Portable POSIX-like unnamed semaphores that work in process-shared memory.

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nelsonb%netscape.com 2001-06-08 02:56:31 +00:00
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Коммит 6166732e49
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/*
* The contents of this file are subject to the Mozilla Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is the Netscape security libraries.
*
* The Initial Developer of the Original Code is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 2001 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU General Public License Version 2 or later (the
* "GPL"), in which case the provisions of the GPL are applicable
* instead of those above. If you wish to allow use of your
* version of this file only under the terms of the GPL and not to
* allow others to use your version of this file under the MPL,
* indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by
* the GPL. If you do not delete the provisions above, a recipient
* may use your version of this file under either the MPL or the
* GPL.
*
* $Id: sslmutex.c,v 1.1 2001/06/08 02:56:29 nelsonb%netscape.com Exp $
*/
#include "sslmutex.h"
#include "prerr.h"
#if defined(LINUX) || defined(AIX)
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include "unix_err.h"
#define SSL_MUTEX_MAGIC 0xfeedfd
#define NONBLOCKING_POSTS 1 /* maybe this is faster */
#if NONBLOCKING_POSTS
#ifndef FNONBLOCK
#define FNONBLOCK O_NONBLOCK
#endif
static int
setNonBlocking(int fd, int nonBlocking)
{
int flags;
int err;
flags = fcntl(fd, F_GETFL, 0);
if (0 > flags)
return flags;
if (nonBlocking)
flags |= FNONBLOCK;
else
flags &= ~FNONBLOCK;
err = fcntl(fd, F_SETFL, flags);
return err;
}
#endif
SECStatus
sslMutex_Init(sslMutex *pMutex, int shared)
{
int err;
int mPipes[3];
char c = 1;
memset(pMutex, -1, sizeof *pMutex);
err = pipe(mPipes);
if (err) {
return err;
}
/* close-on-exec is false by default */
if (!shared) {
err = fcntl(mPipes[0], F_SETFD, FD_CLOEXEC);
if (err)
goto loser;
err = fcntl(mPipes[1], F_SETFD, FD_CLOEXEC);
if (err)
goto loser;
}
#if NONBLOCKING_POSTS
err = setNonBlocking(mPipes[1], 1);
if (err)
goto loser;
#endif
do {
err = write(mPipes[1], &c, 1);
} while (err < 0 && (errno == EINTR || errno == EAGAIN));
if (0 > err)
goto loser;
mPipes[2] = SSL_MUTEX_MAGIC;
memcpy(pMutex, mPipes, sizeof mPipes);
return SECSuccess;
loser:
nss_MD_unix_map_default_error(errno);
close(mPipes[0]);
close(mPipes[1]);
return SECFailure;
}
SECStatus
sslMutex_Destroy(sslMutex *pMutex)
{
int * mPipes = (int *)pMutex;
if (mPipes[2] != SSL_MUTEX_MAGIC) {
PORT_SetError(PR_INVALID_ARGUMENT_ERROR);
return SECFailure;
}
close(mPipes[0]);
close(mPipes[1]);
memset(pMutex, -1, sizeof *pMutex);
return SECSuccess;
}
SECStatus
sslMutex_Unlock(sslMutex *pMutex)
{
int * mPipes = (int *)pMutex;
int cc;
char c = 1;
if (mPipes[2] != SSL_MUTEX_MAGIC) {
PORT_SetError(PR_INVALID_ARGUMENT_ERROR);
return SECFailure;
}
do {
cc = write(mPipes[1], &c, 1);
} while (cc < 0 && (errno == EINTR || errno == EAGAIN));
if (cc == 1)
return SECSuccess;
if (cc < 0)
nss_MD_unix_map_default_error(errno);
else
PORT_SetError(PR_UNKNOWN_ERROR);
return SECFailure;
}
SECStatus
sslMutex_Lock(sslMutex *pMutex)
{
int * mPipes = (int *)pMutex;
int cc;
char c;
if (mPipes[2] != SSL_MUTEX_MAGIC) {
PORT_SetError(PR_INVALID_ARGUMENT_ERROR);
return SECFailure;
}
do {
cc = read(mPipes[0], &c, 1);
} while (cc < 0 && errno == EINTR);
if (cc == 1)
return SECSuccess;
if (cc < 0)
nss_MD_unix_map_default_error(errno);
else
PORT_SetError(PR_UNKNOWN_ERROR);
return SECFailure;
}
#elif defined(WIN32)
#include "win32err.h"
/* The presence of the TRUE element in this struct makes the semaphore
* inheritable. The NULL means use process's default security descriptor.
