feat: 添加 Lab4 练习 15 代码

gogodududu · Feb 26, 2020 · 289a520 · 289a520
1 parent 1c88171
commit 289a520
Show file tree

Hide file tree

Showing 2 changed files with 61 additions and 5 deletions.
diff --git a/kern/syscall.c b/kern/syscall.c
@@ -297,7 +297,36 @@ static int
 sys_ipc_try_send(envid_t envid, uint32_t value, void *srcva, unsigned perm)
 {
 	// LAB 4: Your code here.
-	panic("sys_ipc_try_send not implemented");
+	struct Env *env;
+	if (envid2env(envid, &env, 0) < 0) return -E_BAD_ENV;
+	if (!env->env_ipc_recving) return -E_IPC_NOT_RECV;
+
+	if ((size_t) srcva < UTOP) {
+		if (((size_t) srcva % PGSIZE) != 0) {
+			return -E_INVAL;
+		}
+
+		if ((perm & PTE_U) != PTE_U || (perm & PTE_P) != PTE_P) return -E_INVAL;
+
+		pte_t *pte;
+		struct PageInfo *pp = page_lookup(curenv->env_pgdir, srcva, &pte);
+		if (!pp) return -E_INVAL;
+
+		if ((perm & PTE_W) && ((size_t) *pte & PTE_W) != PTE_W) return -E_INVAL;
+		if ((size_t) env->env_ipc_dstva < UTOP) {
+			if (page_insert(env->env_pgdir, pp, env->env_ipc_dstva, perm) < 0) return -E_NO_MEM;
+			env->env_ipc_perm = perm;
+		}
+	} else {
+		env->env_ipc_perm = 0;
+	}
+
+	env->env_ipc_from = curenv->env_id;
+	env->env_ipc_recving = 0;
+	env->env_ipc_value = value;
+	env->env_status = ENV_RUNNABLE;
+	env->env_tf.tf_regs.reg_eax = 0;
+	return 0;
 }
 
 // Block until a value is ready.  Record that you want to receive
@@ -315,7 +344,11 @@ static int
 sys_ipc_recv(void *dstva)
 {
 	// LAB 4: Your code here.
-	panic("sys_ipc_recv not implemented");
+	if ((size_t) dstva < UTOP && ((size_t) dstva % PGSIZE) != 0) return -E_INVAL;
+	curenv->env_ipc_recving = 1;
+	curenv->env_ipc_dstva = dstva;
+	curenv->env_status = ENV_NOT_RUNNABLE;
+	sys_yield();
 	return 0;
 }
 

diff --git a/lib/ipc.c b/lib/ipc.c
@@ -23,8 +23,17 @@ int32_t
 ipc_recv(envid_t *from_env_store, void *pg, int *perm_store)
 {
 	// LAB 4: Your code here.
-	panic("ipc_recv not implemented");
-	return 0;
+	if (!pg) pg = (void *)-1;
+	int state = sys_ipc_recv(pg);
+	if (state < 0) {
+		if (from_env_store) *from_env_store = 0;
+		if (perm_store) *perm_store = 0;
+		return state;
+	}
+
+	if (from_env_store) *from_env_store = thisenv->env_ipc_from;
+	if (perm_store) *perm_store = thisenv->env_ipc_perm;
+	return thisenv->env_ipc_value;
 }
 
 // Send 'val' (and 'pg' with 'perm', if 'pg' is nonnull) to 'toenv'.
@@ -39,7 +48,21 @@ void
 ipc_send(envid_t to_env, uint32_t val, void *pg, int perm)
 {
 	// LAB 4: Your code here.
-	panic("ipc_send not implemented");
+	if (!pg) {
+		pg = (void *)-1;
+		perm = 0;
+	}
+
+	int state;
+	while (1) {
+		state = sys_ipc_try_send(to_env, val, pg, perm);
+		if (state == 0) return;
+		if (state != -E_IPC_NOT_RECV) {
+			panic("ipc_send: %e", state);
+		}
+
+		sys_yield();
+	}
 }
 
 // Find the first environment of the given type.  We'll use this to