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-rw-r--r--modules/slotmem/mod_slotmem_shm.c788
1 files changed, 788 insertions, 0 deletions
diff --git a/modules/slotmem/mod_slotmem_shm.c b/modules/slotmem/mod_slotmem_shm.c
new file mode 100644
index 0000000..f4eaa84
--- /dev/null
+++ b/modules/slotmem/mod_slotmem_shm.c
@@ -0,0 +1,788 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* Memory handler for a shared memory divided in slot.
+ * This one uses shared memory.
+ *
+ * Shared memory is cleaned-up for each restart, graceful or
+ * otherwise.
+ */
+
+#include "ap_slotmem.h"
+
+#include "httpd.h"
+#include "http_main.h"
+#include "ap_mpm.h" /* for ap_mpm_query() */
+
+#define AP_SLOTMEM_IS_PREGRAB(t) (t->desc->type & AP_SLOTMEM_TYPE_PREGRAB)
+#define AP_SLOTMEM_IS_PERSIST(t) (t->desc->type & AP_SLOTMEM_TYPE_PERSIST)
+#define AP_SLOTMEM_IS_CLEARINUSE(t) (t->desc->type & AP_SLOTMEM_TYPE_CLEARINUSE)
+
+/* The description of the slots to reuse the slotmem */
+typedef struct {
+ apr_size_t size; /* size of each memory slot */
+ unsigned int num; /* number of mem slots */
+ ap_slotmem_type_t type; /* type-specific flags */
+} sharedslotdesc_t;
+
+#define AP_SLOTMEM_OFFSET (APR_ALIGN_DEFAULT(sizeof(sharedslotdesc_t)))
+#define AP_UNSIGNEDINT_OFFSET (APR_ALIGN_DEFAULT(sizeof(unsigned int)))
+
+struct ap_slotmem_instance_t {
+ char *name; /* file based SHM path/name */
+ char *pname; /* persisted file path/name */
+ int fbased; /* filebased? */
+ void *shm; /* ptr to memory segment (apr_shm_t *) */
+ void *base; /* data set start */
+ apr_pool_t *gpool; /* per segment pool (generation cleared) */
+ char *inuse; /* in-use flag table*/
+ unsigned int *num_free; /* slot free count for this instance */
+ void *persist; /* persist dataset start */
+ const sharedslotdesc_t *desc; /* per slot desc */
+ struct ap_slotmem_instance_t *next; /* location of next allocated segment */
+};
+
+/*
+ * Layout for SHM and persisted file :
+ *
+ * +-------------------------------------------------------------+~>
+ * | desc | num_free | base (slots) | inuse (array) | md5 | desc | compat..
+ * +------+-----------------------------------------+------------+~>
+ * ^ ^ ^ \ / ^ :
+ * |______|_____________ SHM (mem->@) ______________| | _____|__/
+ * | |/ |
+ * | ^ v |
+ * |_____________________ File (mem->persist + [meta]) __|
+ */
+
+/* global pool and list of slotmem we are handling */
+static struct ap_slotmem_instance_t *globallistmem = NULL;
+static apr_pool_t *gpool = NULL;
+
+#define DEFAULT_SLOTMEM_PREFIX "slotmem-shm-"
+#define DEFAULT_SLOTMEM_SUFFIX ".shm"
+#define DEFAULT_SLOTMEM_PERSIST_SUFFIX ".persist"
+
+/*
+ * Persist the slotmem in a file
+ * slotmem name and file name.
