Prepare main structure for managing message queues.

libc/inc/sys/msg.h

@@ -27,8 +27,6 @@ struct msgbuf {
 
 /// Keeps track of a stored message.
 struct msg {
-    /// Pointer to the next message on queue.
-    struct msg *msg_next;
     /// The type of message.
     long msg_type;
     /// Pointer to the beginning of the message.
@@ -38,13 +36,9 @@ struct msg {
 };
 
 /// @brief Message queue data structure.
-typedef struct msqid_ds {
+struct msqid_ds {
     /// Ownership and permissions.
     struct ipc_perm msg_perm;
-    /// First message on queue
-    struct msg *msg_first;
-    /// Last message in queue
-    struct msg *msg_last;
     /// Time of last msgsnd(2).
     time_t msg_stime;
     /// Time of last msgrcv(2).
@@ -61,10 +55,14 @@ typedef struct msqid_ds {
     pid_t msg_lspid;
     /// PID of last msgrcv(2).
     pid_t msg_lrpid;
-} msqid_ds_t;
+};
 
 #ifdef __KERNEL__
 
+/// @brief Initializes the message queue system.
+/// @return 0 on success, 1 on failure.
+int msq_init();
+
 /// @brief Get a System V message queue identifier.
 /// @param key can be used either to obtain the identifier of a previously
 /// created message queue, or to create a new set.
@@ -99,7 +97,7 @@ long sys_msgrcv(int msqid, struct msgbuf *msgp, size_t msgsz, long msgtyp, int m
 /// @param cmd The command to perform.
 /// @param buf used with IPC_STAT and IPC_SET.
 /// @return 0 on success, -1 on failure and errno is set to indicate the error.
-long sys_msgctl(int msqid, int cmd, msqid_ds_t *buf);
+long sys_msgctl(int msqid, int cmd, struct msqid_ds *buf);
 
 #else
 
@@ -137,6 +135,6 @@ long msgrcv(int msqid, struct msgbuf *msgp, size_t msgsz, long msgtyp, int msgfl
 /// @param cmd The command to perform.
 /// @param buf used with IPC_STAT and IPC_SET.
 /// @return 0 on success, -1 on failure and errno is set to indicate the error.
-long msgctl(int msqid, int cmd, msqid_ds_t *buf);
+long msgctl(int msqid, int cmd, struct msqid_ds *buf);
 
 #endif

libc/inc/sys/sem.h

@@ -80,7 +80,7 @@ struct sembuf {
 #ifdef __KERNEL__
 
 /// @brief Initializes the semaphore system.
-/// @return int
+/// @return 0 on success, 1 on failure.
 int sem_init();
 
 /// @brief Get a System V semaphore set identifier.

mentos/src/ipc/msg.c

@@ -2,7 +2,6 @@
 /// @brief
 /// @copyright (c) 2014-2023 This file is distributed under the MIT License.
 /// See LICENSE.md for details.
-///! @cond Doxygen_Suppress
 
 // ============================================================================
 // Setup the logging for this file (do this before any other include).
@@ -29,6 +28,8 @@ typedef struct {
     int id;
     /// @brief The message queue data strcutre.
     struct msqid_ds msqid;
+    /// Pointer to the first message in the queue.
+    struct msg *msg_base;
     /// Reference inside the list of message queue management structures.
     list_head list;
 } msq_info_t;
@@ -36,6 +37,24 @@ typedef struct {
 /// @brief List of all current active Message queues.
 list_head msq_list;
 
+// ============================================================================
+// MEMORY MANAGEMENT (Private)
+// ============================================================================
+
+// ============================================================================
+// SEARCH FUNCTIONS (Private)
+// ============================================================================
+
+// ============================================================================
+// SYSTEM FUNCTIONS
+// ============================================================================
+
+int msq_init()
+{
+    list_head_init(&msq_list);
+    return 0;
+}
+
 long sys_msgget(key_t key, int msgflg)
 {
     TODO("Not implemented");
@@ -60,6 +79,10 @@ long sys_msgctl(int msqid, int cmd, struct msqid_ds *buf)
     return 0;
 }
 
+// ============================================================================
+// PROCFS FUNCTIONS
+// ============================================================================
+
 ssize_t procipc_msg_read(vfs_file_t *file, char *buf, off_t offset, size_t nbyte)
 {
     if (!file) {
@@ -90,5 +113,3 @@ ssize_t procipc_msg_read(vfs_file_t *file, char *buf, off_t offset, size_t nbyte
     }
     return write_count;
 }
-
-///! @endcond

mentos/src/kernel.c

@@ -27,6 +27,7 @@
 #include "system/syscall.h"
 #include "sys/module.h"
 #include "sys/sem.h"
+#include "sys/msg.h"
 #include "io/proc_modules.h"
 #include "io/vga/vga.h"
 #include "io/video.h"
@@ -312,6 +313,16 @@ int kmain(boot_info_t *boot_informations)
     }
     print_ok();
 
+    //==========================================================================
+    pr_notice("Initialize IPC/MSQ system...\n");
+    printf("Initialize IPC/MSQ system...");
+    if (msq_init()) {
+        print_fail();
+        pr_emerg("Failed to initialize the IPC/MSQ system!\n");
+        return 1;
+    }
+    print_ok();
+
     //==========================================================================
     pr_notice("Setting up PS/2 driver...\n");
     printf("Setting up PS/2 driver...");