Wasip3: Implement pipe, testing will need cooperative threads though

expected/wasm32-wasip3/defined-symbols.txt

@@ -1005,6 +1005,7 @@ optopt
 optreset
 pathconf
 perror
+pipe
 poll
 posix_close
 posix_fadvise

libc-bottom-half/CMakeLists.txt

@@ -166,6 +166,7 @@ if (WASI STREQUAL "p3")
     sources/wasip3_block_on.c
     sources/wasip3_file.c
     sources/wasip3_file_utils.c
+    sources/wasip3_pipe.c
     sources/wasip3_stdio.c
     sources/wasip3_tcp.c
     sources/wasip3_udp.c

libc-bottom-half/sources/wasip3_pipe.c

@@ -0,0 +1,102 @@
+#include <wasi/version.h>
+
+#ifdef __wasip3__
+#include <common/errors.h>
+#include <stdlib.h>
+#include <wasi/api.h>
+#include <wasi/descriptor_table.h>
+
+typedef struct {
+  wasip3_write_t output;
+} pipe3w_t;
+
+typedef struct {
+  filesystem_tuple2_stream_u8_future_result_void_error_code_t input;
+} pipe3r_t;
+
+static int pipe_read_stream(
+    void *data,
+    filesystem_tuple2_stream_u8_future_result_void_error_code_t **out,
+    off_t **offs) {
+  pipe3r_t *file = (pipe3r_t *)data;
+  *out = &file->input;
+  *offs = 0;
+  return 0;
+}
+
+static void pipe_r_free(void *data) {
+  pipe3r_t *file = (pipe3r_t *)data;
+  filesystem_stream_u8_drop_readable(file->input.f0);
+  free(file);
+}
+
+static int pipe_write_stream(void *data, wasip3_write_t **out, off_t **offs) {
+  pipe3w_t *file = (pipe3w_t *)data;
+  *out = &file->output;
+  *offs = 0;
+  return 0;
+}
+
+static void pipe_w_free(void *data) {
+  pipe3w_t *file = (pipe3w_t *)data;
+  filesystem_stream_u8_drop_writable(file->output.output);
+  free(file);
+}
+
+static descriptor_vtable_t pipe_r_vtable = {
+    .free = pipe_r_free,
+    .get_read_stream3 = pipe_read_stream,
+};
+
+static descriptor_vtable_t pipe_w_vtable = {
+    .free = pipe_w_free,
+    .get_write_stream3 = pipe_write_stream,
+};
+
+int pipe(int pipefd[2]) {
+  pipe3w_t *writehandle = calloc(1, sizeof(pipe3w_t));
+  if (!writehandle) {
+    errno = ENOMEM;
+    return -1;
+  }
+  pipe3r_t *readhandle = calloc(1, sizeof(pipe3r_t));
+  if (!readhandle) {
+    free(writehandle);
+    errno = ENOMEM;
+    return -1;
+  }
+  readhandle->input.f0 = filesystem_stream_u8_new(&writehandle->output.output);
+  descriptor_table_entry_t entry;
+  entry.vtable = &pipe_r_vtable;
+  entry.data = readhandle;
+  int pipefd0 = descriptor_table_insert(entry);
+  if (pipefd0 < 0) {
+    pipe_r_free(readhandle);
+    pipe_w_free(writehandle);
+    return -1;
+  }
+  entry.vtable = &pipe_w_vtable;
+  entry.data = writehandle;
+  int pipefd1 = descriptor_table_insert(entry);
+  if (pipefd1 < 0) {
+    pipe_r_free(readhandle);
+    pipe_w_free(writehandle);
+    descriptor_table_remove(pipefd0);
+    return -1;
+  }
+  // signal non-eof condition
+  writehandle->output.subtask = WASIP3_SUBTASK_STARTING;
+  pipefd[0] = pipefd0;
+  pipefd[1] = pipefd1;
+  return 0;
+}
+
+int pipe2(int pipefd[2], int flags) {
+  if (flags != 0) {
+    errno = EOPNOTSUPP;
+    return -1;
+  }
+  return pipe(pipefd);
+}
+
+#endif

libc-top-half/musl/include/unistd.h

@@ -19,6 +19,7 @@ extern "C" {
 #define SEEK_HOLE 4
 #else
 #include <__header_unistd.h>
+#include <wasi/version.h> // for pipe availability
 #endif
 
 #ifdef __wasilibc_unmodified_upstream /* Use the compiler's definition of NULL */
@@ -45,7 +46,7 @@ extern "C" {
 
 #include <bits/alltypes.h>
 
-#ifdef __wasilibc_unmodified_upstream /* WASI has no pipe */
+#if defined(__wasilibc_unmodified_upstream) || defined(__wasip3__) /* WASI<0.3 has no pipe */
 int pipe(int [2]);
 int pipe2(int [2], int);
 #endif

test/CMakeLists.txt

@@ -271,6 +271,7 @@ add_wasilibc_test(memchr.c LDFLAGS -Wl,--stack-first -Wl,--initial-memory=327680
 add_wasilibc_test(memcmp.c LDFLAGS -Wl,--stack-first -Wl,--initial-memory=327680)
 add_wasilibc_test(opendir.c FS FAILP3 ARGV /)
 add_wasilibc_test(open_relative_path.c FS FAILP3 ARGV /)
+add_wasilibc_test(pipe.c)
 add_wasilibc_test(poll.c FS FAILP3)
 add_wasilibc_test(preadvwritev.c FS FAILP3)
 add_wasilibc_test(preadwrite.c FS FAILP3)

test/src/pipe.c

@@ -0,0 +1,28 @@
+#include "test.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#define PATTERNSIZE 16
+static const char PATTERN[PATTERNSIZE] = {
+    'A', 'B', 'C', 'D', '0', '1', '2', '3', 'a', 'b', 'c', 'd', 0, 1, 2, 3};
+
+#define TEST(c, ...) ((c) ? 1 : (t_error(#c " failed: " __VA_ARGS__), 0))
+
+int main(void) {
+#ifdef __wasip3__ // pipe only works on wasip3 or up
+  int pipefd[2];
+  char buf[PATTERNSIZE];
+  int res;
+
+  TEST(pipe(pipefd) >= 0);
+
+  TEST(write(pipefd[1], PATTERN, PATTERNSIZE) == PATTERNSIZE);
+
+  TEST(read(pipefd[0], buf, PATTERNSIZE) == PATTERNSIZE);
+
+  TEST(close(pipefd[0]) >= 0);
+  TEST(close(pipefd[1]) >= 0);
+#endif
+  return 0;
+}