cpl_multiproc.h

/**********************************************************************
 *
 * Project:  CPL - Common Portability Library
 * Purpose:  CPL Multi-Threading, and process handling portability functions.
 * Author:   Frank Warmerdam, warmerdam@pobox.com
 *
 **********************************************************************
 * Copyright (c) 2002, Frank Warmerdam
 * Copyright (c) 2008-2013, Even Rouault <even dot rouault at spatialys.com>
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/

#ifndef CPL_MULTIPROC_H_INCLUDED_
#define CPL_MULTIPROC_H_INCLUDED_

#include "cpl_port.h"

/*
** There are three primary implementations of the multi-process support
** controlled by one of CPL_MULTIPROC_WIN32, CPL_MULTIPROC_PTHREAD or
** CPL_MULTIPROC_STUB being defined.  If none are defined, the stub
** implementation will be used.
*/

#if defined(_WIN32) && !defined(CPL_MULTIPROC_STUB)
#define CPL_MULTIPROC_WIN32
/* MinGW can have pthread support, so disable it to avoid issues */
/* in cpl_multiproc.cpp */
#undef CPL_MULTIPROC_PTHREAD
#endif

#if !defined(CPL_MULTIPROC_WIN32) && !defined(CPL_MULTIPROC_PTHREAD) &&        \
    !defined(CPL_MULTIPROC_STUB) && !defined(CPL_MULTIPROC_NONE)
#define CPL_MULTIPROC_STUB
#endif

CPL_C_START

typedef void (*CPLThreadFunc)(void *);

void CPL_DLL *CPLLockFile(const char *pszPath, double dfWaitInSeconds);
void CPL_DLL CPLUnlockFile(void *hLock);

typedef struct _CPLMutex CPLMutex;
typedef struct _CPLCond CPLCond;
typedef struct _CPLJoinableThread CPLJoinableThread;

/* Options for CPLCreateMutexEx() and CPLCreateOrAcquireMutexEx() */
#define CPL_MUTEX_RECURSIVE 0
#define CPL_MUTEX_ADAPTIVE 1
#define CPL_MUTEX_REGULAR 2

CPLMutex CPL_DLL *CPLCreateMutex(void);           /* returned acquired */
CPLMutex CPL_DLL *CPLCreateMutexEx(int nOptions); /* returned acquired */
int CPL_DLL CPLCreateOrAcquireMutex(CPLMutex **, double dfWaitInSeconds);
int CPL_DLL CPLCreateOrAcquireMutexEx(CPLMutex **, double dfWaitInSeconds,
                                      int nOptions);
int CPL_DLL CPLAcquireMutex(CPLMutex *hMutex, double dfWaitInSeconds);
void CPL_DLL CPLReleaseMutex(CPLMutex *hMutex);
void CPL_DLL CPLDestroyMutex(CPLMutex *hMutex);
void CPL_DLL CPLCleanupMasterMutex(void);

CPLCond CPL_DLL *CPLCreateCond(void);
void CPL_DLL CPLCondWait(CPLCond *hCond, CPLMutex *hMutex);

typedef enum
{
    COND_TIMED_WAIT_COND,
    COND_TIMED_WAIT_TIME_OUT,
    COND_TIMED_WAIT_OTHER
} CPLCondTimedWaitReason;

CPLCondTimedWaitReason CPL_DLL CPLCondTimedWait(CPLCond *hCond,
                                                CPLMutex *hMutex,
                                                double dfWaitInSeconds);
void CPL_DLL CPLCondSignal(CPLCond *hCond);
void CPL_DLL CPLCondBroadcast(CPLCond *hCond);
void CPL_DLL CPLDestroyCond(CPLCond *hCond);

/** Contrary to what its name suggests, CPLGetPID() actually returns the thread
 * id */
GIntBig CPL_DLL CPLGetPID(void);
int CPL_DLL CPLGetCurrentProcessID(void);
int CPL_DLL CPLCreateThread(CPLThreadFunc pfnMain, void *pArg);
CPLJoinableThread CPL_DLL *CPLCreateJoinableThread(CPLThreadFunc pfnMain,
                                                   void *pArg);
void CPL_DLL CPLJoinThread(CPLJoinableThread *hJoinableThread);
void CPL_DLL CPLSleep(double dfWaitInSeconds);

const char CPL_DLL *CPLGetThreadingModel(void);

int CPL_DLL CPLGetNumCPUs(void);

typedef struct _CPLLock CPLLock;

/* Currently LOCK_ADAPTIVE_MUTEX is Linux-only and LOCK_SPIN only available */
/* on systems with pthread_spinlock API (so not MacOsX). If a requested type */
/* isn't available, it fallbacks to LOCK_RECURSIVE_MUTEX */
typedef enum
{
    LOCK_RECURSIVE_MUTEX,
    LOCK_ADAPTIVE_MUTEX,
    LOCK_SPIN
} CPLLockType;

CPLLock CPL_DLL *CPLCreateLock(CPLLockType eType); /* returned NON acquired */
int CPL_DLL CPLCreateOrAcquireLock(CPLLock **, CPLLockType eType);
int CPL_DLL CPLAcquireLock(CPLLock *);
void CPL_DLL CPLReleaseLock(CPLLock *);
void CPL_DLL CPLDestroyLock(CPLLock *);
void CPL_DLL CPLLockSetDebugPerf(
    CPLLock *,
    int bEnableIn); /* only available on x86/x86_64 with GCC for now */

CPL_C_END

#if defined(__cplusplus) && !defined(CPL_SUPRESS_CPLUSPLUS)

/* Instantiates the mutex if not already done. The parameter x should be a
 * (void**). */
#define CPLMutexHolderD(x) CPLMutexHolder oHolder(x, 1000.0, __FILE__, __LINE__)

