Author: mturk
Date: Tue Nov 8 10:06:40 2011
New Revision: 1199170
URL: http://svn.apache.org/viewvc?rev=1199170&view=rev
Log:
BZ47678: Part 2. Make sure we create (and lock) mutex before creating/attaching
shared memory. This should solve sync problems when multiple processes try to
open the shared memory
Modified:
tomcat/jk/trunk/native/common/jk_shm.c
Modified: tomcat/jk/trunk/native/common/jk_shm.c
URL:
http://svn.apache.org/viewvc/tomcat/jk/trunk/native/common/jk_shm.c?rev=1199170&r1=1199169&r2=1199170&view=diff
==============================================================================
--- tomcat/jk/trunk/native/common/jk_shm.c (original)
+++ tomcat/jk/trunk/native/common/jk_shm.c Tue Nov 8 10:06:40 2011
@@ -164,33 +164,41 @@ int jk_shm_open(const char *fname, size_
#if defined (WIN32)
if (fname) {
- jk_shm_map = CreateFileMapping(INVALID_HANDLE_VALUE,
- jk_get_sa_with_null_dacl(),
- PAGE_READWRITE,
- 0,
- (DWORD)(sizeof(jk_shm_header_t) + sz),
- fname);
- if (GetLastError() == ERROR_ALREADY_EXISTS) {
- attached = 1;
- if (jk_shm_map == NULL || jk_shm_map == INVALID_HANDLE_VALUE) {
- jk_shm_map = OpenFileMapping(PAGE_READWRITE, FALSE, fname);
+ sprintf(lkname, "Global\\%s_MUTEX", fname);
+ jk_shm_hlock = CreateMutex(jk_get_sa_with_null_dacl(), TRUE, lkname);
+ if (jk_shm_hlock == NULL) {
+ if (GetLastError() == ERROR_ALREADY_EXISTS) {
+ attached = 1;
+ jk_shm_hlock = OpenMutex(MUTEX_ALL_ACCESS, FALSE, lkname);
}
}
- if (jk_shm_map == NULL || jk_shm_map == INVALID_HANDLE_VALUE) {
+ if (jk_shm_hlock == NULL) {
JK_TRACE_EXIT(l);
return -1;
}
- sprintf(lkname, "Global\\%s_MUTEX", fname);
if (attached) {
- jk_shm_hlock = OpenMutex(MUTEX_ALL_ACCESS, FALSE, lkname);
+ DWORD ws = WaitForSingleObject(jk_shm_hlock, INFINITE);
+ if (ws == WAIT_FAILED) {
+ CloseHandle(jk_shm_hlock);
+ jk_shm_hlock = NULL;
+ JK_TRACE_EXIT(l);
+ return -1;
+ }
+ jk_shm_map = OpenFileMapping(PAGE_READWRITE, FALSE, fname);
}
else {
- jk_shm_hlock = CreateMutex(jk_get_sa_with_null_dacl(), FALSE,
lkname);
+ jk_shm_map = CreateFileMapping(INVALID_HANDLE_VALUE,
+ jk_get_sa_with_null_dacl(),
+ PAGE_READWRITE,
+ 0,
+ (DWORD)(sizeof(jk_shm_header_t) +
sz),
+ fname);
}
- if (jk_shm_hlock == NULL || jk_shm_hlock == INVALID_HANDLE_VALUE) {
- CloseHandle(jk_shm_map);
- jk_shm_map = NULL;
+ if (jk_shm_map == NULL || jk_shm_map == INVALID_HANDLE_VALUE) {
JK_TRACE_EXIT(l);
+ CloseHandle(jk_shm_hlock);
+ jk_shm_hlock = NULL;
+ jk_shm_map = NULL;
return -1;
}
jk_shmem.hdr = (jk_shm_header_t *)MapViewOfFile(jk_shm_map,
@@ -250,6 +258,10 @@ int jk_shm_open(const char *fname, size_
jk_shmem.hdr->h.data.workers = 0;
}
JK_INIT_CS(&(jk_shmem.cs), rc);
+ if (jk_shm_hlock) {
+ /* Unlock shared memory */
+ ReleaseMutex(jk_shm_hlock);
+ }
if (JK_IS_DEBUG_LEVEL(l))
jk_log(l, JK_LOG_DEBUG,
"%s shared memory %s size=%u free=%u addr=%#lx",
@@ -736,9 +748,9 @@ int jk_shm_lock()
if (rv == WAIT_OBJECT_0 || rv == WAIT_ABANDONED)
rc = JK_TRUE;
else
- rc = JK_FALSE;
+ rc = JK_FALSE;
}
-#else
+#else
if (rc == JK_TRUE && jk_shmem.fd_lock != -1) {
JK_ENTER_LOCK(jk_shmem.fd_lock, rc);
}
@@ -753,9 +765,9 @@ int jk_shm_unlock()
#if defined (WIN32)
if (rc == JK_TRUE && jk_shm_hlock != NULL) {
if (!ReleaseMutex(jk_shm_hlock))
- rc = JK_FALSE;
+ rc = JK_FALSE;
}
-#else
+#else
if (rc == JK_TRUE && jk_shmem.fd_lock != -1) {
JK_LEAVE_LOCK(jk_shmem.fd_lock, rc);
}
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