Merge "Add epoll_pwait2()." into main am: 906d7d41e4

Original change: https://android-review.googlesource.com/c/platform/bionic/+/2656904

Change-Id: I62a2f1f487678f18a602d07771a10d0fa538dfed
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

docs/status.md

@@ -64,7 +64,7 @@ New libc functions in V (API level 35):
     multi-threaded C).
   * `mbsrtowcs_l` and `wcsrtombs_l` aliases for `mbsrtowcs` and `wcsrtombs`.
   * New system call wrappers: `__riscv_flush_icache` (`<sys/cachectl.h>`),
-    `__riscv_hwprobe` (`<sys/hwprobe.h>`).
+    `__riscv_hwprobe` (`<sys/hwprobe.h>`), `epoll_pwait2`/`epoll_pwait2_64` (`<sys/epoll.h>`).
 
 New libc behavior in V (API level 35):
   * Added `LD_SHOW_AUXV` to the dynamic linker to dump the ELF auxiliary

libc/SYSCALLS.TXT

@@ -322,6 +322,7 @@ ssize_t vmsplice(int, const struct iovec*, size_t, unsigned int)  all
 int __epoll_create1:epoll_create1(int)  all
 int epoll_ctl(int, int op, int, struct epoll_event*)  all
 int __epoll_pwait:epoll_pwait(int, struct epoll_event*, int, int, const sigset64_t*, size_t)  all
+int __epoll_pwait2:epoll_pwait2(int, struct epoll_event*, int, const timespec64*, const sigset64_t*, size_t)  all
 
 int __eventfd:eventfd2(unsigned int, int)  all
 

libc/bionic/sys_epoll.cpp

@@ -34,6 +34,8 @@
 
 extern "C" int __epoll_create1(int flags);
 extern "C" int __epoll_pwait(int, epoll_event*, int, int, const sigset64_t*, size_t);
+extern "C" int __epoll_pwait2(int, epoll_event*, int, const __kernel_timespec*, const sigset64_t*,
+                              size_t);
 
 int epoll_create(int size) {
   if (size <= 0) {
@@ -56,6 +58,31 @@ int epoll_pwait64(int fd, epoll_event* events, int max_events, int timeout, cons
   return __epoll_pwait(fd, events, max_events, timeout, ss, sizeof(*ss));
 }
 
+int epoll_pwait2(int fd, epoll_event* events, int max_events, const timespec* timeout,
+                 const sigset_t* ss) {
+  SigSetConverter set{ss};
+  return epoll_pwait2_64(fd, events, max_events, timeout, set.ptr);
+}
+
+int epoll_pwait2_64(int fd, epoll_event* events, int max_events, const timespec* timeout,
+                    const sigset64_t* ss) {
+  // epoll_pwait2() is our first syscall that assumes a 64-bit time_t even for
+  // 32-bit processes, so for ILP32 we need to convert.
+  // TODO: factor this out into a TimeSpecConverter as/when we get more syscalls like this.
+#if __LP64__
+  const __kernel_timespec* kts_ptr = reinterpret_cast<const __kernel_timespec*>(timeout);
+#else
+  __kernel_timespec kts;
+  const __kernel_timespec* kts_ptr = nullptr;
+  if (timeout) {
+    kts.tv_sec = timeout->tv_sec;
+    kts.tv_nsec = timeout->tv_nsec;
+    kts_ptr = &kts;
+  }
+#endif
+  return __epoll_pwait2(fd, events, max_events, kts_ptr, ss, sizeof(*ss));
+}
+
 int epoll_wait(int fd, struct epoll_event* events, int max_events, int timeout) {
   return epoll_pwait64(fd, events, max_events, timeout, nullptr);
 }

libc/include/sys/epoll.h

@@ -26,8 +26,12 @@
  * SUCH DAMAGE.
  */
 
-#ifndef _SYS_EPOLL_H_
-#define _SYS_EPOLL_H_
+#pragma once
+
+/**
+ * @file sys/epoll.h
+ * @brief I/O event file descriptors.
+ */
 
