path: root/ace/Log_Msg.h

// -*- C++ -*-

//=============================================================================
/**
 *  @file    Log_Msg.h
 *
 *  $Id$
 *
 *  @author Douglas C. Schmidt <schmidt@cs.wustl.edu>
 */
//=============================================================================

#ifndef ACE_LOG_MSG_H
#define ACE_LOG_MSG_H
#include "ace/pre.h"

// This stuff must come first to avoid problems with circular
// headers...
// ... but ACE_NDEBUG and ACE_NLOGGING can come from the config.h file, so
// pull that one early.
#include "ace/config-all.h"

// The following ASSERT macro is courtesy of Alexandre Karev
// <akg@na47sun05.cern.ch>.
#if defined (ACE_NDEBUG)
#define ACE_ASSERT(x)
#elif !defined (ACE_ASSERT)
#define ACE_ASSERT(X) \
  do { if(!(X)) { \
  int __ace_error = ACE_OS::last_error (); \
  ACE_Log_Msg *ace___ = ACE_Log_Msg::instance (); \
  ace___->set (__FILE__, __LINE__, -1, __ace_error, ace___->restart (), \
               ace___->msg_ostream (), ace___->msg_callback ()); \
  ace___->log (LM_ERROR, ACE_LIB_TEXT ("ACE_ASSERT: file %N, line %l assertion failed for '%s'.%a\n"), #X, -1); \
  } } while (0)
#endif  /* ACE_NDEBUG */

#if defined (ACE_NLOGGING)
#define ACE_HEX_DUMP(X) do {} while (0)
#define ACE_RETURN(Y) do { return (Y); } while (0)
#define ACE_ERROR_RETURN(X, Y) return (Y)
#define ACE_ERROR_BREAK(X) { break; }
#define ACE_ERROR(X) do {} while (0)
#define ACE_DEBUG(X) do {} while (0)
#define ACE_ERROR_INIT(VALUE, FLAGS)
#else
#define ACE_HEX_DUMP(X) \
  do { \
    int __ace_error = ACE_OS::last_error (); \
    ACE_Log_Msg *ace___ = ACE_Log_Msg::instance (); \
    ace___->conditional_set (__FILE__, __LINE__, 0, __ace_error); \
    ace___->log_hexdump X; \
  } while (0)
#define ACE_RETURN(Y) \
  do { \
    int __ace_error = ACE_OS::last_error (); \
    ACE_Log_Msg *ace___ = ACE_Log_Msg::instance (); \
    ace___->set (__FILE__, __LINE__, Y, __ace_error, ace___->restart (), \
                 ace___->msg_ostream (), ace___->msg_callback ()); \
    return Y; \
  } while (0)
#define ACE_ERROR_RETURN(X, Y) \
  do { \
    int __ace_error = ACE_OS::last_error (); \
    ACE_Log_Msg *ace___ = ACE_Log_Msg::instance (); \
    ace___->conditional_set (__FILE__, __LINE__, Y, __ace_error); \
    ace___->log X; \
    return Y; \
  } while (0)
#define ACE_ERROR(X) \
  do { \
    int __ace_error = ACE_OS::last_error (); \
    ACE_Log_Msg *ace___ = ACE_Log_Msg::instance (); \
    ace___->conditional_set (__FILE__, __LINE__, -1, __ace_error); \
    ace___->log X; \
  } while (0)
#define ACE_DEBUG(X) \
  do { \
    int __ace_error = ACE_OS::last_error (); \
    ACE_Log_Msg *ace___ = ACE_Log_Msg::instance (); \
    ace___->conditional_set (__FILE__, __LINE__, 0, __ace_error); \
    ace___->log X; \
  } while (0)
#define ACE_ERROR_INIT(VALUE, FLAGS) \
  do { \
    ACE_Log_Msg *ace___ = ACE_Log_Msg::instance (); \
    ace___->set_flags (FLAGS); ace___->op_status (VALUE); \
  } while (0)
#define ACE_ERROR_BREAK(X) { ACE_ERROR (X); break; }
#endif /* ACE_NLOGGING */