/* Instantiates the mutex with options if not already done. */
/* The parameter x should be a (void**). */
#define CPLMutexHolderExD(x, nOptions)                                         \
    CPLMutexHolder oHolder(x, 1000.0, __FILE__, __LINE__, nOptions)

/* This variant assumes the mutex has already been created. If not, it will */
/* be a no-op. The parameter x should be a (void*) */
#define CPLMutexHolderOptionalLockD(x)                                         \
    CPLMutexHolder oHolder(x, 1000.0, __FILE__, __LINE__)

/** Object to hold a mutex */
class CPL_DLL CPLMutexHolder
{
  private:
    CPLMutex *hMutex = nullptr;
    // Only used for debugging.
    const char *pszFile = nullptr;
    int nLine = 0;

    CPL_DISALLOW_COPY_ASSIGN(CPLMutexHolder)

  public:
    /** Instantiates the mutex if not already done. */
    explicit CPLMutexHolder(CPLMutex **phMutex, double dfWaitInSeconds = 1000.0,
                            const char *pszFile = __FILE__,
                            int nLine = __LINE__,
                            int nOptions = CPL_MUTEX_RECURSIVE);

    /** This variant assumes the mutex has already been created. If not, it will
     * be a no-op */
    explicit CPLMutexHolder(CPLMutex *hMutex, double dfWaitInSeconds = 1000.0,
                            const char *pszFile = __FILE__,
                            int nLine = __LINE__);

    ~CPLMutexHolder();
};

/* Instantiates the lock if not already done. The parameter x should be a
 * (CPLLock**). */
#define CPLLockHolderD(x, eType)                                               \
    CPLLockHolder oHolder(x, eType, __FILE__, __LINE__);

/* This variant assumes the lock has already been created. If not, it will */
/* be a no-op. The parameter should be (CPLLock*) */
#define CPLLockHolderOptionalLockD(x)                                          \
    CPLLockHolder oHolder(x, __FILE__, __LINE__);

/** Object to hold a lock */
class CPL_DLL CPLLockHolder
{
  private:
    CPLLock *hLock = nullptr;
    const char *pszFile = nullptr;
    int nLine = 0;

    CPL_DISALLOW_COPY_ASSIGN(CPLLockHolder)

  public:
    /** Instantiates the lock if not already done. */
    CPLLockHolder(CPLLock **phSpin, CPLLockType eType,
                  const char *pszFile = __FILE__, int nLine = __LINE__);

    /** This variant assumes the lock has already been created. If not, it will
     * be a no-op */
    explicit CPLLockHolder(CPLLock *hSpin, const char *pszFile = __FILE__,
                           int nLine = __LINE__);

    ~CPLLockHolder();
};

#endif /* def __cplusplus */

/* -------------------------------------------------------------------- */
/*      Thread local storage.                                           */
/* -------------------------------------------------------------------- */

#define CTLS_RLBUFFERINFO 1             /* cpl_conv.cpp */
#define CTLS_WIN32_COND 2               /* cpl_multiproc.cpp */
#define CTLS_CSVTABLEPTR 3              /* cpl_csv.cpp */
#define CTLS_CSVDEFAULTFILENAME 4       /* cpl_csv.cpp */
#define CTLS_ERRORCONTEXT 5             /* cpl_error.cpp */
#define CTLS_VSICURL_CACHEDCONNECTION 6 /* cpl_vsil_curl.cpp */
#define CTLS_PATHBUF 7                  /* cpl_path.cpp */
#define CTLS_ABSTRACTARCHIVE_SPLIT 8    /* cpl_vsil_abstract_archive.cpp */
#define CTLS_GDALOPEN_ANTIRECURSION 9   /* gdaldataset.cpp */
#define CTLS_CPLSPRINTF 10              /* cpl_string.h */
#define CTLS_RESPONSIBLEPID 11          /* gdaldataset.cpp */
#define CTLS_VERSIONINFO 12             /* gdal_misc.cpp */
#define CTLS_VERSIONINFO_LICENCE 13     /* gdal_misc.cpp */
#define CTLS_CONFIGOPTIONS 14           /* cpl_conv.cpp */
#define CTLS_FINDFILE 15                /* cpl_findfile.cpp */
#define CTLS_VSIERRORCONTEXT 16         /* cpl_vsi_error.cpp */
/* 17: unused */
#define CTLS_PROJCONTEXTHOLDER 18      /* ogr_proj_p.cpp */
#define CTLS_GDALDEFAULTOVR_ANTIREC 19 /* gdaldefaultoverviews.cpp */
#define CTLS_HTTPFETCHCALLBACK 20      /* cpl_http.cpp */

#define CTLS_MAX 32

CPL_C_START
void CPL_DLL *CPLGetTLS(int nIndex);
void CPL_DLL *CPLGetTLSEx(int nIndex, int *pbMemoryErrorOccurred);
void CPL_DLL CPLSetTLS(int nIndex, void *pData, int bFreeOnExit);

/* Warning : the CPLTLSFreeFunc must not in any case directly or indirectly */
/* use or fetch any TLS data, or a terminating thread will hang ! */
typedef void (*CPLTLSFreeFunc)(void *pData);
void CPL_DLL CPLSetTLSWithFreeFunc(int nIndex, void *pData,
                                   CPLTLSFreeFunc pfnFree);
void CPL_DLL CPLSetTLSWithFreeFuncEx(int nIndex, void *pData,
                                     CPLTLSFreeFunc pfnFree,
                                     int *pbMemoryErrorOccurred);

void CPL_DLL CPLCleanupTLS(void);
CPL_C_END

#endif /* CPL_MULTIPROC_H_INCLUDED_ */