Add io_create_file, io_open_file

.gitignore

@@ -1,2 +1,3 @@
 example
 example.exe
+file_*.txt

example.c

@@ -1,6 +1,8 @@
 #include <stdio.h>
 #include "io.h"
 
+#define NUM_OPS 3
+
 int main()
 {
     struct io_operation ops[100];
@@ -8,13 +10,26 @@ int main()
     if (!io_context_init(&ioc, ops, sizeof(ops)/sizeof(ops[0])))
         return -1;
     
+    io_handle files[NUM_OPS];
+
+    for (int i = 0; i < NUM_OPS; i++) {
+        char name[1<<8];
+        snprintf(name, sizeof(name), "file_%d.txt", i);
+        files[i] = io_create_file(&ioc, name, IO_CREATE_CANTEXIST, NULL);
+        if (files[i] == IO_INVALID_HANDLE)
+            fprintf(stderr, "Couldn't create '%s'\n", name);
+    }
+
+    int started = 0;
     char msg[] = "Hello, world!\n";
-    for (int i = 0; i < 10; i++) {
+    for (int i = 0; i < NUM_OPS; i++) {
-        if (!io_start_send(&ioc, io_get_stdout(), msg, sizeof(msg), NULL))
+        if (io_start_send(&ioc, files[i], msg, sizeof(msg)-1))
+            started++;
+        else
             fprintf(stderr, "ERROR\n");
     }
 
-    for (int i = 0; i < 10; i++) {
+    for (int i = 0; i < started; i++) {
         struct io_event ev;
         io_wait(&ioc, &ev);
         fprintf(stderr, "CONCLUDED\n");

io.c

@@ -9,14 +9,51 @@
  * Declare Windows symbols locally to avoid including windows.h
  */
 
+#define GENERIC_READ  0x80000000ULL
+#define GENERIC_WRITE 0x40000000ULL
+
+#define CREATE_NEW    1
+#define CREATE_ALWAYS 2
+#define OPEN_EXISTING 3
+#define OPEN_ALWAYS   4
+
+#define FILE_ATTRIBUTE_NORMAL 0x00000080ULL
+#define FILE_FLAG_OVERLAPPED  0x40000000ULL
+
 #define ERROR_IO_PENDING 997l
 
-extern int ReadFile(void *handle, void *dst, unsigned long max, unsigned long *num, struct io_overlap *ov);
+struct security_attr {
-extern int WriteFile(void *handle, const void *src, unsigned long max, unsigned long *num, struct io_overlap *ov);
+    unsigned long size;
-extern void *CreateIoCompletionPort(void *handle, void *existing_ioport, unsigned long *ptr, unsigned long num_threads);
+    void *desc;
-extern int   CloseHandle(void *handle);
+    int inherit_handle;
-extern unsigned long GetLastError();
+};
-extern int GetQueuedCompletionStatus(void *ioport, unsigned long *num, unsigned long *key, struct io_overlap **ov, unsigned long timeout);
+
+extern void*
+CreateFileA(const char *name, unsigned long access,
+            unsigned long share, struct security_attr *sec,
+            unsigned long creation, unsigned long flags, 
+            void *template);
+
+extern int
+ReadFile(void *handle, void *dst, unsigned long max,
+         unsigned long *num, struct io_overlap *ov);
+
+extern int
+WriteFile(void *handle, const void *src, unsigned long max,
+          unsigned long *num, struct io_overlap *ov);
+
+extern void*
+CreateIoCompletionPort(void *handle, void *existing_ioport,
+                       unsigned long *ptr, unsigned long num_threads);
+
+extern int
+CloseHandle(void *handle);
+
+extern unsigned long
+GetLastError();
+
+extern int
+GetQueuedCompletionStatus(void *ioport, unsigned long *num, unsigned long *key, struct io_overlap **ov, unsigned long timeout);
 
 bool io_context_init(struct io_context *ioc,
                      struct io_operation *ops,
@@ -26,6 +63,9 @@ bool io_context_init(struct io_context *ioc,
     if (handle == IO_INVALID_HANDLE)
         return false;
     
