Port polling operations to wasip2 (#608)

catamorphism · web-flow · commit d1793637d8af · 2025-09-05T16:34:35.000-07:00
Port poll() to use wasip2 poll method in all cases
    
At this point, there should be no further uses of the preview1
component adapter for polling methods (__wasi_poll_oneoff())
when __wasilibc_use_wasip2 is defined.
diff --git a/libc-bottom-half/cloudlibc/src/libc/poll/poll.c b/libc-bottom-half/cloudlibc/src/libc/poll/poll.c
@@ -140,7 +140,11 @@ int poll(struct pollfd* fds, nfds_t nfds, int timeout)
     for (size_t i = 0; i < nfds; ++i) {
         descriptor_table_entry_t* entry;
         if (descriptor_table_get_ref(fds[i].fd, &entry)) {
-            found_socket = true;
+            if (entry->tag == DESCRIPTOR_TABLE_ENTRY_TCP_SOCKET
+                || entry->tag == DESCRIPTOR_TABLE_ENTRY_UDP_SOCKET)
+                found_socket = true;
+            else
+                found_non_socket = true;
         } else {
             found_non_socket = true;
         }
@@ -155,16 +159,8 @@ int poll(struct pollfd* fds, nfds_t nfds, int timeout)
             errno = ENOTSUP;
             return -1;
         }
-
-        return poll_wasip2(fds, nfds, timeout);
-    } else if (found_non_socket) {
-        return poll_wasip1(fds, nfds, timeout);
-    } else if (timeout >= 0) {
-        return poll_wasip2(fds, nfds, timeout);
-    } else {
-        errno = ENOTSUP;
-        return -1;
     }
+    return poll_wasip2(fds, nfds, timeout);
 }
 #else // not __wasilibc_use_wasip2
 int poll(struct pollfd* fds, nfds_t nfds, int timeout)
diff --git a/libc-bottom-half/cloudlibc/src/libc/sys/ioctl/ioctl.c b/libc-bottom-half/cloudlibc/src/libc/sys/ioctl/ioctl.c
@@ -57,7 +57,8 @@ int ioctl(int fildes, int request, ...) {
 				return -1;
 			}
 		}
-
+                // TODO: In particular, this doesn't support using FIONREAD
+                // with file descriptors
 		default:
 			errno = ENOPROTOOPT;
 			return -1;
@@ -111,11 +112,6 @@ int ioctl(int fildes, int request, ...) {
       return 0;
     }
     case FIONBIO: {
-#ifdef __wasilibc_use_wasip2
-      // wasip2 doesn't support setting the non-blocking flag
-      errno = ENOTSUP;
-      return -1;
-#else
       // Obtain the current file descriptor flags.
       __wasi_fdstat_t fds;
       __wasi_errno_t error = __wasi_fd_fdstat_get(fildes, &fds);
@@ -140,7 +136,6 @@ int ioctl(int fildes, int request, ...) {
         return -1;
       }
       return 0;
-#endif
     }
     default:
       // Invalid request.
diff --git a/libc-bottom-half/cloudlibc/src/libc/time/clock_nanosleep.c b/libc-bottom-half/cloudlibc/src/libc/time/clock_nanosleep.c
@@ -23,24 +23,22 @@ int clock_nanosleep(clockid_t clock_id, int flags, const struct timespec *rqtp,
   if ((flags & ~TIMER_ABSTIME) != 0)
     return EINVAL;
 
-  // Prepare polling subscription.
-  __wasi_subscription_t sub = {
-    .u.tag = __WASI_EVENTTYPE_CLOCK,
-    .u.u.clock.id = clock_id->id,
-    .u.u.clock.flags = flags,
-  };
-  // Convert to wall_clock_datetime_t
-  wall_clock_datetime_t timeout;
-  if (!timespec_to_timestamp_clamp(rqtp, &timeout))
-    return EINVAL;
-  sub.u.u.clock.timeout = (timeout.seconds * NSEC_PER_SEC)
-      + timeout.nanoseconds;
+  // Note: rmtp is ignored
+
+  if (clock_id != CLOCK_MONOTONIC) {
+    // wasip2 only provides a pollable for monotonic clocks
+    return ENOTSUP;
+  }
+
+  // Prepare pollable
+  int64_t duration = (rqtp->tv_sec * NSEC_PER_SEC) + rqtp->tv_nsec;
+  monotonic_clock_own_pollable_t pollable = monotonic_clock_subscribe_duration(duration);
 
