Cleanup mmap and shm implementation

Better separation of the sma layer and the mmap / shm implementation.

Author: madmajestro

apc_mmap.c

@@ -51,32 +51,29 @@
 # define MAP_ANON MAP_ANONYMOUS
 #endif
 
-apc_segment_t apc_mmap(char *file_mask, size_t size)
+void *apc_mmap(char *file_mask, size_t size)
 {
-	apc_segment_t segment;
-
+	void *shmaddr;
 	int fd = -1;
 	int flags = MAP_SHARED | MAP_NOSYNC;
 
 	/* If no filename was provided, do an anonymous mmap */
-	if(!file_mask || (file_mask && !strlen(file_mask))) {
+	if (!file_mask || (file_mask && !strlen(file_mask))) {
 #if !defined(MAP_ANON)
 		zend_error_noreturn(E_CORE_ERROR, "Anonymous mmap does not appear to be available on this system (MAP_ANON/MAP_ANONYMOUS).  Please see the apc.mmap_file_mask INI option.");
 #else
 		fd = -1;
 		flags = MAP_SHARED | MAP_ANON;
 #endif
-	} else if(!strcmp(file_mask,"/dev/zero")) {
+	} else if (!strcmp(file_mask,"/dev/zero")) {
 		fd = open("/dev/zero", O_RDWR, S_IRUSR | S_IWUSR);
-		if(fd == -1) {
+		if (fd == -1) {
 			zend_error_noreturn(E_CORE_ERROR, "apc_mmap: open on /dev/zero failed");
 		}
 	} else {
-		/*
-		 * Otherwise we do a normal filesystem mmap
-		 */
+		/* Otherwise we do a normal filesystem mmap */
 		fd = mkstemp(file_mask);
-		if(fd == -1) {
+		if (fd == -1) {
 			zend_error_noreturn(E_CORE_ERROR, "apc_mmap: mkstemp on %s failed", file_mask);
 		}
 		if (ftruncate(fd, size) < 0) {
@@ -87,27 +84,25 @@ apc_segment_t apc_mmap(char *file_mask, size_t size)
 		unlink(file_mask);
 	}
 
-	segment.shmaddr = (void *)mmap(NULL, size, PROT_READ | PROT_WRITE, flags, fd, 0);
-	segment.size = size;
+	shmaddr = (void *)mmap(NULL, size, PROT_READ | PROT_WRITE, flags, fd, 0);
 
-	if ((long)segment.shmaddr == -1) {
+	if ((long)shmaddr == -1) {
 		zend_error_noreturn(E_CORE_ERROR, "apc_mmap: Failed to mmap %zu bytes. Is your apc.shm_size too large?", size);
 	}
 
 #ifdef MADV_HUGEPAGE
-	/* enable transparent huge pages to reduce TLB misses (Linux
-	   only) */
-	madvise(segment.shmaddr, size, MADV_HUGEPAGE);
+	/* enable transparent huge pages to reduce TLB misses (Linux only) */
+	madvise(shmaddr, size, MADV_HUGEPAGE);
 #endif
 
 	if (fd != -1) close(fd);
 
-	return segment;
+	return shmaddr;
 }
 
-void apc_unmap(apc_segment_t *segment)
+void apc_unmap(void *shmaddr, size_t size)
 {
-	if (munmap(segment->shmaddr, segment->size) < 0) {
+	if (munmap(shmaddr, size) < 0) {
 		apc_warning("apc_unmap: munmap failed");
 	}
 }

apc_mmap.h

@@ -31,13 +31,12 @@
 #include <limits.h>
 
 #include "apc.h"
-#include "apc_sma.h"
 
 /* Wrapper functions for shared memory mapped files */
 
 #ifdef APC_MMAP
-apc_segment_t apc_mmap(char *file_mask, size_t size);
-void apc_unmap(apc_segment_t* segment);
+void *apc_mmap(char *file_mask, size_t size);
+void apc_unmap(void *shmaddr, size_t size);
 #endif
 