+ * none : no persistent data
+ * rel_name : $server_root/rel_name
+ * /abs_name : $abs_name
+ *
+ */
+static int slotmem_filenames(apr_pool_t *pool,
+ const char *slotname,
+ const char **filename,
+ const char **persistname)
+{
+ const char *fname = NULL, *pname = NULL;
+
+ if (slotname && *slotname && strcasecmp(slotname, "none") != 0) {
+ if (slotname[0] != '/') {
+ /* Each generation needs its own file name. */
+ int generation = 0;
+ ap_mpm_query(AP_MPMQ_GENERATION, &generation);
+ fname = apr_psprintf(pool, "%s%s_%x%s", DEFAULT_SLOTMEM_PREFIX,
+ slotname, generation, DEFAULT_SLOTMEM_SUFFIX);
+ fname = ap_runtime_dir_relative(pool, fname);
+ }
+ else {
+ /* Don't mangle the file name if given an absolute path, it's
+ * up to the caller to provide a unique name when necessary.
+ */
+ fname = slotname;
+ }
+
+ if (persistname) {
+ /* Persisted file names are immutable... */
+ if (slotname[0] != '/') {
+ pname = apr_pstrcat(pool, DEFAULT_SLOTMEM_PREFIX,
+ slotname, DEFAULT_SLOTMEM_SUFFIX,
+ DEFAULT_SLOTMEM_PERSIST_SUFFIX,
+ NULL);
+ pname = ap_runtime_dir_relative(pool, pname);
+ }
+ else {
+ pname = apr_pstrcat(pool, slotname,
+ DEFAULT_SLOTMEM_PERSIST_SUFFIX,
+ NULL);
+ }
+ }
+ }
+
+ *filename = fname;
+ if (persistname) {
+ *persistname = pname;
+ }
+ return (fname != NULL);
+}
+
+static void slotmem_clearinuse(ap_slotmem_instance_t *slot)
+{
+ unsigned int i;
+ char *inuse;
+
+ if (!slot) {
+ return;
+ }
+
+ inuse = slot->inuse;
+
+ for (i = 0; i < slot->desc->num; i++, inuse++) {
+ if (*inuse) {
+ *inuse = 0;
+ (*slot->num_free)++;
+ }
+ }
+}
+
+static void store_slotmem(ap_slotmem_instance_t *slotmem)
+{
+ apr_file_t *fp;
+ apr_status_t rv;
+ apr_size_t nbytes;
+ unsigned char digest[APR_MD5_DIGESTSIZE];
+ const char *storename = slotmem->pname;
+
+ ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(02334)
+ "storing %s", storename);
+
+ if (storename) {
+ rv = apr_file_open(&fp, storename, APR_CREATE | APR_READ | APR_WRITE,
+ APR_OS_DEFAULT, slotmem->gpool);
+ if (APR_STATUS_IS_EEXIST(rv)) {
+ apr_file_remove(storename, slotmem->gpool);
+ rv = apr_file_open(&fp, storename, APR_CREATE | APR_READ | APR_WRITE,
+ APR_OS_DEFAULT, slotmem->gpool);
+ }
+ if (rv != APR_SUCCESS) {
+ return;
+ }
+ if (AP_SLOTMEM_IS_CLEARINUSE(slotmem)) {
+ slotmem_clearinuse(slotmem);
+ }
+ nbytes = (slotmem->desc->size * slotmem->desc->num) +
+ (slotmem->desc->num * sizeof(char)) + AP_UNSIGNEDINT_OFFSET;
+ apr_md5(digest, slotmem->persist, nbytes);
+ rv = apr_file_write_full(fp, slotmem->persist, nbytes, NULL);