+    for (uint32_t i = 0; i < max_ops; i++)
+        ops[i].type = IO_VOID;
+
     ioc->handle = handle;
     ioc->max_ops = max_ops;
     ioc->ops = ops;
@@ -46,8 +86,11 @@ static struct io_operation *alloc_op(struct io_context *ioc)
 }
 
 bool io_start_recv(struct io_context *ioc, io_handle handle,
-                   void *dst, uint32_t max, void *user)
+                   void *dst, uint32_t max)
 {
+    if (handle == IO_INVALID_HANDLE)
+        return false;
+
     struct io_operation *op = alloc_op(ioc);
     if (op == NULL)
         return false;
@@ -58,14 +101,16 @@ bool io_start_recv(struct io_context *ioc, io_handle handle,
 	if (!ok && GetLastError() != ERROR_IO_PENDING)
 		return false;
 
-    op->user = user;
     op->type = IO_RECV;
     return true;
 }
 
 bool io_start_send(struct io_context *ioc, io_handle handle,
-                   void *src, uint32_t num, void *user)
+                   void *src, uint32_t num)
 {
+    if (handle == IO_INVALID_HANDLE)
+        return false;
+
     struct io_operation *op = alloc_op(ioc);
     if (op == NULL)
         return false;
@@ -76,20 +121,133 @@ bool io_start_send(struct io_context *ioc, io_handle handle,
 	if (!ok && GetLastError() != ERROR_IO_PENDING)
 		return false;
 
-    op->user = user;
     op->type = IO_SEND;
     return true;
 }
 
-bool io_start_accept(struct io_context *ioc, io_handle handle, void *user)
+bool io_start_accept(struct io_context *ioc, io_handle handle)
 {
+    if (handle == IO_INVALID_HANDLE)
+        return false;
+
     // TODO
     return false;
 }
 
+static unsigned long
+convert_timeout(int timeout)
+{
+    if (timeout < 0)
+        return ~0U;
+    else
+        return timeout;
+}
+
+static struct io_operation *op_from_ov(struct io_overlap *ov)
+{
+    return (struct io_operation*) ((char*) ov - offsetof(struct io_operation, ov));
+}
+
 void io_wait(struct io_context *ioc, struct io_event *ev)
 {
-    // TODO
+    void *user;
+	struct io_overlap *ov;
+    unsigned long num;
+	int ok = GetQueuedCompletionStatus(ioc->handle, &num, (unsigned long*) &user, &ov, convert_timeout(-1));
+
+    if (!ok) {
+
+        if (ov == NULL) {
+            /*
+             * General failure
+             */
+            ev->error = true;
+            ev->user  = NULL; // The user must discriminate between general errors and specific operation errors through the user pointer. Not ideal
+            ev->type  = IO_VOID;
+        } else {
+            /*
+             * Operation failure
+             */
+
+            struct io_operation *op = op_from_ov(ov);
+
+            ev->error = true;
+            ev->user  = user;
+            ev->type  = op->type;
+
+            switch (op->type) {
+                default:break;
+                case IO_RECV: ev->num = 0; break;
+                case IO_SEND: ev->num = 0; break;
+                case IO_ACCEPT: ev->handle = IO_INVALID_HANDLE; break;
+            }
+
+            op->type = IO_VOID; // Mark unused
+        }
+        return;
+    }
+
+    struct io_operation *op = op_from_ov(ov);
+
+    ev->error = false;
+    ev->user  = user;
+    ev->type  = op->type;
+
+    switch (op->type) {
+        default:break;
+        case IO_RECV: ev->num = num; break;
+        case IO_SEND: ev->num = num; break;
+        case IO_ACCEPT: /* TODO */ break;
+    }
+
+    op->type = IO_VOID; // Mark unused
+}
+
+io_handle io_open_file(struct io_context *ioc,
+                       const char *name,
+                       int flags, void *user)
+{
+    unsigned long access = 0;
+	if (flags & IO_ACCESS_RD) access |= GENERIC_READ;
+	if (flags & IO_ACCESS_WR) access |= GENERIC_WRITE;
+
+	io_handle handle = CreateFileA(name, access, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED, NULL);
+	if (handle == IO_INVALID_HANDLE)
+		return IO_INVALID_HANDLE;
+
+    if (CreateIoCompletionPort(handle, ioc->handle, user, 0) == NULL) {
+		CloseHandle(handle);
+		return IO_INVALID_HANDLE;
+	}
+
+    return handle;
+}
+
+io_handle io_create_file(struct io_context *ioc,
+                         const char *name,
+                         int flags, void *user)
+{
+    unsigned long flags2 = 0;
+
+	if (flags & IO_CREATE_CANTEXIST)
+		flags2 = CREATE_NEW;
+	else {
+		if (flags & IO_CREATE_OVERWRITE)
+			flags2 = CREATE_ALWAYS;
+		else
+			flags2 = OPEN_ALWAYS;
+	}
+
+	io_handle handle = CreateFileA(name, GENERIC_WRITE, 0, NULL, flags2, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED, NULL);
+	if (handle == IO_INVALID_HANDLE)
+        return IO_INVALID_HANDLE;
+
+    if (CreateIoCompletionPort(handle, ioc->handle, user, 0) == NULL) {
+		CloseHandle(handle);
+		return IO_INVALID_HANDLE;
+	}
+
+    return handle;
 }
 