   // Block until polling event is triggered.
-  size_t nevents;
-  __wasi_event_t ev;
-  __wasi_errno_t error = __wasi_poll_oneoff(&sub, &ev, 1, &nevents);
-  return error == 0 && ev.error == 0 ? 0 : ENOTSUP;
+  poll_method_pollable_block(poll_borrow_pollable(pollable));
+
+  poll_pollable_drop_own(pollable);
+  return 0;
 }
 #else
 int clock_nanosleep(clockid_t clock_id, int flags, const struct timespec *rqtp,
diff --git a/libc-bottom-half/cloudlibc/src/libc/unistd/lseek.c b/libc-bottom-half/cloudlibc/src/libc/unistd/lseek.c
@@ -69,13 +69,14 @@ off_t __lseek(int fildes, off_t offset, int whence) {
     }
     }
     // Drop the existing streams
+    if (entry->stream.read_pollable_is_initialized)
+      poll_pollable_drop_own(entry->stream.read_pollable);
+    if (entry->stream.write_pollable_is_initialized)
+      poll_pollable_drop_own(entry->stream.write_pollable);
     if (entry->stream.file_info.readable)
       streams_input_stream_drop_borrow(entry->stream.read_stream);
-    if (entry->stream.file_info.writable) {
-      if (entry->stream.pollable_is_initialized)
-        poll_pollable_drop_own(entry->stream.pollable);
+    if (entry->stream.file_info.writable)
       streams_output_stream_drop_borrow(entry->stream.write_stream);
-    }
 
     // Open a new stream with the right offset
     if (entry->stream.file_info.readable) {
@@ -106,9 +107,10 @@ off_t __lseek(int fildes, off_t offset, int whence) {
 
       // Update output_stream.stream with the new stream
       entry->stream.write_stream = streams_borrow_output_stream(new_stream);
-      entry->stream.pollable_is_initialized = false;
     }
 
+    entry->stream.read_pollable_is_initialized = false;
+    entry->stream.write_pollable_is_initialized = false;
     // Update offset
     entry->stream.offset = offset_to_use;
   } else {
diff --git a/libc-bottom-half/cloudlibc/src/libc/unistd/read.c b/libc-bottom-half/cloudlibc/src/libc/unistd/read.c
@@ -31,6 +31,7 @@ ssize_t read(int fildes, void *buf, size_t nbyte) {
     // Get the input stream
     filesystem_error_code_t error_code;
     streams_own_input_stream_t input_stream_own;
+
     ok = filesystem_method_descriptor_read_via_stream(entry->file.file_handle,
                                                       0,
                                                       &input_stream_own,
@@ -62,7 +63,8 @@ ssize_t read(int fildes, void *buf, size_t nbyte) {
     // for this file
     new_entry.tag = DESCRIPTOR_TABLE_ENTRY_FILE_STREAM;
     new_entry.stream.read_stream = input_stream;
-    new_entry.stream.pollable_is_initialized = false;
+    new_entry.stream.read_pollable_is_initialized = false;
+    new_entry.stream.write_pollable_is_initialized = false;
     new_entry.stream.offset = 0;
     new_entry.stream.file_info.readable = entry->file.readable;
     new_entry.stream.file_info.writable = entry->file.writable;
diff --git a/libc-bottom-half/cloudlibc/src/libc/unistd/write.c b/libc-bottom-half/cloudlibc/src/libc/unistd/write.c
@@ -53,11 +53,11 @@ ssize_t write(int fildes, const void *buf, size_t nbyte) {
       return -1;
     }
     output_stream = entry->stream.write_stream;
-    if (!entry->stream.pollable_is_initialized) {
-      pollable = entry->stream.pollable = streams_method_output_stream_subscribe(output_stream);
-      entry->stream.pollable_is_initialized = true;
+    if (!entry->stream.write_pollable_is_initialized) {
+      pollable = entry->stream.write_pollable = streams_method_output_stream_subscribe(output_stream);
+      entry->stream.write_pollable_is_initialized = true;
     } else
-      pollable = entry->stream.pollable;
+      pollable = entry->stream.write_pollable;
   } else {
       errno = EBADF;
       return -1;
@@ -114,8 +114,9 @@ ssize_t write(int fildes, const void *buf, size_t nbyte) {
       }
       new_entry.stream.read_stream = streams_borrow_input_stream(read_stream);
     }
-    new_entry.stream.pollable = pollable;
-    new_entry.stream.pollable_is_initialized = true;
+    new_entry.stream.write_pollable = pollable;
+    new_entry.stream.read_pollable_is_initialized = false;
+    new_entry.stream.write_pollable_is_initialized = true;
     new_entry.stream.write_stream = output_stream;
     new_entry.stream.offset = contents.len;
     new_entry.stream.file_info.readable = entry->file.readable;
diff --git a/libc-bottom-half/headers/private/wasi/descriptor_table.h b/libc-bottom-half/headers/private/wasi/descriptor_table.h
@@ -128,9 +128,11 @@ typedef struct {
         streams_borrow_output_stream_t write_stream;
         // Current position in stream, relative to the beginning of the *file*, measured in bytes
         off_t offset;
-        // Used for checking readiness to write to stream. Lazily initialized.
-        streams_own_pollable_t pollable;
-        bool pollable_is_initialized;
+        // Used for checking readiness to read/write to stream. Lazily initialized
+        streams_own_pollable_t read_pollable;
+        streams_own_pollable_t write_pollable;
+        bool read_pollable_is_initialized;
+        bool write_pollable_is_initialized;
         // When the stream is closed, the caller should
         // replace this entry in the table with the file handle
         file_t file_info;
diff --git a/libc-bottom-half/headers/private/wasi/file_utils.h b/libc-bottom-half/headers/private/wasi/file_utils.h
@@ -68,6 +68,8 @@ static bool init_stdin() {
   entry.tag = DESCRIPTOR_TABLE_ENTRY_FILE_STREAM;
   entry.stream.read_stream = streams_borrow_input_stream(stdin_get_stdin());
   entry.stream.offset = 0;
+  entry.stream.read_pollable_is_initialized = false;
+  entry.stream.write_pollable_is_initialized = false;
   entry.stream.file_info.readable = true;
   entry.stream.file_info.writable = false;
   // entry.stream.file_info.file_handle is uninitialized, but it will never be used
@@ -81,7 +83,8 @@ static bool init_stdout() {
   entry.tag = DESCRIPTOR_TABLE_ENTRY_FILE_STREAM;
   entry.stream.write_stream = streams_borrow_output_stream(stdout_get_stdout());
   entry.stream.offset = 0;
-  entry.stream.pollable = streams_method_output_stream_subscribe(entry.stream.write_stream);
+  entry.stream.read_pollable_is_initialized = false;
+  entry.stream.write_pollable_is_initialized = false;
   entry.stream.file_info.readable = false;
   entry.stream.file_info.writable = true;
   // entry.stream.file_info.file_handle is uninitialized, but it will never be used
@@ -95,7 +98,8 @@ static bool init_stderr() {
   entry.tag = DESCRIPTOR_TABLE_ENTRY_FILE_STREAM;
   entry.stream.write_stream = streams_borrow_output_stream(stderr_get_stderr());
   entry.stream.offset = 0;
-  entry.stream.pollable = streams_method_output_stream_subscribe(entry.stream.write_stream);
+  entry.stream.read_pollable_is_initialized = false;
+  entry.stream.write_pollable_is_initialized = false;
   entry.stream.file_info.readable = false;
   entry.stream.file_info.writable = true;
   // entry.stream.file_info.file_handle is uninitialized, but it will never be used
diff --git a/libc-bottom-half/sources/__wasilibc_fd_renumber.c b/libc-bottom-half/sources/__wasilibc_fd_renumber.c
@@ -122,8 +122,10 @@ int close(int fd) {
             drop_directory_stream(entry.directory_stream_info.directory_stream);
             break;
         case DESCRIPTOR_TABLE_ENTRY_FILE_STREAM:
-            if (entry.stream.pollable_is_initialized)
-                poll_pollable_drop_own(entry.stream.pollable);
+            if (entry.stream.read_pollable_is_initialized)
+                poll_pollable_drop_own(entry.stream.read_pollable);
+            if (entry.stream.write_pollable_is_initialized)
+                poll_pollable_drop_own(entry.stream.write_pollable);
             if (entry.stream.file_info.readable)
                 streams_input_stream_drop_borrow(entry.stream.read_stream);
             if (entry.stream.file_info.writable)
diff --git a/libc-bottom-half/sources/poll-wasip2.c b/libc-bottom-half/sources/poll-wasip2.c
diff --git a/test/src/misc/clock_nanosleep.c b/test/src/misc/clock_nanosleep.c
diff --git a/test/src/misc/ioctl.c b/test/src/misc/ioctl.c
diff --git a/test/src/misc/poll.c b/test/src/misc/poll.c