 #include <sys/cdefs.h>
 #include <sys/types.h>
@@ -37,14 +41,67 @@
 
 __BEGIN_DECLS
 
+/**
+ * [epoll_create(2)](http://man7.org/linux/man-pages/man2/epoll_create.2.html)
+ * creates a new [epoll](http://man7.org/linux/man-pages/man7/epoll.7.html)
+ * file descriptor.
+ *
+ * Returns a new file descriptor on success and returns -1 and sets `errno` on
+ * failure.
+ */
 int epoll_create(int __size);
+
+/**
+ * [epoll_create1(2)](http://man7.org/linux/man-pages/man2/epoll_create1.2.html)
+ * creates a new [epoll](http://man7.org/linux/man-pages/man7/epoll.7.html)
+ * file descriptor with the given flags.
+ *
+ * Returns a new file descriptor on success and returns -1 and sets `errno` on
+ * failure.
+ */
 int epoll_create1(int __flags);
 
+/**
+ * [epoll_ctl(2)](http://man7.org/linux/man-pages/man2/epoll_ctl.2.html)
+ * adds/modifies/removes file descriptors from the given epoll file descriptor.
+ *
+ * Returns 0 on success and returns -1 and sets `errno` on failure.
+ */
 int epoll_ctl(int __epoll_fd, int __op, int __fd, struct epoll_event* __BIONIC_COMPLICATED_NULLNESS __event);
+
+/**
+ * [epoll_wait(2)](http://man7.org/linux/man-pages/man2/epoll_wait.2.html)
+ * waits for an event on the given epoll file descriptor.
+ *
+ * Returns the number of ready file descriptors on success, 0 on timeout,
+ * or -1 and sets `errno` on failure.
+ */
 int epoll_wait(int __epoll_fd, struct epoll_event* _Nonnull __events, int __event_count, int __timeout_ms);
+
+/**
+ * Like epoll_wait() but atomically applying the given signal mask.
+ */
 int epoll_pwait(int __epoll_fd, struct epoll_event* _Nonnull __events, int __event_count, int __timeout_ms, const sigset_t* _Nullable __mask);
+
+/**
+ * Like epoll_pwait() but using a 64-bit signal mask even on 32-bit systems.
+ *
+ * Available since API level 28.
+ */
 int epoll_pwait64(int __epoll_fd, struct epoll_event* _Nonnull __events, int __event_count, int __timeout_ms, const sigset64_t* _Nullable __mask) __INTRODUCED_IN(28);
 
-__END_DECLS
+/**
+ * Like epoll_pwait() but with a `struct timespec` timeout, for nanosecond resolution.
+ *
+ * Available since API level 35.
+ */
+int epoll_pwait2(int __epoll_fd, struct epoll_event* _Nonnull __events, int __event_count, const struct timespec* _Nullable __timeout, const sigset_t* _Nullable __mask) __INTRODUCED_IN(35);
 
-#endif
+/**
+ * Like epoll_pwait2() but using a 64-bit signal mask even on 32-bit systems.
+ *
+ * Available since API level 35.
+ */
+int epoll_pwait2_64(int __epoll_fd, struct epoll_event* _Nonnull __events, int __event_count, const struct timespec* _Nullable __timeout, const sigset64_t* _Nullable __mask) __INTRODUCED_IN(35);
+
+__END_DECLS

libc/libc.map.txt

@@ -1586,6 +1586,8 @@ LIBC_U { # introduced=UpsideDownCake
 
 LIBC_V { # introduced=VanillaIceCream
   global:
+    epoll_pwait2;
+    epoll_pwait2_64;
     localtime_rz;
     mbsrtowcs_l;
     mktime_z;

tests/sys_epoll_test.cpp

@@ -24,29 +24,101 @@
 
 #include "utils.h"
 
-TEST(sys_epoll, smoke) {
+TEST(sys_epoll, epoll_wait) {
   int epoll_fd = epoll_create(1);
-  ASSERT_NE(-1, epoll_fd) << strerror(errno);
-  epoll_event events[1];
+  ASSERT_NE(-1, epoll_fd);
 