 #endif
@@ -97,6 +255,8 @@ void io_wait(struct io_context *ioc, struct io_event *ev)
 
 #if IO_PLATFORM_LINUX
 
+#include <fcntl.h>
+#include <assert.h>
 #include <string.h>
 #include <unistd.h>
 #include <sys/mman.h>
@@ -124,8 +284,10 @@ bool io_context_init(struct io_context *ioc,
     ioc->ops = ops;
     ioc->max_ops = max_ops;
 
-    for (uint32_t i = 0; i < max_ops; i++)
+    for (uint32_t i = 0; i < max_ops; i++) {
         ioc->ops[i].type = IO_VOID;
+        ioc->ops[i].handle = IO_INVALID_HANDLE;
+    }
 
     struct io_uring_params p;
     void *sq_ptr, *cq_ptr;
@@ -228,21 +390,57 @@ static bool start_oper(struct io_context *ioc,
     return true;
 }
 
-static struct io_operation *alloc_op(struct io_context *ioc)
+static struct io_operation *alloc_op(struct io_context *ioc,
+                                     io_handle handle, void **user)
 {
-    for (uint32_t i = 0; i < ioc->max_ops; i++)
+    assert(handle != IO_INVALID_HANDLE);
-        if (ioc->ops[i].type == IO_VOID)
+
-            return &ioc->ops[i];
+    /*
-    return NULL;
+     * Look for an empty struct and the struct associated to
+     * this handle.
+     */
+    struct io_operation *ref = NULL;
+    struct io_operation *empty = NULL;
+
+    for (uint32_t i = 0; i < ioc->max_ops; i++) {
+
+        struct io_operation *op = &ioc->ops[i];
+
+        if (op->handle == handle) {
+            ref = op;
+            if (empty) break;
+        } else {
+            if (op->type == IO_VOID && op->handle == IO_INVALID_HANDLE) {
+                empty = op;
+                if (ref) break;
+            }
+        }
+    }
+    assert(ref && empty);
+
+    *user = ref->user;
+
+    /*
+     * If the reference slot is unused, use that one,
+     * else use the first empty one.
+     */
+    if (ref->type == IO_VOID)
+        return ref;
+    else
+        return empty;
 }
 
 bool io_start_recv(struct io_context *ioc, io_handle handle,
-                   void *dst, uint32_t max, void *user)
+                   void *dst, uint32_t max)
 {
+    if (handle == IO_INVALID_HANDLE)
+        return false;
+
+    void *user;
     struct io_operation *op;
     struct io_uring_sqe sqe;
 
-    op = alloc_op(ioc);
+    op = alloc_op(ioc, handle, &user);
     if (op == NULL)
         return false;
 
@@ -262,12 +460,16 @@ bool io_start_recv(struct io_context *ioc, io_handle handle,
 }
 
 bool io_start_send(struct io_context *ioc, io_handle handle,
-                   void *src, uint32_t num, void *user)
+                   void *src, uint32_t num)
 {
+    if (handle == IO_INVALID_HANDLE)
+        return false;
+
+    void *user;
     struct io_operation *op;
     struct io_uring_sqe sqe;
 
-    op = alloc_op(ioc);
+    op = alloc_op(ioc, handle, &user);
     if (op == NULL)
         return false;
 
@@ -286,12 +488,16 @@ bool io_start_send(struct io_context *ioc, io_handle handle,
     return true;
 }
 
-bool io_start_accept(struct io_context *ioc, io_handle handle, void *user)
+bool io_start_accept(struct io_context *ioc, io_handle handle)
 {
+    if (handle == IO_INVALID_HANDLE)
+        return false;
+
+    void *user;
     struct io_operation *op;
     struct io_uring_sqe sqe;
 