+ if (rv == APR_SUCCESS) {
+ rv = apr_file_write_full(fp, digest, APR_MD5_DIGESTSIZE, NULL);
+ }
+ if (rv == APR_SUCCESS) {
+ rv = apr_file_write_full(fp, slotmem->desc, AP_SLOTMEM_OFFSET,
+ NULL);
+ }
+ apr_file_close(fp);
+ if (rv != APR_SUCCESS) {
+ apr_file_remove(storename, slotmem->gpool);
+ }
+ }
+}
+
+static apr_status_t restore_slotmem(sharedslotdesc_t *desc,
+ const char *storename, apr_size_t size,
+ apr_pool_t *pool)
+{
+ apr_file_t *fp;
+ apr_status_t rv = APR_ENOTIMPL;
+ void *ptr = (char *)desc + AP_SLOTMEM_OFFSET;
+ apr_size_t nbytes = size - AP_SLOTMEM_OFFSET;
+ unsigned char digest[APR_MD5_DIGESTSIZE];
+ unsigned char digest2[APR_MD5_DIGESTSIZE];
+ char desc_buf[AP_SLOTMEM_OFFSET];
+
+ ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(02335)
+ "restoring %s", storename);
+
+ if (storename) {
+ rv = apr_file_open(&fp, storename, APR_READ | APR_WRITE, APR_OS_DEFAULT,
+ pool);
+ if (rv == APR_SUCCESS) {
+ rv = apr_file_read_full(fp, ptr, nbytes, NULL);
+ if (rv == APR_SUCCESS || rv == APR_EOF) {
+ /*
+ * if at EOF, don't bother checking md5
+ * - backwards compatibility
+ * */
+ if (apr_file_eof(fp) != APR_EOF) {
+ rv = apr_file_read_full(fp, digest, APR_MD5_DIGESTSIZE, NULL);
+ if (rv == APR_SUCCESS || rv == APR_EOF) {
+ apr_md5(digest2, ptr, nbytes);
+ if (memcmp(digest, digest2, APR_MD5_DIGESTSIZE)) {
+ rv = APR_EMISMATCH;
+ }
+ /*
+ * if at EOF, don't bother checking desc
+ * - backwards compatibility
+ * */
+ else if (apr_file_eof(fp) != APR_EOF) {
+ rv = apr_file_read_full(fp, desc_buf, sizeof(desc_buf), NULL);
+ if (rv == APR_SUCCESS || rv == APR_EOF) {
+ if (memcmp(desc, desc_buf, sizeof(desc_buf))) {
+ rv = APR_EMISMATCH;
+ }
+ else {
+ rv = APR_SUCCESS;
+ }
+ }
+ else {
+ rv = APR_INCOMPLETE;
+ }
+ }
+ else {
+ rv = APR_EOF;
+ }
+ }
+ else {
+ rv = APR_INCOMPLETE;
+ }
+ }
+ else {
+ rv = APR_EOF;
+ }
+ if (rv == APR_EMISMATCH) {
+ ap_log_error(APLOG_MARK, APLOG_ERR, 0, ap_server_conf, APLOGNO(02551)
+ "persisted slotmem md5/desc mismatch");
+ }
+ else if (rv == APR_EOF) {
+ ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, APLOGNO(02552)
+ "persisted slotmem at EOF... bypassing md5/desc match check "
+ "(old persist file?)");
+ rv = APR_SUCCESS;
+ }
+ }
+ else {
+ rv = APR_INCOMPLETE;
+ }
+ if (rv == APR_INCOMPLETE) {
+ ap_log_error(APLOG_MARK, APLOG_ERR, 0, ap_server_conf, APLOGNO(02553)
+ "persisted slotmem read had unexpected size");
+ }
+ apr_file_close(fp);
+ }
+ }
+ return rv;
+}
+
+/*
+ * Whether the module is called from a MPM that re-enter main() and
+ * pre/post_config phases.