#include "ace/Log_Record.h"
#include "ace/OS_Log_Msg_Attributes.h"

#if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
#endif /* ACE_LACKS_PRAGMA_ONCE */

#if defined (__Lynx__)
# undef STDERR
#endif /* __Lynx__ */

#if defined (THREAD)
// This workaround is necessary for nasty libraries that #define
// THREAD 1.
#define ACE_THREAD_HACK THREAD
#undef THREAD
#endif /* THREAD */

class ACE_Log_Msg_Callback;

// ****************************************************************

#define ACE_LOG_MSG ACE_Log_Msg::instance ()

// Forward declaration
class ACE_Thread_Descriptor;

/**
 * @class ACE_Log_Msg
 *
 * @brief Provides a variable length argument message logging
 * abstraction.
 *
 * This class is very flexible since it allows formatted error
 * messages to be printed in a thread-safe manner to various
 * locations, such as stdout, stderr, cerr, a distributed logger, etc.
 * The current message is also kept in a thread-specific storage
 * location (i.e., there is one ACE_Log_Msg object per-thread), which
 * can be used to communicate errors between framework methods and
 * callers.  A message is logged by the log() method, only if the
 * message priority is currently enabled.  Moreover, only the current
 * log message is stored here -- it will be overwritten by the
 * subsequent call to <log>.
 *
 * The ACE_Log_Msg class uses two priority masks to control its
 * logging behavior.  The <priority_mask_> object attribute is thread
 * specific and specifies the priority levels logged by the thread.
 * The <process_priority_mask_> class attribute is not thread-specific
 * and specifies the priority levels that will be logged by all
 * threads in the process.  By default, all levels are enabled for
 * <priority_mask_> and all levels are disabled for
 * <process_priority_mask_> (i.e. each thread determines which
 * priority levels will be logged).  Both priority masks can be
 * modified using the priority_mask() method of this class.
 */
class ACE_Export ACE_Log_Msg
{

public:
  // Logger Flags.
  enum
  {
    /// Write messages to stderr.
    STDERR = 1,
    /// Write messages to the local client logger deamon.
    LOGGER = 2,
    /// Write messages to the ostream * stored in thread-specific
    /// storage.
    OSTREAM = 4,
    /// Write messages to the callback object.
    MSG_CALLBACK = 8,
    /// Display messages in a verbose manner.
    VERBOSE = 16,
    /// Display messages in a less verbose manner (i.e., only print
    /// information that can change between calls).
    VERBOSE_LITE = 32,
    /// Do not print messages at all (just leave in thread-specific
    /// storage for later inspection).
    SILENT = 64,
    /// Write messages to the system's event log.
    SYSLOG = 128
 };

  // = Initialization and termination routines.

  /// Returns a pointer to the Singleton.
  static ACE_Log_Msg *instance (void);

  /// Returns non-null if an ACE_Log_Msg exists for the calling thread.
  static int exists (void);

  /// Clears the flag from the default priority mask used to
  /// initialize ACE_Log_Msg instances.
  static void disable_debug_messages (ACE_Log_Priority priority = LM_DEBUG);

  /// Sets the flag in the default priority mask used to initialize
  /// ACE_Log_Msg instances.
  static void enable_debug_messages (ACE_Log_Priority priority = LM_DEBUG);

  /// Initialize logger.
  ACE_Log_Msg (void);

  /// cleanup logger.
  ~ACE_Log_Msg (void);

  /// Initialize the ACE logging facility.
  /**
   * Initialize the ACE logging facility. Supplies the program name
   * that is available to each logging message call. Default arguments
   * set up logging to STDERR only.
   *
   * @param prog_name  The name of the calling program.
   * @param flags      A bitwise-or of options flags used to set the
   *                   initial behavior and logging sink(s). (see the
   *                   enum above for the valid values).
   * @param logger_key The name of ACE_FIFO rendezvous point where the
   *                   local client logger daemon is listening for logging
   *                   messages. Only meaningful if the LOGGER bit is
   *                   set in the <flags> argument.
   */
  int open (const ACE_TCHAR *prog_name,
            u_long options_flags = ACE_Log_Msg::STDERR,
            const ACE_TCHAR *logger_key = 0);

  // = Set/get the options flags.