-    op = alloc_op(ioc);
+    op = alloc_op(ioc, handle, &user);
     if (op == NULL)
         return false;
 
@@ -351,4 +557,65 @@ void io_wait(struct io_context *ioc, struct io_event *ev)
     atomic_store(ioc->completions.head, head+1);
 }
 
+static struct io_operation*
+unassociated_operation_struct(struct io_context *ioc)
+{
+    for (uint32_t i = 0; i < ioc->max_ops; i++) {
+        struct io_operation *op = &ioc->ops[i];
+        if (op->type == IO_VOID && op->handle == IO_INVALID_HANDLE)
+            return op;
+    }
+    return NULL;
+}
+
+io_handle io_open_file(struct io_context *ioc,
+                       const char *name,
+                       int flags, void *user)
+{
+    struct io_operation *op;
+    op = unassociated_operation_struct(ioc);
+    if (op == NULL)
+        return IO_INVALID_HANDLE;
+
+    int flags2 = 0;
+	if (flags & IO_ACCESS_RD) flags2 |= O_RDONLY;
+	if (flags & IO_ACCESS_WR) flags2 |= O_WRONLY;
+
+	io_handle fd = open(name, flags2);
+	if (fd < 0)
+		return IO_INVALID_HANDLE;
+
+    op->handle = fd;
+    op->user = user;
+    return fd;
+}
+
+io_handle io_create_file(struct io_context *ioc,
+                         const char *name,
+                         int flags, void *user)
+{
+    struct io_operation *op;
+    op = unassociated_operation_struct(ioc);
+    if (op == NULL)
+        return IO_INVALID_HANDLE;
+
+    int flags2 = O_CREAT | O_WRONLY;
+
+	if (flags & IO_CREATE_CANTEXIST)
+		flags2 |= O_EXCL;
+	else {
+		if (flags & IO_CREATE_OVERWRITE)
+			flags2 |= O_TRUNC;
+	}
+
+    // TODO: is 0666 ok?
+	int fd = open(name, flags2, 0666);
+	if (fd < 0)
+		return IO_INVALID_HANDLE;
+
+    op->handle = fd;
+    op->user = user;
+    return fd;
+}
+
 #endif

io.h

@@ -61,9 +61,15 @@ enum io_optype {
 };
 
 struct io_operation {
-    enum io_optype type; // =IO_VOID when the struct is unused
+
     void *user;
 
+    enum io_optype type;
+
+    #if IO_PLATFORM_LINUX
+    io_handle handle;
+    #endif
+
     #if IO_PLATFORM_WINDOWS
     struct io_overlap ov;
     #endif
@@ -145,17 +151,16 @@ void io_context_free(struct io_context *ioc);
  * bytes actually written from "dst". 
  */
 bool io_start_recv(struct io_context *ioc, io_handle handle,
-                   void *dst, uint32_t max, void *user);
+                   void *dst, uint32_t max);
 
 /*
  * Works like "io_start_recv" but for sending.
  */
 bool io_start_send(struct io_context *ioc, io_handle handle,
-                   void *src, uint32_t num, void *user);
+                   void *src, uint32_t num);
 
 
-bool io_start_accept(struct io_context *ioc, io_handle handle,
+bool io_start_accept(struct io_context *ioc, io_handle handle);
-                     void *user);
 
 /*
  * Wait for the completion of an I/O event.
@@ -163,11 +168,20 @@ bool io_start_accept(struct io_context *ioc, io_handle handle,
 void io_wait(struct io_context *ioc,
              struct io_event *ev);
 
+/*
+ * Flags for "io_open_file" and "io_create_file"
+ */
+enum {
+    IO_ACCESS_RD = 1 << 0,
+    IO_ACCESS_WR = 1 << 1,
+    IO_CREATE_OVERWRITE = 1 << 2,
+    IO_CREATE_CANTEXIST = 1 << 3,
+};
+
 io_handle io_open_file(struct io_context *ioc,
-                       const char *name, int flags);
+                       const char *name, int flags,
+                       void *user);
 
 io_handle io_create_file(struct io_context *ioc,
-                         const char *name, int flags);
+                         const char *name, int flags,
-
+                         void *user);
-io_handle io_listen(struct io_context *ioc,
-                    const char *addr, int port);