// Copyright (c) 2006, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// All functions here are thread-hostile due to file caching unless
// commented otherwise.
#ifndef _SYSINFO_H_
#define _SYSINFO_H_
#include <config.h>
#include <time.h>
#if (defined(_WIN32) || defined(__MINGW32__)) && (!defined(__CYGWIN__) && !defined(__CYGWIN32__))
#include <windows.h> // for DWORD
#include <TlHelp32.h> // for CreateToolhelp32Snapshot
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h> // for pid_t
#endif
#include <stddef.h> // for size_t
#include <limits.h> // for PATH_MAX
#include "base/basictypes.h"
#include "base/logging.h" // for RawFD
// This getenv function is safe to call before the C runtime is initialized.
// On Windows, it utilizes GetEnvironmentVariable() and on unix it uses
// /proc/self/environ instead calling getenv(). It's intended to be used in
// routines that run before main(), when the state required for getenv() may
// not be set up yet. In particular, errno isn't set up until relatively late
// (after the pthreads library has a chance to make it threadsafe), and
// getenv() doesn't work until then.
// On some platforms, this call will utilize the same, static buffer for
// repeated GetenvBeforeMain() calls. Callers should not expect pointers from
// this routine to be long lived.
// Note that on unix, /proc only has the environment at the time the
// application was started, so this routine ignores setenv() calls/etc. Also
// note it only reads the first 16K of the environment.
extern const char* GetenvBeforeMain(const char* name);
// This takes as an argument an environment-variable name (like
// CPUPROFILE) whose value is supposed to be a file-path, and sets
// path to that path, and returns true. Non-trivial for surprising
// reasons, as documented in sysinfo.cc. path must have space PATH_MAX.
extern bool GetUniquePathFromEnv(const char* env_name, char* path);
extern int NumCPUs();
void SleepForMilliseconds(int milliseconds);
// processor cycles per second of each processor. Thread-safe.
extern double CyclesPerSecond(void);
// Return true if we're running POSIX (e.g., NPTL on Linux) threads,
// as opposed to a non-POSIX thread libary. The thing that we care
// about is whether a thread's pid is the same as the thread that
// spawned it. If so, this function returns true.
// Thread-safe.
// Note: We consider false negatives to be OK.
bool HasPosixThreads();
#ifndef SWIG // SWIG doesn't like struct Buffer and variable arguments.
// A ProcMapsIterator abstracts access to /proc/maps for a given
// process. Needs to be stack-allocatable and avoid using stdio/malloc
// so it can be used in the google stack dumper, heap-profiler, etc.
//
// On Windows and Mac OS X, this iterator iterates *only* over DLLs
// mapped into this process space. For Linux, FreeBSD, and Solaris,
// it iterates over *all* mapped memory regions, including anonymous
// mmaps. For other O/Ss, it is unlikely to work at all, and Valid()
// will always return false. Also note: this routine only works on
// FreeBSD if procfs is mounted: make sure this is in your /etc/fstab:
// proc /proc procfs rw 0 0
class ProcMapsIterator {
public:
struct Buffer {
#ifdef __FreeBSD__
// FreeBSD requires us to read all of the maps file at once, so
// we have to make a buffer that's "always" big enough
static const size_t kBufSize = 102400;
#else // a one-line buffer is good enough
static const size_t kBufSize = PATH_MAX + 1024;
#endif
char buf_[kBufSize];
};
// Create a new iterator for the specified pid. pid can be 0 for "self".
explicit ProcMapsIterator(pid_t pid);
// Create an iterator with specified storage (for use in signal
// handler). "buffer" should point to a ProcMapsIterator::Buffer
// buffer can be NULL in which case a bufer will be allocated.
ProcMapsIterator(pid_t pid, Buffer *buffer);
// Iterate through maps_backing instead of maps if use_maps_backing
// is true. Otherwise the same as above. buffer can be NULL and
// it will allocate a buffer itself.
ProcMapsIterator(pid_t pid, Buffer *buffer,
bool use_maps_backing);
// Returns true if the iterator successfully initialized;
bool Valid() const;
// Returns a pointer to the most recently parsed line. Only valid
// after Next() returns true, and until the iterator is destroyed or
// Next() is called again. This may give strange results on non-Linux
// systems. Prefer FormatLine() if that may be a concern.
const char *CurrentLine() const { return stext_; }
// Writes the "canonical" form of the /proc/xxx/maps info for a single
// line to the passed-in buffer. Returns the number of bytes written,
// or 0 if it was not able to write the complete line. (To guarantee
// success, buffer should have size at least Buffer::kBufSize.)