  /**
   * Enable the bits in the logger's options flags.
   * Disable the bits in the logger's options flags.
   * Return the bits in the logger's options flags.
   */
  void set_flags (u_long f);
  void clr_flags (u_long f);
  u_long flags (void);

  /** @name Allow apps to acquire and release internal synchronization
   *        lock
   *
   * This lock is used internally by the <ACE_Log_Msg>
   * implementation. By exporting the lock, applications can hold the
   * lock atomically over a number of calls to <ACE_Log_Msg>.
   */
  //@{

  /// Acquire the internal lock.
  int acquire (void);

  /// Release the internal lock.
  int release (void);
  //@}

  /// Call after doing a <fork> to resynchronize the process id and
  /// <program_name> variables.
  void sync (const ACE_TCHAR *program_name);

  // = Set/get methods.  Note that these are non-static and thus will
  // be thread-specific.

  /// Set the result of the operation status (by convention, -1 means
  /// error).
  void op_status (int status);

  /// Get the result of the operation status (by convention, -1 means
  /// error).
  int op_status (void);

  /// Set the value of the errnum (by convention this corresponds to
  /// errno).
  void errnum (int);

  /// Get the value of the errnum (by convention this corresponds to
  /// errno).
  int errnum (void);

  /// Set the line number where an error occurred.
  void linenum (int);

  /// Get the line number where an error occurred.
  int linenum (void);

  /// Set the file name where an error occurred.
  void file (const char *);

  /// Get the file name where an error occurred.
  const char *file (void);

  /// Set the message that describes what type of error occurred.
  void msg (const ACE_TCHAR *);

  /// Get the message that describes what type of error occurred.
  const ACE_TCHAR *msg (void);

  /// Set the field that indicates whether interrupted calls should be
  /// restarted.
  void restart (int);

  /// Get the field that indicates whether interrupted calls should be
  /// restarted.
  int restart (void);

  // = Notice that the following two function is equivalent to
  //   "void msg_ostream (HANDLE)" and "HANDLE msg_ostream (void)"
  //   on Windows CE.  There is no <iostream.h> support on CE.

  /// Update the ostream without overwriting the delete_ostream_ flag.
  void msg_ostream (ACE_OSTREAM_TYPE *);

  /**
   * delete_stream == 1, forces Log_Msg.h to delete the stream in
   * its own ~dtor (assumes control of the stream)
   * use only with proper ostream (eg: fstream), not (cout, cerr)
   */
  void msg_ostream (ACE_OSTREAM_TYPE *, int delete_ostream);

  /// Get the ostream that is used to print error messages.
  ACE_OSTREAM_TYPE *msg_ostream (void) const;

  /**
   * Set a new callback object and return the existing callback to
   * allow "chaining".  Note that <ACE_Log_Msg_Callback>s are not
   * inherited when spawning a new thread, so you'll need to reset
   * them in each thread.
   */
  ACE_Log_Msg_Callback *msg_callback (ACE_Log_Msg_Callback *c);
  ACE_Log_Msg_Callback *msg_callback (void) const;

  // = Nesting depth increment and decrement.
  int inc (void);
  int dec (void);

  // = Get/set trace depth.
  int trace_depth (void);
  void trace_depth (int);

  // = Get/set trace active status.
  int trace_active (void);
  void trace_active (int value);

  /// Get the TSS thread descriptor.
  ACE_Thread_Descriptor *thr_desc (void) const;

  /**
   * Set the TSS thread descriptor.  This method will call
   * td->acquire_release to block execution until this call
   * return.
   */
  void thr_desc (ACE_Thread_Descriptor *td);