*/
SECStatus
sslMutex_Init(sslMutex *pMutex, int shared)
{
HANDLE hMutex;
SECURITY_ATTRIBUTES attributes =
{ sizeof(SECURITY_ATTRIBUTES), NULL, TRUE };
PR_ASSERT(pMutex != 0 && (*pMutex == 0 || *pMutex == INVALID_HANDLE_VALUE));
if (!pMutex || ((hMutex = *pMutex) != 0 && hMutex != INVALID_HANDLE_VALUE)) {
PORT_SetError(PR_INVALID_ARGUMENT_ERROR);
return SECFailure;
}
attributes.bInheritHandle = (shared ? TRUE : FALSE);
hMutex = CreateMutex(&attributes, FALSE, NULL);
if (hMutex == NULL) {
hMutex = INVALID_HANDLE_VALUE;
nss_MD_win32_map_default_error(GetLastError());
return SECFailure;
}
*pMutex = hMutex;
return SECSuccess;
}
int
sslMutex_Destroy(sslMutex *pMutex)
{
HANDLE hMutex;
int rv;
PR_ASSERT(pMutex != 0 && *pMutex != 0 && *pMutex != INVALID_HANDLE_VALUE);
if (!pMutex || (hMutex = *pMutex) == 0 || hMutex == INVALID_HANDLE_VALUE) {
PORT_SetError(PR_INVALID_ARGUMENT_ERROR);
return SECFailure;
}
rv = CloseHandle(hMutex); /* ignore error */
if (rv) {
*pMutex = hMutex = INVALID_HANDLE_VALUE;
return SECSuccess;
}
nss_MD_win32_map_default_error(GetLastError());
return SECFailure;
}
int
sslMutex_Unlock(sslMutex *pMutex)
{
BOOL success = FALSE;
HANDLE hMutex;
PR_ASSERT(pMutex != 0 && *pMutex != 0 && *pMutex != INVALID_HANDLE_VALUE);
if (!pMutex || (hMutex = *pMutex) == 0 || hMutex == INVALID_HANDLE_VALUE) {
PORT_SetError(PR_INVALID_ARGUMENT_ERROR);
return SECFailure;
}
success = ReleaseMutex(hMutex);
if (!success) {
nss_MD_win32_map_default_error(GetLastError());
return SECFailure;
}
return SECSuccess;
}
int
sslMutex_Lock(sslMutex *pMutex)
{
HANDLE hMutex;
DWORD event;
DWORD lastError;
SECStatus rv;
PR_ASSERT(pMutex != 0 && *pMutex != 0 && *pMutex != INVALID_HANDLE_VALUE);
if (!pMutex || (hMutex = *pMutex) == 0 || hMutex == INVALID_HANDLE_VALUE) {
PORT_SetError(PR_INVALID_ARGUMENT_ERROR);
return SECFailure; /* what else ? */
}
event = WaitForSingleObject(hMutex, INFINITE);
switch (event) {
case WAIT_OBJECT_0:
case WAIT_ABANDONED:
rv = SECSuccess;
break;
case WAIT_TIMEOUT:
case WAIT_IO_COMPLETION:
default: /* should never happen. nothing we can do. */
PR_ASSERT(!("WaitForSingleObject returned invalid value."));
PORT_SetError(PR_UNKNOWN_ERROR);
rv = SECFailure;
break;
case WAIT_FAILED: /* failure returns this */
rv = SECFailure;
lastError = GetLastError(); /* for debugging */
nss_MD_win32_map_default_error(lastError);
break;
}
return rv;
}
#elif defined(XP_UNIX)
#include <errno.h>
#include "unix_err.h"
SECStatus
sslMutex_Init(sslMutex *pMutex, int shared)
{
int rv;
do {
rv = sem_init(pMutex, shared, 1);
} while (rv < 0 && errno == EINTR);
if (rv < 0) {
nss_MD_unix_map_default_error(errno);
return SECFailure;
}
return SECSuccess;
}
SECStatus
sslMutex_Destroy(sslMutex *pMutex)
{
int rv;
do {
rv = sem_destroy(pMutex);
} while (rv < 0 && errno == EINTR);
if (rv < 0) {
nss_MD_unix_map_default_error(errno);
return SECFailure;
}
return SECSuccess;
}
SECStatus
sslMutex_Unlock(sslMutex *pMutex)
{
int rv;
do {
rv = sem_post(pMutex);
} while (rv < 0 && errno == EINTR);
if (rv < 0) {
nss_MD_unix_map_default_error(errno);
return SECFailure;
}
return SECSuccess;
}
SECStatus
sslMutex_Lock(sslMutex *pMutex)
{
int rv;
do {
rv = sem_wait(pMutex);
} while (rv < 0 && errno == EINTR);
if (rv < 0) {
nss_MD_unix_map_default_error(errno);
return SECFailure;
}
return SECSuccess;
}
#else
SECStatus
