More work on IPC

11 files changed, 263 insertions, 27 deletions

diff --git a/src/kernel/Makefile b/src/kernel/Makefile
index 3508bb9..5de25f8 100644
--- a/src/kernel/Makefile
+++ b/src/kernel/Makefile
@@ -14,7 +14,7 @@ OBJECTS = core/loader_.o core/kmain.o core/sys.o \
 		  task/idt.o task/idt_.o task/task.o task/task_.o task/syscall.o \
 		  lib/stdlib.o lib/bitset.o lib/mutex.o \
 		  mem/mem.o mem/paging.o mem/gdt.o mem/heap.o mem/seg.o \
-		  ipc/shm.o \
+		  ipc/shm.o ipc/object.o \
 		  linker/elf.o
 OUT = kernel.elf
 
diff --git a/src/kernel/ipc/object.c b/src/kernel/ipc/object.c
new file mode 100644
index 0000000..70c31b2
--- /dev/null
+++ b/src/kernel/ipc/object.c
@@ -0,0 +1,113 @@
+#include "object.h"
+#include <lib/mutex.h>
+#include <mem/mem.h>
+
+struct object* obj_new(struct process* owner) {
+	struct object* ret = kmalloc(sizeof(struct object));
+	ret->owner = owner;
+	ret->descriptors = 0;
+	ret->busyMutex = MUTEX_UNLOCKED;
+	ret->request = 0;
+	return ret;
+}
+
+void obj_delete(struct object* obj) {
+	if (obj->descriptors > 0) return;
+	if (obj->busyMutex != MUTEX_UNLOCKED) return;
+	if (obj->request != 0) return;
+	kfree(obj);
+}
+
+int obj_createP(struct process* p) {
+	return objdesc_add(p, obj_new(p));
+}
+
+void obj_closeP(struct process* p, int id) {
+	struct object* obj = objdesc_read(p, id);
+	if (obj == 0) return;
+	objdesc_rm(p, id);
+	if (obj->owner == p) {
+		if (obj->descriptors > 0) {
+			obj->owner = 0; // set object to be invalid
+			//if a request was being handled, give it a null response
+		} else {
+			obj_delete(obj);
+		}
+	} else {
+		if (obj->descriptors == 0 && obj->owner == 0) {
+			obj_delete(obj);
+		}
+		//future : send message becuz object was closed
+	}
+}
+
+void obj_closeall(struct process* p) {
+	while (p->objects != 0) obj_closeP(p, p->objects->id);
+}
+
+// DESCRIPTORS
+
+int objdesc_add(struct process* proc, struct object* obj) {
+	struct obj_descriptor *ret = kmalloc(sizeof(struct obj_descriptor));
+	ret->obj = obj;
+	ret->id = proc->next_objdesc;
+	ret->next = proc->objects;
+	proc->objects = ret;
+	obj->descriptors++;
+	proc->next_objdesc++;
+	return ret->id;
+}
+
+int objdesc_get(struct process* proc, struct object* obj) {
+	struct obj_descriptor *it = proc->objects;
+	while (it != 0) {
+		if (it->obj == obj) return it->id;
+		it = it->next;
+	}
+	return -1;
+}
+
+struct object* objdesc_read(struct process* proc, int id) {
+	struct obj_descriptor *it = proc->objects;
+	while (it != 0) {
+		if (it->id == id) return it->obj;
+		it = it->next;
+	}
+	return 0;
+}
+
+void objdesc_rm(struct process* proc, int id) {
+	struct obj_descriptor *e = proc->objects;
+	if (e != 0 && e->id == id) {
+		proc->objects = e->next;
+		e->obj->descriptors--;
+		kfree(e);
+		return;
+	}
+	while (e->next != 0) {
+		if (e->next->id == id) {
+			e->next = e->next->next;
+			e->next->obj->descriptors--;
+			kfree(e->next);
+			return;
+		}
+		e = e->next;
+	}
+}
+
+// SYSCALLS
+
+int object_create() {
+	return obj_createP(current_thread->process);
+}
+
+int object_owned(int id) {
+	struct object *obj = objdesc_read(current_thread->process, id);
+	if (obj == 0) return -1;
+	if (obj->owner == current_thread->process) return 1;
+	return 0;
+}
+
+void object_close(int id) {
+	obj_closeP(current_thread->process, id);
+}
diff --git a/src/kernel/ipc/object.h b/src/kernel/ipc/object.h
index ef90a66..9dd3a1e 100644
--- a/src/kernel/ipc/object.h
+++ b/src/kernel/ipc/object.h
@@ -3,24 +3,37 @@
 