#if defined (ACE_HAS_WIN32_STRUCTURAL_EXCEPTIONS) && defined(ACE_LEGACY_MODE)
  // These functions are disabled without ACE_LEGACY_MODE
  // because the *semantics* have changed (the objects are no longer
  // TSS).
  /// Get/Set TSS exception action.
  /// NOTE: The action is no longer TSS, they are global!
  ACE_SEH_EXCEPT_HANDLER seh_except_selector (void);
  ACE_SEH_EXCEPT_HANDLER seh_except_selector (ACE_SEH_EXCEPT_HANDLER);

  /// Get/Set TSS exception handler.
  /// NOTE: The handler is no longer TSS, they are global!
  ACE_SEH_EXCEPT_HANDLER seh_except_handler (void);
  ACE_SEH_EXCEPT_HANDLER seh_except_handler (ACE_SEH_EXCEPT_HANDLER);
#endif /* ACE_HAS_WIN32_STRUCTURAL_EXCEPTIONS && ACE_LEGACY_MODE */

  // = Stop/start/query tracing status on a per-thread basis...
  void stop_tracing (void);
  void start_tracing (void);
  int  tracing_enabled (void);

  typedef enum
  {
    PROCESS = 0,
    THREAD = 1
  } MASK_TYPE;

  // = Get/set the priority mask.
  /// Get the current <ACE_Log_Priority> mask.
  /// Set the <ACE_Log_Priority> mask, returns original mask.
  u_long priority_mask (MASK_TYPE = THREAD);
  u_long priority_mask (u_long, MASK_TYPE = THREAD);

  /// Return true if the requested priority is enabled.
  int log_priority_enabled (ACE_Log_Priority log_priority);

  /// Return true if the requested priority is enabled.
  int log_priority_enabled (ACE_Log_Priority log_priority,
                            const char *,
                            ...);

#if defined (ACE_USES_WCHAR)
  // We are not using ACE_TCHAR for this since ACE_HEX_DUMP
  // doesn't take in a ACE_TCHAR.  log_hexdump takes in a char
  // string, so this must be able to take in a char string even
  // when using ACE_USES_WCHAR.
  /// Return true if the requested priority is enabled.
  int log_priority_enabled (ACE_Log_Priority log_priority,
                            const wchar_t *,
                            ...);
#endif /* ACE_USES_WCHAR */

  /// Optimize reading of the pid (avoids a system call if the value is
  /// cached...).
  pid_t getpid (void) const;

  // = Set/get the name of the local host.
  const ACE_TCHAR *local_host (void) const;
  void local_host (const ACE_TCHAR *);

  /**
   * Set the line number, file name, operational status, error number,
   * restart flag, ostream, and the callback object.  This combines
   * all the other set methods into a single method.
   */
  void set (const char *file,
            int line,
            int op_status = -1,
            int errnum = 0,
            int restart = 1,
            ACE_OSTREAM_TYPE *os = 0,
            ACE_Log_Msg_Callback *c = 0);

  /// These values are only actually set if the requested priority is
  /// enabled.
  void conditional_set (const char *file,
                        int line,
                        int op_status,
                        int errnum);