sslMutex_Init(sslMutex *pMutex, int shared)
{
PORT_Assert(!("sslMutex_Init not implemented!"));
PORT_SetError(PR_NOT_IMPLEMENTED_ERROR);
return SECFailure;
}
SECStatus
sslMutex_Destroy(sslMutex *pMutex)
{
PORT_Assert(!("sslMutex_Destroy not implemented!"));
PORT_SetError(PR_NOT_IMPLEMENTED_ERROR);
return SECFailure;
}
SECStatus
sslMutex_Unlock(sslMutex *pMutex)
{
PORT_Assert(!("sslMutex_Unlock not implemented!"));
PORT_SetError(PR_NOT_IMPLEMENTED_ERROR);
return SECFailure;
}
SECStatus
sslMutex_Lock(sslMutex *pMutex)
{
PORT_Assert(!("sslMutex_Lock not implemented!"));
PORT_SetError(PR_NOT_IMPLEMENTED_ERROR);
return SECFailure;
}
#endif

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/*
* The contents of this file are subject to the Mozilla Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is the Netscape security libraries.
*
* The Initial Developer of the Original Code is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 2001 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU General Public License Version 2 or later (the
* "GPL"), in which case the provisions of the GPL are applicable
* instead of those above. If you wish to allow use of your
* version of this file only under the terms of the GPL and not to
* allow others to use your version of this file under the MPL,
* indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by
* the GPL. If you do not delete the provisions above, a recipient
* may use your version of this file under either the MPL or the
* GPL.
*
* $Id: sslmutex.h,v 1.1 2001/06/08 02:56:31 nelsonb%netscape.com Exp $
*/
#ifndef __SSLMUTEX_H_
#define __SSLMUTEX_H_ 1
/* What SSL really wants is portable process-shared unnamed mutexes in
* shared memory, that have the property that if the process that holds
* them dies, they are released automatically, and that (unlike fcntl
* record locking) lock to the thread, not to the process.
* NSPR doesn't provide that.
* Windows has mutexes that meet that description, but they're not portable.
* POSIX mutexes are not automatically released when the holder dies,
* and other processes/threads cannot release the mutex on behalf of the
* dead holder.
* POSIX semaphores can be used to accomplish this on systems that implement
* process-shared unnamed POSIX semaphores, because a watchdog thread can
* discover and release semaphores that were held by a dead process.
* On systems that do not support process-shared POSIX unnamed semaphores,
* they can be emulated using pipes.
* The performance cost of doing that is not yet measured.
*
* So, this API looks a lot like POSIX pthread mutexes.
*/
#if defined(WIN32)
#include <wtypes.h>
typedef HANDLE sslMutex;
typedef int sslPID;
#elif defined(LINUX) || defined(AIX)
#include <sys/types.h>
typedef struct { int ps[3]; } sslMutex;
typedef pid_t sslPID;
#elif defined(XP_UNIX) /* other types of Unix */
#include <sys/types.h> /* for pid_t */
#include <semaphore.h> /* for sem_t, and sem_* functions */
typedef sem_t sslMutex;
typedef pid_t sslPID;
#else
/* what platform is this ?? */
typedef int sslMutex;
typedef int sslPID;
#endif
#include "seccomon.h"
SEC_BEGIN_PROTOS
extern SECStatus sslMutex_Init(sslMutex *sem, int shared);
extern SECStatus sslMutex_Destroy(sslMutex *sem);
extern SECStatus sslMutex_Unlock(sslMutex *sem);
extern SECStatus sslMutex_Lock(sslMutex *sem);
SEC_END_PROTOS
#endif