 #include <task/task.h>
 
-#define OS_INACTIVE  0		//No one doing anything on this
-#define OS_LISTENING 1		//A thread is waiting for a request on this object
-#define OS_REQUESTPENDING 2	//A request is waiting for a thread to handle it
-#define OS_BUSY	3			//A thread is currently handling a request
-
 struct object {
-	struct process *owner;
+	struct process *owner;	//when 0, object is invalid and cannot handle requests
 	int descriptors;
-	uint32_t busyMutex;
+	uint32_t busyMutex;			//if busy, either a blocking request is being processed, or a sent message is waiting for being recieved
 	struct request *request;
 };
 
 struct obj_descriptor {
 	struct object *obj;
 	int id;
-	int owned;
 	struct obj_descriptor *next;
 };
 
+//Objects
+struct object* obj_new(struct process *owner);
+void obj_delete(struct object* obj);
+
+int obj_createP(struct process* p);
+void obj_closeP(struct process* p, int id);
+void obj_closeall(struct process* p);
+
+//Object descriptors
+int objdesc_add(struct process* proc, struct object* obj);		// add a descriptor
+int objdesc_get(struct process* proc, struct object* obj);		// look in descriptors for the one corresponding to the object
+struct object* objdesc_read(struct process* proc, int id);		// get the object correspoinding to the id
+void objdesc_rm(struct process* proc, int id);					// remove descriptor for an object
+
+//Syscalls
+int object_create();
+int object_owned(int id);		//does current process own object ? 1=yes 0=no
+void object_close(int id);		//closes descriptor to specified object. if we are the owner, make all requests to object fail.
+
 #endif
 
diff --git a/src/kernel/ipc/request.c b/src/kernel/ipc/request.c
new file mode 100644
index 0000000..51a0bbc
--- /dev/null
+++ b/src/kernel/ipc/request.c
@@ -0,0 +1,55 @@
+#include "request.h"
+
+int request_get(int obj, uint32_t ptr, int wait) {
+	//check if we own the object, if not return -2
+	//check if a request is pending. if request is being processed, return -3
+	//if not (busymutex unlocked or request==0) && wait, then wait, else return -1
+	//if request pending, write it to ptr
+	// if request is nonblocking and no shm is to be mapped, delete it and unlock objects busymutex
+	//return 0
+}
+
+int request_has(int obj) {
+	//check if we own the object, if not return -2
+	//check if a request is pending.
+	// if being processed, return 2
+	// if waiting for ack, return 1
+	// if none (busymutex unlocked or request==0), return 0
+}
+
+void request_answer(int obj, uint32_t answer) {
+	//check if we own the object, if not return
+	//if no blocking request is being processed (including non-acknowledged waiting requests), return
+	//set blocking request to finished, and set its answer
+	//dereference request from object, unlock objects busymutex
+}
+
+int request_mapShm(int obj, uint32_t pos, int number) {
+	//check if we own the object, if not return -2
+	//if no request is being processes (including non-acknowledged waiting requests), return -3
+	//check if the requests has shm in parameter [number], if not return -4
+	//map shm to position
+	//if request is nonblocking and no more shm is to be mapped, delete request and free object busymutex
+	//return 0
+}
+
+static struct request *mkrequest(int obj, struct thread *requester,
+		uint32_t func, uint32_t a, uint32_t b, uint32_t c) {
+	// get object from descriptor id, if none return 0
+	// waitlock object's busy mutex
+	// if object cannot answer (owner == 0) return 0
+	// create request, fill it up, reference it from object
+	// return request	
+}
+
+int request(int obj, uint32_t func, uint32_t a, uint32_t b, uint32_t c, uint32_t answerptr) {
+	//call mkrequest with parameters (requester thread = current thread)
+	//if returned value is 0, return -1
+	//sleep until request is handled
+	//write answer to *answerptr, delete request, return 0
+}
+
+int send_msg(int obj, uint32_t func, uint32_t a, uint32_t b, uint32_t c) {
+	//call mkrequest with parameters (requester thread = 0)
+	//if returned value is 0, return -1 else return 0
+}
diff --git a/src/kernel/ipc/request.h b/src/kernel/ipc/request.h
index bf90c68..4a35dc3 100644
--- a/src/kernel/ipc/request.h
+++ b/src/kernel/ipc/request.h
@@ -10,13 +10,12 @@
 
 struct request {
 	struct object *obj;
-	struct thread *requester;
-	uint32_t func, param1, param2, param3;
-	struct seg_map *shm_cli, *shm_srv;
-	int answerType;
+	struct thread *requester;	//0 if nonblocking message
+	uint32_t func, params[3];
+	struct seg_map *shm_srv[3], *shm_cli[3];
 	union {
-		int num;
-		struct object* obj;
+		int64_t ll;
+		uint32_t n;
 	} answer;
 };
 