  /**
   * Format a message to the thread-safe ACE logging mechanism.  Valid
   * options (prefixed by '%', as in printf format strings) include:
   *  + 'A': print an ACE_timer_t value (which could be either double
   *         or ACE_UINT32.)
   *  + 'a': abort the program at this point abruptly.
   *  + 'c': print a character
   *  + 'C': print a character string
   *  + 'i', 'd': print a decimal number
   *  + 'I': indent according to nesting depth (obtained from
   *         <ACE_Trace::get_nesting_indent>).
   *  + 'e', 'E', 'f', 'F', 'g', 'G': print a double
   *  + 'l': print line number where an error occurred.
   *  + 'm': return the message corresponding to errno value, e.g., as
   *         done by strerror()
   *  + 'N': print file name where the error occurred.
   *  + 'n': print the name of the program (or "<unknown>" if not set)
   *  + 'o': print as an octal number
   *  + 'P': print out the current process id
   *  + 'p': print out the appropriate errno message from sys_errlist,
   *         e.g., as done by perror()
   *  + 'Q': print out the uint64 number
   *  + 'r': call the function pointed to by the corresponding argument
   *  + 'R': print return status
   *  + 'S': print out the appropriate _sys_siglist entry corresponding
   *         to var-argument.
   *  + 's': print out a character string
   *  + 'T': print timestamp in hour:minute:sec:usec format.
   *  + 'D': print timestamp in month/day/year hour:minute:sec:usec format.
   *  + 't': print thread id (1 if single-threaded)
   *  + 'u': print as unsigned int
   *  + 'w': prints a wide character
   *  + 'W': print a wide character string
   *  + 'X', 'x': print as a hex number
   *  + '%': print out a single percent sign, '%'
   */
  ssize_t log (ACE_Log_Priority priority, const ACE_TCHAR *format, ...);

#if defined (ACE_HAS_WCHAR)
  ssize_t log (ACE_Log_Priority priority, const ACE_ANTI_TCHAR *format, ...);
#endif /* ACE_HAS_WCHAR */

  /**
   * An alternative logging mechanism that makes it possible to
   * integrate variable argument lists from other logging mechanisms
   * into the ACE mechanism.
   */
  ssize_t log (const ACE_TCHAR *format,
               ACE_Log_Priority priority,
               va_list argp);

  /// Log a custom built log record to the currently enabled logging
  /// sinks.
  ssize_t log (ACE_Log_Record &log_record,
               int suppress_stderr = 0);

  /**
   * Method to log hex dump.  This is useful for debugging.  Calls
   * <log> to do the actual print, but formats first to make the chars
   * printable.
   */
  int log_hexdump (ACE_Log_Priority log_priority,
                   const char *buffer,
                   int size,
                   const ACE_TCHAR *text = 0);

  static void init_hook (ACE_OS_Log_Msg_Attributes &attributes
# if defined (ACE_HAS_WIN32_STRUCTURAL_EXCEPTIONS)
                         , ACE_SEH_EXCEPT_HANDLER selector = 0
                         , ACE_SEH_EXCEPT_HANDLER handler = 0
# endif /* ACE_HAS_WIN32_STRUCTURAL_EXCEPTIONS */
  /**
   * Init hook, create a Log_Msg_Attribute object, initialize its
   * attributes from the TSS Log_Msg and save the object in the
   * <attributes> argument
   */
                         );

  /**
   * Inherit hook, the <attributes> field is a Log_Msg_Attribute
   * object, invoke the <inherit_log_msg> method on it, then destroy
   * it and set the <attribute> argument to 0
   */
  static void inherit_hook (ACE_OS_Thread_Descriptor *thr_desc,
                            ACE_OS_Log_Msg_Attributes &attributes);

  /// Dump the state of an object.
  void dump (void) const;

  /// Declare the dynamic allocation hooks.
  ACE_ALLOC_HOOK_DECLARE;

private:
  /// Status of operation (-1 means failure, >= 0 means success).
  int status_;

  /// Type of error that occurred (see <sys/errno.h>).
  int errnum_;

  /// Line number where the error occurred.
  int linenum_;

  /// File where the error occurred.
  char file_[MAXPATHLEN + 1];

  /// The log message, which resides in thread-specific storage.  Note
  /// that only the current log message is stored here -- it will be
  /// overwritten by the subsequent call to <log>.
  ACE_TCHAR msg_[ACE_Log_Record::MAXLOGMSGLEN];

  /// Indicates whether we should restart system calls that are
  /// interrupted.
  int restart_;

  /// The ostream where logging messages can be written.
  ACE_OSTREAM_TYPE *ostream_;

  /// The callback object.
  ACE_Log_Msg_Callback *msg_callback_;

  /// Depth of the nesting for printing traces.
  int trace_depth_;

  /// Are we already within an ACE_Trace constructor call?
  int trace_active_;

