diff lib/Support/Unix/Process.inc @ 83:60c9769439b8

LLVM 3.7
author Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp>
date Wed, 18 Feb 2015 14:55:36 +0900
parents 54457678186b
children afa8332a0e37
line wrap: on
line diff
--- a/lib/Support/Unix/Process.inc	Mon Sep 08 22:07:30 2014 +0900
+++ b/lib/Support/Unix/Process.inc	Wed Feb 18 14:55:36 2015 +0900
@@ -14,15 +14,25 @@
 #include "Unix.h"
 #include "llvm/ADT/Hashing.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/Mutex.h"
 #include "llvm/Support/MutexGuard.h"
 #include "llvm/Support/TimeValue.h"
+#if HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
 #ifdef HAVE_SYS_TIME_H
 #include <sys/time.h>
 #endif
 #ifdef HAVE_SYS_RESOURCE_H
 #include <sys/resource.h>
 #endif
+#ifdef HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#if HAVE_SIGNAL_H
+#include <signal.h>
+#endif
 // DragonFlyBSD, OpenBSD, and Bitrig have deprecated <malloc.h> for
 // <stdlib.h> instead. Unix.h includes this for us already.
 #if defined(HAVE_MALLOC_H) && !defined(__DragonFly__) && \
@@ -47,10 +57,6 @@
 using namespace llvm;
 using namespace sys;
 
-process::id_type self_process::get_id() {
-  return getpid();
-}
-
 static std::pair<TimeValue, TimeValue> getRUsageTimes() {
 #if defined(HAVE_GETRUSAGE)
   struct rusage RU;
@@ -70,43 +76,19 @@
 #endif
 }
 
-TimeValue self_process::get_user_time() const {
-#if _POSIX_TIMERS > 0 && _POSIX_CPUTIME > 0
-  // Try to get a high resolution CPU timer.
-  struct timespec TS;
-  if (::clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &TS) == 0)
-    return TimeValue(static_cast<TimeValue::SecondsType>(TS.tv_sec),
-                     static_cast<TimeValue::NanoSecondsType>(TS.tv_nsec));
-#endif
-
-  // Otherwise fall back to rusage based timing.
-  return getRUsageTimes().first;
-}
-
-TimeValue self_process::get_system_time() const {
-  // We can only collect system time by inspecting the results of getrusage.
-  return getRUsageTimes().second;
-}
-
 // On Cygwin, getpagesize() returns 64k(AllocationGranularity) and
 // offset in mmap(3) should be aligned to the AllocationGranularity.
-static unsigned getPageSize() {
+unsigned Process::getPageSize() {
 #if defined(HAVE_GETPAGESIZE)
-  const int page_size = ::getpagesize();
+  static const int page_size = ::getpagesize();
 #elif defined(HAVE_SYSCONF)
-  long page_size = ::sysconf(_SC_PAGE_SIZE);
+  static long page_size = ::sysconf(_SC_PAGE_SIZE);
 #else
 #warning Cannot get the page size on this machine
 #endif
   return static_cast<unsigned>(page_size);
 }
 
-// This constructor guaranteed to be run exactly once on a single thread, and
-// sets up various process invariants that can be queried cheaply from then on.
-self_process::self_process() : PageSize(getPageSize()) {
-}
-
-
 size_t Process::GetMallocUsage() {
 #if defined(HAVE_MALLINFO)
   struct mallinfo mi;
@@ -198,6 +180,97 @@
   return std::error_code();
 }
 
+namespace {
+class FDCloser {
+public:
+  FDCloser(int &FD) : FD(FD), KeepOpen(false) {}
+  void keepOpen() { KeepOpen = true; }
+  ~FDCloser() {
+    if (!KeepOpen && FD >= 0)
+      ::close(FD);
+  }
+
+private:
+  FDCloser(const FDCloser &) = delete;
+  void operator=(const FDCloser &) = delete;
+
+  int &FD;
+  bool KeepOpen;
+};
+}
+
+std::error_code Process::FixupStandardFileDescriptors() {
+  int NullFD = -1;
+  FDCloser FDC(NullFD);
+  const int StandardFDs[] = {STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO};
+  for (int StandardFD : StandardFDs) {
+    struct stat st;
+    errno = 0;
+    while (fstat(StandardFD, &st) < 0) {
+      assert(errno && "expected errno to be set if fstat failed!");
+      // fstat should return EBADF if the file descriptor is closed.
+      if (errno == EBADF)
+        break;
+      // retry fstat if we got EINTR, otherwise bubble up the failure.
+      if (errno != EINTR)
+        return std::error_code(errno, std::generic_category());
+    }
+    // if fstat succeeds, move on to the next FD.
+    if (!errno)
+      continue;
+    assert(errno == EBADF && "expected errno to have EBADF at this point!");
+
+    if (NullFD < 0) {
+      while ((NullFD = open("/dev/null", O_RDWR)) < 0) {
+        if (errno == EINTR)
+          continue;
+        return std::error_code(errno, std::generic_category());
+      }
+    }
+
+    if (NullFD == StandardFD)
+      FDC.keepOpen();
+    else if (dup2(NullFD, StandardFD) < 0)
+      return std::error_code(errno, std::generic_category());
+  }
+  return std::error_code();
+}
+
+std::error_code Process::SafelyCloseFileDescriptor(int FD) {
+  // Create a signal set filled with *all* signals.
+  sigset_t FullSet;
+  if (sigfillset(&FullSet) < 0)
+    return std::error_code(errno, std::generic_category());
+  // Atomically swap our current signal mask with a full mask.
+  sigset_t SavedSet;
+#if LLVM_ENABLE_THREADS
+  if (int EC = pthread_sigmask(SIG_SETMASK, &FullSet, &SavedSet))
+    return std::error_code(EC, std::generic_category());
+#else
+  if (sigprocmask(SIG_SETMASK, &FullSet, &SavedSet) < 0)
+    return std::error_code(errno, std::generic_category());
+#endif
+  // Attempt to close the file descriptor.
+  // We need to save the error, if one occurs, because our subsequent call to
+  // pthread_sigmask might tamper with errno.
+  int ErrnoFromClose = 0;
+  if (::close(FD) < 0)
+    ErrnoFromClose = errno;
+  // Restore the signal mask back to what we saved earlier.
+  int EC = 0;
+#if LLVM_ENABLE_THREADS
+  EC = pthread_sigmask(SIG_SETMASK, &SavedSet, nullptr);
+#else
+  if (sigprocmask(SIG_SETMASK, &SavedSet, nullptr) < 0)
+    EC = errno;
+#endif
+  // The error code from close takes precedence over the one from
+  // pthread_sigmask.
+  if (ErrnoFromClose)
+    return std::error_code(ErrnoFromClose, std::generic_category());
+  return std::error_code(EC, std::generic_category());
+}
+
 bool Process::StandardInIsUserInput() {
   return FileDescriptorIsDisplayed(STDIN_FILENO);
 }
@@ -263,11 +336,14 @@
 extern "C" int tigetnum(char *capname);
 #endif
 
+#ifdef HAVE_TERMINFO
+static ManagedStatic<sys::Mutex> TermColorMutex;
+#endif
+
 static bool terminalHasColors(int fd) {
 #ifdef HAVE_TERMINFO
   // First, acquire a global lock because these C routines are thread hostile.
-  static sys::Mutex M;
-  MutexGuard G(M);
+  MutexGuard G(*TermColorMutex);
 
   int errret = 0;
   if (setupterm((char *)nullptr, fd, &errret) != 0)