quakeforge/include/QF/va.h
Bill Currie 7970525ef4 [util] Make va thread-safe
It now takes a context pointer (opaque data) that holds the buffers it
uses for the temporary strings. If the context pointer is null, a static
context is used (making those uses of va NOT thread-safe). Most calls to
va use the static context, but all such calls have been formatted
consistently so they are easy to find when it comes time to do a full
audit.
2021-01-31 16:05:48 +09:00

95 lines
3.2 KiB
C

/*
va.h
Definitions common to client and server.
Copyright (C) 1996-1997 Id Software, Inc.
Copyright (C) 2000 Marcus Sundberg <mackan@stacken.kth.se>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to:
Free Software Foundation, Inc.
59 Temple Place - Suite 330
Boston, MA 02111-1307, USA
*/
#ifndef __QF_va_h
#define __QF_va_h
/** \addtogroup misc
Formatted printing.
*/
///@{
/** Opaque context for va so it can have per-thread data.
*/
typedef struct va_ctx_s va_ctx_t;
/** Create a va context with the specified number of buffers.
*
* Having multiple buffers allows va to be used in short chains.
*
* \param buffers The number of buffers to create in the context. va() will
* cycle through the buffers for each call.
* \return Pointer to the context. Pass to va() for thread-safe usage.
*/
va_ctx_t *va_create_context (int buffers);
/** Destroy a va context.
*
* \param ctx The context to be destroyed. Must have been created by
* va_create_context().
* \note Any pointers to strings returned by va() using the context
* referenced by \a ctx will become invalid as the backing
* memory for the strings will have been freed.
*/
void va_destroy_context (va_ctx_t *ctx);
/** Does a varargs printf into a private buffer.
*
* \param ctx Context used for storing the private buffer such that va
* can be used in a multi-threaded environment. If null then
* a static context is used, in which case va is NOT
* thread-safe.
* \param format Standard printf() format string.
* \return Pointer to the beginning of the output string. The memory
* for the returned string is owned by the context pointed to
* by \a ctx.
* \note The static context is created with 4 buffers, so va (0,...)
* can be used to produce mildly complex output (eg, 3 calls
* to va sent to a 4th) with a reduced risk of strings being
* trampled.
*/
char *va(va_ctx_t *ctx, const char *format, ...) __attribute__((format(printf,2,3)));
/** Does a varargs printf into a malloced buffer.
*
* Combines the effect of strdup and sprintf, but in a safe manner. Essentially
* the equivalent of strdup (va (ctx, format, ...));
*
* \param format Standard printf() format string.
* \return Pointer to the beginning of the output string. The caller
* is responsible for freeing the memory holding the string.
* \note As nva() creates a new buffer every time it is called, it
* is thread-safe and there is no risk of the string being
* trampled. In addition, it does not use va(), so combining
* nva() with va() is safe.
*/
char *nva(const char *format, ...) __attribute__((format(printf,1,2)));
///@}
#endif//__QF_va_h