+ */
+static APR_INLINE int is_child_process(void)
+{
+#ifdef WIN32
+ return getenv("AP_PARENT_PID") != NULL;
+#else
+ return 0;
+#endif
+}
+
+static apr_status_t cleanup_slotmem(void *param)
+{
+ int is_child = is_child_process();
+ ap_slotmem_instance_t *next = globallistmem;
+
+ while (next) {
+ if (!is_child && AP_SLOTMEM_IS_PERSIST(next)) {
+ store_slotmem(next);
+ }
+ apr_shm_destroy(next->shm);
+ apr_shm_remove(next->name, next->gpool);
+ next = next->next;
+ }
+
+ globallistmem = NULL;
+ return APR_SUCCESS;
+}
+
+static apr_status_t slotmem_doall(ap_slotmem_instance_t *mem,
+ ap_slotmem_callback_fn_t *func,
+ void *data, apr_pool_t *pool)
+{
+ unsigned int i;
+ char *ptr;
+ char *inuse;
+ apr_status_t retval = APR_SUCCESS;
+
+ if (!mem) {
+ return APR_ENOSHMAVAIL;
+ }
+
+ ptr = (char *)mem->base;
+ inuse = mem->inuse;
+ for (i = 0; i < mem->desc->num; i++, inuse++) {
+ if (!AP_SLOTMEM_IS_PREGRAB(mem) || *inuse) {
+ retval = func((void *) ptr, data, pool);
+ if (retval != APR_SUCCESS)
+ break;
+ }
+ ptr += mem->desc->size;
+ }
+ return retval;
+}
+
+static apr_status_t slotmem_create(ap_slotmem_instance_t **new,
+ const char *name, apr_size_t item_size,
+ unsigned int item_num,
+ ap_slotmem_type_t type, apr_pool_t *pool)
+{
+ int fbased = 1;
+ int restored = 0;
+ char *ptr;
+ sharedslotdesc_t *desc;
+ ap_slotmem_instance_t *res;
+ ap_slotmem_instance_t *next = globallistmem;
+ const char *fname, *pname = NULL;
+ apr_shm_t *shm;
+ apr_size_t basesize = (item_size * item_num);
+ apr_size_t size = AP_SLOTMEM_OFFSET + AP_UNSIGNEDINT_OFFSET +
+ (item_num * sizeof(char)) + basesize;
+ int persist = (type & AP_SLOTMEM_TYPE_PERSIST) != 0;
+ apr_status_t rv;
+
+ *new = NULL;
+ if (gpool == NULL) {
+ return APR_ENOSHMAVAIL;
+ }
+ if (slotmem_filenames(pool, name, &fname, persist ? &pname : NULL)) {
+ /* first try to attach to existing slotmem */
+ if (next) {
+ for (;;) {
+ if (strcmp(next->name, fname) == 0) {
+ /* we already have it */
+ *new = next;
+ ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(02603)
+ "create found %s in global list", fname);
+ return APR_SUCCESS;
+ }
+ if (!next->next) {
+ break;
+ }
+ next = next->next;
+ }
+ }
+ ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(02602)
+ "create didn't find %s in global list", fname);
+ }
+ else {
+ fbased = 0;
+ fname = "none";
+ }
+
+ /* first try to attach to existing shared memory */
+ ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(02300)
+ "create %s: %"APR_SIZE_T_FMT"/%u", fname, item_size,
+ item_num);
+
+ {
+ /* For MPMs that run pre/post_config() phases in both the parent
+ * and children processes (e.g. winnt), SHMs created by the
+ * parent exist in the children already; attach them.
+ */
+ if (fbased) {
+ if (is_child_process()) {
+ rv = apr_shm_attach(&shm, fname, gpool);
+ }
+ else {
+ apr_shm_remove(fname, pool);
+ rv = apr_shm_create(&shm, size, fname, gpool);
+ }
+ }
+ else {
+ rv = apr_shm_create(&shm, size, NULL, gpool);
+ }
+ ap_log_error(APLOG_MARK, rv == APR_SUCCESS ? APLOG_DEBUG : APLOG_ERR,
+ rv, ap_server_conf, APLOGNO(02611)
+ "create: apr_shm_%s(%s) %s",
+ fbased && is_child_process() ? "attach" : "create",
+ fname, rv == APR_SUCCESS ? "succeeded" : "failed");
+ if (rv != APR_SUCCESS) {
+ return rv;
+ }
+
+ desc = (sharedslotdesc_t *)apr_shm_baseaddr_get(shm);
+ memset(desc, 0, size);
+ desc->size = item_size;
+ desc->num = item_num;
+ desc->type = type;
+
+ /*
+ * TODO: Error check the below... What error makes
+ * sense if the restore fails? Any?