Original file line number	Diff line number	Diff line change
`@@ -57,7 +57,8 @@ int ioctl(int fildes, int request, ...) {`
`57`	`57`	`return -1;`
`58`	`58`	`}`
`59`	`59`	`}`
`60`		`-`
	`60`	`+ // TODO: In particular, this doesn't support using FIONREAD`
	`61`	`+ // with file descriptors`
`61`	`62`	`default:`
`62`	`63`	`errno = ENOPROTOOPT;`
`63`	`64`	`return -1;`
`@@ -111,11 +112,6 @@ int ioctl(int fildes, int request, ...) {`
`111`	`112`	`return 0;`
`112`	`113`	`}`
`113`	`114`	`case FIONBIO: {`
`114`		`-#ifdef __wasilibc_use_wasip2`
`115`		`- // wasip2 doesn't support setting the non-blocking flag`
`116`		`- errno = ENOTSUP;`
`117`		`- return -1;`
`118`		`-#else`
`119`	`115`	`// Obtain the current file descriptor flags.`
`120`	`116`	`__wasi_fdstat_t fds;`
`121`	`117`	`__wasi_errno_t error = __wasi_fd_fdstat_get(fildes, &fds);`
`@@ -140,7 +136,6 @@ int ioctl(int fildes, int request, ...) {`
`140`	`136`	`return -1;`
`141`	`137`	`}`
`142`	`138`	`return 0;`
`143`		`-#endif`
`144`	`139`	`}`
`145`	`140`	`default:`
`146`	`141`	`// Invalid request.`