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#include "fs.h"
#include "common.h"
#include "list.h"
#include "alloc.h"
#include "spinlock.h"
#include "vmm.h"
#include "sharedmemory.h"
static List* gShmList = NULL;
static Spinlock gShmListLock;
static FileSystemNode* gShmRoot = NULL;
static FileSystemDirent gDirent;
static BOOL sharedmemorydir_open(File *file, uint32 flags);
static FileSystemDirent *sharedmemorydir_readdir(FileSystemNode *node, uint32 index);
static FileSystemNode *sharedmemorydir_finddir(FileSystemNode *node, char *name);
typedef struct SharedMemory {
FileSystemNode* node;
List* physicalAddressList;
Spinlock physicalAddressListLock;
//TODO: permissions
} SharedMemory;
void initializeSharedMemory() {
Spinlock_Init(&gShmListLock);
gShmList = List_Create();
gShmRoot = getFileSystemNode("/system/shm");
if (NULL == gShmRoot) {
WARNING("/system/shm not found!!");
}
else {
gShmRoot->open = sharedmemorydir_open;
gShmRoot->finddir = sharedmemorydir_finddir;
gShmRoot->readdir = sharedmemorydir_readdir;
}
}
static BOOL sharedmemorydir_open(File *file, uint32 flags) {
return TRUE;
}
static FileSystemDirent *sharedmemorydir_readdir(FileSystemNode *node, uint32 index) {
FileSystemDirent* result = NULL;
int counter = 0;
Spinlock_Lock(&gShmListLock);
List_Foreach (n, gShmList) {
SharedMemory* p = (SharedMemory*)n->data;
if (counter == index) {
strcpy(gDirent.name, p->node->name);
gDirent.fileType = p->node->nodeType;
result = &gDirent;
break;
}
++counter;
}
Spinlock_Unlock(&gShmListLock);
return result;
}
static FileSystemNode *sharedmemorydir_finddir(FileSystemNode *node, char *name) {
FileSystemNode* result = NULL;
Spinlock_Lock(&gShmListLock);
List_Foreach (n, gShmList) {
SharedMemory* p = (SharedMemory*)n->data;
if (strcmp(name, p->node->name) == 0) {
result = p->node;
break;
}
}
Spinlock_Unlock(&gShmListLock);
return result;
}
static BOOL sharedmemory_open(File *file, uint32 flags) {
return TRUE;
}
static void sharedmemory_unlink(File *file) {
destroySharedMemory(file->node->name);
}
static int32 sharedmemory_ftruncate(File *file, int32 length) {
if (length <= 0) {
return -1;
}
SharedMemory* sharedMem = (SharedMemory*)file->node->privateNodeData;
if (0 != file->node->length) {
//already set
return -1;
}
int pageCount = (length / PAGESIZE_4M) + 1;
Spinlock_Lock(&sharedMem->physicalAddressListLock);
for (int i = 0; i < pageCount; ++i) {
char* pAddress = getPageFrame4M();
List_Append(sharedMem->physicalAddressList, pAddress);
}
file->node->length = length;
Spinlock_Unlock(&sharedMem->physicalAddressListLock);
return 0;
}
static void* sharedmemory_mmap(File* file, uint32 size, uint32 offset, uint32 flags) {
void* result = NULL;
SharedMemory* sharedMem = (SharedMemory*)file->node->privateNodeData;
Spinlock_Lock(&sharedMem->physicalAddressListLock);
if (List_GetCount(sharedMem->physicalAddressList) > 0) {
result = mapMemory(file->thread->owner, size, 0, sharedMem->physicalAddressList);
}
Spinlock_Unlock(&sharedMem->physicalAddressListLock);
return result;
}
FileSystemNode* getSharedMemoryNode(const char* name) {
FileSystemNode* result = NULL;
Spinlock_Lock(&gShmListLock);
List_Foreach (n, gShmList) {
SharedMemory* p = (SharedMemory*)n->data;
if (strcmp(name, p->node->name) == 0) {
result = p->node;
break;
}
}
Spinlock_Unlock(&gShmListLock);
return result;
}
FileSystemNode* createSharedMemory(const char* name) {
if (getSharedMemoryNode(name) != NULL) {
return NULL;
}
SharedMemory* sharedMem = (SharedMemory*)kmalloc(sizeof(SharedMemory));
memset((uint8*)sharedMem, 0, sizeof(SharedMemory));
FileSystemNode* node = (FileSystemNode*)kmalloc(sizeof(FileSystemNode));
memset((uint8*)node, 0, sizeof(FileSystemNode));
strcpy(node->name, name);
node->nodeType = FT_CharacterDevice;
node->open = sharedmemory_open;
//TODO: node->shm_unlink = sharedmemory_unlink;
node->ftruncate = sharedmemory_ftruncate;
node->mmap = sharedmemory_mmap;
node->privateNodeData = sharedMem;
sharedMem->node = node;
sharedMem->physicalAddressList = List_Create();
Spinlock_Init(&sharedMem->physicalAddressListLock);
Spinlock_Lock(&gShmListLock);
List_Append(gShmList, sharedMem);
Spinlock_Unlock(&gShmListLock);
return node;
}
void destroySharedMemory(const char* name) {
SharedMemory* sharedMem = NULL;
Spinlock_Lock(&gShmListLock);
List_Foreach (n, gShmList) {
SharedMemory* p = (SharedMemory*)n->data;
if (strcmp(name, p->node->name) == 0) {
sharedMem = (SharedMemory*)p;
break;
}
}
if (sharedMem) {
Spinlock_Lock(&sharedMem->physicalAddressListLock);
kfree(sharedMem->node);
List_Destroy(sharedMem->physicalAddressList);
List_RemoveFirstOccurrence(gShmList, sharedMem);
Spinlock_Unlock(&sharedMem->physicalAddressListLock);
kfree(sharedMem);
}
Spinlock_Unlock(&gShmListLock);
}
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