   // Regular epoll_wait.
+  epoll_event events[1] = {};
   ASSERT_EQ(0, epoll_wait(epoll_fd, events, 1, 1));
+}
+
+TEST(sys_epoll, epoll_pwait_no_sigset) {
+  int epoll_fd = epoll_create(1);
+  ASSERT_NE(-1, epoll_fd);
 
   // epoll_pwait without a sigset (which is equivalent to epoll_wait).
+  epoll_event events[1] = {};
   ASSERT_EQ(0, epoll_pwait(epoll_fd, events, 1, 1, nullptr));
+}
 
+TEST(sys_epoll, epoll_pwait64_no_sigset) {
 #if defined(__BIONIC__)
+  int epoll_fd = epoll_create(1);
+  ASSERT_NE(-1, epoll_fd);
+
   // epoll_pwait64 without a sigset (which is equivalent to epoll_wait).
+  epoll_event events[1] = {};
   ASSERT_EQ(0, epoll_pwait64(epoll_fd, events, 1, 1, nullptr));
+#else
+  GTEST_SKIP() << "epoll_pwait64 is bionic-only";
 #endif
+}
+
+TEST(sys_epoll, epoll_pwait2_no_sigset) {
+#if defined(__BIONIC__)
+  int epoll_fd = epoll_create(1);
+  ASSERT_NE(-1, epoll_fd);
+
+  // epoll_pwait2 without a sigset (which is equivalent to epoll_wait).
+  epoll_event events[1] = {};
+  timespec ts = {.tv_nsec = 500};
+  int rc = epoll_pwait2(epoll_fd, events, 1, &ts, nullptr);
+  if (rc == -1 && errno == ENOSYS) GTEST_SKIP() << "no epoll_pwait2 in this kernel";
+  ASSERT_EQ(0, rc) << strerror(errno);
+#else
+  GTEST_SKIP() << "epoll_pwait2 is only in glibc 2.35+";
+#endif
+}
+
+TEST(sys_epoll, epoll_pwait_with_sigset) {
+  int epoll_fd = epoll_create(1);
+  ASSERT_NE(-1, epoll_fd);
 
   // epoll_pwait with a sigset.
+  epoll_event events[1] = {};
   sigset_t ss;
   sigemptyset(&ss);
   sigaddset(&ss, SIGPIPE);
   ASSERT_EQ(0, epoll_pwait(epoll_fd, events, 1, 1, &ss));
 }
 
+TEST(sys_epoll, epoll_pwait2_with_sigset) {
+  int epoll_fd = epoll_create(1);
+  ASSERT_NE(-1, epoll_fd);
+
+#if defined(__BIONIC__)
+  epoll_event events[1] = {};
+  timespec ts = {.tv_nsec = 500};
+  sigset_t ss2;
+  sigemptyset(&ss2);
+  sigaddset(&ss2, SIGPIPE);
+  int rc = epoll_pwait2(epoll_fd, events, 1, &ts, &ss2);
+  if (rc == -1 && errno == ENOSYS) GTEST_SKIP() << "no epoll_pwait2 in this kernel";
+  ASSERT_EQ(0, rc) << strerror(errno);
+#else
+  GTEST_SKIP() << "epoll_pwait2 is only in glibc 2.35+";
+#endif
+}
+
+TEST(sys_epoll, epoll_pwait2_64_with_sigset) {
+  int epoll_fd = epoll_create(1);
+  ASSERT_NE(-1, epoll_fd);
+
+#if defined(__BIONIC__)
+  epoll_event events[1] = {};
+  timespec ts = {.tv_nsec = 500};
+  sigset64_t ss2;
+  sigemptyset64(&ss2);
+  sigaddset64(&ss2, SIGPIPE);
+  int rc = epoll_pwait2_64(epoll_fd, events, 1, &ts, &ss2);
+  if (rc == -1 && errno == ENOSYS) GTEST_SKIP() << "no epoll_pwait2 in this kernel";
+  ASSERT_EQ(0, rc) << strerror(errno);
+#else
+  GTEST_SKIP() << "epoll_pwait2_64 is bionic-only";
+#endif
+}
+
 TEST(sys_epoll, epoll_create_invalid_size) {
   errno = 0;
   ASSERT_EQ(-1, epoll_create(0));