  /// Are we allowing tracing in this thread?
  int tracing_enabled_;

  /// Are we deleting this ostream?
  int delete_ostream_;

  /**
   * If we're running in the context of an <ACE_Thread_Manager> this
   * will point to the thread descriptor adapter which holds the
   * thread descriptor of the thread.  This can be used to repidly
   * access all thread data kept in <ACE_Thread_Descriptor>.
   */
  ACE_Thread_Descriptor *thr_desc_;

  /**
   * Keeps track of all the per-thread <ACE_Log_Priority> values that
   * are currently enabled.  Default is for all logging priorities to
   * be _disabled_.
   */
  u_long priority_mask_;

  // = The following fields are *not* kept in thread-specific storage.

  // We only want one instance for the entire process!

  /**
   * Keeps track of all the per-process <ACE_Log_Priority> values that
   * are currently enabled.  Default is for all logging priorities to
   * be enabled.
   */
  static u_long process_priority_mask_;

  /// Records the program name.
  static const ACE_TCHAR *program_name_;

  /// Name of the local host (used when printing messages).
  static const ACE_TCHAR *local_host_;

  /// Process id of the current process.
  static pid_t pid_;

  /// Options flags.
  static u_long flags_;

  /// Offset of msg_[].
  static int msg_off_;

  /**
   * Number of existing Log_Msg instances; when 0, delete program/host
   * names
   * Priority mask to use for each new instance
   */
  static int instance_count_;
  static u_long default_priority_mask_;

  // Anonymous struct since there will only be one instance.  This
  // struct keeps information stored away in case we actually end up
  // calling log() if the log priority is correct.
  struct
  {
    int is_set_;
    const char *file_;
    int line_;
    int op_status_;
    int errnum_;
  } conditional_values_;

#if defined (ACE_MT_SAFE) && (ACE_MT_SAFE != 0)
  static int key_created_;
# if defined (ACE_HAS_THREAD_SPECIFIC_STORAGE) || \
    defined (ACE_HAS_TSS_EMULATION)
  static ACE_thread_key_t log_msg_tss_key_;
# endif /* ACE_HAS_THREAD_SPECIFIC_STORAGE || ACE_HAS_TSS_EMULATION */
#endif /* ACE_MT_SAFE */

  /// For cleanup, at program termination.
  static void close (void);

  /// Decouple the OS layer from the Log_Msg layer.
  static void sync_hook (const ACE_TCHAR *prg_name);

  /// Return the TSS singleton thread descriptor
  static ACE_OS_Thread_Descriptor *thr_desc_hook (void);

  friend void ACE_OS::cleanup_tss (const u_int);

  // = Disallow these operations.
  ACE_Log_Msg &operator= (const ACE_Log_Msg &);
  ACE_Log_Msg (const ACE_Log_Msg &);
};

#if defined (ACE_MT_SAFE) && (ACE_MT_SAFE != 0)
# if defined (ACE_HAS_THREAD_SPECIFIC_STORAGE) || \
     defined (ACE_HAS_TSS_EMULATION)
/* static */
#  if defined (ACE_HAS_THR_C_DEST)
#   define LOCAL_EXTERN_PREFIX extern "C"
#  else
#   define LOCAL_EXTERN_PREFIX
#  endif /* ACE_HAS_THR_C_DEST */
LOCAL_EXTERN_PREFIX
void
ACE_TSS_cleanup (void *ptr);
# endif /* ACE_HAS_THREAD_SPECIFIC_STORAGE || ACE_HAS_TSS_EMULATION */
#endif /* ACE_MT_SAFE */

#if defined (ACE_THREAD_HACK)
#define THREAD ACE_THREAD_HACK
#undef ACE_THREAD_HACK
#endif /* ACE_THREAD_HACK */

#if defined(ACE_LEGACY_MODE)
#include "ace/Log_Msg_Callback.h"
#endif /* ACE_LEGACY_MODE */

#include "ace/post.h"
#endif /* ACE_LOG_MSG_H */