@@ -25,5 +24,14 @@ struct user_request {
 	int hasShm;
 };
 
+//syscalls
+int request_get(int obj, uint32_t ptr, int wait);
+int request_has(int obj);
+void request_answer(int obj, uint32_t answer);
+int request_mapShm(int obj, uint32_t pos, int number);
+
+int request(int obj, uint32_t func, uint32_t a, uint32_t b, uint32_t c, uint32_t answerptr);
+int send_msg(int obj, uint32_t func, uint32_t a, uint32_t b, uint32_t c);
+
 #endif
 
diff --git a/src/kernel/ipc/shm.c b/src/kernel/ipc/shm.c
index 0a0d3ee..1cdacfb 100644
--- a/src/kernel/ipc/shm.c
+++ b/src/kernel/ipc/shm.c
@@ -1,6 +1,7 @@
 #include "shm.h"
 #include <mem/mem.h>
 #include <mem/seg.h>
+#include <task/task.h>
 
 struct segment* shmseg_make(size_t len, struct process* owner) {
 	struct shmseg *ss = kmalloc(sizeof(struct shmseg));
@@ -54,3 +55,28 @@ void shmseg_delete(struct segment *seg) {
 	}
 	kfree(ss->frames);
 }
+
+struct segment_map* shmseg_getByOff(struct process* pr, size_t offset) {
+	struct segment_map* m = pr->pagedir->mappedSegs;
+	while (m != 0) {
+		if (m->start == offset && m->seg->delete == shmseg_delete) return m;
+		m = m->next;
+	}
+	return 0;
+}
+
+// **** **** SHM syscalls **** ****
+int shm_create(size_t offset, size_t len) {
+	if (offset >= 0xE0000000) return -1;
+	if (len >= 0x10000000) return -1;
+	if (offset+len >= 0xE0000000) return -1;
+	seg_map(shmseg_make(len, current_thread->process), current_thread->process->pagedir, offset);
+	return 0;
+}
+
+int shm_delete(size_t offset) {
+	struct segment_map *s = shmseg_getByOff(current_thread->process, offset);
+	if (s == 0) return -1;
+	seg_unmap(s);
+	return 0;
+}
diff --git a/src/kernel/ipc/shm.h b/src/kernel/ipc/shm.h
index b409955..895a619 100644
--- a/src/kernel/ipc/shm.h
+++ b/src/kernel/ipc/shm.h
@@ -16,9 +16,12 @@ void shmseg_unmap(struct segment_map*);
 void shmseg_delete(struct segment *seg);
 int shmseg_handleFault(struct segment_map *map, size_t addr, int write);
 
+		//find a shared memory segment in current address space by its offset
+struct segment_map* shmseg_getByOff(struct process* pr, size_t offset);	
+
 //Shared memory syscalls
-void shm_create(size_t offset, size_t len);
-void shm_delete(size_t offset);
+int shm_create(size_t offset, size_t len);
+int shm_delete(size_t offset);
 
 #endif
 
diff --git a/src/kernel/task/idt.c b/src/kernel/task/idt.c
index cff4ae9..0f3c2f2 100644
--- a/src/kernel/task/idt.c
+++ b/src/kernel/task/idt.c
@@ -198,7 +198,6 @@ void idt_handleIrq(int number, int_callback func) {
 void idt_waitIrq(int number) {
 	if (number < 16 && number >= 0 && proc_priv() <= PL_DRIVER) {
 		irq_wakeup[number] = current_thread;
-		current_thread->state = TS_WAKEWAIT;
-		tasking_schedule();
+		thread_goInactive();
 	}
 }
diff --git a/src/kernel/task/syscall.c b/src/kernel/task/syscall.c
index 752864c..51c46f1 100644
--- a/src/kernel/task/syscall.c
+++ b/src/kernel/task/syscall.c
@@ -8,6 +8,7 @@
 	r->eax = name(r->ebx, r->ecx); }
 #define CALL0V(name, scname) static void scname(struct registers* r) { name(); }
 #define CALL1V(name, scname) static void scname(struct registers* r) { name(r->ebx); }
+#define CALL2V(name, scname) static void scname(struct registers* r) { name(r->ebx, r->ecx); }
 
