server: implement a SharedMemoryServer with (de)initilization of the memory buffer

1 files changed, 49 insertions, 0 deletions

diff --git a/src/server/shared_memory_server.h b/src/server/shared_memory_server.h
new file mode 100644
index 0000000..034466d
--- /dev/null
+++ b/src/server/shared_memory_server.h
@@ -0,0 +1,49 @@
+#pragma once
+
+#include "hashtable.h"
+#include "shared_memory.h"
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+template <typename K, typename V>
+class SharedMemoryServer {
+public:
+    SharedMemoryServer(size_t size)
+        : hash_table(size)
+    {
+        shm_fd = shm_open(SHM_NAME, O_CREAT | O_RDWR, 0666);
+
+        ftruncate(shm_fd, sizeof(SharedMemory));
+
+        shm = (SharedMemory*)
+            mmap(0, sizeof(SharedMemory), PROT_READ | PROT_WRITE, MAP_SHARED, shm_fd, 0);
+
+        pthread_mutexattr_t mutex_attr;
+        pthread_condattr_t cond_attr;
+        pthread_mutexattr_init(&mutex_attr);
+        pthread_mutexattr_setpshared(&mutex_attr, PTHREAD_PROCESS_SHARED);
+        pthread_condattr_init(&cond_attr);
+        pthread_condattr_setpshared(&cond_attr, PTHREAD_PROCESS_SHARED);
+
+        pthread_mutex_init(&shm->mutex, &mutex_attr);
+        pthread_cond_init(&shm->cond_var, &cond_attr);
+
+        shm->head = (shm->tail = 0);
+    }
+
+    ~SharedMemoryServer()
+    {
+        munmap(shm, sizeof(SharedMemory));
+        close(shm_fd);
+        shm_unlink(SHM_NAME);
+    }
+
+    void process_requests();
+
+private:
+    HashTable<K, V> hash_table;
+
+    int shm_fd;
+    SharedMemory* shm;
+};