+ * For now, we continue with a fresh new slotmem,
+ * but NOTICE in the log.
+ */
+ if (persist) {
+ rv = restore_slotmem(desc, pname, size, pool);
+ if (rv == APR_SUCCESS) {
+ restored = 1;
+ }
+ else {
+ /* just in case, re-zero */
+ ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf,
+ APLOGNO(02554) "could not restore %s", fname);
+ memset((char *)desc + AP_SLOTMEM_OFFSET, 0,
+ size - AP_SLOTMEM_OFFSET);
+ }
+ }
+ }
+
+ ptr = (char *)desc + AP_SLOTMEM_OFFSET;
+
+ /* For the chained slotmem stuff */
+ res = apr_pcalloc(gpool, sizeof(ap_slotmem_instance_t));
+ res->name = apr_pstrdup(gpool, fname);
+ res->pname = apr_pstrdup(gpool, pname);
+ res->fbased = fbased;
+ res->shm = shm;
+ res->persist = (void *)ptr;
+ res->num_free = (unsigned int *)ptr;
+ ptr += AP_UNSIGNEDINT_OFFSET;
+ if (!restored) {
+ *res->num_free = item_num;
+ }
+ res->base = (void *)ptr;
+ res->desc = desc;
+ res->gpool = gpool;
+ res->next = NULL;
+ res->inuse = ptr + basesize;
+ if (fbased) {
+ if (globallistmem == NULL) {
+ globallistmem = res;
+ }
+ else {
+ next->next = res;
+ }
+ }
+
+ *new = res;
+ return APR_SUCCESS;
+}
+
+static apr_status_t slotmem_attach(ap_slotmem_instance_t **new,
+ const char *name, apr_size_t *item_size,
+ unsigned int *item_num, apr_pool_t *pool)
+{
+ char *ptr;
+ ap_slotmem_instance_t *res;
+ ap_slotmem_instance_t *next = globallistmem;
+ sharedslotdesc_t *desc;
+ const char *fname;
+ apr_shm_t *shm;
+ apr_status_t rv;
+
+ if (gpool == NULL) {
+ return APR_ENOSHMAVAIL;
+ }
+ if (!slotmem_filenames(pool, name, &fname, NULL)) {
+ return APR_ENOSHMAVAIL;
+ }
+
+ ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(02301)
+ "attach looking for %s", fname);
+
+ /* first try to attach to existing slotmem */
+ if (next) {
+ for (;;) {
+ if (strcmp(next->name, fname) == 0) {
+ /* we already have it */
+ *new = next;
+ *item_size = next->desc->size;
+ *item_num = next->desc->num;
+ ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf,
+ APLOGNO(02302)
+ "attach found %s: %"APR_SIZE_T_FMT"/%u", fname,
+ *item_size, *item_num);
+ return APR_SUCCESS;
+ }
+ if (!next->next) {
+ break;
+ }
+ next = next->next;
+ }
+ }
+
+ /* next try to attach to existing shared memory */
+ rv = apr_shm_attach(&shm, fname, gpool);
+ if (rv != APR_SUCCESS) {
+ return rv;
+ }
+
+ /* Read the description of the slotmem */
+ desc = (sharedslotdesc_t *)apr_shm_baseaddr_get(shm);
+ ptr = (char *)desc + AP_SLOTMEM_OFFSET;
+
+ /* For the chained slotmem stuff */
+ res = apr_pcalloc(gpool, sizeof(ap_slotmem_instance_t));
+ res->name = apr_pstrdup(gpool, fname);
+ res->fbased = 1;
+ res->shm = shm;
+ res->persist = (void *)ptr;
+ res->num_free = (unsigned int *)ptr;
+ ptr += AP_UNSIGNEDINT_OFFSET;
+ res->base = (void *)ptr;
+ res->desc = desc;
