lib: robust locking in shared memory and crash recovery

This PR enhances the shared memory providing recovery if a process
crashes. It adds a SHM_DU_TIMEOUT_MICROS variable, setting an
expiration time for SDU's when shared memory is full. If an
application doesn't read a blocking SDU within this time, the shared
memory will be cleansed of all SDU's for this application and the
application's rbuff will be cleared.

Some refactoring of the API's. Fixed wrong pthread checks in IRMd.

Fixes #13
Fixes #14

3 files changed, 22 insertions, 34 deletions

diff --git a/include/ouroboros/config.h.in b/include/ouroboros/config.h.in
index 0dce7acd..6861c6cb 100644
--- a/include/ouroboros/config.h.in
+++ b/include/ouroboros/config.h.in
@@ -26,13 +26,19 @@
 #define PROJECT_NAME           "@CMAKE_PROJECT_NAME@"
 #define PROJECT_VERSION        "@PACKAGE_VERSION@"
 #define INSTALL_PREFIX         "@CMAKE_INSTALL_PREFIX@"
-#define _POSIX_C_SOURCE        200112L
+#define _POSIX_C_SOURCE        200809L
 #define IPCP_SHIM_UDP_EXEC     "@IPCP_SHIM_UDP_TARGET@"
 #define IPCP_SHIM_ETH_LLC_EXEC "@IPCP_SHIM_ETH_LLC_TARGET@"
 #define IPCP_NORMAL_EXEC       "@IPCP_NORMAL_TARGET@"
 #define IPCP_LOCAL_EXEC        "@IPCP_LOCAL_TARGET@"
 #define AP_MAX_FLOWS           256
+#define SHM_DU_BUFF_BLOCK_SIZE sysconf(_SC_PAGESIZE)
+#define SHM_DU_MAP_FILENAME    "ouroboros_du_map"
+#define SHM_BLOCKS_IN_MAP      (1 << 14)
+#define SHM_DU_TIMEOUT_MICROS  2000
 #define DU_BUFF_HEADSPACE      128
 #define DU_BUFF_TAILSPACE      0
+#define SHM_AP_RBUFF_PREFIX    "ouroboros_rb_"
+#define SHM_RBUFF_SIZE         (1 << 14)
 
 #endif
diff --git a/include/ouroboros/shm_ap_rbuff.h b/include/ouroboros/shm_ap_rbuff.h
index 053709bb..78926869 100644
--- a/include/ouroboros/shm_ap_rbuff.h
+++ b/include/ouroboros/shm_ap_rbuff.h
@@ -24,15 +24,8 @@
 #ifndef OUROBOROS_SHM_AP_RBUFF_H
 #define OUROBOROS_SHM_AP_RBUFF_H
 
-#ifndef SHM_AP_RBUFF
-#define SHM_AP_RBUFF_PREFIX "ouroboros_rb_"
-#endif
-
-#ifndef SHM_RBUFF_SIZE
-#define SHM_RBUFF_SIZE (1 << 14)
-#endif
-
 #include <sys/types.h>
+#include <stdbool.h>
 
 struct shm_ap_rbuff;
 
@@ -42,7 +35,7 @@ struct rb_entry {
 };
 
 struct shm_ap_rbuff * shm_ap_rbuff_create();
-struct shm_ap_rbuff * shm_ap_rbuff_open();
+struct shm_ap_rbuff * shm_ap_rbuff_open(pid_t api);
 void                  shm_ap_rbuff_close(struct shm_ap_rbuff * rb);
 void                  shm_ap_rbuff_destroy(struct shm_ap_rbuff * rb);
 int                   shm_ap_rbuff_write(struct shm_ap_rbuff * rb,
@@ -50,5 +43,6 @@ int                   shm_ap_rbuff_write(struct shm_ap_rbuff * rb,
 struct rb_entry *     shm_ap_rbuff_read(struct shm_ap_rbuff * rb);
 ssize_t               shm_ap_rbuff_read_port(struct shm_ap_rbuff * rb,
                                              int port_id);
-
+pid_t                 shm_ap_rbuff_get_api(struct shm_ap_rbuff * rb);
+void                  shm_ap_rbuff_reset(struct shm_ap_rbuff * rb);
 #endif /* OUROBOROS_SHM_AP_RBUFF_H */
diff --git a/include/ouroboros/shm_du_map.h b/include/ouroboros/shm_du_map.h
index 2d215651..e8934bae 100644
--- a/include/ouroboros/shm_du_map.h
+++ b/include/ouroboros/shm_du_map.h
@@ -24,18 +24,6 @@
 #ifndef OUROBOROS_SHM_DU_MAP_H
 #define OUROBOROS_SHM_DU_MAP_H
 
-#ifndef SHM_DU_BUFF_BLOCK_SIZE
-#define SHM_DU_BUFF_BLOCK_SIZE sysconf(_SC_PAGESIZE)
-#endif
-
-#ifndef SHM_DU_MAP_FILENAME
-#define SHM_DU_MAP_FILENAME "ouroboros_du_map"
-#endif
-
-#ifndef SHM_BLOCKS_IN_MAP
-#define SHM_BLOCKS_IN_MAP (1 << 14)
-#endif
-
 #include "common.h"
 #include <sys/types.h>
 #include <pthread.h>
@@ -51,18 +39,18 @@ pid_t               shm_du_map_owner(struct shm_du_map * dum);
 void *              shm_du_map_sanitize(void * o);
 
 /* returns the index of the buffer in the DU map */
-ssize_t  shm_create_du_buff(struct shm_du_map * dum,
-                            size_t              size,
-                            size_t              headspace,
-                            uint8_t           * data,
-                            size_t              len);
+ssize_t  shm_du_map_write(struct shm_du_map * dum,
+                          pid_t               dst_api,
+                          size_t              headspace,
+                          size_t              tailspace,
+                          uint8_t *           data,
+                          size_t              data_len);
 
-/* FIXME: revise these */
-int       shm_du_map_read_sdu(uint8_t **          dst,
-                              struct shm_du_map * dum,
-                              ssize_t             idx);
-int       shm_release_du_buff(struct shm_du_map  * dum,
-                              ssize_t idx);
+int       shm_du_map_read(uint8_t **          dst,
+                          struct shm_du_map * dum,
+                          ssize_t             idx);
+int       shm_du_map_remove(struct shm_du_map  * dum,
+                            ssize_t idx);
 
 /* FIXME: use shm_du_map * and index */
 uint8_t * shm_du_buff_head_alloc(struct shm_du_buff * sdb,