 #endif

apc_shm.c

@@ -45,7 +45,7 @@
 # define SHM_A 0222 /* write permission */
 #endif
 
-int apc_shm_create(int proj, size_t size)
+static int apc_shm_create(size_t size)
 {
 	int shmid;			/* shared memory id */
 	int oflag;			/* permissions on shm */
@@ -59,33 +59,32 @@ int apc_shm_create(int proj, size_t size)
 	return shmid;
 }
 
-void apc_shm_destroy(int shmid)
+static void apc_shm_destroy(int shmid)
 {
 	/* we expect this call to fail often, so we do not check */
 	shmctl(shmid, IPC_RMID, 0);
 }
 
-apc_segment_t apc_shm_attach(int shmid, size_t size)
+void *apc_shm_attach(size_t size)
 {
-	apc_segment_t segment; /* shm segment */
+	void *shmaddr;
+	int shmid = apc_shm_create(size);
 
-	if ((zend_long)(segment.shmaddr = shmat(shmid, 0, 0)) == -1) {
+	if ((zend_long)(shmaddr = shmat(shmid, 0, 0)) == -1) {
 		zend_error_noreturn(E_CORE_ERROR, "apc_shm_attach: shmat failed:");
 	}
 
-	segment.size = size;
-
 	/*
 	 * We set the shmid for removal immediately after attaching to it. The
 	 * segment won't disappear until all processes have detached from it.
 	 */
 	apc_shm_destroy(shmid);
-	return segment;
+	return shmaddr;
 }
 
-void apc_shm_detach(apc_segment_t* segment)
+void apc_shm_detach(void *shmaddr)
 {
-	if (shmdt(segment->shmaddr) < 0) {
+	if (shmdt(shmaddr) < 0) {
 		apc_warning("apc_shm_detach: shmdt failed:");
 	}
 }

apc_shm.h

@@ -33,14 +33,10 @@
 #include <time.h>
 #endif
 
-#include "apc_sma.h"
-
 /* Wrapper functions for unix shared memory */
 
-extern int apc_shm_create(int proj, size_t size);
-extern void apc_shm_destroy(int shmid);
-extern apc_segment_t apc_shm_attach(int shmid, size_t size);
-extern void apc_shm_detach(apc_segment_t* segment);
+void *apc_shm_attach(size_t size);
+void apc_shm_detach(void *shmaddr);
 
 #endif
 

apc_sma.c

@@ -325,18 +325,11 @@ PHP_APCU_API void apc_sma_init(apc_sma_t* sma, void** data, apc_sma_expunge_f ex
 		void*       shmaddr;
 
 #ifdef APC_MMAP
-		sma->segs[i] = apc_mmap(mask, sma->size);
+		sma->segs[i].shmaddr = apc_mmap(mask, sma->size);
 		if(sma->num != 1)
 			memcpy(&mask[strlen(mask)-6], "XXXXXX", 6);
 #else
-		{
-			int j = apc_shm_create(i, sma->size);
-#ifdef PHP_WIN32
-			/* TODO remove the line below after 7.1 EOL. */
-			SetLastError(0);
-#endif
-			sma->segs[i] = apc_shm_attach(j, sma->size);
-		}
+		sma->segs[i].shmaddr = apc_shm_attach(sma->size);
 #endif
 
 		sma->segs[i].size = sma->size;
@@ -389,9 +382,9 @@ PHP_APCU_API void apc_sma_detach(apc_sma_t* sma) {
 
 	for (i = 0; i < sma->num; i++) {
 #ifdef APC_MMAP
-		apc_unmap(&sma->segs[i]);
+		apc_unmap(sma->segs[i].shmaddr, sma->segs[i].size);
 #else
-		apc_shm_detach(&sma->segs[i]);
+		apc_shm_detach(sma->segs[i].shmaddr);
 #endif
 	}