+ res->gpool = gpool;
+ res->inuse = ptr + (desc->size * desc->num);
+ res->next = NULL;
+
+ *new = res;
+ *item_size = desc->size;
+ *item_num = desc->num;
+ ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf,
+ APLOGNO(02303)
+ "attach found %s: %"APR_SIZE_T_FMT"/%u", fname,
+ *item_size, *item_num);
+ return APR_SUCCESS;
+}
+
+static apr_status_t slotmem_dptr(ap_slotmem_instance_t *slot,
+ unsigned int id, void **mem)
+{
+ char *ptr;
+
+ if (!slot) {
+ return APR_ENOSHMAVAIL;
+ }
+ if (id >= slot->desc->num) {
+ return APR_EINVAL;
+ }
+
+ ptr = (char *)slot->base + slot->desc->size * id;
+ if (!ptr) {
+ return APR_ENOSHMAVAIL;
+ }
+ *mem = (void *)ptr;
+ return APR_SUCCESS;
+}
+
+static apr_status_t slotmem_get(ap_slotmem_instance_t *slot, unsigned int id,
+ unsigned char *dest, apr_size_t dest_len)
+{
+ void *ptr;
+ char *inuse;
+ apr_status_t ret;
+
+ if (!slot) {
+ return APR_ENOSHMAVAIL;
+ }
+
+ inuse = slot->inuse + id;
+ if (id >= slot->desc->num) {
+ return APR_EINVAL;
+ }
+ if (AP_SLOTMEM_IS_PREGRAB(slot) && !*inuse) {
+ return APR_NOTFOUND;
+ }
+ ret = slotmem_dptr(slot, id, &ptr);
+ if (ret != APR_SUCCESS) {
+ return ret;
+ }
+ *inuse = 1;
+ memcpy(dest, ptr, dest_len); /* bounds check? */
+ return APR_SUCCESS;
+}
+
+static apr_status_t slotmem_put(ap_slotmem_instance_t *slot, unsigned int id,
+ unsigned char *src, apr_size_t src_len)
+{
+ void *ptr;
+ char *inuse;
+ apr_status_t ret;
+
+ if (!slot) {
+ return APR_ENOSHMAVAIL;
+ }
+
+ inuse = slot->inuse + id;
+ if (id >= slot->desc->num) {
+ return APR_EINVAL;
+ }
+ if (AP_SLOTMEM_IS_PREGRAB(slot) && !*inuse) {
+ return APR_NOTFOUND;
+ }
+ ret = slotmem_dptr(slot, id, &ptr);
+ if (ret != APR_SUCCESS) {
+ return ret;
+ }
+ *inuse=1;
+ memcpy(ptr, src, src_len); /* bounds check? */
+ return APR_SUCCESS;
+}
+
+static unsigned int slotmem_num_slots(ap_slotmem_instance_t *slot)
+{
+ return slot->desc->num;
+}
+
+static unsigned int slotmem_num_free_slots(ap_slotmem_instance_t *slot)
+{
+ if (AP_SLOTMEM_IS_PREGRAB(slot))
+ return *slot->num_free;
+ else {
+ unsigned int i, counter=0;
+ char *inuse = slot->inuse;
+ for (i=0; i<slot->desc->num; i++, inuse++) {
+ if (!*inuse)
+ counter++;
+ }
+ return counter;
+ }
+}
+
+static apr_size_t slotmem_slot_size(ap_slotmem_instance_t *slot)
+{
+ return slot->desc->size;
+}
+
+static apr_status_t slotmem_grab(ap_slotmem_instance_t *slot, unsigned int *id)
+{
+ unsigned int i;
+ char *inuse;
+
+ if (!slot) {
+ return APR_ENOSHMAVAIL;
+ }
+
+ inuse = slot->inuse;
+
+ for (i = 0; i < slot->desc->num; i++, inuse++) {
+ if (!*inuse) {
+ break;
+ }
+ }
+ if (i >= slot->desc->num) {
+ ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(02293)
+ "slotmem(%s) grab failed. Num %u/num_free %u",