// Takes as arguments values set via a call to Next(). The
// "canonical" form of the line (taken from linux's /proc/xxx/maps):
// <start_addr(hex)>-<end_addr(hex)> <perms(rwxp)> <offset(hex)> +
// <major_dev(hex)>:<minor_dev(hex)> <inode> <filename> Note: the
// eg
// 08048000-0804c000 r-xp 00000000 03:01 3793678 /bin/cat
// If you don't have the dev_t (dev), feel free to pass in 0.
// (Next() doesn't return a dev_t, though NextExt does.)
//
// Note: if filename and flags were obtained via a call to Next(),
// then the output of this function is only valid if Next() returned
// true, and only until the iterator is destroyed or Next() is
// called again. (Since filename, at least, points into CurrentLine.)
static int FormatLine(char* buffer, int bufsize,
uint64 start, uint64 end, const char *flags,
uint64 offset, int64 inode, const char *filename,
dev_t dev);
// Find the next entry in /proc/maps; return true if found or false
// if at the end of the file.
//
// Any of the result pointers can be NULL if you're not interested
// in those values.
//
// If "flags" and "filename" are passed, they end up pointing to
// storage within the ProcMapsIterator that is valid only until the
// iterator is destroyed or Next() is called again. The caller may
// modify the contents of these strings (up as far as the first NUL,
// and only until the subsequent call to Next()) if desired.
// The offsets are all uint64 in order to handle the case of a
// 32-bit process running on a 64-bit kernel
//
// IMPORTANT NOTE: see top-of-class notes for details about what
// mapped regions Next() iterates over, depending on O/S.
// TODO(csilvers): make flags and filename const.
bool Next(uint64 *start, uint64 *end, char **flags,
uint64 *offset, int64 *inode, char **filename);
bool NextExt(uint64 *start, uint64 *end, char **flags,
uint64 *offset, int64 *inode, char **filename,
uint64 *file_mapping, uint64 *file_pages,
uint64 *anon_mapping, uint64 *anon_pages,
dev_t *dev);
~ProcMapsIterator();
private:
void Init(pid_t pid, Buffer *buffer, bool use_maps_backing);
char *ibuf_; // input buffer
char *stext_; // start of text
char *etext_; // end of text
char *nextline_; // start of next line
char *ebuf_; // end of buffer (1 char for a nul)
#if (defined(_WIN32) || defined(__MINGW32__)) && (!defined(__CYGWIN__) && !defined(__CYGWIN32__))
HANDLE snapshot_; // filehandle on dll info
// In a change from the usual W-A pattern, there is no A variant of
// MODULEENTRY32. Tlhelp32.h #defines the W variant, but not the A.
// We want the original A variants, and this #undef is the only
// way I see to get them. Redefining it when we're done prevents us
// from affecting other .cc files.
# ifdef MODULEENTRY32 // Alias of W
# undef MODULEENTRY32
MODULEENTRY32 module_; // info about current dll (and dll iterator)
# define MODULEENTRY32 MODULEENTRY32W
# else // It's the ascii, the one we want.
MODULEENTRY32 module_; // info about current dll (and dll iterator)
# endif
#elif defined(__MACH__)
int current_image_; // dll's are called "images" in macos parlance
int current_load_cmd_; // the segment of this dll we're examining
#elif defined(__sun__) // Solaris
int fd_;
char current_filename_[PATH_MAX];
#else
int fd_; // filehandle on /proc/*/maps
#endif
pid_t pid_;
char flags_[10];
Buffer* dynamic_buffer_; // dynamically-allocated Buffer
bool using_maps_backing_; // true if we are looking at maps_backing instead of maps.
};
#endif /* #ifndef SWIG */
// Helper routines
namespace tcmalloc {
int FillProcSelfMaps(char buf[], int size, bool* wrote_all);
void DumpProcSelfMaps(RawFD fd);
}
#endif /* #ifndef _SYSINFO_H_ */