thodg/libgit2/src/thread.c

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• Hash : fd2d4759
  Author :
  Date : 2020-12-05T22:22:38
  

  threads: git_tls_data to git_tlsdata Use a no-allocation approach to the TLS data abstraction.

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• src/thread.c

• /*
   * Copyright (C) the libgit2 contributors. All rights reserved.
   *
   * This file is part of libgit2, distributed under the GNU GPL v2 with
   * a Linking Exception. For full terms see the included COPYING file.
   */
  
  #include "common.h"
  
  #if !defined(GIT_THREADS)
  
  #define TLSDATA_MAX 16
  
  typedef struct {
  	void *value;
  	void (GIT_SYSTEM_CALL *destroy_fn)(void *);
  } tlsdata_value;
  
  static tlsdata_value tlsdata_values[TLSDATA_MAX];
  static int tlsdata_cnt = 0;
  
  int git_tlsdata_init(git_tlsdata_key *key, void (GIT_SYSTEM_CALL *destroy_fn)(void *))
  {
  	if (tlsdata_cnt >= TLSDATA_MAX)
  		return -1;
  
  	tlsdata_values[tlsdata_cnt].value = NULL;
  	tlsdata_values[tlsdata_cnt].destroy_fn = destroy_fn;
  
  	*key = tlsdata_cnt;
  	tlsdata_cnt++;
  
  	return 0;
  }
  
  int git_tlsdata_set(git_tlsdata_key key, void *value)
  {
  	if (key < 0 || key > tlsdata_cnt)
  		return -1;
  
  	tlsdata_values[key].value = value;
  	return 0;
  }
  
  void *git_tlsdata_get(git_tlsdata_key key)
  {
  	if (key < 0 || key > tlsdata_cnt)
  		return NULL;
  
  	return tlsdata_values[key].value;
  }
  
  int git_tlsdata_dispose(git_tlsdata_key key)
  {
  	void *value;
  	void (*destroy_fn)(void *) = NULL;
  
  	if (key < 0 || key > tlsdata_cnt)
  		return -1;
  
  	value = tlsdata_values[key].value;
  	destroy_fn = tlsdata_values[key].destroy_fn;
  
  	tlsdata_values[key].value = NULL;
  	tlsdata_values[key].destroy_fn = NULL;
  
  	if (value && destroy_fn)
  		destroy_fn(value);
  
  	return 0;
  }
  
  #elif defined(GIT_WIN32)
  
  int git_tlsdata_init(git_tlsdata_key *key, void (GIT_SYSTEM_CALL *destroy_fn)(void *))
  {
  	DWORD fls_index = FlsAlloc(destroy_fn);
  
  	if (fls_index == FLS_OUT_OF_INDEXES)
  		return -1;
  
  	*key = fls_index;
  	return 0;
  }
  
  int git_tlsdata_set(git_tlsdata_key key, void *value)
  {
  	if (!FlsSetValue(key, value))
  		return -1;
  
  	return 0;
  }
  
  void *git_tlsdata_get(git_tlsdata_key key)
  {
  	return FlsGetValue(key);
  }
  
  int git_tlsdata_dispose(git_tlsdata_key key)
  {
  	if (!FlsFree(key))
  		return -1;
  
  	return 0;
  }
  
  #elif defined(_POSIX_THREADS)
  
  int git_tlsdata_init(git_tlsdata_key *key, void (GIT_SYSTEM_CALL *destroy_fn)(void *))
  {
  	if (pthread_key_create(key, destroy_fn) != 0)
  		return -1;
  
  	return 0;
  }
  
  int git_tlsdata_set(git_tlsdata_key key, void *value)
  {
  	if (pthread_setspecific(key, value) != 0)
  		return -1;
  
  	return 0;
  }
  
  void *git_tlsdata_get(git_tlsdata_key key)
  {
  	return pthread_getspecific(key);
  }
  
  int git_tlsdata_dispose(git_tlsdata_key key)
  {
  	if (pthread_key_delete(key) != 0)
  		return -1;
  
  	return 0;
  }
  
  #else
  # error unknown threading model
  #endif
  

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