 CALL0V(thread_exit, thread_exit_sc);
 CALL0V(tasking_switch, schedule_sc);
@@ -15,17 +16,23 @@ CALL1V(thread_sleep, thread_sleep_sc);
 CALL1V(process_exit, process_exit_sc);
 CALL1(monitor_write, printk_sc);
 CALL1V(idt_waitIrq, irq_wait_sc);
+CALL0(proc_priv, proc_priv_sc);
+CALL2(shm_create, shm_create_sc);
+CALL1(shm_delete, shm_delete_sc);
 
 static void thread_new_sc(struct registers* r) {
 	thread_new(current_thread->process, (thread_entry)r->ebx, (void*)r->ecx);
 }
 
 int_callback syscalls[] = {
-	thread_exit_sc,
+	thread_exit_sc,			//0
 	schedule_sc,
 	thread_sleep_sc,
 	process_exit_sc,
 	printk_sc,
-	thread_new_sc,
+	thread_new_sc,			//5
 	irq_wait_sc,
+	proc_priv_sc,
+	shm_create_sc,
+	shm_delete_sc,
 	0 };
diff --git a/src/kernel/task/task.c b/src/kernel/task/task.c
index 622eaa1..6959676 100644
--- a/src/kernel/task/task.c
+++ b/src/kernel/task/task.c
@@ -88,10 +88,6 @@ void tasking_switch() {
 		: : "r"(current_thread->ebp), "r"(current_thread->esp), "r"(current_thread->eip));
 }
 
-void tasking_schedule() {
-	asm volatile("int $64" : : "a"(1));
-}
-
 void tasking_updateKernelPagetable(uint32_t idx, struct page_table *table, uint32_t tablephysical) {
 	if (idx < 896) return;
 	struct process* it = processes;
@@ -119,13 +115,19 @@ uint32_t tasking_handleException(struct registers *regs) {
 		thread_exit_stackJmp(EX_TH_EXCEPTION);
 	}
 	PANIC("This should never have happened. Please report this.");
+	return 0;
 }
 
 void thread_sleep(uint32_t msecs) {
 	if (current_thread == 0) return;
 	current_thread->state = TS_SLEEPING;
 	current_thread->timeWait = timer_time() + msecs;
-	tasking_schedule();
+	tasking_switch();
+}
+
+void thread_goInactive() {
+	current_thread->state = TS_WAKEWAIT;
+	tasking_switch();
 }
 
 int proc_priv() {
@@ -271,6 +273,11 @@ struct process *process_new(struct process* parent, uint32_t uid, uint32_t privi
 	p->pagedir = pagedir_new();
 	p->next = processes;
 	p->stacksBottom = 0xDF000000;
+
+	p->next_objdesc = 0;
+	p->objects = 0;
+	obj_createP(p);	//create process' root object and add descriptor 0 to it
+
 	processes = p;
 	return p;
 }
@@ -296,6 +303,7 @@ static void process_delete(struct process *pr) {
 		while (it->next->process == pr) thread_delete(it->next);
 		it = it->next;
 	}
+	obj_closeall(pr);
 	pagedir_delete(pr->pagedir);
 	if (processes == pr) {
 		processes = pr->next;
diff --git a/src/kernel/task/task.h b/src/kernel/task/task.h
index dd5461e..b2a5434 100644
--- a/src/kernel/task/task.h
+++ b/src/kernel/task/task.h
@@ -3,6 +3,7 @@
 
 #include <types.h>
 #include <mem/paging.h>
+#include <ipc/object.h>
 #include "idt.h"
 
 #define TS_RUNNING 0	
@@ -29,6 +30,9 @@ struct process {
 	struct page_directory *pagedir;
 	size_t stacksBottom;
 
+	struct obj_descriptor *objects;
+	uint32_t next_objdesc;
+
 	struct process *next;	//Forms a linked list
 };
 
@@ -48,11 +52,11 @@ extern struct thread *current_thread;
 
 void tasking_init();
 void tasking_switch();
-void tasking_schedule();
 void tasking_updateKernelPagetable(uint32_t idx, struct page_table *table, uint32_t tablePhysical);
 uint32_t tasking_handleException(struct registers *regs);
 
 void thread_sleep(uint32_t msecs);
+void thread_goInactive();	//Blocks the current thread. another one must be there to wake it up at some point.
 int proc_priv();	//Returns current privilege level
 void thread_exit();
 void process_exit(uint32_t retval);