+ slot->name, slotmem_num_slots(slot),
+ slotmem_num_free_slots(slot));
+ return APR_EINVAL;
+ }
+ *inuse = 1;
+ *id = i;
+ (*slot->num_free)--;
+ return APR_SUCCESS;
+}
+
+static apr_status_t slotmem_fgrab(ap_slotmem_instance_t *slot, unsigned int id)
+{
+ char *inuse;
+
+ if (!slot) {
+ return APR_ENOSHMAVAIL;
+ }
+
+ if (id >= slot->desc->num) {
+ ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(02397)
+ "slotmem(%s) fgrab failed. Num %u/num_free %u",
+ slot->name, slotmem_num_slots(slot),
+ slotmem_num_free_slots(slot));
+ return APR_EINVAL;
+ }
+ inuse = slot->inuse + id;
+
+ if (!*inuse) {
+ *inuse = 1;
+ (*slot->num_free)--;
+ }
+ return APR_SUCCESS;
+}
+
+static apr_status_t slotmem_release(ap_slotmem_instance_t *slot,
+ unsigned int id)
+{
+ char *inuse;
+
+ if (!slot) {
+ return APR_ENOSHMAVAIL;
+ }
+
+ inuse = slot->inuse;
+
+ if (id >= slot->desc->num || !inuse[id] ) {
+ ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(02294)
+ "slotmem(%s) release failed. Num %u/inuse[%u] %d",
+ slot->name, slotmem_num_slots(slot),
+ id, (int)inuse[id]);
+ if (id >= slot->desc->num) {
+ return APR_EINVAL;
+ } else {
+ return APR_NOTFOUND;
+ }
+ }
+ inuse[id] = 0;
+ (*slot->num_free)++;
+ return APR_SUCCESS;
+}
+
+static const ap_slotmem_provider_t storage = {
+ "sharedmem",
+ &slotmem_doall,
+ &slotmem_create,
+ &slotmem_attach,
+ &slotmem_dptr,
+ &slotmem_get,
+ &slotmem_put,
+ &slotmem_num_slots,
+ &slotmem_num_free_slots,
+ &slotmem_slot_size,
+ &slotmem_grab,
+ &slotmem_release,
+ &slotmem_fgrab
+};
+
+/* make the storage usable from outside */
+static const ap_slotmem_provider_t *slotmem_shm_getstorage(void)
+{
+ return (&storage);
+}
+
+/*
+ * Make sure the shared memory is cleaned
+ */
+static int post_config(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp,
+ server_rec *s)
+{
+ apr_pool_cleanup_register(p, NULL, cleanup_slotmem, apr_pool_cleanup_null);
+ return OK;
+}
+
+static int pre_config(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp)
+{
+ gpool = p;
+ globallistmem = NULL;
+ return OK;
+}
+
+static void ap_slotmem_shm_register_hook(apr_pool_t *p)
+{
+ const ap_slotmem_provider_t *storage = slotmem_shm_getstorage();
+ ap_register_provider(p, AP_SLOTMEM_PROVIDER_GROUP, "shm",
+ AP_SLOTMEM_PROVIDER_VERSION, storage);
+ ap_hook_post_config(post_config, NULL, NULL, APR_HOOK_LAST);
+ ap_hook_pre_config(pre_config, NULL, NULL, APR_HOOK_MIDDLE);
+}
+
+AP_DECLARE_MODULE(slotmem_shm) = {
+ STANDARD20_MODULE_STUFF,
+ NULL, /* create per-directory config structure */
+ NULL, /* merge per-directory config structures */
+ NULL, /* create per-server config structure */
+ NULL, /* merge per-server config structures */
+ NULL, /* command apr_table_t */
+ ap_slotmem_shm_register_hook /* register hooks */
+};