.2.2
diff -u -r1.21.2.2 shm.c
--- shm.c 26 Feb 2004 21:18:01 -0000 1.21.2.2
+++ shm.c 28 May 2004 11:21:23 -0000
@@ -377,6 +377,70 @@
return APR_ENOTIMPL;
}
+APR_DECLARE(apr_status_t) apr_shm_remove(const char *filename,
+ apr_pool_t *pool)
+{
+ apr_status_t rv;
+#if APR_USE_SHMEM_SHMGET
+ apr_status_t status;
+ apr_file_t *file;
+ key_t shmkey;
+ int shmid;
+#endif
+
+#if APR_USE_SHMEM_MMAP_TMP
+ rv = apr_file_remove(filename, pool);
+ if (rv != APR_SUCCESS) {
+ return rv;
+ }
+ return APR_SUCCESS;
+#endif
+#if APR_USE_SHMEM_MMAP_SHM
+ if (shm_unlink(filename) == -1) {
+ return errno;
+ }
+ return APR_SUCCESS;
+#endif
+#if APR_USE_SHMEM_SHMGET
+ /* At this point we don't know whether file exists or not
+ * so opening it with only CREATE flag i.e. without EXCL
+ */
+ status = apr_file_open(&file, filename,
+ APR_WRITE | APR_CREATE,
+ APR_OS_DEFAULT, pool);
+ if (status != APR_SUCCESS) {
+ return status;
+ }
+
+ /* ftok() (on solaris at least) requires that the file actually
+ * exist before calling ftok(). */
+ shmkey = ftok(filename, 1);
+ if (shmkey == (key_t)-1) {
+ return errno;
+ }
+
+ if ((shmid = shmget(shmkey, 0, SHM_R | SHM_W)) < 0) {
+ return errno;
+ }
+
+ /* Indicate that the segment is to be destroyed as soon
+ * as all processes have detached. This also disallows any
+ * new attachments to the segment. */
+ if (shmctl(shmid, IPC_RMID, NULL) == -1) {
+ return errno;
+ }
+ rv = apr_file_remove(filename, pool);
+ if (rv != APR_SUCCESS) {
+ return rv;
+ }
+ return APR_SUCCESS;
+#endif
+
+ /* No support for anonymous shm */
+ return APR_ENOTIMPL;
+}
+
+
APR_DECLARE(apr_status_t) apr_shm_destroy(apr_shm_t *m)
{
return apr_pool_cleanup_run(m->pool, m, shm_cleanup_owner);
Index: testshm.c
===================================================================
RCS file: /home/cvspublic/apr/test/testshm.c,v
retrieving revision 1.8.2.1
diff -u -r1.8.2.1 testshm.c
--- testshm.c 13 Feb 2004 09:33:52 -0000 1.8.2.1
+++ testshm.c 28 May 2004 11:40:15 -0000
@@ -245,6 +245,56 @@
return APR_SUCCESS;
}
+static apr_status_t test_named_remove(apr_pool_t *parpool)
+{
+ apr_status_t rv;
+ apr_pool_t *pool;
+ apr_shm_t *shm;
+ int exit_int;
+
+ rv = apr_pool_create(&pool, parpool);
+ if (rv != APR_SUCCESS) {
+ fprintf(stderr, "Error creating child pool\n");
+ return rv;
+ }
+
+ printf("Creating named shared memory block first time(%"
+ APR_SIZE_T_FMT " bytes)........", SHARED_SIZE);
+ rv = apr_shm_create(&shm, SHARED_SIZE, SHARED_FILENAME, pool);
+ if (rv != APR_SUCCESS) {
+ fprintf(stderr, "Error allocating shared memory block\n");
+ return rv;
+ }
+ fprintf(stdout, "OK\n");
+
+ printf("Removing named shared memory block...");
+ rv = apr_shm_remove(SHARED_FILENAME, pool);
+ if (rv != APR_SUCCESS) {
+ fprintf(stderr, "Error removing shared memory block\n");
+ return rv;
+ }
+ fprintf(stdout, "OK\n");
+
+ printf("Creating named shared memory block second time(%"
+ APR_SIZE_T_FMT " bytes)........", SHARED_SIZE);
+ rv = apr_shm_create(&shm, SHARED_SIZE, SHARED_FILENAME, pool);
+ if (rv != APR_SUCCESS) {
+ fprintf(stderr, "Error allocating shared memory block\n");
+ return rv;
+ }
+ fprintf(stdout, "OK\n");
+
+ printf("Destroying shared memory segment...");
+ rv = apr_shm_destroy(shm);
+ if (rv != APR_SUCCESS) {
+ printf("FAILED\n");
+ return rv;
+ }
+ printf("OK\n");
+
+ return APR_SUCCESS;
+}
+
int main(void)
{
apr_status_t rv;
@@ -282,6 +332,13 @@
exit(-3);
}
printf("Named shared memory test passed!\n");
+
+ if ((rv = test_named_remove(pool)) != APR_SUCCESS) {
+ printf("Name-based shared memory remove test FAILED: [%d] %s \n",
+ rv, apr_strerror(rv, errmsg, sizeof(errmsg)));
+ exit(-3);
+ }
+ printf("Named shared memory removal test passed!\n");
return 0;
}
